xnu-6153.61.1.tar.gz

[apple/xnu.git] / osfmk / vm / vm_resident.c

/*
 * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
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 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
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/*
 * @OSF_COPYRIGHT@
 */
/*
 * Mach Operating System
 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */
/*
 *      File:   vm/vm_page.c
 *      Author: Avadis Tevanian, Jr., Michael Wayne Young
 *
 *      Resident memory management module.
 */

#include <debug.h>
#include <libkern/OSAtomic.h>
#include <libkern/OSDebug.h>

#include <mach/clock_types.h>
#include <mach/vm_prot.h>
#include <mach/vm_statistics.h>
#include <mach/sdt.h>
#include <kern/counters.h>
#include <kern/sched_prim.h>
#include <kern/policy_internal.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/kalloc.h>
#include <kern/zalloc.h>
#include <kern/ledger.h>
#include <vm/pmap.h>
#include <vm/vm_init.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_kern.h>                 /* kernel_memory_allocate() */
#include <kern/misc_protos.h>
#include <zone_debug.h>
#include <mach_debug/zone_info.h>
#include <vm/cpm.h>
#include <pexpert/pexpert.h>
#include <san/kasan.h>

#include <vm/vm_protos.h>
#include <vm/memory_object.h>
#include <vm/vm_purgeable_internal.h>
#include <vm/vm_compressor.h>
#if defined (__x86_64__)
#include <i386/misc_protos.h>
#endif

#if CONFIG_PHANTOM_CACHE
#include <vm/vm_phantom_cache.h>
#endif

#include <IOKit/IOHibernatePrivate.h>

#include <sys/kdebug.h>

#if defined(HAS_APPLE_PAC)
#include <ptrauth.h>
#endif

#if MACH_ASSERT

#define ASSERT_PMAP_FREE(mem) pmap_assert_free(VM_PAGE_GET_PHYS_PAGE(mem))

#else /* MACH_ASSERT */

#define ASSERT_PMAP_FREE(mem) /* nothing */

#endif /* MACH_ASSERT */

extern boolean_t vm_pageout_running;
extern thread_t  vm_pageout_scan_thread;
extern boolean_t vps_dynamic_priority_enabled;

char    vm_page_inactive_states[VM_PAGE_Q_STATE_ARRAY_SIZE];
char    vm_page_pageable_states[VM_PAGE_Q_STATE_ARRAY_SIZE];
char    vm_page_non_speculative_pageable_states[VM_PAGE_Q_STATE_ARRAY_SIZE];
char    vm_page_active_or_inactive_states[VM_PAGE_Q_STATE_ARRAY_SIZE];

#if CONFIG_SECLUDED_MEMORY
struct vm_page_secluded_data vm_page_secluded;
void secluded_suppression_init(void);
#endif /* CONFIG_SECLUDED_MEMORY */

boolean_t       hibernate_cleaning_in_progress = FALSE;
boolean_t       vm_page_free_verify = TRUE;

uint32_t        vm_lopage_free_count = 0;
uint32_t        vm_lopage_free_limit = 0;
uint32_t        vm_lopage_lowater    = 0;
boolean_t       vm_lopage_refill = FALSE;
boolean_t       vm_lopage_needed = FALSE;

lck_mtx_ext_t   vm_page_queue_lock_ext;
lck_mtx_ext_t   vm_page_queue_free_lock_ext;
lck_mtx_ext_t   vm_purgeable_queue_lock_ext;

int             speculative_age_index = 0;
int             speculative_steal_index = 0;
struct vm_speculative_age_q vm_page_queue_speculative[VM_PAGE_MAX_SPECULATIVE_AGE_Q + 1];

boolean_t       hibernation_vmqueues_inspection = FALSE; /* Tracks if the hibernation code is looking at the VM queues.
                                                          * Updated and checked behind the vm_page_queues_lock. */

__private_extern__ void         vm_page_init_lck_grp(void);

static void             vm_page_free_prepare(vm_page_t  page);
static vm_page_t        vm_page_grab_fictitious_common(ppnum_t phys_addr);

static void vm_tag_init(void);

uint64_t        vm_min_kernel_and_kext_address = VM_MIN_KERNEL_AND_KEXT_ADDRESS;
uint32_t        vm_packed_from_vm_pages_array_mask = VM_PACKED_FROM_VM_PAGES_ARRAY;
uint32_t        vm_packed_pointer_shift = VM_PACKED_POINTER_SHIFT;

/*
 *      Associated with page of user-allocatable memory is a
 *      page structure.
 */

/*
 *      These variables record the values returned by vm_page_bootstrap,
 *      for debugging purposes.  The implementation of pmap_steal_memory
 *      and pmap_startup here also uses them internally.
 */

vm_offset_t virtual_space_start;
vm_offset_t virtual_space_end;
uint32_t        vm_page_pages;

/*
 *      The vm_page_lookup() routine, which provides for fast
 *      (virtual memory object, offset) to page lookup, employs
 *      the following hash table.  The vm_page_{insert,remove}
 *      routines install and remove associations in the table.
 *      [This table is often called the virtual-to-physical,
 *      or VP, table.]
 */
typedef struct {
        vm_page_packed_t page_list;
#if     MACH_PAGE_HASH_STATS
        int             cur_count;              /* current count */
        int             hi_count;               /* high water mark */
#endif /* MACH_PAGE_HASH_STATS */
} vm_page_bucket_t;


#define BUCKETS_PER_LOCK        16

vm_page_bucket_t *vm_page_buckets;              /* Array of buckets */
unsigned int    vm_page_bucket_count = 0;       /* How big is array? */
unsigned int    vm_page_hash_mask;              /* Mask for hash function */
unsigned int    vm_page_hash_shift;             /* Shift for hash function */
uint32_t        vm_page_bucket_hash;            /* Basic bucket hash */
unsigned int    vm_page_bucket_lock_count = 0;          /* How big is array of locks? */

#ifndef VM_TAG_ACTIVE_UPDATE
#error VM_TAG_ACTIVE_UPDATE
#endif
#ifndef VM_MAX_TAG_ZONES
#error VM_MAX_TAG_ZONES
#endif

boolean_t   vm_tag_active_update = VM_TAG_ACTIVE_UPDATE;
lck_spin_t      *vm_page_bucket_locks;
lck_spin_t      vm_objects_wired_lock;
lck_spin_t      vm_allocation_sites_lock;

vm_allocation_site_t            vm_allocation_sites_static[VM_KERN_MEMORY_FIRST_DYNAMIC + 1];
vm_allocation_site_t *          vm_allocation_sites[VM_MAX_TAG_VALUE];
#if VM_MAX_TAG_ZONES
vm_allocation_zone_total_t **   vm_allocation_zone_totals;
#endif /* VM_MAX_TAG_ZONES */

vm_tag_t vm_allocation_tag_highest;

#if VM_PAGE_BUCKETS_CHECK
boolean_t vm_page_buckets_check_ready = FALSE;
#if VM_PAGE_FAKE_BUCKETS
vm_page_bucket_t *vm_page_fake_buckets; /* decoy buckets */
vm_map_offset_t vm_page_fake_buckets_start, vm_page_fake_buckets_end;
#endif /* VM_PAGE_FAKE_BUCKETS */
#endif /* VM_PAGE_BUCKETS_CHECK */



#if     MACH_PAGE_HASH_STATS
/* This routine is only for debug.  It is intended to be called by
 * hand by a developer using a kernel debugger.  This routine prints
 * out vm_page_hash table statistics to the kernel debug console.
 */
void
hash_debug(void)
{
        int     i;
        int     numbuckets = 0;
        int     highsum = 0;
        int     maxdepth = 0;

        for (i = 0; i < vm_page_bucket_count; i++) {
                if (vm_page_buckets[i].hi_count) {
                        numbuckets++;
                        highsum += vm_page_buckets[i].hi_count;
                        if (vm_page_buckets[i].hi_count > maxdepth) {
                                maxdepth = vm_page_buckets[i].hi_count;
                        }
                }
        }
        printf("Total number of buckets: %d\n", vm_page_bucket_count);
        printf("Number used buckets:     %d = %d%%\n",
            numbuckets, 100 * numbuckets / vm_page_bucket_count);
        printf("Number unused buckets:   %d = %d%%\n",
            vm_page_bucket_count - numbuckets,
            100 * (vm_page_bucket_count - numbuckets) / vm_page_bucket_count);
        printf("Sum of bucket max depth: %d\n", highsum);
        printf("Average bucket depth:    %d.%2d\n",
            highsum / vm_page_bucket_count,
            highsum % vm_page_bucket_count);
        printf("Maximum bucket depth:    %d\n", maxdepth);
}
#endif /* MACH_PAGE_HASH_STATS */

/*
 *      The virtual page size is currently implemented as a runtime
 *      variable, but is constant once initialized using vm_set_page_size.
 *      This initialization must be done in the machine-dependent
 *      bootstrap sequence, before calling other machine-independent
 *      initializations.
 *
 *      All references to the virtual page size outside this
 *      module must use the PAGE_SIZE, PAGE_MASK and PAGE_SHIFT
 *      constants.
 */
#if defined(__arm__) || defined(__arm64__)
vm_size_t       page_size;
vm_size_t       page_mask;
int             page_shift;
#else
vm_size_t       page_size  = PAGE_SIZE;
vm_size_t       page_mask  = PAGE_MASK;
int             page_shift = PAGE_SHIFT;
#endif

vm_page_t       vm_pages = VM_PAGE_NULL;
vm_page_t       vm_page_array_beginning_addr;
vm_page_t       vm_page_array_ending_addr;

unsigned int    vm_pages_count = 0;

/*
 *      Resident pages that represent real memory
 *      are allocated from a set of free lists,
 *      one per color.
 */
unsigned int    vm_colors;
unsigned int    vm_color_mask;                  /* mask is == (vm_colors-1) */
unsigned int    vm_cache_geometry_colors = 0;   /* set by hw dependent code during startup */
unsigned int    vm_free_magazine_refill_limit = 0;


struct vm_page_queue_free_head {
        vm_page_queue_head_t    qhead;
} __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));

struct vm_page_queue_free_head  vm_page_queue_free[MAX_COLORS];


unsigned int    vm_page_free_wanted;
unsigned int    vm_page_free_wanted_privileged;
#if CONFIG_SECLUDED_MEMORY
unsigned int    vm_page_free_wanted_secluded;
#endif /* CONFIG_SECLUDED_MEMORY */
unsigned int    vm_page_free_count;

/*
 *      Occasionally, the virtual memory system uses
 *      resident page structures that do not refer to
 *      real pages, for example to leave a page with
 *      important state information in the VP table.
 *
 *      These page structures are allocated the way
 *      most other kernel structures are.
 */
zone_t  vm_page_array_zone;
zone_t  vm_page_zone;
vm_locks_array_t vm_page_locks;
decl_lck_mtx_data(, vm_page_alloc_lock);
lck_mtx_ext_t vm_page_alloc_lock_ext;

unsigned int    vm_page_local_q_count = 0;
unsigned int    vm_page_local_q_soft_limit = 250;
unsigned int    vm_page_local_q_hard_limit = 500;
struct vplq     *vm_page_local_q = NULL;

/* N.B. Guard and fictitious pages must not
 * be assigned a zero phys_page value.
 */
/*
 *      Fictitious pages don't have a physical address,
 *      but we must initialize phys_page to something.
 *      For debugging, this should be a strange value
 *      that the pmap module can recognize in assertions.
 */
const ppnum_t vm_page_fictitious_addr = (ppnum_t) -1;

/*
 *      Guard pages are not accessible so they don't
 *      need a physical address, but we need to enter
 *      one in the pmap.
 *      Let's make it recognizable and make sure that
 *      we don't use a real physical page with that
 *      physical address.
 */
const ppnum_t vm_page_guard_addr = (ppnum_t) -2;

/*
 *      Resident page structures are also chained on
 *      queues that are used by the page replacement
 *      system (pageout daemon).  These queues are
 *      defined here, but are shared by the pageout
 *      module.  The inactive queue is broken into
 *      file backed and anonymous for convenience as the
 *      pageout daemon often assignes a higher
 *      importance to anonymous pages (less likely to pick)
 */
vm_page_queue_head_t    vm_page_queue_active __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));
vm_page_queue_head_t    vm_page_queue_inactive __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));
#if CONFIG_SECLUDED_MEMORY
vm_page_queue_head_t    vm_page_queue_secluded __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));
#endif /* CONFIG_SECLUDED_MEMORY */
vm_page_queue_head_t    vm_page_queue_anonymous __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));  /* inactive memory queue for anonymous pages */
vm_page_queue_head_t    vm_page_queue_throttled __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));

queue_head_t    vm_objects_wired;

void vm_update_darkwake_mode(boolean_t);

#if CONFIG_BACKGROUND_QUEUE
vm_page_queue_head_t    vm_page_queue_background __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));
uint32_t        vm_page_background_target;
uint32_t        vm_page_background_target_snapshot;
uint32_t        vm_page_background_count;
uint64_t        vm_page_background_promoted_count;

uint32_t        vm_page_background_internal_count;
uint32_t        vm_page_background_external_count;

uint32_t        vm_page_background_mode;
uint32_t        vm_page_background_exclude_external;
#endif

unsigned int    vm_page_active_count;
unsigned int    vm_page_inactive_count;
#if CONFIG_SECLUDED_MEMORY
unsigned int    vm_page_secluded_count;
unsigned int    vm_page_secluded_count_free;
unsigned int    vm_page_secluded_count_inuse;
unsigned int    vm_page_secluded_count_over_target;
#endif /* CONFIG_SECLUDED_MEMORY */
unsigned int    vm_page_anonymous_count;
unsigned int    vm_page_throttled_count;
unsigned int    vm_page_speculative_count;

unsigned int    vm_page_wire_count;
unsigned int    vm_page_wire_count_on_boot = 0;
unsigned int    vm_page_stolen_count = 0;
unsigned int    vm_page_wire_count_initial;
unsigned int    vm_page_gobble_count = 0;
unsigned int    vm_page_kern_lpage_count = 0;

uint64_t        booter_size;  /* external so it can be found in core dumps */

#define VM_PAGE_WIRE_COUNT_WARNING      0
#define VM_PAGE_GOBBLE_COUNT_WARNING    0

unsigned int    vm_page_purgeable_count = 0; /* # of pages purgeable now */
unsigned int    vm_page_purgeable_wired_count = 0; /* # of purgeable pages that are wired now */
uint64_t        vm_page_purged_count = 0;    /* total count of purged pages */

unsigned int    vm_page_xpmapped_external_count = 0;
unsigned int    vm_page_external_count = 0;
unsigned int    vm_page_internal_count = 0;
unsigned int    vm_page_pageable_external_count = 0;
unsigned int    vm_page_pageable_internal_count = 0;

#if DEVELOPMENT || DEBUG
unsigned int    vm_page_speculative_recreated = 0;
unsigned int    vm_page_speculative_created = 0;
unsigned int    vm_page_speculative_used = 0;
#endif

vm_page_queue_head_t    vm_page_queue_cleaned __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));

unsigned int    vm_page_cleaned_count = 0;

uint64_t        max_valid_dma_address = 0xffffffffffffffffULL;
ppnum_t         max_valid_low_ppnum = PPNUM_MAX;


/*
 *      Several page replacement parameters are also
 *      shared with this module, so that page allocation
 *      (done here in vm_page_alloc) can trigger the
 *      pageout daemon.
 */
unsigned int    vm_page_free_target = 0;
unsigned int    vm_page_free_min = 0;
unsigned int    vm_page_throttle_limit = 0;
unsigned int    vm_page_inactive_target = 0;
#if CONFIG_SECLUDED_MEMORY
unsigned int    vm_page_secluded_target = 0;
#endif /* CONFIG_SECLUDED_MEMORY */
unsigned int    vm_page_anonymous_min = 0;
unsigned int    vm_page_free_reserved = 0;


/*
 *      The VM system has a couple of heuristics for deciding
 *      that pages are "uninteresting" and should be placed
 *      on the inactive queue as likely candidates for replacement.
 *      These variables let the heuristics be controlled at run-time
 *      to make experimentation easier.
 */

boolean_t vm_page_deactivate_hint = TRUE;

struct vm_page_stats_reusable vm_page_stats_reusable;

/*
 *      vm_set_page_size:
 *
 *      Sets the page size, perhaps based upon the memory
 *      size.  Must be called before any use of page-size
 *      dependent functions.
 *
 *      Sets page_shift and page_mask from page_size.
 */
void
vm_set_page_size(void)
{
        page_size  = PAGE_SIZE;
        page_mask  = PAGE_MASK;
        page_shift = PAGE_SHIFT;

        if ((page_mask & page_size) != 0) {
                panic("vm_set_page_size: page size not a power of two");
        }

        for (page_shift = 0;; page_shift++) {
                if ((1U << page_shift) == page_size) {
                        break;
                }
        }
}

#if defined (__x86_64__)

#define MAX_CLUMP_SIZE      16
#define DEFAULT_CLUMP_SIZE  4

unsigned int vm_clump_size, vm_clump_mask, vm_clump_shift, vm_clump_promote_threshold;

#if DEVELOPMENT || DEBUG
unsigned long vm_clump_stats[MAX_CLUMP_SIZE + 1];
unsigned long vm_clump_allocs, vm_clump_inserts, vm_clump_inrange, vm_clump_promotes;

static inline void
vm_clump_update_stats(unsigned int c)
{
        assert(c <= vm_clump_size);
        if (c > 0 && c <= vm_clump_size) {
                vm_clump_stats[c] += c;
        }
        vm_clump_allocs += c;
}
#endif  /*  if DEVELOPMENT || DEBUG */

/* Called once to setup the VM clump knobs */
static void
vm_page_setup_clump( void )
{
        unsigned int override, n;

        vm_clump_size = DEFAULT_CLUMP_SIZE;
        if (PE_parse_boot_argn("clump_size", &override, sizeof(override))) {
                vm_clump_size = override;
        }

        if (vm_clump_size > MAX_CLUMP_SIZE) {
                panic("vm_page_setup_clump:: clump_size is too large!");
        }
        if (vm_clump_size < 1) {
                panic("vm_page_setup_clump:: clump_size must be >= 1");
        }
        if ((vm_clump_size & (vm_clump_size - 1)) != 0) {
                panic("vm_page_setup_clump:: clump_size must be a power of 2");
        }

        vm_clump_promote_threshold = vm_clump_size;
        vm_clump_mask = vm_clump_size - 1;
        for (vm_clump_shift = 0, n = vm_clump_size; n > 1; n >>= 1, vm_clump_shift++) {
                ;
        }

#if DEVELOPMENT || DEBUG
        bzero(vm_clump_stats, sizeof(vm_clump_stats));
        vm_clump_allocs = vm_clump_inserts = vm_clump_inrange = vm_clump_promotes = 0;
#endif  /*  if DEVELOPMENT || DEBUG */
}

#endif  /* #if defined (__x86_64__) */

#define COLOR_GROUPS_TO_STEAL   4

/* Called once during statup, once the cache geometry is known.
 */
static void
vm_page_set_colors( void )
{
        unsigned int    n, override;

#if defined (__x86_64__)
        /* adjust #colors because we need to color outside the clump boundary */
        vm_cache_geometry_colors >>= vm_clump_shift;
#endif
        if (PE_parse_boot_argn("colors", &override, sizeof(override))) {                /* colors specified as a boot-arg? */
                n = override;
        } else if (vm_cache_geometry_colors) {                  /* do we know what the cache geometry is? */
                n = vm_cache_geometry_colors;
        } else {
                n = DEFAULT_COLORS;                             /* use default if all else fails */
        }
        if (n == 0) {
                n = 1;
        }
        if (n > MAX_COLORS) {
                n = MAX_COLORS;
        }

        /* the count must be a power of 2  */
        if ((n & (n - 1)) != 0) {
                n = DEFAULT_COLORS;                             /* use default if all else fails */
        }
        vm_colors = n;
        vm_color_mask = n - 1;

        vm_free_magazine_refill_limit = vm_colors * COLOR_GROUPS_TO_STEAL;

#if defined (__x86_64__)
        /* adjust for reduction in colors due to clumping and multiple cores */
        if (real_ncpus) {
                vm_free_magazine_refill_limit *= (vm_clump_size * real_ncpus);
        }
#endif
}

/*
 * During single threaded early boot we don't initialize all pages.
 * This avoids some delay during boot. They'll be initialized and
 * added to the free list as needed or after we are multithreaded by
 * what becomes the pageout thread.
 */
static boolean_t fill = FALSE;
static unsigned int fillval;
uint_t vm_delayed_count = 0;    /* when non-zero, indicates we may have more pages to init */
ppnum_t delay_above_pnum = PPNUM_MAX;

/*
 * For x86 first 8 Gig initializes quickly and gives us lots of lowmem + mem above to start off with.
 * If ARM ever uses delayed page initialization, this value may need to be quite different.
 */
#define DEFAULT_DELAY_ABOVE_PHYS_GB (8)

/*
 * When we have to dip into more delayed pages due to low memory, free up
 * a large chunk to get things back to normal. This avoids contention on the
 * delayed code allocating page by page.
 */
#define VM_DELAY_PAGE_CHUNK ((1024 * 1024 * 1024) / PAGE_SIZE)

/*
 * Get and initialize the next delayed page.
 */
static vm_page_t
vm_get_delayed_page(int grab_options)
{
        vm_page_t p;
        ppnum_t   pnum;

        /*
         * Get a new page if we have one.
         */
        lck_mtx_lock(&vm_page_queue_free_lock);
        if (vm_delayed_count == 0) {
                lck_mtx_unlock(&vm_page_queue_free_lock);
                return NULL;
        }
        if (!pmap_next_page(&pnum)) {
                vm_delayed_count = 0;
                lck_mtx_unlock(&vm_page_queue_free_lock);
                return NULL;
        }

        assert(vm_delayed_count > 0);
        --vm_delayed_count;

#if defined(__x86_64__)
        /* x86 cluster code requires increasing phys_page in vm_pages[] */
        if (vm_pages_count > 0) {
                assert(pnum > vm_pages[vm_pages_count - 1].vmp_phys_page);
        }
#endif
        p = &vm_pages[vm_pages_count];
        assert(p < vm_page_array_ending_addr);
        vm_page_init(p, pnum, FALSE);
        ++vm_pages_count;
        ++vm_page_pages;
        lck_mtx_unlock(&vm_page_queue_free_lock);

        /*
         * These pages were initially counted as wired, undo that now.
         */
        if (grab_options & VM_PAGE_GRAB_Q_LOCK_HELD) {
                LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        } else {
                LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_NOTOWNED);
                vm_page_lockspin_queues();
        }
        --vm_page_wire_count;
        --vm_page_wire_count_initial;
        if (vm_page_wire_count_on_boot != 0) {
                --vm_page_wire_count_on_boot;
        }
        if (!(grab_options & VM_PAGE_GRAB_Q_LOCK_HELD)) {
                vm_page_unlock_queues();
        }


        if (fill) {
                fillPage(pnum, fillval);
        }
        return p;
}

static void vm_page_module_init_delayed(void);

/*
 * Free all remaining delayed pages to the free lists.
 */
void
vm_free_delayed_pages(void)
{
        vm_page_t   p;
        vm_page_t   list = NULL;
        uint_t      cnt = 0;
        vm_offset_t start_free_va;
        int64_t     free_size;

        while ((p = vm_get_delayed_page(VM_PAGE_GRAB_OPTIONS_NONE)) != NULL) {
                if (vm_himemory_mode) {
                        vm_page_release(p, FALSE);
                } else {
                        p->vmp_snext = list;
                        list = p;
                }
                ++cnt;
        }

        /*
         * Free the pages in reverse order if not himemory mode.
         * Hence the low memory pages will be first on free lists. (LIFO)
         */
        while (list != NULL) {
                p = list;
                list = p->vmp_snext;
                p->vmp_snext = NULL;
                vm_page_release(p, FALSE);
        }
#if DEVELOPMENT || DEBUG
        kprintf("vm_free_delayed_pages: initialized %d free pages\n", cnt);
#endif

        /*
         * Free up any unused full pages at the end of the vm_pages[] array
         */
        start_free_va = round_page((vm_offset_t)&vm_pages[vm_pages_count]);

#if defined(__x86_64__)
        /*
         * Since x86 might have used large pages for vm_pages[], we can't
         * free starting in the middle of a partially used large page.
         */
        if (pmap_query_pagesize(kernel_pmap, start_free_va) == I386_LPGBYTES) {
                start_free_va = ((start_free_va + I386_LPGMASK) & ~I386_LPGMASK);
        }
#endif
        if (start_free_va < (vm_offset_t)vm_page_array_ending_addr) {
                free_size = trunc_page((vm_offset_t)vm_page_array_ending_addr - start_free_va);
                if (free_size > 0) {
                        ml_static_mfree(start_free_va, (vm_offset_t)free_size);
                        vm_page_array_ending_addr = (void *)start_free_va;

                        /*
                         * Note there's no locking here, as only this thread will ever change this value.
                         * The reader, vm_page_diagnose, doesn't grab any locks for the counts it looks at.
                         */
                        vm_page_stolen_count -= (free_size >> PAGE_SHIFT);

#if DEVELOPMENT || DEBUG
                        kprintf("Freeing final unused %ld bytes from vm_pages[] at 0x%lx\n",
                            (long)free_size, (long)start_free_va);
#endif
                }
        }


        /*
         * now we can create the VM page array zone
         */
        vm_page_module_init_delayed();
}

/*
 * Try and free up enough delayed pages to match a contig memory allocation.
 */
static void
vm_free_delayed_pages_contig(
        uint_t    npages,
        ppnum_t   max_pnum,
        ppnum_t   pnum_mask)
{
        vm_page_t p;
        ppnum_t   pnum;
        uint_t    cnt = 0;

        /*
         * Treat 0 as the absolute max page number.
         */
        if (max_pnum == 0) {
                max_pnum = PPNUM_MAX;
        }

        /*
         * Free till we get a properly aligned start page
         */
        for (;;) {
                p = vm_get_delayed_page(VM_PAGE_GRAB_OPTIONS_NONE);
                if (p == NULL) {
                        return;
                }
                pnum = VM_PAGE_GET_PHYS_PAGE(p);
                vm_page_release(p, FALSE);
                if (pnum >= max_pnum) {
                        return;
                }
                if ((pnum & pnum_mask) == 0) {
                        break;
                }
        }

        /*
         * Having a healthy pool of free pages will help performance. We don't
         * want to fall back to the delayed code for every page allocation.
         */
        if (vm_page_free_count < VM_DELAY_PAGE_CHUNK) {
                npages += VM_DELAY_PAGE_CHUNK;
        }

        /*
         * Now free up the pages
         */
        for (cnt = 1; cnt < npages; ++cnt) {
                p = vm_get_delayed_page(VM_PAGE_GRAB_OPTIONS_NONE);
                if (p == NULL) {
                        return;
                }
                vm_page_release(p, FALSE);
        }
}


lck_grp_t               vm_page_lck_grp_free;
lck_grp_t               vm_page_lck_grp_queue;
lck_grp_t               vm_page_lck_grp_local;
lck_grp_t               vm_page_lck_grp_purge;
lck_grp_t               vm_page_lck_grp_alloc;
lck_grp_t               vm_page_lck_grp_bucket;
lck_grp_attr_t          vm_page_lck_grp_attr;
lck_attr_t              vm_page_lck_attr;


__private_extern__ void
vm_page_init_lck_grp(void)
{
        /*
         * initialze the vm_page lock world
         */
        lck_grp_attr_setdefault(&vm_page_lck_grp_attr);
        lck_grp_init(&vm_page_lck_grp_free, "vm_page_free", &vm_page_lck_grp_attr);
        lck_grp_init(&vm_page_lck_grp_queue, "vm_page_queue", &vm_page_lck_grp_attr);
        lck_grp_init(&vm_page_lck_grp_local, "vm_page_queue_local", &vm_page_lck_grp_attr);
        lck_grp_init(&vm_page_lck_grp_purge, "vm_page_purge", &vm_page_lck_grp_attr);
        lck_grp_init(&vm_page_lck_grp_alloc, "vm_page_alloc", &vm_page_lck_grp_attr);
        lck_grp_init(&vm_page_lck_grp_bucket, "vm_page_bucket", &vm_page_lck_grp_attr);
        lck_attr_setdefault(&vm_page_lck_attr);
        lck_mtx_init_ext(&vm_page_alloc_lock, &vm_page_alloc_lock_ext, &vm_page_lck_grp_alloc, &vm_page_lck_attr);

        vm_compressor_init_locks();
}

#define ROUNDUP_NEXTP2(X) (1U << (32 - __builtin_clz((X) - 1)))

void
vm_page_init_local_q()
{
        unsigned int            num_cpus;
        unsigned int            i;
        struct vplq             *t_local_q;

        num_cpus = ml_get_max_cpus();

        /*
         * no point in this for a uni-processor system
         */
        if (num_cpus >= 2) {
#if KASAN
                /* KASAN breaks the expectation of a size-aligned object by adding a
                 * redzone, so explicitly align. */
                t_local_q = (struct vplq *)kalloc(num_cpus * sizeof(struct vplq) + VM_PACKED_POINTER_ALIGNMENT);
                t_local_q = (void *)(((uintptr_t)t_local_q + (VM_PACKED_POINTER_ALIGNMENT - 1)) & ~(VM_PACKED_POINTER_ALIGNMENT - 1));
#else
                /* round the size up to the nearest power of two */
                t_local_q = (struct vplq *)kalloc(ROUNDUP_NEXTP2(num_cpus * sizeof(struct vplq)));
#endif

                for (i = 0; i < num_cpus; i++) {
                        struct vpl      *lq;

                        lq = &t_local_q[i].vpl_un.vpl;
                        VPL_LOCK_INIT(lq, &vm_page_lck_grp_local, &vm_page_lck_attr);
                        vm_page_queue_init(&lq->vpl_queue);
                        lq->vpl_count = 0;
                        lq->vpl_internal_count = 0;
                        lq->vpl_external_count = 0;
                }
                vm_page_local_q_count = num_cpus;

                vm_page_local_q = (struct vplq *)t_local_q;
        }
}

/*
 * vm_init_before_launchd
 *
 * This should be called right before launchd is loaded.
 */
void
vm_init_before_launchd()
{
        vm_page_lockspin_queues();
        vm_page_wire_count_on_boot = vm_page_wire_count;
        vm_page_unlock_queues();
}


/*
 *      vm_page_bootstrap:
 *
 *      Initializes the resident memory module.
 *
 *      Allocates memory for the page cells, and
 *      for the object/offset-to-page hash table headers.
 *      Each page cell is initialized and placed on the free list.
 *      Returns the range of available kernel virtual memory.
 */

void
vm_page_bootstrap(
        vm_offset_t             *startp,
        vm_offset_t             *endp)
{
        unsigned int            i;
        unsigned int            log1;
        unsigned int            log2;
        unsigned int            size;

        /*
         *      Initialize the page queues.
         */
        vm_page_init_lck_grp();

        lck_mtx_init_ext(&vm_page_queue_free_lock, &vm_page_queue_free_lock_ext, &vm_page_lck_grp_free, &vm_page_lck_attr);
        lck_mtx_init_ext(&vm_page_queue_lock, &vm_page_queue_lock_ext, &vm_page_lck_grp_queue, &vm_page_lck_attr);
        lck_mtx_init_ext(&vm_purgeable_queue_lock, &vm_purgeable_queue_lock_ext, &vm_page_lck_grp_purge, &vm_page_lck_attr);

        for (i = 0; i < PURGEABLE_Q_TYPE_MAX; i++) {
                int group;

                purgeable_queues[i].token_q_head = 0;
                purgeable_queues[i].token_q_tail = 0;
                for (group = 0; group < NUM_VOLATILE_GROUPS; group++) {
                        queue_init(&purgeable_queues[i].objq[group]);
                }

                purgeable_queues[i].type = i;
                purgeable_queues[i].new_pages = 0;
#if MACH_ASSERT
                purgeable_queues[i].debug_count_tokens = 0;
                purgeable_queues[i].debug_count_objects = 0;
#endif
        }
        ;
        purgeable_nonvolatile_count = 0;
        queue_init(&purgeable_nonvolatile_queue);

        for (i = 0; i < MAX_COLORS; i++) {
                vm_page_queue_init(&vm_page_queue_free[i].qhead);
        }

        vm_page_queue_init(&vm_lopage_queue_free);
        vm_page_queue_init(&vm_page_queue_active);
        vm_page_queue_init(&vm_page_queue_inactive);
#if CONFIG_SECLUDED_MEMORY
        vm_page_queue_init(&vm_page_queue_secluded);
#endif /* CONFIG_SECLUDED_MEMORY */
        vm_page_queue_init(&vm_page_queue_cleaned);
        vm_page_queue_init(&vm_page_queue_throttled);
        vm_page_queue_init(&vm_page_queue_anonymous);
        queue_init(&vm_objects_wired);

        for (i = 0; i <= VM_PAGE_MAX_SPECULATIVE_AGE_Q; i++) {
                vm_page_queue_init(&vm_page_queue_speculative[i].age_q);

                vm_page_queue_speculative[i].age_ts.tv_sec = 0;
                vm_page_queue_speculative[i].age_ts.tv_nsec = 0;
        }
#if CONFIG_BACKGROUND_QUEUE
        vm_page_queue_init(&vm_page_queue_background);

        vm_page_background_count = 0;
        vm_page_background_internal_count = 0;
        vm_page_background_external_count = 0;
        vm_page_background_promoted_count = 0;

        vm_page_background_target = (unsigned int)(atop_64(max_mem) / 25);

        if (vm_page_background_target > VM_PAGE_BACKGROUND_TARGET_MAX) {
                vm_page_background_target = VM_PAGE_BACKGROUND_TARGET_MAX;
        }

        vm_page_background_mode = VM_PAGE_BG_LEVEL_1;
        vm_page_background_exclude_external = 0;

        PE_parse_boot_argn("vm_page_bg_mode", &vm_page_background_mode, sizeof(vm_page_background_mode));
        PE_parse_boot_argn("vm_page_bg_exclude_external", &vm_page_background_exclude_external, sizeof(vm_page_background_exclude_external));
        PE_parse_boot_argn("vm_page_bg_target", &vm_page_background_target, sizeof(vm_page_background_target));

        if (vm_page_background_mode > VM_PAGE_BG_LEVEL_1) {
                vm_page_background_mode = VM_PAGE_BG_LEVEL_1;
        }
#endif
        vm_page_free_wanted = 0;
        vm_page_free_wanted_privileged = 0;
#if CONFIG_SECLUDED_MEMORY
        vm_page_free_wanted_secluded = 0;
#endif /* CONFIG_SECLUDED_MEMORY */

#if defined (__x86_64__)
        /* this must be called before vm_page_set_colors() */
        vm_page_setup_clump();
#endif

        vm_page_set_colors();

        bzero(vm_page_inactive_states, sizeof(vm_page_inactive_states));
        vm_page_inactive_states[VM_PAGE_ON_INACTIVE_INTERNAL_Q] = 1;
        vm_page_inactive_states[VM_PAGE_ON_INACTIVE_EXTERNAL_Q] = 1;
        vm_page_inactive_states[VM_PAGE_ON_INACTIVE_CLEANED_Q] = 1;

        bzero(vm_page_pageable_states, sizeof(vm_page_pageable_states));
        vm_page_pageable_states[VM_PAGE_ON_INACTIVE_INTERNAL_Q] = 1;
        vm_page_pageable_states[VM_PAGE_ON_INACTIVE_EXTERNAL_Q] = 1;
        vm_page_pageable_states[VM_PAGE_ON_INACTIVE_CLEANED_Q] = 1;
        vm_page_pageable_states[VM_PAGE_ON_ACTIVE_Q] = 1;
        vm_page_pageable_states[VM_PAGE_ON_SPECULATIVE_Q] = 1;
        vm_page_pageable_states[VM_PAGE_ON_THROTTLED_Q] = 1;
#if CONFIG_SECLUDED_MEMORY
        vm_page_pageable_states[VM_PAGE_ON_SECLUDED_Q] = 1;
#endif /* CONFIG_SECLUDED_MEMORY */

        bzero(vm_page_non_speculative_pageable_states, sizeof(vm_page_non_speculative_pageable_states));
        vm_page_non_speculative_pageable_states[VM_PAGE_ON_INACTIVE_INTERNAL_Q] = 1;
        vm_page_non_speculative_pageable_states[VM_PAGE_ON_INACTIVE_EXTERNAL_Q] = 1;
        vm_page_non_speculative_pageable_states[VM_PAGE_ON_INACTIVE_CLEANED_Q] = 1;
        vm_page_non_speculative_pageable_states[VM_PAGE_ON_ACTIVE_Q] = 1;
        vm_page_non_speculative_pageable_states[VM_PAGE_ON_THROTTLED_Q] = 1;
#if CONFIG_SECLUDED_MEMORY
        vm_page_non_speculative_pageable_states[VM_PAGE_ON_SECLUDED_Q] = 1;
#endif /* CONFIG_SECLUDED_MEMORY */

        bzero(vm_page_active_or_inactive_states, sizeof(vm_page_active_or_inactive_states));
        vm_page_active_or_inactive_states[VM_PAGE_ON_INACTIVE_INTERNAL_Q] = 1;
        vm_page_active_or_inactive_states[VM_PAGE_ON_INACTIVE_EXTERNAL_Q] = 1;
        vm_page_active_or_inactive_states[VM_PAGE_ON_INACTIVE_CLEANED_Q] = 1;
        vm_page_active_or_inactive_states[VM_PAGE_ON_ACTIVE_Q] = 1;
#if CONFIG_SECLUDED_MEMORY
        vm_page_active_or_inactive_states[VM_PAGE_ON_SECLUDED_Q] = 1;
#endif /* CONFIG_SECLUDED_MEMORY */

        for (i = 0; i < VM_KERN_MEMORY_FIRST_DYNAMIC; i++) {
                vm_allocation_sites_static[i].refcount = 2;
                vm_allocation_sites_static[i].tag = i;
                vm_allocation_sites[i] = &vm_allocation_sites_static[i];
        }
        vm_allocation_sites_static[VM_KERN_MEMORY_FIRST_DYNAMIC].refcount = 2;
        vm_allocation_sites_static[VM_KERN_MEMORY_FIRST_DYNAMIC].tag = VM_KERN_MEMORY_ANY;
        vm_allocation_sites[VM_KERN_MEMORY_ANY] = &vm_allocation_sites_static[VM_KERN_MEMORY_FIRST_DYNAMIC];

        /*
         *      Steal memory for the map and zone subsystems.
         */
#if CONFIG_GZALLOC
        gzalloc_configure();
#endif
        kernel_debug_string_early("vm_map_steal_memory");
        vm_map_steal_memory();

        /*
         *      Allocate (and initialize) the virtual-to-physical
         *      table hash buckets.
         *
         *      The number of buckets should be a power of two to
         *      get a good hash function.  The following computation
         *      chooses the first power of two that is greater
         *      than the number of physical pages in the system.
         */

        if (vm_page_bucket_count == 0) {
                unsigned int npages = pmap_free_pages();

                vm_page_bucket_count = 1;
                while (vm_page_bucket_count < npages) {
                        vm_page_bucket_count <<= 1;
                }
        }
        vm_page_bucket_lock_count = (vm_page_bucket_count + BUCKETS_PER_LOCK - 1) / BUCKETS_PER_LOCK;

        vm_page_hash_mask = vm_page_bucket_count - 1;

        /*
         *      Calculate object shift value for hashing algorithm:
         *              O = log2(sizeof(struct vm_object))
         *              B = log2(vm_page_bucket_count)
         *              hash shifts the object left by
         *              B/2 - O
         */
        size = vm_page_bucket_count;
        for (log1 = 0; size > 1; log1++) {
                size /= 2;
        }
        size = sizeof(struct vm_object);
        for (log2 = 0; size > 1; log2++) {
                size /= 2;
        }
        vm_page_hash_shift = log1 / 2 - log2 + 1;

        vm_page_bucket_hash = 1 << ((log1 + 1) >> 1);           /* Get (ceiling of sqrt of table size) */
        vm_page_bucket_hash |= 1 << ((log1 + 1) >> 2);          /* Get (ceiling of quadroot of table size) */
        vm_page_bucket_hash |= 1;                                                       /* Set bit and add 1 - always must be 1 to insure unique series */

        if (vm_page_hash_mask & vm_page_bucket_count) {
                printf("vm_page_bootstrap: WARNING -- strange page hash\n");
        }

#if VM_PAGE_BUCKETS_CHECK
#if VM_PAGE_FAKE_BUCKETS
        /*
         * Allocate a decoy set of page buckets, to detect
         * any stomping there.
         */
        vm_page_fake_buckets = (vm_page_bucket_t *)
            pmap_steal_memory(vm_page_bucket_count *
            sizeof(vm_page_bucket_t));
        vm_page_fake_buckets_start = (vm_map_offset_t) vm_page_fake_buckets;
        vm_page_fake_buckets_end =
            vm_map_round_page((vm_page_fake_buckets_start +
            (vm_page_bucket_count *
            sizeof(vm_page_bucket_t))),
            PAGE_MASK);
        char *cp;
        for (cp = (char *)vm_page_fake_buckets_start;
            cp < (char *)vm_page_fake_buckets_end;
            cp++) {
                *cp = 0x5a;
        }
#endif /* VM_PAGE_FAKE_BUCKETS */
#endif /* VM_PAGE_BUCKETS_CHECK */

        kernel_debug_string_early("vm_page_buckets");
        vm_page_buckets = (vm_page_bucket_t *)
            pmap_steal_memory(vm_page_bucket_count *
            sizeof(vm_page_bucket_t));

        kernel_debug_string_early("vm_page_bucket_locks");
        vm_page_bucket_locks = (lck_spin_t *)
            pmap_steal_memory(vm_page_bucket_lock_count *
            sizeof(lck_spin_t));

        for (i = 0; i < vm_page_bucket_count; i++) {
                vm_page_bucket_t *bucket = &vm_page_buckets[i];

                bucket->page_list = VM_PAGE_PACK_PTR(VM_PAGE_NULL);
#if     MACH_PAGE_HASH_STATS
                bucket->cur_count = 0;
                bucket->hi_count = 0;
#endif /* MACH_PAGE_HASH_STATS */
        }

        for (i = 0; i < vm_page_bucket_lock_count; i++) {
                lck_spin_init(&vm_page_bucket_locks[i], &vm_page_lck_grp_bucket, &vm_page_lck_attr);
        }

        lck_spin_init(&vm_objects_wired_lock, &vm_page_lck_grp_bucket, &vm_page_lck_attr);
        lck_spin_init(&vm_allocation_sites_lock, &vm_page_lck_grp_bucket, &vm_page_lck_attr);
        vm_tag_init();

#if VM_PAGE_BUCKETS_CHECK
        vm_page_buckets_check_ready = TRUE;
#endif /* VM_PAGE_BUCKETS_CHECK */

        /*
         *      Machine-dependent code allocates the resident page table.
         *      It uses vm_page_init to initialize the page frames.
         *      The code also returns to us the virtual space available
         *      to the kernel.  We don't trust the pmap module
         *      to get the alignment right.
         */

        kernel_debug_string_early("pmap_startup");
        pmap_startup(&virtual_space_start, &virtual_space_end);
        virtual_space_start = round_page(virtual_space_start);
        virtual_space_end = trunc_page(virtual_space_end);

        *startp = virtual_space_start;
        *endp = virtual_space_end;

        /*
         *      Compute the initial "wire" count.
         *      Up until now, the pages which have been set aside are not under
         *      the VM system's control, so although they aren't explicitly
         *      wired, they nonetheless can't be moved. At this moment,
         *      all VM managed pages are "free", courtesy of pmap_startup.
         */
        assert((unsigned int) atop_64(max_mem) == atop_64(max_mem));
        vm_page_wire_count = ((unsigned int) atop_64(max_mem)) -
            vm_page_free_count - vm_lopage_free_count;
#if CONFIG_SECLUDED_MEMORY
        vm_page_wire_count -= vm_page_secluded_count;
#endif
        vm_page_wire_count_initial = vm_page_wire_count;

        /* capture this for later use */
        booter_size = ml_get_booter_memory_size();

        printf("vm_page_bootstrap: %d free pages, %d wired pages, (up to %d of which are delayed free)\n",
            vm_page_free_count, vm_page_wire_count, vm_delayed_count);

        kernel_debug_string_early("vm_page_bootstrap complete");
        simple_lock_init(&vm_paging_lock, 0);
}

#ifndef MACHINE_PAGES
/*
 * This is the early boot time allocator for data structures needed to bootstrap the VM system.
 * On x86 it will allocate large pages if size is sufficiently large. We don't need to do this
 * on ARM yet, due to the combination of a large base page size and smaller RAM devices.
 */
static void *
pmap_steal_memory_internal(
        vm_size_t size,
        boolean_t might_free)
{
        kern_return_t kr;
        vm_offset_t addr;
        vm_offset_t map_addr;
        ppnum_t phys_page;

        /*
         * Size needs to be aligned to word size.
         */
        size = (size + sizeof(void *) - 1) & ~(sizeof(void *) - 1);

        /*
         * On the first call, get the initial values for virtual address space
         * and page align them.
         */
        if (virtual_space_start == virtual_space_end) {
                pmap_virtual_space(&virtual_space_start, &virtual_space_end);
                virtual_space_start = round_page(virtual_space_start);
                virtual_space_end = trunc_page(virtual_space_end);

#if defined(__x86_64__)
                /*
                 * Release remaining unused section of preallocated KVA and the 4K page tables
                 * that map it. This makes the VA available for large page mappings.
                 */
                Idle_PTs_release(virtual_space_start, virtual_space_end);
#endif
        }

        /*
         * Allocate the virtual space for this request. On x86, we'll align to a large page
         * address if the size is big enough to back with at least 1 large page.
         */
#if defined(__x86_64__)
        if (size >= I386_LPGBYTES) {
                virtual_space_start = ((virtual_space_start + I386_LPGMASK) & ~I386_LPGMASK);
        }
#endif
        addr = virtual_space_start;
        virtual_space_start += size;

        //kprintf("pmap_steal_memory: %08lX - %08lX; size=%08lX\n", (long)addr, (long)virtual_space_start, (long)size); /* (TEST/DEBUG) */

        /*
         * Allocate and map physical pages to back the new virtual space.
         */
        map_addr = round_page(addr);
        while (map_addr < addr + size) {
#if defined(__x86_64__)
                /*
                 * Back with a large page if properly aligned on x86
                 */
                if ((map_addr & I386_LPGMASK) == 0 &&
                    map_addr + I386_LPGBYTES <= addr + size &&
                    pmap_pre_expand_large(kernel_pmap, map_addr) == KERN_SUCCESS &&
                    pmap_next_page_large(&phys_page) == KERN_SUCCESS) {
                        kr = pmap_enter(kernel_pmap, map_addr, phys_page,
                            VM_PROT_READ | VM_PROT_WRITE, VM_PROT_NONE,
                            VM_WIMG_USE_DEFAULT | VM_MEM_SUPERPAGE, FALSE);

                        if (kr != KERN_SUCCESS) {
                                panic("pmap_steal_memory: pmap_enter() large failed, new_addr=%#lx, phys_page=%u",
                                    (unsigned long)map_addr, phys_page);
                        }
                        map_addr += I386_LPGBYTES;
                        vm_page_wire_count += I386_LPGBYTES >> PAGE_SHIFT;
                        vm_page_stolen_count += I386_LPGBYTES >> PAGE_SHIFT;
                        vm_page_kern_lpage_count++;
                        continue;
                }
#endif

                if (!pmap_next_page_hi(&phys_page, might_free)) {
                        panic("pmap_steal_memory() size: 0x%llx\n", (uint64_t)size);
                }

#if defined(__x86_64__)
                pmap_pre_expand(kernel_pmap, map_addr);
#endif

                kr = pmap_enter(kernel_pmap, map_addr, phys_page,
                    VM_PROT_READ | VM_PROT_WRITE, VM_PROT_NONE,
                    VM_WIMG_USE_DEFAULT, FALSE);

                if (kr != KERN_SUCCESS) {
                        panic("pmap_steal_memory() pmap_enter failed, map_addr=%#lx, phys_page=%u",
                            (unsigned long)map_addr, phys_page);
                }
                map_addr += PAGE_SIZE;

                /*
                 * Account for newly stolen memory
                 */
                vm_page_wire_count++;
                vm_page_stolen_count++;
        }

#if defined(__x86_64__)
        /*
         * The call with might_free is currently the last use of pmap_steal_memory*().
         * Notify the pmap layer to record which high pages were allocated so far.
         */
        if (might_free) {
                pmap_hi_pages_done();
        }
#endif
#if KASAN
        kasan_notify_address(round_page(addr), size);
#endif
        return (void *) addr;
}

void *
pmap_steal_memory(
        vm_size_t size)
{
        return pmap_steal_memory_internal(size, FALSE);
}

void *
pmap_steal_freeable_memory(
        vm_size_t size)
{
        return pmap_steal_memory_internal(size, TRUE);
}

#if CONFIG_SECLUDED_MEMORY
/* boot-args to control secluded memory */
unsigned int secluded_mem_mb = 0;       /* # of MBs of RAM to seclude */
int secluded_for_iokit = 1;             /* IOKit can use secluded memory */
int secluded_for_apps = 1;              /* apps can use secluded memory */
int secluded_for_filecache = 2;         /* filecache can use seclude memory */
#if 11
int secluded_for_fbdp = 0;
#endif
uint64_t secluded_shutoff_trigger = 0;
#endif /* CONFIG_SECLUDED_MEMORY */


#if defined(__arm__) || defined(__arm64__)
extern void patch_low_glo_vm_page_info(void *, void *, uint32_t);
unsigned int vm_first_phys_ppnum = 0;
#endif

void vm_page_release_startup(vm_page_t mem);
void
pmap_startup(
        vm_offset_t     *startp,
        vm_offset_t     *endp)
{
        unsigned int    i, npages;
        ppnum_t         phys_page;
        uint64_t        mem_sz;
        uint64_t        start_ns;
        uint64_t        now_ns;
        uint_t          low_page_count = 0;

#if    defined(__LP64__)
        /*
         * make sure we are aligned on a 64 byte boundary
         * for VM_PAGE_PACK_PTR (it clips off the low-order
         * 6 bits of the pointer)
         */
        if (virtual_space_start != virtual_space_end) {
                virtual_space_start = round_page(virtual_space_start);
        }
#endif

        /*
         * We calculate how many page frames we will have
         * and then allocate the page structures in one chunk.
         *
         * Note that the calculation here doesn't take into account
         * the memory needed to map what's being allocated, i.e. the page
         * table entries. So the actual number of pages we get will be
         * less than this. To do someday: include that in the computation.
         */
        mem_sz = pmap_free_pages() * (uint64_t)PAGE_SIZE;
        mem_sz += round_page(virtual_space_start) - virtual_space_start;        /* Account for any slop */
        npages = (uint_t)(mem_sz / (PAGE_SIZE + sizeof(*vm_pages)));    /* scaled to include the vm_page_ts */

        vm_pages = (vm_page_t) pmap_steal_freeable_memory(npages * sizeof *vm_pages);

        /*
         * Check if we want to initialize pages to a known value
         */
        if (PE_parse_boot_argn("fill", &fillval, sizeof(fillval))) {
                fill = TRUE;
        }
#if     DEBUG
        /* This slows down booting the DEBUG kernel, particularly on
         * large memory systems, but is worthwhile in deterministically
         * trapping uninitialized memory usage.
         */
        if (!fill) {
                fill = TRUE;
                fillval = 0xDEB8F177;
        }
#endif
        if (fill) {
                kprintf("Filling vm_pages with pattern: 0x%x\n", fillval);
        }

#if CONFIG_SECLUDED_MEMORY
        /*
         * Figure out how much secluded memory to have before we start
         * release pages to free lists.
         * The default, if specified nowhere else, is no secluded mem.
         */
        secluded_mem_mb = 0;
        if (max_mem > 1 * 1024 * 1024 * 1024) {
                /* default to 90MB for devices with > 1GB of RAM */
                secluded_mem_mb = 90;
        }
        /* override with value from device tree, if provided */
        PE_get_default("kern.secluded_mem_mb",
            &secluded_mem_mb, sizeof(secluded_mem_mb));
        /* override with value from boot-args, if provided */
        PE_parse_boot_argn("secluded_mem_mb",
            &secluded_mem_mb,
            sizeof(secluded_mem_mb));

        vm_page_secluded_target = (unsigned int)
            ((secluded_mem_mb * 1024ULL * 1024ULL) / PAGE_SIZE);
        PE_parse_boot_argn("secluded_for_iokit",
            &secluded_for_iokit,
            sizeof(secluded_for_iokit));
        PE_parse_boot_argn("secluded_for_apps",
            &secluded_for_apps,
            sizeof(secluded_for_apps));
        PE_parse_boot_argn("secluded_for_filecache",
            &secluded_for_filecache,
            sizeof(secluded_for_filecache));
#if 11
        PE_parse_boot_argn("secluded_for_fbdp",
            &secluded_for_fbdp,
            sizeof(secluded_for_fbdp));
#endif

        /*
         * On small devices, allow a large app to effectively suppress
         * secluded memory until it exits.
         */
        if (max_mem <= 1 * 1024 * 1024 * 1024 && vm_page_secluded_target != 0) {
                /*
                 * Get an amount from boot-args, else use 500MB.
                 * 500MB was chosen from a Peace daemon tentpole test which used munch
                 * to induce jetsam thrashing of false idle daemons.
                 */
                int secluded_shutoff_mb;
                if (PE_parse_boot_argn("secluded_shutoff_mb", &secluded_shutoff_mb,
                    sizeof(secluded_shutoff_mb))) {
                        secluded_shutoff_trigger = (uint64_t)secluded_shutoff_mb * 1024 * 1024;
                } else {
                        secluded_shutoff_trigger = 500 * 1024 * 1024;
                }

                if (secluded_shutoff_trigger != 0) {
                        secluded_suppression_init();
                }
        }

#endif /* CONFIG_SECLUDED_MEMORY */

#if defined(__x86_64__)

        /*
         * Decide how much memory we delay freeing at boot time.
         */
        uint32_t delay_above_gb;
        if (!PE_parse_boot_argn("delay_above_gb", &delay_above_gb, sizeof(delay_above_gb))) {
                delay_above_gb = DEFAULT_DELAY_ABOVE_PHYS_GB;
        }

        if (delay_above_gb == 0) {
                delay_above_pnum = PPNUM_MAX;
        } else {
                delay_above_pnum = delay_above_gb * (1024 * 1024 * 1024 / PAGE_SIZE);
        }

        /* make sure we have sane breathing room: 1G above low memory */
        if (delay_above_pnum <= max_valid_low_ppnum) {
                delay_above_pnum = max_valid_low_ppnum + ((1024 * 1024 * 1024) >> PAGE_SHIFT);
        }

        if (delay_above_pnum < PPNUM_MAX) {
                printf("pmap_startup() delaying init/free of page nums > 0x%x\n", delay_above_pnum);
        }

#endif /* defined(__x86_64__) */

        /*
         * Initialize and release the page frames.
         */
        kernel_debug_string_early("Initialize and free the page frames");

        vm_page_array_beginning_addr = &vm_pages[0];
        vm_page_array_ending_addr = &vm_pages[npages];  /* used by ptr packing/unpacking code */

        vm_delayed_count = 0;

        absolutetime_to_nanoseconds(mach_absolute_time(), &start_ns);
        vm_pages_count = 0;
        for (i = 0; i < npages; i++) {
                /* Did we run out of pages? */
                if (!pmap_next_page(&phys_page)) {
                        break;
                }

                if (phys_page < max_valid_low_ppnum) {
                        ++low_page_count;
                }

                /* Are we at high enough pages to delay the rest? */
                if (low_page_count > vm_lopage_free_limit && phys_page > delay_above_pnum) {
                        vm_delayed_count = pmap_free_pages();
                        break;
                }

#if defined(__arm__) || defined(__arm64__)
                if (i == 0) {
                        vm_first_phys_ppnum = phys_page;
                        patch_low_glo_vm_page_info((void *)vm_page_array_beginning_addr,
                            (void *)vm_page_array_ending_addr, vm_first_phys_ppnum);
                }
                assert((i + vm_first_phys_ppnum) == phys_page);
#endif

#if defined(__x86_64__)
                /* The x86 clump freeing code requires increasing ppn's to work correctly */
                if (i > 0) {
                        assert(phys_page > vm_pages[i - 1].vmp_phys_page);
                }
#endif
                ++vm_pages_count;
                vm_page_init(&vm_pages[i], phys_page, FALSE);
                if (fill) {
                        fillPage(phys_page, fillval);
                }
                if (vm_himemory_mode) {
                        vm_page_release_startup(&vm_pages[i]);
                }
        }
        vm_page_pages = vm_pages_count; /* used to report to user space */

        if (!vm_himemory_mode) {
                do {
                        vm_page_release_startup(&vm_pages[--i]);
                } while (i != 0);
        }

        absolutetime_to_nanoseconds(mach_absolute_time(), &now_ns);
        printf("pmap_startup() init/release time: %lld microsec\n", (now_ns - start_ns) / NSEC_PER_USEC);
        printf("pmap_startup() delayed init/release of %d pages\n", vm_delayed_count);

#if    defined(__LP64__)

        if ((vm_page_t)(VM_PAGE_UNPACK_PTR(VM_PAGE_PACK_PTR(&vm_pages[0]))) != &vm_pages[0]) {
                panic("VM_PAGE_PACK_PTR failed on &vm_pages[0] - %p", (void *)&vm_pages[0]);
        }

        if ((vm_page_t)(VM_PAGE_UNPACK_PTR(VM_PAGE_PACK_PTR(&vm_pages[vm_pages_count - 1]))) != &vm_pages[vm_pages_count - 1]) {
                panic("VM_PAGE_PACK_PTR failed on &vm_pages[vm_pages_count-1] - %p", (void *)&vm_pages[vm_pages_count - 1]);
        }
#endif

        VM_CHECK_MEMORYSTATUS;

        /*
         * We have to re-align virtual_space_start,
         * because pmap_steal_memory has been using it.
         */
        virtual_space_start = round_page(virtual_space_start);
        *startp = virtual_space_start;
        *endp = virtual_space_end;
}
#endif  /* MACHINE_PAGES */

/*
 * Create the zone that represents the vm_pages[] array. Nothing ever allocates
 * or frees to this zone. It's just here for reporting purposes via zprint command.
 * This needs to be done after all initially delayed pages are put on the free lists.
 */
static void
vm_page_module_init_delayed(void)
{
        uint64_t vm_page_zone_pages, vm_page_array_zone_data_size;

        vm_page_array_zone = zinit((vm_size_t) sizeof(struct vm_page),
            0, PAGE_SIZE, "vm pages array");

        zone_change(vm_page_array_zone, Z_CALLERACCT, FALSE);
        zone_change(vm_page_array_zone, Z_EXPAND, FALSE);
        zone_change(vm_page_array_zone, Z_EXHAUST, TRUE);
        zone_change(vm_page_array_zone, Z_FOREIGN, TRUE);
        zone_change(vm_page_array_zone, Z_GZALLOC_EXEMPT, TRUE);

        /*
         * Reflect size and usage information for vm_pages[].
         */
        vm_page_array_zone->count = vm_pages_count;
        vm_page_array_zone->countfree = (int)(vm_page_array_ending_addr - &vm_pages[vm_pages_count]);
        vm_page_array_zone->sum_count = vm_pages_count;
        vm_page_array_zone_data_size = (uintptr_t)((void *)vm_page_array_ending_addr - (void *)vm_pages);
        vm_page_array_zone->cur_size = vm_page_array_zone_data_size;
        vm_page_zone_pages = ((round_page(vm_page_array_zone_data_size)) / PAGE_SIZE);
        OSAddAtomic64(vm_page_zone_pages, &(vm_page_array_zone->page_count));
        /* since zone accounts for these, take them out of stolen */
        VM_PAGE_MOVE_STOLEN(vm_page_zone_pages);
}

/*
 * Create the vm_pages zone. This is used for the vm_page structures for the pages
 * that are scavanged from other boot time usages by ml_static_mfree(). As such,
 * this needs to happen in early VM bootstrap.
 */
void
vm_page_module_init(void)
{
        vm_size_t vm_page_with_ppnum_size;

        /*
         * Since the pointers to elements in this zone will be packed, they
         * must have appropriate size. Not strictly what sizeof() reports.
         */
        vm_page_with_ppnum_size =
            (sizeof(struct vm_page_with_ppnum) + (VM_PACKED_POINTER_ALIGNMENT - 1)) &
            ~(VM_PACKED_POINTER_ALIGNMENT - 1);

        vm_page_zone = zinit(vm_page_with_ppnum_size, 0, PAGE_SIZE, "vm pages");

        zone_change(vm_page_zone, Z_CALLERACCT, FALSE);
        zone_change(vm_page_zone, Z_EXPAND, FALSE);
        zone_change(vm_page_zone, Z_EXHAUST, TRUE);
        zone_change(vm_page_zone, Z_FOREIGN, TRUE);
        zone_change(vm_page_zone, Z_GZALLOC_EXEMPT, TRUE);
        zone_change(vm_page_zone, Z_ALIGNMENT_REQUIRED, TRUE);
}

/*
 *      Routine:        vm_page_create
 *      Purpose:
 *              After the VM system is up, machine-dependent code
 *              may stumble across more physical memory.  For example,
 *              memory that it was reserving for a frame buffer.
 *              vm_page_create turns this memory into available pages.
 */

void
vm_page_create(
        ppnum_t start,
        ppnum_t end)
{
        ppnum_t         phys_page;
        vm_page_t       m;

        for (phys_page = start;
            phys_page < end;
            phys_page++) {
                while ((m = (vm_page_t) vm_page_grab_fictitious_common(phys_page))
                    == VM_PAGE_NULL) {
                        vm_page_more_fictitious();
                }

                m->vmp_fictitious = FALSE;
                pmap_clear_noencrypt(phys_page);

                lck_mtx_lock(&vm_page_queue_free_lock);
                vm_page_pages++;
                lck_mtx_unlock(&vm_page_queue_free_lock);
                vm_page_release(m, FALSE);
        }
}

/*
 *      vm_page_hash:
 *
 *      Distributes the object/offset key pair among hash buckets.
 *
 *      NOTE:   The bucket count must be a power of 2
 */
#define vm_page_hash(object, offset) (\
        ( (natural_t)((uintptr_t)object * vm_page_bucket_hash) + ((uint32_t)atop_64(offset) ^ vm_page_bucket_hash))\
         & vm_page_hash_mask)


/*
 *      vm_page_insert:         [ internal use only ]
 *
 *      Inserts the given mem entry into the object/object-page
 *      table and object list.
 *
 *      The object must be locked.
 */
void
vm_page_insert(
        vm_page_t               mem,
        vm_object_t             object,
        vm_object_offset_t      offset)
{
        vm_page_insert_internal(mem, object, offset, VM_KERN_MEMORY_NONE, FALSE, TRUE, FALSE, FALSE, NULL);
}

void
vm_page_insert_wired(
        vm_page_t               mem,
        vm_object_t             object,
        vm_object_offset_t      offset,
        vm_tag_t                tag)
{
        vm_page_insert_internal(mem, object, offset, tag, FALSE, TRUE, FALSE, FALSE, NULL);
}

void
vm_page_insert_internal(
        vm_page_t               mem,
        vm_object_t             object,
        vm_object_offset_t      offset,
        vm_tag_t                tag,
        boolean_t               queues_lock_held,
        boolean_t               insert_in_hash,
        boolean_t               batch_pmap_op,
        boolean_t               batch_accounting,
        uint64_t                *delayed_ledger_update)
{
        vm_page_bucket_t        *bucket;
        lck_spin_t              *bucket_lock;
        int                     hash_id;
        task_t                  owner;
        int                     ledger_idx_volatile;
        int                     ledger_idx_nonvolatile;
        int                     ledger_idx_volatile_compressed;
        int                     ledger_idx_nonvolatile_compressed;
        boolean_t               do_footprint;

#if 0
        /*
         * we may not hold the page queue lock
         * so this check isn't safe to make
         */
        VM_PAGE_CHECK(mem);
#endif

        assert(page_aligned(offset));

        assert(!VM_PAGE_WIRED(mem) || mem->vmp_private || mem->vmp_fictitious || (tag != VM_KERN_MEMORY_NONE));

        /* the vm_submap_object is only a placeholder for submaps */
        assert(object != vm_submap_object);

        vm_object_lock_assert_exclusive(object);
        LCK_MTX_ASSERT(&vm_page_queue_lock,
            queues_lock_held ? LCK_MTX_ASSERT_OWNED
            : LCK_MTX_ASSERT_NOTOWNED);

        if (queues_lock_held == FALSE) {
                assert(!VM_PAGE_PAGEABLE(mem));
        }

        if (insert_in_hash == TRUE) {
#if DEBUG || VM_PAGE_CHECK_BUCKETS
                if (mem->vmp_tabled || mem->vmp_object) {
                        panic("vm_page_insert: page %p for (obj=%p,off=0x%llx) "
                            "already in (obj=%p,off=0x%llx)",
                            mem, object, offset, VM_PAGE_OBJECT(mem), mem->vmp_offset);
                }
#endif
                if (object->internal && (offset >= object->vo_size)) {
                        panic("vm_page_insert_internal: (page=%p,obj=%p,off=0x%llx,size=0x%llx) inserted at offset past object bounds",
                            mem, object, offset, object->vo_size);
                }

                assert(vm_page_lookup(object, offset) == VM_PAGE_NULL);

                /*
                 *      Record the object/offset pair in this page
                 */

                mem->vmp_object = VM_PAGE_PACK_OBJECT(object);
                mem->vmp_offset = offset;

#if CONFIG_SECLUDED_MEMORY
                if (object->eligible_for_secluded) {
                        vm_page_secluded.eligible_for_secluded++;
                }
#endif /* CONFIG_SECLUDED_MEMORY */

                /*
                 *      Insert it into the object_object/offset hash table
                 */
                hash_id = vm_page_hash(object, offset);
                bucket = &vm_page_buckets[hash_id];
                bucket_lock = &vm_page_bucket_locks[hash_id / BUCKETS_PER_LOCK];

                lck_spin_lock_grp(bucket_lock, &vm_page_lck_grp_bucket);

                mem->vmp_next_m = bucket->page_list;
                bucket->page_list = VM_PAGE_PACK_PTR(mem);
                assert(mem == (vm_page_t)(VM_PAGE_UNPACK_PTR(bucket->page_list)));

#if     MACH_PAGE_HASH_STATS
                if (++bucket->cur_count > bucket->hi_count) {
                        bucket->hi_count = bucket->cur_count;
                }
#endif /* MACH_PAGE_HASH_STATS */
                mem->vmp_hashed = TRUE;
                lck_spin_unlock(bucket_lock);
        }

        {
                unsigned int    cache_attr;

                cache_attr = object->wimg_bits & VM_WIMG_MASK;

                if (cache_attr != VM_WIMG_USE_DEFAULT) {
                        PMAP_SET_CACHE_ATTR(mem, object, cache_attr, batch_pmap_op);
                }
        }
        /*
         *      Now link into the object's list of backed pages.
         */
        vm_page_queue_enter(&object->memq, mem, vmp_listq);
        object->memq_hint = mem;
        mem->vmp_tabled = TRUE;

        /*
         *      Show that the object has one more resident page.
         */

        object->resident_page_count++;
        if (VM_PAGE_WIRED(mem)) {
                assert(mem->vmp_wire_count > 0);
                VM_OBJECT_WIRED_PAGE_UPDATE_START(object);
                VM_OBJECT_WIRED_PAGE_ADD(object, mem);
                VM_OBJECT_WIRED_PAGE_UPDATE_END(object, tag);
        }
        assert(object->resident_page_count >= object->wired_page_count);

        if (batch_accounting == FALSE) {
                if (object->internal) {
                        OSAddAtomic(1, &vm_page_internal_count);
                } else {
                        OSAddAtomic(1, &vm_page_external_count);
                }
        }

        /*
         * It wouldn't make sense to insert a "reusable" page in
         * an object (the page would have been marked "reusable" only
         * at the time of a madvise(MADV_FREE_REUSABLE) if it was already
         * in the object at that time).
         * But a page could be inserted in a "all_reusable" object, if
         * something faults it in (a vm_read() from another task or a
         * "use-after-free" issue in user space, for example).  It can
         * also happen if we're relocating a page from that object to
         * a different physical page during a physically-contiguous
         * allocation.
         */
        assert(!mem->vmp_reusable);
        if (object->all_reusable) {
                OSAddAtomic(+1, &vm_page_stats_reusable.reusable_count);
        }

        if (object->purgable == VM_PURGABLE_DENY &&
            !object->vo_ledger_tag) {
                owner = TASK_NULL;
        } else {
                owner = VM_OBJECT_OWNER(object);
                vm_object_ledger_tag_ledgers(object,
                    &ledger_idx_volatile,
                    &ledger_idx_nonvolatile,
                    &ledger_idx_volatile_compressed,
                    &ledger_idx_nonvolatile_compressed,
                    &do_footprint);
        }
        if (owner &&
            (object->purgable == VM_PURGABLE_NONVOLATILE ||
            object->purgable == VM_PURGABLE_DENY ||
            VM_PAGE_WIRED(mem))) {
                if (delayed_ledger_update) {
                        *delayed_ledger_update += PAGE_SIZE;
                } else {
                        /* more non-volatile bytes */
                        ledger_credit(owner->ledger,
                            ledger_idx_nonvolatile,
                            PAGE_SIZE);
                        if (do_footprint) {
                                /* more footprint */
                                ledger_credit(owner->ledger,
                                    task_ledgers.phys_footprint,
                                    PAGE_SIZE);
                        }
                }
        } else if (owner &&
            (object->purgable == VM_PURGABLE_VOLATILE ||
            object->purgable == VM_PURGABLE_EMPTY)) {
                assert(!VM_PAGE_WIRED(mem));
                /* more volatile bytes */
                ledger_credit(owner->ledger,
                    ledger_idx_volatile,
                    PAGE_SIZE);
        }

        if (object->purgable == VM_PURGABLE_VOLATILE) {
                if (VM_PAGE_WIRED(mem)) {
                        OSAddAtomic(+1, &vm_page_purgeable_wired_count);
                } else {
                        OSAddAtomic(+1, &vm_page_purgeable_count);
                }
        } else if (object->purgable == VM_PURGABLE_EMPTY &&
            mem->vmp_q_state == VM_PAGE_ON_THROTTLED_Q) {
                /*
                 * This page belongs to a purged VM object but hasn't
                 * been purged (because it was "busy").
                 * It's in the "throttled" queue and hence not
                 * visible to vm_pageout_scan().  Move it to a pageable
                 * queue, so that it can eventually be reclaimed, instead
                 * of lingering in the "empty" object.
                 */
                if (queues_lock_held == FALSE) {
                        vm_page_lockspin_queues();
                }
                vm_page_deactivate(mem);
                if (queues_lock_held == FALSE) {
                        vm_page_unlock_queues();
                }
        }

#if VM_OBJECT_TRACKING_OP_MODIFIED
        if (vm_object_tracking_inited &&
            object->internal &&
            object->resident_page_count == 0 &&
            object->pager == NULL &&
            object->shadow != NULL &&
            object->shadow->copy == object) {
                void *bt[VM_OBJECT_TRACKING_BTDEPTH];
                int numsaved = 0;

                numsaved = OSBacktrace(bt, VM_OBJECT_TRACKING_BTDEPTH);
                btlog_add_entry(vm_object_tracking_btlog,
                    object,
                    VM_OBJECT_TRACKING_OP_MODIFIED,
                    bt,
                    numsaved);
        }
#endif /* VM_OBJECT_TRACKING_OP_MODIFIED */
}

/*
 *      vm_page_replace:
 *
 *      Exactly like vm_page_insert, except that we first
 *      remove any existing page at the given offset in object.
 *
 *      The object must be locked.
 */
void
vm_page_replace(
        vm_page_t               mem,
        vm_object_t             object,
        vm_object_offset_t      offset)
{
        vm_page_bucket_t *bucket;
        vm_page_t        found_m = VM_PAGE_NULL;
        lck_spin_t      *bucket_lock;
        int             hash_id;

#if 0
        /*
         * we don't hold the page queue lock
         * so this check isn't safe to make
         */
        VM_PAGE_CHECK(mem);
#endif
        vm_object_lock_assert_exclusive(object);
#if DEBUG || VM_PAGE_CHECK_BUCKETS
        if (mem->vmp_tabled || mem->vmp_object) {
                panic("vm_page_replace: page %p for (obj=%p,off=0x%llx) "
                    "already in (obj=%p,off=0x%llx)",
                    mem, object, offset, VM_PAGE_OBJECT(mem), mem->vmp_offset);
        }
#endif
        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_NOTOWNED);

        assert(!VM_PAGE_PAGEABLE(mem));

        /*
         *      Record the object/offset pair in this page
         */
        mem->vmp_object = VM_PAGE_PACK_OBJECT(object);
        mem->vmp_offset = offset;

        /*
         *      Insert it into the object_object/offset hash table,
         *      replacing any page that might have been there.
         */

        hash_id = vm_page_hash(object, offset);
        bucket = &vm_page_buckets[hash_id];
        bucket_lock = &vm_page_bucket_locks[hash_id / BUCKETS_PER_LOCK];

        lck_spin_lock_grp(bucket_lock, &vm_page_lck_grp_bucket);

        if (bucket->page_list) {
                vm_page_packed_t *mp = &bucket->page_list;
                vm_page_t m = (vm_page_t)(VM_PAGE_UNPACK_PTR(*mp));

                do {
                        /*
                         * compare packed object pointers
                         */
                        if (m->vmp_object == mem->vmp_object && m->vmp_offset == offset) {
                                /*
                                 * Remove old page from hash list
                                 */
                                *mp = m->vmp_next_m;
                                m->vmp_hashed = FALSE;
                                m->vmp_next_m = VM_PAGE_PACK_PTR(NULL);

                                found_m = m;
                                break;
                        }
                        mp = &m->vmp_next_m;
                } while ((m = (vm_page_t)(VM_PAGE_UNPACK_PTR(*mp))));

                mem->vmp_next_m = bucket->page_list;
        } else {
                mem->vmp_next_m = VM_PAGE_PACK_PTR(NULL);
        }
        /*
         * insert new page at head of hash list
         */
        bucket->page_list = VM_PAGE_PACK_PTR(mem);
        mem->vmp_hashed = TRUE;

        lck_spin_unlock(bucket_lock);

        if (found_m) {
                /*
                 * there was already a page at the specified
                 * offset for this object... remove it from
                 * the object and free it back to the free list
                 */
                vm_page_free_unlocked(found_m, FALSE);
        }
        vm_page_insert_internal(mem, object, offset, VM_KERN_MEMORY_NONE, FALSE, FALSE, FALSE, FALSE, NULL);
}

/*
 *      vm_page_remove:         [ internal use only ]
 *
 *      Removes the given mem entry from the object/offset-page
 *      table and the object page list.
 *
 *      The object must be locked.
 */

void
vm_page_remove(
        vm_page_t       mem,
        boolean_t       remove_from_hash)
{
        vm_page_bucket_t *bucket;
        vm_page_t       this;
        lck_spin_t      *bucket_lock;
        int             hash_id;
        task_t          owner;
        vm_object_t     m_object;
        int             ledger_idx_volatile;
        int             ledger_idx_nonvolatile;
        int             ledger_idx_volatile_compressed;
        int             ledger_idx_nonvolatile_compressed;
        int             do_footprint;

        m_object = VM_PAGE_OBJECT(mem);

        vm_object_lock_assert_exclusive(m_object);
        assert(mem->vmp_tabled);
        assert(!mem->vmp_cleaning);
        assert(!mem->vmp_laundry);

        if (VM_PAGE_PAGEABLE(mem)) {
                LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        }
#if 0
        /*
         * we don't hold the page queue lock
         * so this check isn't safe to make
         */
        VM_PAGE_CHECK(mem);
#endif
        if (remove_from_hash == TRUE) {
                /*
                 *      Remove from the object_object/offset hash table
                 */
                hash_id = vm_page_hash(m_object, mem->vmp_offset);
                bucket = &vm_page_buckets[hash_id];
                bucket_lock = &vm_page_bucket_locks[hash_id / BUCKETS_PER_LOCK];

                lck_spin_lock_grp(bucket_lock, &vm_page_lck_grp_bucket);

                if ((this = (vm_page_t)(VM_PAGE_UNPACK_PTR(bucket->page_list))) == mem) {
                        /* optimize for common case */

                        bucket->page_list = mem->vmp_next_m;
                } else {
                        vm_page_packed_t        *prev;

                        for (prev = &this->vmp_next_m;
                            (this = (vm_page_t)(VM_PAGE_UNPACK_PTR(*prev))) != mem;
                            prev = &this->vmp_next_m) {
                                continue;
                        }
                        *prev = this->vmp_next_m;
                }
#if     MACH_PAGE_HASH_STATS
                bucket->cur_count--;
#endif /* MACH_PAGE_HASH_STATS */
                mem->vmp_hashed = FALSE;
                this->vmp_next_m = VM_PAGE_PACK_PTR(NULL);
                lck_spin_unlock(bucket_lock);
        }
        /*
         *      Now remove from the object's list of backed pages.
         */

        vm_page_remove_internal(mem);

        /*
         *      And show that the object has one fewer resident
         *      page.
         */

        assert(m_object->resident_page_count > 0);
        m_object->resident_page_count--;

        if (m_object->internal) {
#if DEBUG
                assert(vm_page_internal_count);
#endif /* DEBUG */

                OSAddAtomic(-1, &vm_page_internal_count);
        } else {
                assert(vm_page_external_count);
                OSAddAtomic(-1, &vm_page_external_count);

                if (mem->vmp_xpmapped) {
                        assert(vm_page_xpmapped_external_count);
                        OSAddAtomic(-1, &vm_page_xpmapped_external_count);
                }
        }
        if (!m_object->internal &&
            m_object->cached_list.next &&
            m_object->cached_list.prev) {
                if (m_object->resident_page_count == 0) {
                        vm_object_cache_remove(m_object);
                }
        }

        if (VM_PAGE_WIRED(mem)) {
                assert(mem->vmp_wire_count > 0);
                VM_OBJECT_WIRED_PAGE_UPDATE_START(m_object);
                VM_OBJECT_WIRED_PAGE_REMOVE(m_object, mem);
                VM_OBJECT_WIRED_PAGE_UPDATE_END(m_object, m_object->wire_tag);
        }
        assert(m_object->resident_page_count >=
            m_object->wired_page_count);
        if (mem->vmp_reusable) {
                assert(m_object->reusable_page_count > 0);
                m_object->reusable_page_count--;
                assert(m_object->reusable_page_count <=
                    m_object->resident_page_count);
                mem->vmp_reusable = FALSE;
                OSAddAtomic(-1, &vm_page_stats_reusable.reusable_count);
                vm_page_stats_reusable.reused_remove++;
        } else if (m_object->all_reusable) {
                OSAddAtomic(-1, &vm_page_stats_reusable.reusable_count);
                vm_page_stats_reusable.reused_remove++;
        }

        if (m_object->purgable == VM_PURGABLE_DENY &&
            !m_object->vo_ledger_tag) {
                owner = TASK_NULL;
        } else {
                owner = VM_OBJECT_OWNER(m_object);
                vm_object_ledger_tag_ledgers(m_object,
                    &ledger_idx_volatile,
                    &ledger_idx_nonvolatile,
                    &ledger_idx_volatile_compressed,
                    &ledger_idx_nonvolatile_compressed,
                    &do_footprint);
        }
        if (owner &&
            (m_object->purgable == VM_PURGABLE_NONVOLATILE ||
            m_object->purgable == VM_PURGABLE_DENY ||
            VM_PAGE_WIRED(mem))) {
                /* less non-volatile bytes */
                ledger_debit(owner->ledger,
                    ledger_idx_nonvolatile,
                    PAGE_SIZE);
                if (do_footprint) {
                        /* less footprint */
                        ledger_debit(owner->ledger,
                            task_ledgers.phys_footprint,
                            PAGE_SIZE);
                }
        } else if (owner &&
            (m_object->purgable == VM_PURGABLE_VOLATILE ||
            m_object->purgable == VM_PURGABLE_EMPTY)) {
                assert(!VM_PAGE_WIRED(mem));
                /* less volatile bytes */
                ledger_debit(owner->ledger,
                    ledger_idx_volatile,
                    PAGE_SIZE);
        }
        if (m_object->purgable == VM_PURGABLE_VOLATILE) {
                if (VM_PAGE_WIRED(mem)) {
                        assert(vm_page_purgeable_wired_count > 0);
                        OSAddAtomic(-1, &vm_page_purgeable_wired_count);
                } else {
                        assert(vm_page_purgeable_count > 0);
                        OSAddAtomic(-1, &vm_page_purgeable_count);
                }
        }

        if (m_object->set_cache_attr == TRUE) {
                pmap_set_cache_attributes(VM_PAGE_GET_PHYS_PAGE(mem), 0);
        }

        mem->vmp_tabled = FALSE;
        mem->vmp_object = 0;
        mem->vmp_offset = (vm_object_offset_t) -1;
}


/*
 *      vm_page_lookup:
 *
 *      Returns the page associated with the object/offset
 *      pair specified; if none is found, VM_PAGE_NULL is returned.
 *
 *      The object must be locked.  No side effects.
 */

#define VM_PAGE_HASH_LOOKUP_THRESHOLD   10

#if DEBUG_VM_PAGE_LOOKUP

struct {
        uint64_t        vpl_total;
        uint64_t        vpl_empty_obj;
        uint64_t        vpl_bucket_NULL;
        uint64_t        vpl_hit_hint;
        uint64_t        vpl_hit_hint_next;
        uint64_t        vpl_hit_hint_prev;
        uint64_t        vpl_fast;
        uint64_t        vpl_slow;
        uint64_t        vpl_hit;
        uint64_t        vpl_miss;

        uint64_t        vpl_fast_elapsed;
        uint64_t        vpl_slow_elapsed;
} vm_page_lookup_stats __attribute__((aligned(8)));

#endif

#define KDP_VM_PAGE_WALK_MAX    1000

vm_page_t
kdp_vm_page_lookup(
        vm_object_t             object,
        vm_object_offset_t      offset)
{
        vm_page_t cur_page;
        int num_traversed = 0;

        if (not_in_kdp) {
                panic("panic: kdp_vm_page_lookup done outside of kernel debugger");
        }

        vm_page_queue_iterate(&object->memq, cur_page, vmp_listq) {
                if (cur_page->vmp_offset == offset) {
                        return cur_page;
                }
                num_traversed++;

                if (num_traversed >= KDP_VM_PAGE_WALK_MAX) {
                        return VM_PAGE_NULL;
                }
        }

        return VM_PAGE_NULL;
}

vm_page_t
vm_page_lookup(
        vm_object_t             object,
        vm_object_offset_t      offset)
{
        vm_page_t       mem;
        vm_page_bucket_t *bucket;
        vm_page_queue_entry_t   qe;
        lck_spin_t      *bucket_lock = NULL;
        int             hash_id;
#if DEBUG_VM_PAGE_LOOKUP
        uint64_t        start, elapsed;

        OSAddAtomic64(1, &vm_page_lookup_stats.vpl_total);
#endif
        vm_object_lock_assert_held(object);

        if (object->resident_page_count == 0) {
#if DEBUG_VM_PAGE_LOOKUP
                OSAddAtomic64(1, &vm_page_lookup_stats.vpl_empty_obj);
#endif
                return VM_PAGE_NULL;
        }

        mem = object->memq_hint;

        if (mem != VM_PAGE_NULL) {
                assert(VM_PAGE_OBJECT(mem) == object);

                if (mem->vmp_offset == offset) {
#if DEBUG_VM_PAGE_LOOKUP
                        OSAddAtomic64(1, &vm_page_lookup_stats.vpl_hit_hint);
#endif
                        return mem;
                }
                qe = (vm_page_queue_entry_t)vm_page_queue_next(&mem->vmp_listq);

                if (!vm_page_queue_end(&object->memq, qe)) {
                        vm_page_t       next_page;

                        next_page = (vm_page_t)((uintptr_t)qe);
                        assert(VM_PAGE_OBJECT(next_page) == object);

                        if (next_page->vmp_offset == offset) {
                                object->memq_hint = next_page; /* new hint */
#if DEBUG_VM_PAGE_LOOKUP
                                OSAddAtomic64(1, &vm_page_lookup_stats.vpl_hit_hint_next);
#endif
                                return next_page;
                        }
                }
                qe = (vm_page_queue_entry_t)vm_page_queue_prev(&mem->vmp_listq);

                if (!vm_page_queue_end(&object->memq, qe)) {
                        vm_page_t prev_page;

                        prev_page = (vm_page_t)((uintptr_t)qe);
                        assert(VM_PAGE_OBJECT(prev_page) == object);

                        if (prev_page->vmp_offset == offset) {
                                object->memq_hint = prev_page; /* new hint */
#if DEBUG_VM_PAGE_LOOKUP
                                OSAddAtomic64(1, &vm_page_lookup_stats.vpl_hit_hint_prev);
#endif
                                return prev_page;
                        }
                }
        }
        /*
         * Search the hash table for this object/offset pair
         */
        hash_id = vm_page_hash(object, offset);
        bucket = &vm_page_buckets[hash_id];

        /*
         * since we hold the object lock, we are guaranteed that no
         * new pages can be inserted into this object... this in turn
         * guarantess that the page we're looking for can't exist
         * if the bucket it hashes to is currently NULL even when looked
         * at outside the scope of the hash bucket lock... this is a
         * really cheap optimiztion to avoid taking the lock
         */
        if (!bucket->page_list) {
#if DEBUG_VM_PAGE_LOOKUP
                OSAddAtomic64(1, &vm_page_lookup_stats.vpl_bucket_NULL);
#endif
                return VM_PAGE_NULL;
        }

#if DEBUG_VM_PAGE_LOOKUP
        start = mach_absolute_time();
#endif
        if (object->resident_page_count <= VM_PAGE_HASH_LOOKUP_THRESHOLD) {
                /*
                 * on average, it's roughly 3 times faster to run a short memq list
                 * than to take the spin lock and go through the hash list
                 */
                mem = (vm_page_t)vm_page_queue_first(&object->memq);

                while (!vm_page_queue_end(&object->memq, (vm_page_queue_entry_t)mem)) {
                        if (mem->vmp_offset == offset) {
                                break;
                        }

                        mem = (vm_page_t)vm_page_queue_next(&mem->vmp_listq);
                }
                if (vm_page_queue_end(&object->memq, (vm_page_queue_entry_t)mem)) {
                        mem = NULL;
                }
        } else {
                vm_page_object_t        packed_object;

                packed_object = VM_PAGE_PACK_OBJECT(object);

                bucket_lock = &vm_page_bucket_locks[hash_id / BUCKETS_PER_LOCK];

                lck_spin_lock_grp(bucket_lock, &vm_page_lck_grp_bucket);

                for (mem = (vm_page_t)(VM_PAGE_UNPACK_PTR(bucket->page_list));
                    mem != VM_PAGE_NULL;
                    mem = (vm_page_t)(VM_PAGE_UNPACK_PTR(mem->vmp_next_m))) {
#if 0
                        /*
                         * we don't hold the page queue lock
                         * so this check isn't safe to make
                         */
                        VM_PAGE_CHECK(mem);
#endif
                        if ((mem->vmp_object == packed_object) && (mem->vmp_offset == offset)) {
                                break;
                        }
                }
                lck_spin_unlock(bucket_lock);
        }

#if DEBUG_VM_PAGE_LOOKUP
        elapsed = mach_absolute_time() - start;

        if (bucket_lock) {
                OSAddAtomic64(1, &vm_page_lookup_stats.vpl_slow);
                OSAddAtomic64(elapsed, &vm_page_lookup_stats.vpl_slow_elapsed);
        } else {
                OSAddAtomic64(1, &vm_page_lookup_stats.vpl_fast);
                OSAddAtomic64(elapsed, &vm_page_lookup_stats.vpl_fast_elapsed);
        }
        if (mem != VM_PAGE_NULL) {
                OSAddAtomic64(1, &vm_page_lookup_stats.vpl_hit);
        } else {
                OSAddAtomic64(1, &vm_page_lookup_stats.vpl_miss);
        }
#endif
        if (mem != VM_PAGE_NULL) {
                assert(VM_PAGE_OBJECT(mem) == object);

                object->memq_hint = mem;
        }
        return mem;
}


/*
 *      vm_page_rename:
 *
 *      Move the given memory entry from its
 *      current object to the specified target object/offset.
 *
 *      The object must be locked.
 */
void
vm_page_rename(
        vm_page_t               mem,
        vm_object_t             new_object,
        vm_object_offset_t      new_offset)
{
        boolean_t       internal_to_external, external_to_internal;
        vm_tag_t        tag;
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(mem);

        assert(m_object != new_object);
        assert(m_object);

        /*
         *      Changes to mem->vmp_object require the page lock because
         *      the pageout daemon uses that lock to get the object.
         */
        vm_page_lockspin_queues();

        internal_to_external = FALSE;
        external_to_internal = FALSE;

        if (mem->vmp_q_state == VM_PAGE_ON_ACTIVE_LOCAL_Q) {
                /*
                 * it's much easier to get the vm_page_pageable_xxx accounting correct
                 * if we first move the page to the active queue... it's going to end
                 * up there anyway, and we don't do vm_page_rename's frequently enough
                 * for this to matter.
                 */
                vm_page_queues_remove(mem, FALSE);
                vm_page_activate(mem);
        }
        if (VM_PAGE_PAGEABLE(mem)) {
                if (m_object->internal && !new_object->internal) {
                        internal_to_external = TRUE;
                }
                if (!m_object->internal && new_object->internal) {
                        external_to_internal = TRUE;
                }
        }

        tag = m_object->wire_tag;
        vm_page_remove(mem, TRUE);
        vm_page_insert_internal(mem, new_object, new_offset, tag, TRUE, TRUE, FALSE, FALSE, NULL);

        if (internal_to_external) {
                vm_page_pageable_internal_count--;
                vm_page_pageable_external_count++;
        } else if (external_to_internal) {
                vm_page_pageable_external_count--;
                vm_page_pageable_internal_count++;
        }

        vm_page_unlock_queues();
}

/*
 *      vm_page_init:
 *
 *      Initialize the fields in a new page.
 *      This takes a structure with random values and initializes it
 *      so that it can be given to vm_page_release or vm_page_insert.
 */
void
vm_page_init(
        vm_page_t mem,
        ppnum_t   phys_page,
        boolean_t lopage)
{
        uint_t    i;
        uintptr_t *p;

        assert(phys_page);

#if DEBUG
        if ((phys_page != vm_page_fictitious_addr) && (phys_page != vm_page_guard_addr)) {
                if (!(pmap_valid_page(phys_page))) {
                        panic("vm_page_init: non-DRAM phys_page 0x%x\n", phys_page);
                }
        }
#endif /* DEBUG */

        /*
         * Initialize the fields of the vm_page. If adding any new fields to vm_page,
         * try to use initial values which match 0. This minimizes the number of writes
         * needed for boot-time initialization.
         *
         * Kernel bzero() isn't an inline yet, so do it by hand for performance.
         */
        assert(VM_PAGE_NOT_ON_Q == 0);
        assert(sizeof(*mem) % sizeof(uintptr_t) == 0);
        for (p = (uintptr_t *)(void *)mem, i = sizeof(*mem) / sizeof(uintptr_t); i != 0; --i) {
                *p++ = 0;
        }
        mem->vmp_offset = (vm_object_offset_t)-1;
        mem->vmp_busy = TRUE;
        mem->vmp_lopage = lopage;

        VM_PAGE_SET_PHYS_PAGE(mem, phys_page);
#if 0
        /*
         * we're leaving this turned off for now... currently pages
         * come off the free list and are either immediately dirtied/referenced
         * due to zero-fill or COW faults, or are used to read or write files...
         * in the file I/O case, the UPL mechanism takes care of clearing
         * the state of the HW ref/mod bits in a somewhat fragile way.
         * Since we may change the way this works in the future (to toughen it up),
         * I'm leaving this as a reminder of where these bits could get cleared
         */

        /*
         * make sure both the h/w referenced and modified bits are
         * clear at this point... we are especially dependent on
         * not finding a 'stale' h/w modified in a number of spots
         * once this page goes back into use
         */
        pmap_clear_refmod(phys_page, VM_MEM_MODIFIED | VM_MEM_REFERENCED);
#endif
}

/*
 *      vm_page_grab_fictitious:
 *
 *      Remove a fictitious page from the free list.
 *      Returns VM_PAGE_NULL if there are no free pages.
 */
int     c_vm_page_grab_fictitious = 0;
int     c_vm_page_grab_fictitious_failed = 0;
int     c_vm_page_release_fictitious = 0;
int     c_vm_page_more_fictitious = 0;

vm_page_t
vm_page_grab_fictitious_common(
        ppnum_t phys_addr)
{
        vm_page_t       m;

        if ((m = (vm_page_t)zget(vm_page_zone))) {
                vm_page_init(m, phys_addr, FALSE);
                m->vmp_fictitious = TRUE;

                c_vm_page_grab_fictitious++;
        } else {
                c_vm_page_grab_fictitious_failed++;
        }

        return m;
}

vm_page_t
vm_page_grab_fictitious(void)
{
        return vm_page_grab_fictitious_common(vm_page_fictitious_addr);
}

int vm_guard_count;


vm_page_t
vm_page_grab_guard(void)
{
        vm_page_t page;
        page = vm_page_grab_fictitious_common(vm_page_guard_addr);
        if (page) {
                OSAddAtomic(1, &vm_guard_count);
        }
        return page;
}


/*
 *      vm_page_release_fictitious:
 *
 *      Release a fictitious page to the zone pool
 */
void
vm_page_release_fictitious(
        vm_page_t m)
{
        assert((m->vmp_q_state == VM_PAGE_NOT_ON_Q) || (m->vmp_q_state == VM_PAGE_IS_WIRED));
        assert(m->vmp_fictitious);
        assert(VM_PAGE_GET_PHYS_PAGE(m) == vm_page_fictitious_addr ||
            VM_PAGE_GET_PHYS_PAGE(m) == vm_page_guard_addr);


        if (VM_PAGE_GET_PHYS_PAGE(m) == vm_page_guard_addr) {
                OSAddAtomic(-1, &vm_guard_count);
        }

        c_vm_page_release_fictitious++;

        zfree(vm_page_zone, m);
}

/*
 *      vm_page_more_fictitious:
 *
 *      Add more fictitious pages to the zone.
 *      Allowed to block. This routine is way intimate
 *      with the zones code, for several reasons:
 *      1. we need to carve some page structures out of physical
 *         memory before zones work, so they _cannot_ come from
 *         the zone_map.
 *      2. the zone needs to be collectable in order to prevent
 *         growth without bound. These structures are used by
 *         the device pager (by the hundreds and thousands), as
 *         private pages for pageout, and as blocking pages for
 *         pagein. Temporary bursts in demand should not result in
 *         permanent allocation of a resource.
 *      3. To smooth allocation humps, we allocate single pages
 *         with kernel_memory_allocate(), and cram them into the
 *         zone.
 */

void
vm_page_more_fictitious(void)
{
        vm_offset_t     addr;
        kern_return_t   retval;

        c_vm_page_more_fictitious++;

        /*
         * Allocate a single page from the zone_map. Do not wait if no physical
         * pages are immediately available, and do not zero the space. We need
         * our own blocking lock here to prevent having multiple,
         * simultaneous requests from piling up on the zone_map lock. Exactly
         * one (of our) threads should be potentially waiting on the map lock.
         * If winner is not vm-privileged, then the page allocation will fail,
         * and it will temporarily block here in the vm_page_wait().
         */
        lck_mtx_lock(&vm_page_alloc_lock);
        /*
         * If another thread allocated space, just bail out now.
         */
        if (zone_free_count(vm_page_zone) > 5) {
                /*
                 * The number "5" is a small number that is larger than the
                 * number of fictitious pages that any single caller will
                 * attempt to allocate. Otherwise, a thread will attempt to
                 * acquire a fictitious page (vm_page_grab_fictitious), fail,
                 * release all of the resources and locks already acquired,
                 * and then call this routine. This routine finds the pages
                 * that the caller released, so fails to allocate new space.
                 * The process repeats infinitely. The largest known number
                 * of fictitious pages required in this manner is 2. 5 is
                 * simply a somewhat larger number.
                 */
                lck_mtx_unlock(&vm_page_alloc_lock);
                return;
        }

        retval = kernel_memory_allocate(zone_map,
            &addr, PAGE_SIZE, 0,
            KMA_KOBJECT | KMA_NOPAGEWAIT, VM_KERN_MEMORY_ZONE);
        if (retval != KERN_SUCCESS) {
                /*
                 * No page was available. Drop the
                 * lock to give another thread a chance at it, and
                 * wait for the pageout daemon to make progress.
                 */
                lck_mtx_unlock(&vm_page_alloc_lock);
                vm_page_wait(THREAD_UNINT);
                return;
        }

        zcram(vm_page_zone, addr, PAGE_SIZE);

        lck_mtx_unlock(&vm_page_alloc_lock);
}


/*
 *      vm_pool_low():
 *
 *      Return true if it is not likely that a non-vm_privileged thread
 *      can get memory without blocking.  Advisory only, since the
 *      situation may change under us.
 */
int
vm_pool_low(void)
{
        /* No locking, at worst we will fib. */
        return vm_page_free_count <= vm_page_free_reserved;
}

boolean_t vm_darkwake_mode = FALSE;

/*
 * vm_update_darkwake_mode():
 *
 * Tells the VM that the system is in / out of darkwake.
 *
 * Today, the VM only lowers/raises the background queue target
 * so as to favor consuming more/less background pages when
 * darwake is ON/OFF.
 *
 * We might need to do more things in the future.
 */

void
vm_update_darkwake_mode(boolean_t darkwake_mode)
{
        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_NOTOWNED);

        vm_page_lockspin_queues();

        if (vm_darkwake_mode == darkwake_mode) {
                /*
                 * No change.
                 */
                vm_page_unlock_queues();
                return;
        }

        vm_darkwake_mode = darkwake_mode;

        if (vm_darkwake_mode == TRUE) {
#if CONFIG_BACKGROUND_QUEUE

                /* save background target to restore later */
                vm_page_background_target_snapshot = vm_page_background_target;

                /* target is set to 0...no protection for background pages */
                vm_page_background_target = 0;

#endif /* CONFIG_BACKGROUND_QUEUE */
        } else if (vm_darkwake_mode == FALSE) {
#if CONFIG_BACKGROUND_QUEUE

                if (vm_page_background_target_snapshot) {
                        vm_page_background_target = vm_page_background_target_snapshot;
                }
#endif /* CONFIG_BACKGROUND_QUEUE */
        }
        vm_page_unlock_queues();
}

#if CONFIG_BACKGROUND_QUEUE

void
vm_page_update_background_state(vm_page_t mem)
{
        if (vm_page_background_mode == VM_PAGE_BG_DISABLED) {
                return;
        }

        if (mem->vmp_in_background == FALSE) {
                return;
        }

        task_t  my_task = current_task();

        if (my_task) {
                if (task_get_darkwake_mode(my_task)) {
                        return;
                }
        }

#if BACKGROUNDQ_BASED_ON_QOS
        if (proc_get_effective_thread_policy(current_thread(), TASK_POLICY_QOS) <= THREAD_QOS_LEGACY) {
                return;
        }
#else
        if (my_task) {
                if (proc_get_effective_task_policy(my_task, TASK_POLICY_DARWIN_BG)) {
                        return;
                }
        }
#endif
        vm_page_lockspin_queues();

        mem->vmp_in_background = FALSE;
        vm_page_background_promoted_count++;

        vm_page_remove_from_backgroundq(mem);

        vm_page_unlock_queues();
}


void
vm_page_assign_background_state(vm_page_t mem)
{
        if (vm_page_background_mode == VM_PAGE_BG_DISABLED) {
                return;
        }

        task_t  my_task = current_task();

        if (my_task) {
                if (task_get_darkwake_mode(my_task)) {
                        mem->vmp_in_background = TRUE;
                        return;
                }
        }

#if BACKGROUNDQ_BASED_ON_QOS
        if (proc_get_effective_thread_policy(current_thread(), TASK_POLICY_QOS) <= THREAD_QOS_LEGACY) {
                mem->vmp_in_background = TRUE;
        } else {
                mem->vmp_in_background = FALSE;
        }
#else
        if (my_task) {
                mem->vmp_in_background = proc_get_effective_task_policy(my_task, TASK_POLICY_DARWIN_BG);
        }
#endif
}


void
vm_page_remove_from_backgroundq(
        vm_page_t       mem)
{
        vm_object_t     m_object;

        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);

        if (mem->vmp_on_backgroundq) {
                vm_page_queue_remove(&vm_page_queue_background, mem, vmp_backgroundq);

                mem->vmp_backgroundq.next = 0;
                mem->vmp_backgroundq.prev = 0;
                mem->vmp_on_backgroundq = FALSE;

                vm_page_background_count--;

                m_object = VM_PAGE_OBJECT(mem);

                if (m_object->internal) {
                        vm_page_background_internal_count--;
                } else {
                        vm_page_background_external_count--;
                }
        } else {
                assert(VM_PAGE_UNPACK_PTR(mem->vmp_backgroundq.next) == (uintptr_t)NULL &&
                    VM_PAGE_UNPACK_PTR(mem->vmp_backgroundq.prev) == (uintptr_t)NULL);
        }
}


void
vm_page_add_to_backgroundq(
        vm_page_t       mem,
        boolean_t       first)
{
        vm_object_t     m_object;

        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);

        if (vm_page_background_mode == VM_PAGE_BG_DISABLED) {
                return;
        }

        if (mem->vmp_on_backgroundq == FALSE) {
                m_object = VM_PAGE_OBJECT(mem);

                if (vm_page_background_exclude_external && !m_object->internal) {
                        return;
                }

                if (first == TRUE) {
                        vm_page_queue_enter_first(&vm_page_queue_background, mem, vmp_backgroundq);
                } else {
                        vm_page_queue_enter(&vm_page_queue_background, mem, vmp_backgroundq);
                }
                mem->vmp_on_backgroundq = TRUE;

                vm_page_background_count++;

                if (m_object->internal) {
                        vm_page_background_internal_count++;
                } else {
                        vm_page_background_external_count++;
                }
        }
}

#endif /* CONFIG_BACKGROUND_QUEUE */

/*
 * This can be switched to FALSE to help debug drivers
 * that are having problems with memory > 4G.
 */
boolean_t       vm_himemory_mode = TRUE;

/*
 * this interface exists to support hardware controllers
 * incapable of generating DMAs with more than 32 bits
 * of address on platforms with physical memory > 4G...
 */
unsigned int    vm_lopages_allocated_q = 0;
unsigned int    vm_lopages_allocated_cpm_success = 0;
unsigned int    vm_lopages_allocated_cpm_failed = 0;
vm_page_queue_head_t    vm_lopage_queue_free __attribute__((aligned(VM_PACKED_POINTER_ALIGNMENT)));

vm_page_t
vm_page_grablo(void)
{
        vm_page_t       mem;

        if (vm_lopage_needed == FALSE) {
                return vm_page_grab();
        }

        lck_mtx_lock_spin(&vm_page_queue_free_lock);

        if (!vm_page_queue_empty(&vm_lopage_queue_free)) {
                vm_page_queue_remove_first(&vm_lopage_queue_free, mem, vmp_pageq);
                assert(vm_lopage_free_count);
                assert(mem->vmp_q_state == VM_PAGE_ON_FREE_LOPAGE_Q);
                mem->vmp_q_state = VM_PAGE_NOT_ON_Q;

                vm_lopage_free_count--;
                vm_lopages_allocated_q++;

                if (vm_lopage_free_count < vm_lopage_lowater) {
                        vm_lopage_refill = TRUE;
                }

                lck_mtx_unlock(&vm_page_queue_free_lock);

#if CONFIG_BACKGROUND_QUEUE
                vm_page_assign_background_state(mem);
#endif
        } else {
                lck_mtx_unlock(&vm_page_queue_free_lock);

                if (cpm_allocate(PAGE_SIZE, &mem, atop(PPNUM_MAX), 0, FALSE, KMA_LOMEM) != KERN_SUCCESS) {
                        lck_mtx_lock_spin(&vm_page_queue_free_lock);
                        vm_lopages_allocated_cpm_failed++;
                        lck_mtx_unlock(&vm_page_queue_free_lock);

                        return VM_PAGE_NULL;
                }
                assert(mem->vmp_q_state == VM_PAGE_NOT_ON_Q);

                mem->vmp_busy = TRUE;

                vm_page_lockspin_queues();

                mem->vmp_gobbled = FALSE;
                vm_page_gobble_count--;
                vm_page_wire_count--;

                vm_lopages_allocated_cpm_success++;
                vm_page_unlock_queues();
        }
        assert(mem->vmp_busy);
        assert(!mem->vmp_pmapped);
        assert(!mem->vmp_wpmapped);
        assert(!pmap_is_noencrypt(VM_PAGE_GET_PHYS_PAGE(mem)));

        VM_PAGE_ZERO_PAGEQ_ENTRY(mem);

        disable_preemption();
        PROCESSOR_DATA(current_processor(), page_grab_count) += 1;
        VM_DEBUG_EVENT(vm_page_grab, VM_PAGE_GRAB, DBG_FUNC_NONE, 0, 1, 0, 0);
        enable_preemption();

        return mem;
}


/*
 *      vm_page_grab:
 *
 *      first try to grab a page from the per-cpu free list...
 *      this must be done while pre-emption is disabled... if
 *      a page is available, we're done...
 *      if no page is available, grab the vm_page_queue_free_lock
 *      and see if current number of free pages would allow us
 *      to grab at least 1... if not, return VM_PAGE_NULL as before...
 *      if there are pages available, disable preemption and
 *      recheck the state of the per-cpu free list... we could
 *      have been preempted and moved to a different cpu, or
 *      some other thread could have re-filled it... if still
 *      empty, figure out how many pages we can steal from the
 *      global free queue and move to the per-cpu queue...
 *      return 1 of these pages when done... only wakeup the
 *      pageout_scan thread if we moved pages from the global
 *      list... no need for the wakeup if we've satisfied the
 *      request from the per-cpu queue.
 */

#if CONFIG_SECLUDED_MEMORY
vm_page_t vm_page_grab_secluded(void);
#endif /* CONFIG_SECLUDED_MEMORY */

static inline void
vm_page_grab_diags(void);

vm_page_t
vm_page_grab(void)
{
        return vm_page_grab_options(VM_PAGE_GRAB_OPTIONS_NONE);
}

#if HIBERNATION
boolean_t       hibernate_rebuild_needed = FALSE;
#endif /* HIBERNATION */

vm_page_t
vm_page_grab_options(
        int grab_options)
{
        vm_page_t       mem;

        disable_preemption();

        if ((mem = PROCESSOR_DATA(current_processor(), free_pages))) {
return_page_from_cpu_list:
                assert(mem->vmp_q_state == VM_PAGE_ON_FREE_LOCAL_Q);

#if HIBERNATION
                if (hibernate_rebuild_needed) {
                        panic("%s:%d should not modify cpu->free_pages while hibernating", __FUNCTION__, __LINE__);
                }
#endif /* HIBERNATION */

                vm_page_grab_diags();
                PROCESSOR_DATA(current_processor(), page_grab_count) += 1;
                PROCESSOR_DATA(current_processor(), free_pages) = mem->vmp_snext;
                VM_DEBUG_EVENT(vm_page_grab, VM_PAGE_GRAB, DBG_FUNC_NONE, grab_options, 0, 0, 0);

                enable_preemption();
                VM_PAGE_ZERO_PAGEQ_ENTRY(mem);
                mem->vmp_q_state = VM_PAGE_NOT_ON_Q;

                assert(mem->vmp_listq.next == 0 && mem->vmp_listq.prev == 0);
                assert(mem->vmp_tabled == FALSE);
                assert(mem->vmp_object == 0);
                assert(!mem->vmp_laundry);
                ASSERT_PMAP_FREE(mem);
                assert(mem->vmp_busy);
                assert(!mem->vmp_pmapped);
                assert(!mem->vmp_wpmapped);
                assert(!pmap_is_noencrypt(VM_PAGE_GET_PHYS_PAGE(mem)));

#if CONFIG_BACKGROUND_QUEUE
                vm_page_assign_background_state(mem);
#endif
                return mem;
        }
        enable_preemption();


        /*
         *      Optionally produce warnings if the wire or gobble
         *      counts exceed some threshold.
         */
#if VM_PAGE_WIRE_COUNT_WARNING
        if (vm_page_wire_count >= VM_PAGE_WIRE_COUNT_WARNING) {
                printf("mk: vm_page_grab(): high wired page count of %d\n",
                    vm_page_wire_count);
        }
#endif
#if VM_PAGE_GOBBLE_COUNT_WARNING
        if (vm_page_gobble_count >= VM_PAGE_GOBBLE_COUNT_WARNING) {
                printf("mk: vm_page_grab(): high gobbled page count of %d\n",
                    vm_page_gobble_count);
        }
#endif

        /*
         * If free count is low and we have delayed pages from early boot,
         * get one of those instead.
         */
        if (__improbable(vm_delayed_count > 0 &&
            vm_page_free_count <= vm_page_free_target &&
            (mem = vm_get_delayed_page(grab_options)) != NULL)) {
                return mem;
        }

        lck_mtx_lock_spin(&vm_page_queue_free_lock);

        /*
         *      Only let privileged threads (involved in pageout)
         *      dip into the reserved pool.
         */
        if ((vm_page_free_count < vm_page_free_reserved) &&
            !(current_thread()->options & TH_OPT_VMPRIV)) {
                /* no page for us in the free queue... */
                lck_mtx_unlock(&vm_page_queue_free_lock);
                mem = VM_PAGE_NULL;

#if CONFIG_SECLUDED_MEMORY
                /* ... but can we try and grab from the secluded queue? */
                if (vm_page_secluded_count > 0 &&
                    ((grab_options & VM_PAGE_GRAB_SECLUDED) ||
                    task_can_use_secluded_mem(current_task(), TRUE))) {
                        mem = vm_page_grab_secluded();
                        if (grab_options & VM_PAGE_GRAB_SECLUDED) {
                                vm_page_secluded.grab_for_iokit++;
                                if (mem) {
                                        vm_page_secluded.grab_for_iokit_success++;
                                }
                        }
                        if (mem) {
                                VM_CHECK_MEMORYSTATUS;

                                disable_preemption();
                                vm_page_grab_diags();
                                PROCESSOR_DATA(current_processor(), page_grab_count) += 1;
                                VM_DEBUG_EVENT(vm_page_grab, VM_PAGE_GRAB, DBG_FUNC_NONE, grab_options, 0, 0, 0);
                                enable_preemption();

                                return mem;
                        }
                }
#else /* CONFIG_SECLUDED_MEMORY */
                (void) grab_options;
#endif /* CONFIG_SECLUDED_MEMORY */
        } else {
                vm_page_t        head;
                vm_page_t        tail;
                unsigned int     pages_to_steal;
                unsigned int     color;
                unsigned int clump_end, sub_count;

                while (vm_page_free_count == 0) {
                        lck_mtx_unlock(&vm_page_queue_free_lock);
                        /*
                         * must be a privileged thread to be
                         * in this state since a non-privileged
                         * thread would have bailed if we were
                         * under the vm_page_free_reserved mark
                         */
                        VM_PAGE_WAIT();
                        lck_mtx_lock_spin(&vm_page_queue_free_lock);
                }

                disable_preemption();

                if ((mem = PROCESSOR_DATA(current_processor(), free_pages))) {
                        lck_mtx_unlock(&vm_page_queue_free_lock);

                        /*
                         * we got preempted and moved to another processor
                         * or we got preempted and someone else ran and filled the cache
                         */
                        goto return_page_from_cpu_list;
                }
                if (vm_page_free_count <= vm_page_free_reserved) {
                        pages_to_steal = 1;
                } else {
                        if (vm_free_magazine_refill_limit <= (vm_page_free_count - vm_page_free_reserved)) {
                                pages_to_steal = vm_free_magazine_refill_limit;
                        } else {
                                pages_to_steal = (vm_page_free_count - vm_page_free_reserved);
                        }
                }
                color = PROCESSOR_DATA(current_processor(), start_color);
                head = tail = NULL;

                vm_page_free_count -= pages_to_steal;
                clump_end = sub_count = 0;

                while (pages_to_steal--) {
                        while (vm_page_queue_empty(&vm_page_queue_free[color].qhead)) {
                                color = (color + 1) & vm_color_mask;
                        }
#if defined(__x86_64__)
                        vm_page_queue_remove_first_with_clump(&vm_page_queue_free[color].qhead,
                            mem, clump_end);
#else
                        vm_page_queue_remove_first(&vm_page_queue_free[color].qhead,
                            mem, vmp_pageq);
#endif

                        assert(mem->vmp_q_state == VM_PAGE_ON_FREE_Q);

                        VM_PAGE_ZERO_PAGEQ_ENTRY(mem);

#if defined(__arm__) || defined(__arm64__)
                        color = (color + 1) & vm_color_mask;
#else

#if DEVELOPMENT || DEBUG

                        sub_count++;
                        if (clump_end) {
                                vm_clump_update_stats(sub_count);
                                sub_count = 0;
                                color = (color + 1) & vm_color_mask;
                        }
#else
                        if (clump_end) {
                                color = (color + 1) & vm_color_mask;
                        }

#endif /* if DEVELOPMENT || DEBUG */

#endif  /* if defined(__arm__) || defined(__arm64__) */

                        if (head == NULL) {
                                head = mem;
                        } else {
                                tail->vmp_snext = mem;
                        }
                        tail = mem;

                        assert(mem->vmp_listq.next == 0 && mem->vmp_listq.prev == 0);
                        assert(mem->vmp_tabled == FALSE);
                        assert(mem->vmp_object == 0);
                        assert(!mem->vmp_laundry);

                        mem->vmp_q_state = VM_PAGE_ON_FREE_LOCAL_Q;

                        ASSERT_PMAP_FREE(mem);
                        assert(mem->vmp_busy);
                        assert(!mem->vmp_pmapped);
                        assert(!mem->vmp_wpmapped);
                        assert(!pmap_is_noencrypt(VM_PAGE_GET_PHYS_PAGE(mem)));
                }
#if defined (__x86_64__) && (DEVELOPMENT || DEBUG)
                vm_clump_update_stats(sub_count);
#endif
                lck_mtx_unlock(&vm_page_queue_free_lock);

#if HIBERNATION
                if (hibernate_rebuild_needed) {
                        panic("%s:%d should not modify cpu->free_pages while hibernating", __FUNCTION__, __LINE__);
                }
#endif /* HIBERNATION */
                PROCESSOR_DATA(current_processor(), free_pages) = head->vmp_snext;
                PROCESSOR_DATA(current_processor(), start_color) = color;

                /*
                 * satisfy this request
                 */
                vm_page_grab_diags();
                PROCESSOR_DATA(current_processor(), page_grab_count) += 1;
                VM_DEBUG_EVENT(vm_page_grab, VM_PAGE_GRAB, DBG_FUNC_NONE, grab_options, 0, 0, 0);
                mem = head;
                assert(mem->vmp_q_state == VM_PAGE_ON_FREE_LOCAL_Q);

                VM_PAGE_ZERO_PAGEQ_ENTRY(mem);
                mem->vmp_q_state = VM_PAGE_NOT_ON_Q;

                enable_preemption();
        }
        /*
         *      Decide if we should poke the pageout daemon.
         *      We do this if the free count is less than the low
         *      water mark. VM Pageout Scan will keep running till
         *      the free_count > free_target (& hence above free_min).
         *      This wakeup is to catch the possibility of the counts
         *      dropping between VM Pageout Scan parking and this check.
         *
         *      We don't have the counts locked ... if they change a little,
         *      it doesn't really matter.
         */
        if (vm_page_free_count < vm_page_free_min) {
                lck_mtx_lock(&vm_page_queue_free_lock);
                if (vm_pageout_running == FALSE) {
                        lck_mtx_unlock(&vm_page_queue_free_lock);
                        thread_wakeup((event_t) &vm_page_free_wanted);
                } else {
                        lck_mtx_unlock(&vm_page_queue_free_lock);
                }
        }

        VM_CHECK_MEMORYSTATUS;

        if (mem) {
//              dbgLog(VM_PAGE_GET_PHYS_PAGE(mem), vm_page_free_count, vm_page_wire_count, 4);  /* (TEST/DEBUG) */

#if CONFIG_BACKGROUND_QUEUE
                vm_page_assign_background_state(mem);
#endif
        }
        return mem;
}

#if CONFIG_SECLUDED_MEMORY
vm_page_t
vm_page_grab_secluded(void)
{
        vm_page_t       mem;
        vm_object_t     object;
        int             refmod_state;

        if (vm_page_secluded_count == 0) {
                /* no secluded pages to grab... */
                return VM_PAGE_NULL;
        }

        /* secluded queue is protected by the VM page queue lock */
        vm_page_lock_queues();

        if (vm_page_secluded_count == 0) {
                /* no secluded pages to grab... */
                vm_page_unlock_queues();
                return VM_PAGE_NULL;
        }

#if 00
        /* can we grab from the secluded queue? */
        if (vm_page_secluded_count > vm_page_secluded_target ||
            (vm_page_secluded_count > 0 &&
            task_can_use_secluded_mem(current_task(), TRUE))) {
                /* OK */
        } else {
                /* can't grab from secluded queue... */
                vm_page_unlock_queues();
                return VM_PAGE_NULL;
        }
#endif

        /* we can grab a page from secluded queue! */
        assert((vm_page_secluded_count_free +
            vm_page_secluded_count_inuse) ==
            vm_page_secluded_count);
        if (current_task()->task_can_use_secluded_mem) {
                assert(num_tasks_can_use_secluded_mem > 0);
        }
        assert(!vm_page_queue_empty(&vm_page_queue_secluded));
        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        mem = (vm_page_t)vm_page_queue_first(&vm_page_queue_secluded);
        assert(mem->vmp_q_state == VM_PAGE_ON_SECLUDED_Q);
        vm_page_queues_remove(mem, TRUE);

        object = VM_PAGE_OBJECT(mem);

        assert(!mem->vmp_fictitious);
        assert(!VM_PAGE_WIRED(mem));
        if (object == VM_OBJECT_NULL) {
                /* free for grab! */
                vm_page_unlock_queues();
                vm_page_secluded.grab_success_free++;

                assert(mem->vmp_busy);
                assert(mem->vmp_q_state == VM_PAGE_NOT_ON_Q);
                assert(VM_PAGE_OBJECT(mem) == VM_OBJECT_NULL);
                assert(mem->vmp_pageq.next == 0);
                assert(mem->vmp_pageq.prev == 0);
                assert(mem->vmp_listq.next == 0);
                assert(mem->vmp_listq.prev == 0);
#if CONFIG_BACKGROUND_QUEUE
                assert(mem->vmp_on_backgroundq == 0);
                assert(mem->vmp_backgroundq.next == 0);
                assert(mem->vmp_backgroundq.prev == 0);
#endif /* CONFIG_BACKGROUND_QUEUE */
                return mem;
        }

        assert(!object->internal);
//      vm_page_pageable_external_count--;

        if (!vm_object_lock_try(object)) {
//              printf("SECLUDED: page %p: object %p locked\n", mem, object);
                vm_page_secluded.grab_failure_locked++;
reactivate_secluded_page:
                vm_page_activate(mem);
                vm_page_unlock_queues();
                return VM_PAGE_NULL;
        }
        if (mem->vmp_busy ||
            mem->vmp_cleaning ||
            mem->vmp_laundry) {
                /* can't steal page in this state... */
                vm_object_unlock(object);
                vm_page_secluded.grab_failure_state++;
                goto reactivate_secluded_page;
        }

        mem->vmp_busy = TRUE;
        refmod_state = pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(mem));
        if (refmod_state & VM_MEM_REFERENCED) {
                mem->vmp_reference = TRUE;
        }
        if (refmod_state & VM_MEM_MODIFIED) {
                SET_PAGE_DIRTY(mem, FALSE);
        }
        if (mem->vmp_dirty || mem->vmp_precious) {
                /* can't grab a dirty page; re-activate */
//              printf("SECLUDED: dirty page %p\n", mem);
                PAGE_WAKEUP_DONE(mem);
                vm_page_secluded.grab_failure_dirty++;
                vm_object_unlock(object);
                goto reactivate_secluded_page;
        }
        if (mem->vmp_reference) {
                /* it's been used but we do need to grab a page... */
        }

        vm_page_unlock_queues();

        /* finish what vm_page_free() would have done... */
        vm_page_free_prepare_object(mem, TRUE);
        vm_object_unlock(object);
        object = VM_OBJECT_NULL;
        if (vm_page_free_verify) {
                ASSERT_PMAP_FREE(mem);
        }
        pmap_clear_noencrypt(VM_PAGE_GET_PHYS_PAGE(mem));
        vm_page_secluded.grab_success_other++;

        assert(mem->vmp_busy);
        assert(mem->vmp_q_state == VM_PAGE_NOT_ON_Q);
        assert(VM_PAGE_OBJECT(mem) == VM_OBJECT_NULL);
        assert(mem->vmp_pageq.next == 0);
        assert(mem->vmp_pageq.prev == 0);
        assert(mem->vmp_listq.next == 0);
        assert(mem->vmp_listq.prev == 0);
#if CONFIG_BACKGROUND_QUEUE
        assert(mem->vmp_on_backgroundq == 0);
        assert(mem->vmp_backgroundq.next == 0);
        assert(mem->vmp_backgroundq.prev == 0);
#endif /* CONFIG_BACKGROUND_QUEUE */

        return mem;
}

uint64_t
vm_page_secluded_drain(void)
{
        vm_page_t local_freeq;
        int local_freed;
        uint64_t num_reclaimed;
        unsigned int saved_secluded_count, saved_secluded_target;

        num_reclaimed = 0;
        local_freeq = NULL;
        local_freed = 0;

        vm_page_lock_queues();

        saved_secluded_count = vm_page_secluded_count;
        saved_secluded_target = vm_page_secluded_target;
        vm_page_secluded_target = 0;
        VM_PAGE_SECLUDED_COUNT_OVER_TARGET_UPDATE();
        while (vm_page_secluded_count) {
                vm_page_t secluded_page;

                assert((vm_page_secluded_count_free +
                    vm_page_secluded_count_inuse) ==
                    vm_page_secluded_count);
                secluded_page = (vm_page_t)vm_page_queue_first(&vm_page_queue_secluded);
                assert(secluded_page->vmp_q_state == VM_PAGE_ON_SECLUDED_Q);

                vm_page_queues_remove(secluded_page, FALSE);
                assert(!secluded_page->vmp_fictitious);
                assert(!VM_PAGE_WIRED(secluded_page));

                if (secluded_page->vmp_object == 0) {
                        /* transfer to free queue */
                        assert(secluded_page->vmp_busy);
                        secluded_page->vmp_snext = local_freeq;
                        local_freeq = secluded_page;
                        local_freed += 1;
                } else {
                        /* transfer to head of active queue */
                        vm_page_enqueue_active(secluded_page, FALSE);
                        secluded_page = VM_PAGE_NULL;
                }
                num_reclaimed++;
        }
        vm_page_secluded_target = saved_secluded_target;
        VM_PAGE_SECLUDED_COUNT_OVER_TARGET_UPDATE();

//      printf("FBDP %s:%d secluded_count %d->%d, target %d, reclaimed %lld\n", __FUNCTION__, __LINE__, saved_secluded_count, vm_page_secluded_count, vm_page_secluded_target, num_reclaimed);

        vm_page_unlock_queues();

        if (local_freed) {
                vm_page_free_list(local_freeq, TRUE);
                local_freeq = NULL;
                local_freed = 0;
        }

        return num_reclaimed;
}
#endif /* CONFIG_SECLUDED_MEMORY */


static inline void
vm_page_grab_diags()
{
#if DEVELOPMENT || DEBUG
        task_t task = current_task();
        if (task == NULL) {
                return;
        }

        ledger_credit(task->ledger, task_ledgers.pages_grabbed, 1);
#endif /* DEVELOPMENT || DEBUG */
}

/*
 *      vm_page_release:
 *
 *      Return a page to the free list.
 */

void
vm_page_release(
        vm_page_t       mem,
        boolean_t       page_queues_locked)
{
        unsigned int    color;
        int     need_wakeup = 0;
        int     need_priv_wakeup = 0;
#if CONFIG_SECLUDED_MEMORY
        int     need_secluded_wakeup = 0;
#endif /* CONFIG_SECLUDED_MEMORY */
        event_t wakeup_event = NULL;

        if (page_queues_locked) {
                LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        } else {
                LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_NOTOWNED);
        }

        assert(!mem->vmp_private && !mem->vmp_fictitious);
        if (vm_page_free_verify) {
                ASSERT_PMAP_FREE(mem);
        }
//      dbgLog(VM_PAGE_GET_PHYS_PAGE(mem), vm_page_free_count, vm_page_wire_count, 5);  /* (TEST/DEBUG) */

        pmap_clear_noencrypt(VM_PAGE_GET_PHYS_PAGE(mem));

        lck_mtx_lock_spin(&vm_page_queue_free_lock);

        assert(mem->vmp_q_state == VM_PAGE_NOT_ON_Q);
        assert(mem->vmp_busy);
        assert(!mem->vmp_laundry);
        assert(mem->vmp_object == 0);
        assert(mem->vmp_pageq.next == 0 && mem->vmp_pageq.prev == 0);
        assert(mem->vmp_listq.next == 0 && mem->vmp_listq.prev == 0);
#if CONFIG_BACKGROUND_QUEUE
        assert(mem->vmp_backgroundq.next == 0 &&
            mem->vmp_backgroundq.prev == 0 &&
            mem->vmp_on_backgroundq == FALSE);
#endif
        if ((mem->vmp_lopage == TRUE || vm_lopage_refill == TRUE) &&
            vm_lopage_free_count < vm_lopage_free_limit &&
            VM_PAGE_GET_PHYS_PAGE(mem) < max_valid_low_ppnum) {
                /*
                 * this exists to support hardware controllers
                 * incapable of generating DMAs with more than 32 bits
                 * of address on platforms with physical memory > 4G...
                 */
                vm_page_queue_enter_first(&vm_lopage_queue_free, mem, vmp_pageq);
                vm_lopage_free_count++;

                if (vm_lopage_free_count >= vm_lopage_free_limit) {
                        vm_lopage_refill = FALSE;
                }

                mem->vmp_q_state = VM_PAGE_ON_FREE_LOPAGE_Q;
                mem->vmp_lopage = TRUE;
#if CONFIG_SECLUDED_MEMORY
        } else if (vm_page_free_count > vm_page_free_reserved &&
            vm_page_secluded_count < vm_page_secluded_target &&
            num_tasks_can_use_secluded_mem == 0) {
                /*
                 * XXX FBDP TODO: also avoid refilling secluded queue
                 * when some IOKit objects are already grabbing from it...
                 */
                if (!page_queues_locked) {
                        if (!vm_page_trylock_queues()) {
                                /* take locks in right order */
                                lck_mtx_unlock(&vm_page_queue_free_lock);
                                vm_page_lock_queues();
                                lck_mtx_lock_spin(&vm_page_queue_free_lock);
                        }
                }
                mem->vmp_lopage = FALSE;
                LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
                vm_page_queue_enter_first(&vm_page_queue_secluded, mem, vmp_pageq);
                mem->vmp_q_state = VM_PAGE_ON_SECLUDED_Q;
                vm_page_secluded_count++;
                VM_PAGE_SECLUDED_COUNT_OVER_TARGET_UPDATE();
                vm_page_secluded_count_free++;
                if (!page_queues_locked) {
                        vm_page_unlock_queues();
                }
                LCK_MTX_ASSERT(&vm_page_queue_free_lock, LCK_MTX_ASSERT_OWNED);
                if (vm_page_free_wanted_secluded > 0) {
                        vm_page_free_wanted_secluded--;
                        need_secluded_wakeup = 1;
                }
#endif /* CONFIG_SECLUDED_MEMORY */
        } else {
                mem->vmp_lopage = FALSE;
                mem->vmp_q_state = VM_PAGE_ON_FREE_Q;

                color = VM_PAGE_GET_COLOR(mem);
#if defined(__x86_64__)
                vm_page_queue_enter_clump(&vm_page_queue_free[color].qhead, mem);
#else
                vm_page_queue_enter(&vm_page_queue_free[color].qhead, mem, vmp_pageq);
#endif
                vm_page_free_count++;
                /*
                 *      Check if we should wake up someone waiting for page.
                 *      But don't bother waking them unless they can allocate.
                 *
                 *      We wakeup only one thread, to prevent starvation.
                 *      Because the scheduling system handles wait queues FIFO,
                 *      if we wakeup all waiting threads, one greedy thread
                 *      can starve multiple niceguy threads.  When the threads
                 *      all wakeup, the greedy threads runs first, grabs the page,
                 *      and waits for another page.  It will be the first to run
                 *      when the next page is freed.
                 *
                 *      However, there is a slight danger here.
                 *      The thread we wake might not use the free page.
                 *      Then the other threads could wait indefinitely
                 *      while the page goes unused.  To forestall this,
                 *      the pageout daemon will keep making free pages
                 *      as long as vm_page_free_wanted is non-zero.
                 */

                assert(vm_page_free_count > 0);
                if (vm_page_free_wanted_privileged > 0) {
                        vm_page_free_wanted_privileged--;
                        need_priv_wakeup = 1;
#if CONFIG_SECLUDED_MEMORY
                } else if (vm_page_free_wanted_secluded > 0 &&
                    vm_page_free_count > vm_page_free_reserved) {
                        vm_page_free_wanted_secluded--;
                        need_secluded_wakeup = 1;
#endif /* CONFIG_SECLUDED_MEMORY */
                } else if (vm_page_free_wanted > 0 &&
                    vm_page_free_count > vm_page_free_reserved) {
                        vm_page_free_wanted--;
                        need_wakeup = 1;
                }
        }
        vm_pageout_vminfo.vm_page_pages_freed++;

        VM_DEBUG_CONSTANT_EVENT(vm_page_release, VM_PAGE_RELEASE, DBG_FUNC_NONE, 1, 0, 0, 0);

        lck_mtx_unlock(&vm_page_queue_free_lock);

        if (need_priv_wakeup) {
                wakeup_event = &vm_page_free_wanted_privileged;
        }
#if CONFIG_SECLUDED_MEMORY
        else if (need_secluded_wakeup) {
                wakeup_event = &vm_page_free_wanted_secluded;
        }
#endif /* CONFIG_SECLUDED_MEMORY */
        else if (need_wakeup) {
                wakeup_event = &vm_page_free_count;
        }

        if (wakeup_event) {
                if (vps_dynamic_priority_enabled == TRUE) {
                        thread_t thread_woken = NULL;
                        wakeup_one_with_inheritor((event_t) wakeup_event, THREAD_AWAKENED, LCK_WAKE_DO_NOT_TRANSFER_PUSH, &thread_woken);
                        thread_deallocate(thread_woken);
                } else {
                        thread_wakeup_one((event_t) wakeup_event);
                }
        }

        VM_CHECK_MEMORYSTATUS;
}

/*
 * This version of vm_page_release() is used only at startup
 * when we are single-threaded and pages are being released
 * for the first time. Hence, no locking or unnecessary checks are made.
 * Note: VM_CHECK_MEMORYSTATUS invoked by the caller.
 */
void
vm_page_release_startup(
        vm_page_t       mem)
{
        vm_page_queue_t queue_free;

        if (vm_lopage_free_count < vm_lopage_free_limit &&
            VM_PAGE_GET_PHYS_PAGE(mem) < max_valid_low_ppnum) {
                mem->vmp_lopage = TRUE;
                mem->vmp_q_state = VM_PAGE_ON_FREE_LOPAGE_Q;
                vm_lopage_free_count++;
                queue_free = &vm_lopage_queue_free;
#if CONFIG_SECLUDED_MEMORY
        } else if (vm_page_secluded_count < vm_page_secluded_target) {
                mem->vmp_lopage = FALSE;
                mem->vmp_q_state = VM_PAGE_ON_SECLUDED_Q;
                vm_page_secluded_count++;
                VM_PAGE_SECLUDED_COUNT_OVER_TARGET_UPDATE();
                vm_page_secluded_count_free++;
                queue_free = &vm_page_queue_secluded;
#endif /* CONFIG_SECLUDED_MEMORY */
        } else {
                mem->vmp_lopage = FALSE;
                mem->vmp_q_state = VM_PAGE_ON_FREE_Q;
                vm_page_free_count++;
                queue_free = &vm_page_queue_free[VM_PAGE_GET_COLOR(mem)].qhead;
        }
        if (mem->vmp_q_state == VM_PAGE_ON_FREE_Q) {
#if defined(__x86_64__)
                vm_page_queue_enter_clump(queue_free, mem);
#else
                vm_page_queue_enter(queue_free, mem, vmp_pageq);
#endif
        } else {
                vm_page_queue_enter_first(queue_free, mem, vmp_pageq);
        }
}

/*
 *      vm_page_wait:
 *
 *      Wait for a page to become available.
 *      If there are plenty of free pages, then we don't sleep.
 *
 *      Returns:
 *              TRUE:  There may be another page, try again
 *              FALSE: We were interrupted out of our wait, don't try again
 */

boolean_t
vm_page_wait(
        int     interruptible )
{
        /*
         *      We can't use vm_page_free_reserved to make this
         *      determination.  Consider: some thread might
         *      need to allocate two pages.  The first allocation
         *      succeeds, the second fails.  After the first page is freed,
         *      a call to vm_page_wait must really block.
         */
        kern_return_t   wait_result;
        int             need_wakeup = 0;
        int             is_privileged = current_thread()->options & TH_OPT_VMPRIV;
        event_t         wait_event = NULL;

        lck_mtx_lock_spin(&vm_page_queue_free_lock);

        if (is_privileged && vm_page_free_count) {
                lck_mtx_unlock(&vm_page_queue_free_lock);
                return TRUE;
        }

        if (vm_page_free_count >= vm_page_free_target) {
                lck_mtx_unlock(&vm_page_queue_free_lock);
                return TRUE;
        }

        if (is_privileged) {
                if (vm_page_free_wanted_privileged++ == 0) {
                        need_wakeup = 1;
                }
                wait_event = (event_t)&vm_page_free_wanted_privileged;
#if CONFIG_SECLUDED_MEMORY
        } else if (secluded_for_apps &&
            task_can_use_secluded_mem(current_task(), FALSE)) {
#if 00
                /* XXX FBDP: need pageq lock for this... */
                /* XXX FBDP: might wait even if pages available, */
                /* XXX FBDP: hopefully not for too long... */
                if (vm_page_secluded_count > 0) {
                        lck_mtx_unlock(&vm_page_queue_free_lock);
                        return TRUE;
                }
#endif
                if (vm_page_free_wanted_secluded++ == 0) {
                        need_wakeup = 1;
                }
                wait_event = (event_t)&vm_page_free_wanted_secluded;
#endif /* CONFIG_SECLUDED_MEMORY */
        } else {
                if (vm_page_free_wanted++ == 0) {
                        need_wakeup = 1;
                }
                wait_event = (event_t)&vm_page_free_count;
        }

        /*
         * We don't do a vm_pageout_scan wakeup if we already have
         * some waiters because vm_pageout_scan checks for waiters
         * before it returns and does so behind the vm_page_queue_free_lock,
         * which we own when we bump the waiter counts.
         */

        if (vps_dynamic_priority_enabled == TRUE) {
                /*
                 * We are waking up vm_pageout_scan here. If it needs
                 * the vm_page_queue_free_lock before we unlock it
                 * we'll end up just blocking and incur an extra
                 * context switch. Could be a perf. issue.
                 */

                counter(c_vm_page_wait_block++);

                if (need_wakeup) {
                        thread_wakeup((event_t)&vm_page_free_wanted);
                }

                /*
                 * LD: This event is going to get recorded every time because
                 * we don't get back THREAD_WAITING from lck_mtx_sleep_with_inheritor.
                 * We just block in that routine.
                 */
                VM_DEBUG_CONSTANT_EVENT(vm_page_wait_block, VM_PAGE_WAIT_BLOCK, DBG_FUNC_START,
                    vm_page_free_wanted_privileged,
                    vm_page_free_wanted,
#if CONFIG_SECLUDED_MEMORY
                    vm_page_free_wanted_secluded,
#else /* CONFIG_SECLUDED_MEMORY */
                    0,
#endif /* CONFIG_SECLUDED_MEMORY */
                    0);
                wait_result =  lck_mtx_sleep_with_inheritor(&vm_page_queue_free_lock,
                    LCK_SLEEP_UNLOCK,
                    wait_event,
                    vm_pageout_scan_thread,
                    interruptible,
                    0);
        } else {
                wait_result = assert_wait(wait_event, interruptible);

                lck_mtx_unlock(&vm_page_queue_free_lock);
                counter(c_vm_page_wait_block++);

                if (need_wakeup) {
                        thread_wakeup((event_t)&vm_page_free_wanted);
                }

                if (wait_result == THREAD_WAITING) {
                        VM_DEBUG_CONSTANT_EVENT(vm_page_wait_block, VM_PAGE_WAIT_BLOCK, DBG_FUNC_START,
                            vm_page_free_wanted_privileged,
                            vm_page_free_wanted,
#if CONFIG_SECLUDED_MEMORY
                            vm_page_free_wanted_secluded,
#else /* CONFIG_SECLUDED_MEMORY */
                            0,
#endif /* CONFIG_SECLUDED_MEMORY */
                            0);
                        wait_result = thread_block(THREAD_CONTINUE_NULL);
                        VM_DEBUG_CONSTANT_EVENT(vm_page_wait_block,
                            VM_PAGE_WAIT_BLOCK, DBG_FUNC_END, 0, 0, 0, 0);
                }
        }

        return (wait_result == THREAD_AWAKENED) || (wait_result == THREAD_NOT_WAITING);
}

/*
 *      vm_page_alloc:
 *
 *      Allocate and return a memory cell associated
 *      with this VM object/offset pair.
 *
 *      Object must be locked.
 */

vm_page_t
vm_page_alloc(
        vm_object_t             object,
        vm_object_offset_t      offset)
{
        vm_page_t       mem;
        int             grab_options;

        vm_object_lock_assert_exclusive(object);
        grab_options = 0;
#if CONFIG_SECLUDED_MEMORY
        if (object->can_grab_secluded) {
                grab_options |= VM_PAGE_GRAB_SECLUDED;
        }
#endif /* CONFIG_SECLUDED_MEMORY */
        mem = vm_page_grab_options(grab_options);
        if (mem == VM_PAGE_NULL) {
                return VM_PAGE_NULL;
        }

        vm_page_insert(mem, object, offset);

        return mem;
}

/*
 *      vm_page_alloc_guard:
 *
 *      Allocate a fictitious page which will be used
 *      as a guard page.  The page will be inserted into
 *      the object and returned to the caller.
 */

vm_page_t
vm_page_alloc_guard(
        vm_object_t             object,
        vm_object_offset_t      offset)
{
        vm_page_t       mem;

        vm_object_lock_assert_exclusive(object);
        mem = vm_page_grab_guard();
        if (mem == VM_PAGE_NULL) {
                return VM_PAGE_NULL;
        }

        vm_page_insert(mem, object, offset);

        return mem;
}


counter(unsigned int c_laundry_pages_freed = 0; )

/*
 *      vm_page_free_prepare:
 *
 *      Removes page from any queue it may be on
 *      and disassociates it from its VM object.
 *
 *      Object and page queues must be locked prior to entry.
 */
static void
vm_page_free_prepare(
        vm_page_t       mem)
{
        vm_page_free_prepare_queues(mem);
        vm_page_free_prepare_object(mem, TRUE);
}


void
vm_page_free_prepare_queues(
        vm_page_t       mem)
{
        vm_object_t     m_object;

        VM_PAGE_CHECK(mem);

        assert(mem->vmp_q_state != VM_PAGE_ON_FREE_Q);
        assert(!mem->vmp_cleaning);
        m_object = VM_PAGE_OBJECT(mem);

        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        if (m_object) {
                vm_object_lock_assert_exclusive(m_object);
        }
        if (mem->vmp_laundry) {
                /*
                 * We may have to free a page while it's being laundered
                 * if we lost its pager (due to a forced unmount, for example).
                 * We need to call vm_pageout_steal_laundry() before removing
                 * the page from its VM object, so that we can remove it
                 * from its pageout queue and adjust the laundry accounting
                 */
                vm_pageout_steal_laundry(mem, TRUE);
                counter(++c_laundry_pages_freed);
        }

        vm_page_queues_remove(mem, TRUE);

        if (VM_PAGE_WIRED(mem)) {
                assert(mem->vmp_wire_count > 0);

                if (m_object) {
                        VM_OBJECT_WIRED_PAGE_UPDATE_START(m_object);
                        VM_OBJECT_WIRED_PAGE_REMOVE(m_object, mem);
                        VM_OBJECT_WIRED_PAGE_UPDATE_END(m_object, m_object->wire_tag);

                        assert(m_object->resident_page_count >=
                            m_object->wired_page_count);

                        if (m_object->purgable == VM_PURGABLE_VOLATILE) {
                                OSAddAtomic(+1, &vm_page_purgeable_count);
                                assert(vm_page_purgeable_wired_count > 0);
                                OSAddAtomic(-1, &vm_page_purgeable_wired_count);
                        }
                        if ((m_object->purgable == VM_PURGABLE_VOLATILE ||
                            m_object->purgable == VM_PURGABLE_EMPTY) &&
                            m_object->vo_owner != TASK_NULL) {
                                task_t          owner;
                                int             ledger_idx_volatile;
                                int             ledger_idx_nonvolatile;
                                int             ledger_idx_volatile_compressed;
                                int             ledger_idx_nonvolatile_compressed;
                                boolean_t       do_footprint;

                                owner = VM_OBJECT_OWNER(m_object);
                                vm_object_ledger_tag_ledgers(
                                        m_object,
                                        &ledger_idx_volatile,
                                        &ledger_idx_nonvolatile,
                                        &ledger_idx_volatile_compressed,
                                        &ledger_idx_nonvolatile_compressed,
                                        &do_footprint);
                                /*
                                 * While wired, this page was accounted
                                 * as "non-volatile" but it should now
                                 * be accounted as "volatile".
                                 */
                                /* one less "non-volatile"... */
                                ledger_debit(owner->ledger,
                                    ledger_idx_nonvolatile,
                                    PAGE_SIZE);
                                if (do_footprint) {
                                        /* ... and "phys_footprint" */
                                        ledger_debit(owner->ledger,
                                            task_ledgers.phys_footprint,
                                            PAGE_SIZE);
                                }
                                /* one more "volatile" */
                                ledger_credit(owner->ledger,
                                    ledger_idx_volatile,
                                    PAGE_SIZE);
                        }
                }
                if (!mem->vmp_private && !mem->vmp_fictitious) {
                        vm_page_wire_count--;
                }

                mem->vmp_q_state = VM_PAGE_NOT_ON_Q;
                mem->vmp_wire_count = 0;
                assert(!mem->vmp_gobbled);
        } else if (mem->vmp_gobbled) {
                if (!mem->vmp_private && !mem->vmp_fictitious) {
                        vm_page_wire_count--;
                }
                vm_page_gobble_count--;
        }
}


void
vm_page_free_prepare_object(
        vm_page_t       mem,
        boolean_t       remove_from_hash)
{
        if (mem->vmp_tabled) {
                vm_page_remove(mem, remove_from_hash);  /* clears tabled, object, offset */
        }
        PAGE_WAKEUP(mem);               /* clears wanted */

        if (mem->vmp_private) {
                mem->vmp_private = FALSE;
                mem->vmp_fictitious = TRUE;
                VM_PAGE_SET_PHYS_PAGE(mem, vm_page_fictitious_addr);
        }
        if (!mem->vmp_fictitious) {
                assert(mem->vmp_pageq.next == 0);
                assert(mem->vmp_pageq.prev == 0);
                assert(mem->vmp_listq.next == 0);
                assert(mem->vmp_listq.prev == 0);
#if CONFIG_BACKGROUND_QUEUE
                assert(mem->vmp_backgroundq.next == 0);
                assert(mem->vmp_backgroundq.prev == 0);
#endif /* CONFIG_BACKGROUND_QUEUE */
                assert(mem->vmp_next_m == 0);
                ASSERT_PMAP_FREE(mem);
                vm_page_init(mem, VM_PAGE_GET_PHYS_PAGE(mem), mem->vmp_lopage);
        }
}


/*
 *      vm_page_free:
 *
 *      Returns the given page to the free list,
 *      disassociating it with any VM object.
 *
 *      Object and page queues must be locked prior to entry.
 */
void
vm_page_free(
        vm_page_t       mem)
{
        vm_page_free_prepare(mem);

        if (mem->vmp_fictitious) {
                vm_page_release_fictitious(mem);
        } else {
                vm_page_release(mem,
                    TRUE);             /* page queues are locked */
        }
}


void
vm_page_free_unlocked(
        vm_page_t       mem,
        boolean_t       remove_from_hash)
{
        vm_page_lockspin_queues();
        vm_page_free_prepare_queues(mem);
        vm_page_unlock_queues();

        vm_page_free_prepare_object(mem, remove_from_hash);

        if (mem->vmp_fictitious) {
                vm_page_release_fictitious(mem);
        } else {
                vm_page_release(mem, FALSE); /* page queues are not locked */
        }
}


/*
 * Free a list of pages.  The list can be up to several hundred pages,
 * as blocked up by vm_pageout_scan().
 * The big win is not having to take the free list lock once
 * per page.
 *
 * The VM page queues lock (vm_page_queue_lock) should NOT be held.
 * The VM page free queues lock (vm_page_queue_free_lock) should NOT be held.
 */
void
vm_page_free_list(
        vm_page_t       freeq,
        boolean_t       prepare_object)
{
        vm_page_t       mem;
        vm_page_t       nxt;
        vm_page_t       local_freeq;
        int             pg_count;

        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_NOTOWNED);
        LCK_MTX_ASSERT(&vm_page_queue_free_lock, LCK_MTX_ASSERT_NOTOWNED);

        while (freeq) {
                pg_count = 0;
                local_freeq = VM_PAGE_NULL;
                mem = freeq;

                /*
                 * break up the processing into smaller chunks so
                 * that we can 'pipeline' the pages onto the
                 * free list w/o introducing too much
                 * contention on the global free queue lock
                 */
                while (mem && pg_count < 64) {
                        assert((mem->vmp_q_state == VM_PAGE_NOT_ON_Q) ||
                            (mem->vmp_q_state == VM_PAGE_IS_WIRED));
#if CONFIG_BACKGROUND_QUEUE
                        assert(mem->vmp_backgroundq.next == 0 &&
                            mem->vmp_backgroundq.prev == 0 &&
                            mem->vmp_on_backgroundq == FALSE);
#endif
                        nxt = mem->vmp_snext;
                        mem->vmp_snext = NULL;
                        assert(mem->vmp_pageq.prev == 0);

                        if (vm_page_free_verify && !mem->vmp_fictitious && !mem->vmp_private) {
                                ASSERT_PMAP_FREE(mem);
                        }
                        if (prepare_object == TRUE) {
                                vm_page_free_prepare_object(mem, TRUE);
                        }

                        if (!mem->vmp_fictitious) {
                                assert(mem->vmp_busy);

                                if ((mem->vmp_lopage == TRUE || vm_lopage_refill == TRUE) &&
                                    vm_lopage_free_count < vm_lopage_free_limit &&
                                    VM_PAGE_GET_PHYS_PAGE(mem) < max_valid_low_ppnum) {
                                        vm_page_release(mem, FALSE); /* page queues are not locked */
#if CONFIG_SECLUDED_MEMORY
                                } else if (vm_page_secluded_count < vm_page_secluded_target &&
                                    num_tasks_can_use_secluded_mem == 0) {
                                        vm_page_release(mem,
                                            FALSE);             /* page queues are not locked */
#endif /* CONFIG_SECLUDED_MEMORY */
                                } else {
                                        /*
                                         * IMPORTANT: we can't set the page "free" here
                                         * because that would make the page eligible for
                                         * a physically-contiguous allocation (see
                                         * vm_page_find_contiguous()) right away (we don't
                                         * hold the vm_page_queue_free lock).  That would
                                         * cause trouble because the page is not actually
                                         * in the free queue yet...
                                         */
                                        mem->vmp_snext = local_freeq;
                                        local_freeq = mem;
                                        pg_count++;

                                        pmap_clear_noencrypt(VM_PAGE_GET_PHYS_PAGE(mem));
                                }
                        } else {
                                assert(VM_PAGE_GET_PHYS_PAGE(mem) == vm_page_fictitious_addr ||
                                    VM_PAGE_GET_PHYS_PAGE(mem) == vm_page_guard_addr);
                                vm_page_release_fictitious(mem);
                        }
                        mem = nxt;
                }
                freeq = mem;

                if ((mem = local_freeq)) {
                        unsigned int    avail_free_count;
                        unsigned int    need_wakeup = 0;
                        unsigned int    need_priv_wakeup = 0;
#if CONFIG_SECLUDED_MEMORY
                        unsigned int    need_wakeup_secluded = 0;
#endif /* CONFIG_SECLUDED_MEMORY */
                        event_t         priv_wakeup_event, secluded_wakeup_event, normal_wakeup_event;
                        boolean_t       priv_wakeup_all, secluded_wakeup_all, normal_wakeup_all;

                        lck_mtx_lock_spin(&vm_page_queue_free_lock);

                        while (mem) {
                                int     color;

                                nxt = mem->vmp_snext;

                                assert(mem->vmp_q_state == VM_PAGE_NOT_ON_Q);
                                assert(mem->vmp_busy);
                                mem->vmp_lopage = FALSE;
                                mem->vmp_q_state = VM_PAGE_ON_FREE_Q;

                                color = VM_PAGE_GET_COLOR(mem);
#if defined(__x86_64__)
                                vm_page_queue_enter_clump(&vm_page_queue_free[color].qhead, mem);
#else
                                vm_page_queue_enter(&vm_page_queue_free[color].qhead,
                                    mem, vmp_pageq);
#endif
                                mem = nxt;
                        }
                        vm_pageout_vminfo.vm_page_pages_freed += pg_count;
                        vm_page_free_count += pg_count;
                        avail_free_count = vm_page_free_count;

                        VM_DEBUG_CONSTANT_EVENT(vm_page_release, VM_PAGE_RELEASE, DBG_FUNC_NONE, pg_count, 0, 0, 0);

                        if (vm_page_free_wanted_privileged > 0 && avail_free_count > 0) {
                                if (avail_free_count < vm_page_free_wanted_privileged) {
                                        need_priv_wakeup = avail_free_count;
                                        vm_page_free_wanted_privileged -= avail_free_count;
                                        avail_free_count = 0;
                                } else {
                                        need_priv_wakeup = vm_page_free_wanted_privileged;
                                        avail_free_count -= vm_page_free_wanted_privileged;
                                        vm_page_free_wanted_privileged = 0;
                                }
                        }
#if CONFIG_SECLUDED_MEMORY
                        if (vm_page_free_wanted_secluded > 0 &&
                            avail_free_count > vm_page_free_reserved) {
                                unsigned int available_pages;
                                available_pages = (avail_free_count -
                                    vm_page_free_reserved);
                                if (available_pages <
                                    vm_page_free_wanted_secluded) {
                                        need_wakeup_secluded = available_pages;
                                        vm_page_free_wanted_secluded -=
                                            available_pages;
                                        avail_free_count -= available_pages;
                                } else {
                                        need_wakeup_secluded =
                                            vm_page_free_wanted_secluded;
                                        avail_free_count -=
                                            vm_page_free_wanted_secluded;
                                        vm_page_free_wanted_secluded = 0;
                                }
                        }
#endif /* CONFIG_SECLUDED_MEMORY */
                        if (vm_page_free_wanted > 0 && avail_free_count > vm_page_free_reserved) {
                                unsigned int  available_pages;

                                available_pages = avail_free_count - vm_page_free_reserved;

                                if (available_pages >= vm_page_free_wanted) {
                                        need_wakeup = vm_page_free_wanted;
                                        vm_page_free_wanted = 0;
                                } else {
                                        need_wakeup = available_pages;
                                        vm_page_free_wanted -= available_pages;
                                }
                        }
                        lck_mtx_unlock(&vm_page_queue_free_lock);

                        priv_wakeup_event = NULL;
                        secluded_wakeup_event = NULL;
                        normal_wakeup_event = NULL;

                        priv_wakeup_all = FALSE;
                        secluded_wakeup_all = FALSE;
                        normal_wakeup_all = FALSE;


                        if (need_priv_wakeup != 0) {
                                /*
                                 * There shouldn't be that many VM-privileged threads,
                                 * so let's wake them all up, even if we don't quite
                                 * have enough pages to satisfy them all.
                                 */
                                priv_wakeup_event = (event_t)&vm_page_free_wanted_privileged;
                                priv_wakeup_all = TRUE;
                        }
#if CONFIG_SECLUDED_MEMORY
                        if (need_wakeup_secluded != 0 &&
                            vm_page_free_wanted_secluded == 0) {
                                secluded_wakeup_event = (event_t)&vm_page_free_wanted_secluded;
                                secluded_wakeup_all = TRUE;
                                need_wakeup_secluded = 0;
                        } else {
                                secluded_wakeup_event = (event_t)&vm_page_free_wanted_secluded;
                        }
#endif /* CONFIG_SECLUDED_MEMORY */
                        if (need_wakeup != 0 && vm_page_free_wanted == 0) {
                                /*
                                 * We don't expect to have any more waiters
                                 * after this, so let's wake them all up at
                                 * once.
                                 */
                                normal_wakeup_event = (event_t) &vm_page_free_count;
                                normal_wakeup_all = TRUE;
                                need_wakeup = 0;
                        } else {
                                normal_wakeup_event = (event_t) &vm_page_free_count;
                        }

                        if (priv_wakeup_event ||
#if CONFIG_SECLUDED_MEMORY
                            secluded_wakeup_event ||
#endif /* CONFIG_SECLUDED_MEMORY */
                            normal_wakeup_event) {
                                if (vps_dynamic_priority_enabled == TRUE) {
                                        thread_t thread_woken = NULL;

                                        if (priv_wakeup_all == TRUE) {
                                                wakeup_all_with_inheritor(priv_wakeup_event, THREAD_AWAKENED);
                                        }

#if CONFIG_SECLUDED_MEMORY
                                        if (secluded_wakeup_all == TRUE) {
                                                wakeup_all_with_inheritor(secluded_wakeup_event, THREAD_AWAKENED);
                                        }

                                        while (need_wakeup_secluded-- != 0) {
                                                /*
                                                 * Wake up one waiter per page we just released.
                                                 */
                                                wakeup_one_with_inheritor(secluded_wakeup_event, THREAD_AWAKENED, LCK_WAKE_DO_NOT_TRANSFER_PUSH, &thread_woken);
                                                thread_deallocate(thread_woken);
                                        }
#endif /* CONFIG_SECLUDED_MEMORY */

                                        if (normal_wakeup_all == TRUE) {
                                                wakeup_all_with_inheritor(normal_wakeup_event, THREAD_AWAKENED);
                                        }

                                        while (need_wakeup-- != 0) {
                                                /*
                                                 * Wake up one waiter per page we just released.
                                                 */
                                                wakeup_one_with_inheritor(normal_wakeup_event, THREAD_AWAKENED, LCK_WAKE_DO_NOT_TRANSFER_PUSH, &thread_woken);
                                                thread_deallocate(thread_woken);
                                        }
                                } else {
                                        /*
                                         * Non-priority-aware wakeups.
                                         */

                                        if (priv_wakeup_all == TRUE) {
                                                thread_wakeup(priv_wakeup_event);
                                        }

#if CONFIG_SECLUDED_MEMORY
                                        if (secluded_wakeup_all == TRUE) {
                                                thread_wakeup(secluded_wakeup_event);
                                        }

                                        while (need_wakeup_secluded-- != 0) {
                                                /*
                                                 * Wake up one waiter per page we just released.
                                                 */
                                                thread_wakeup_one(secluded_wakeup_event);
                                        }

#endif /* CONFIG_SECLUDED_MEMORY */
                                        if (normal_wakeup_all == TRUE) {
                                                thread_wakeup(normal_wakeup_event);
                                        }

                                        while (need_wakeup-- != 0) {
                                                /*
                                                 * Wake up one waiter per page we just released.
                                                 */
                                                thread_wakeup_one(normal_wakeup_event);
                                        }
                                }
                        }

                        VM_CHECK_MEMORYSTATUS;
                }
        }
}


/*
 *      vm_page_wire:
 *
 *      Mark this page as wired down by yet
 *      another map, removing it from paging queues
 *      as necessary.
 *
 *      The page's object and the page queues must be locked.
 */


void
vm_page_wire(
        vm_page_t mem,
        vm_tag_t           tag,
        boolean_t          check_memorystatus)
{
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(mem);

//      dbgLog(current_thread(), mem->vmp_offset, m_object, 1); /* (TEST/DEBUG) */

        VM_PAGE_CHECK(mem);
        if (m_object) {
                vm_object_lock_assert_exclusive(m_object);
        } else {
                /*
                 * In theory, the page should be in an object before it
                 * gets wired, since we need to hold the object lock
                 * to update some fields in the page structure.
                 * However, some code (i386 pmap, for example) might want
                 * to wire a page before it gets inserted into an object.
                 * That's somewhat OK, as long as nobody else can get to
                 * that page and update it at the same time.
                 */
        }
        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        if (!VM_PAGE_WIRED(mem)) {
                if (mem->vmp_laundry) {
                        vm_pageout_steal_laundry(mem, TRUE);
                }

                vm_page_queues_remove(mem, TRUE);

                assert(mem->vmp_wire_count == 0);
                mem->vmp_q_state = VM_PAGE_IS_WIRED;

                if (m_object) {
                        VM_OBJECT_WIRED_PAGE_UPDATE_START(m_object);
                        VM_OBJECT_WIRED_PAGE_ADD(m_object, mem);
                        VM_OBJECT_WIRED_PAGE_UPDATE_END(m_object, tag);

                        assert(m_object->resident_page_count >=
                            m_object->wired_page_count);
                        if (m_object->purgable == VM_PURGABLE_VOLATILE) {
                                assert(vm_page_purgeable_count > 0);
                                OSAddAtomic(-1, &vm_page_purgeable_count);
                                OSAddAtomic(1, &vm_page_purgeable_wired_count);
                        }
                        if ((m_object->purgable == VM_PURGABLE_VOLATILE ||
                            m_object->purgable == VM_PURGABLE_EMPTY) &&
                            m_object->vo_owner != TASK_NULL) {
                                task_t          owner;
                                int             ledger_idx_volatile;
                                int             ledger_idx_nonvolatile;
                                int             ledger_idx_volatile_compressed;
                                int             ledger_idx_nonvolatile_compressed;
                                boolean_t       do_footprint;

                                owner = VM_OBJECT_OWNER(m_object);
                                vm_object_ledger_tag_ledgers(
                                        m_object,
                                        &ledger_idx_volatile,
                                        &ledger_idx_nonvolatile,
                                        &ledger_idx_volatile_compressed,
                                        &ledger_idx_nonvolatile_compressed,
                                        &do_footprint);
                                /* less volatile bytes */
                                ledger_debit(owner->ledger,
                                    ledger_idx_volatile,
                                    PAGE_SIZE);
                                /* more not-quite-volatile bytes */
                                ledger_credit(owner->ledger,
                                    ledger_idx_nonvolatile,
                                    PAGE_SIZE);
                                if (do_footprint) {
                                        /* more footprint */
                                        ledger_credit(owner->ledger,
                                            task_ledgers.phys_footprint,
                                            PAGE_SIZE);
                                }
                        }
                        if (m_object->all_reusable) {
                                /*
                                 * Wired pages are not counted as "re-usable"
                                 * in "all_reusable" VM objects, so nothing
                                 * to do here.
                                 */
                        } else if (mem->vmp_reusable) {
                                /*
                                 * This page is not "re-usable" when it's
                                 * wired, so adjust its state and the
                                 * accounting.
                                 */
                                vm_object_reuse_pages(m_object,
                                    mem->vmp_offset,
                                    mem->vmp_offset + PAGE_SIZE_64,
                                    FALSE);
                        }
                }
                assert(!mem->vmp_reusable);

                if (!mem->vmp_private && !mem->vmp_fictitious && !mem->vmp_gobbled) {
                        vm_page_wire_count++;
                }
                if (mem->vmp_gobbled) {
                        vm_page_gobble_count--;
                }
                mem->vmp_gobbled = FALSE;

                if (check_memorystatus == TRUE) {
                        VM_CHECK_MEMORYSTATUS;
                }
        }
        assert(!mem->vmp_gobbled);
        assert(mem->vmp_q_state == VM_PAGE_IS_WIRED);
        mem->vmp_wire_count++;
        if (__improbable(mem->vmp_wire_count == 0)) {
                panic("vm_page_wire(%p): wire_count overflow", mem);
        }
        VM_PAGE_CHECK(mem);
}

/*
 *      vm_page_unwire:
 *
 *      Release one wiring of this page, potentially
 *      enabling it to be paged again.
 *
 *      The page's object and the page queues must be locked.
 */
void
vm_page_unwire(
        vm_page_t       mem,
        boolean_t       queueit)
{
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(mem);

//      dbgLog(current_thread(), mem->vmp_offset, m_object, 0); /* (TEST/DEBUG) */

        VM_PAGE_CHECK(mem);
        assert(VM_PAGE_WIRED(mem));
        assert(mem->vmp_wire_count > 0);
        assert(!mem->vmp_gobbled);
        assert(m_object != VM_OBJECT_NULL);
        vm_object_lock_assert_exclusive(m_object);
        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        if (--mem->vmp_wire_count == 0) {
                mem->vmp_q_state = VM_PAGE_NOT_ON_Q;

                VM_OBJECT_WIRED_PAGE_UPDATE_START(m_object);
                VM_OBJECT_WIRED_PAGE_REMOVE(m_object, mem);
                VM_OBJECT_WIRED_PAGE_UPDATE_END(m_object, m_object->wire_tag);
                if (!mem->vmp_private && !mem->vmp_fictitious) {
                        vm_page_wire_count--;
                }

                assert(m_object->resident_page_count >=
                    m_object->wired_page_count);
                if (m_object->purgable == VM_PURGABLE_VOLATILE) {
                        OSAddAtomic(+1, &vm_page_purgeable_count);
                        assert(vm_page_purgeable_wired_count > 0);
                        OSAddAtomic(-1, &vm_page_purgeable_wired_count);
                }
                if ((m_object->purgable == VM_PURGABLE_VOLATILE ||
                    m_object->purgable == VM_PURGABLE_EMPTY) &&
                    m_object->vo_owner != TASK_NULL) {
                        task_t          owner;
                        int             ledger_idx_volatile;
                        int             ledger_idx_nonvolatile;
                        int             ledger_idx_volatile_compressed;
                        int             ledger_idx_nonvolatile_compressed;
                        boolean_t       do_footprint;

                        owner = VM_OBJECT_OWNER(m_object);
                        vm_object_ledger_tag_ledgers(
                                m_object,
                                &ledger_idx_volatile,
                                &ledger_idx_nonvolatile,
                                &ledger_idx_volatile_compressed,
                                &ledger_idx_nonvolatile_compressed,
                                &do_footprint);
                        /* more volatile bytes */
                        ledger_credit(owner->ledger,
                            ledger_idx_volatile,
                            PAGE_SIZE);
                        /* less not-quite-volatile bytes */
                        ledger_debit(owner->ledger,
                            ledger_idx_nonvolatile,
                            PAGE_SIZE);
                        if (do_footprint) {
                                /* less footprint */
                                ledger_debit(owner->ledger,
                                    task_ledgers.phys_footprint,
                                    PAGE_SIZE);
                        }
                }
                assert(m_object != kernel_object);
                assert(mem->vmp_pageq.next == 0 && mem->vmp_pageq.prev == 0);

                if (queueit == TRUE) {
                        if (m_object->purgable == VM_PURGABLE_EMPTY) {
                                vm_page_deactivate(mem);
                        } else {
                                vm_page_activate(mem);
                        }
                }

                VM_CHECK_MEMORYSTATUS;
        }
        VM_PAGE_CHECK(mem);
}

/*
 *      vm_page_deactivate:
 *
 *      Returns the given page to the inactive list,
 *      indicating that no physical maps have access
 *      to this page.  [Used by the physical mapping system.]
 *
 *      The page queues must be locked.
 */
void
vm_page_deactivate(
        vm_page_t       m)
{
        vm_page_deactivate_internal(m, TRUE);
}


void
vm_page_deactivate_internal(
        vm_page_t       m,
        boolean_t       clear_hw_reference)
{
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(m);

        VM_PAGE_CHECK(m);
        assert(m_object != kernel_object);
        assert(VM_PAGE_GET_PHYS_PAGE(m) != vm_page_guard_addr);

//      dbgLog(VM_PAGE_GET_PHYS_PAGE(m), vm_page_free_count, vm_page_wire_count, 6);    /* (TEST/DEBUG) */
        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        /*
         *      This page is no longer very interesting.  If it was
         *      interesting (active or inactive/referenced), then we
         *      clear the reference bit and (re)enter it in the
         *      inactive queue.  Note wired pages should not have
         *      their reference bit cleared.
         */
        assert( !(m->vmp_absent && !m->vmp_unusual));

        if (m->vmp_gobbled) {           /* can this happen? */
                assert( !VM_PAGE_WIRED(m));

                if (!m->vmp_private && !m->vmp_fictitious) {
                        vm_page_wire_count--;
                }
                vm_page_gobble_count--;
                m->vmp_gobbled = FALSE;
        }
        /*
         * if this page is currently on the pageout queue, we can't do the
         * vm_page_queues_remove (which doesn't handle the pageout queue case)
         * and we can't remove it manually since we would need the object lock
         * (which is not required here) to decrement the activity_in_progress
         * reference which is held on the object while the page is in the pageout queue...
         * just let the normal laundry processing proceed
         */
        if (m->vmp_laundry || m->vmp_private || m->vmp_fictitious ||
            (m->vmp_q_state == VM_PAGE_USED_BY_COMPRESSOR) ||
            (m->vmp_q_state == VM_PAGE_ON_PAGEOUT_Q) ||
            VM_PAGE_WIRED(m)) {
                return;
        }
        if (!m->vmp_absent && clear_hw_reference == TRUE) {
                pmap_clear_reference(VM_PAGE_GET_PHYS_PAGE(m));
        }

        m->vmp_reference = FALSE;
        m->vmp_no_cache = FALSE;

        if (!VM_PAGE_INACTIVE(m)) {
                vm_page_queues_remove(m, FALSE);

                if (!VM_DYNAMIC_PAGING_ENABLED() &&
                    m->vmp_dirty && m_object->internal &&
                    (m_object->purgable == VM_PURGABLE_DENY ||
                    m_object->purgable == VM_PURGABLE_NONVOLATILE ||
                    m_object->purgable == VM_PURGABLE_VOLATILE)) {
                        vm_page_check_pageable_safe(m);
                        vm_page_queue_enter(&vm_page_queue_throttled, m, vmp_pageq);
                        m->vmp_q_state = VM_PAGE_ON_THROTTLED_Q;
                        vm_page_throttled_count++;
                } else {
                        if (m_object->named && m_object->ref_count == 1) {
                                vm_page_speculate(m, FALSE);
#if DEVELOPMENT || DEBUG
                                vm_page_speculative_recreated++;
#endif
                        } else {
                                vm_page_enqueue_inactive(m, FALSE);
                        }
                }
        }
}

/*
 * vm_page_enqueue_cleaned
 *
 * Put the page on the cleaned queue, mark it cleaned, etc.
 * Being on the cleaned queue (and having m->clean_queue set)
 * does ** NOT ** guarantee that the page is clean!
 *
 * Call with the queues lock held.
 */

void
vm_page_enqueue_cleaned(vm_page_t m)
{
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(m);

        assert(VM_PAGE_GET_PHYS_PAGE(m) != vm_page_guard_addr);
        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        assert( !(m->vmp_absent && !m->vmp_unusual));

        if (VM_PAGE_WIRED(m)) {
                return;
        }

        if (m->vmp_gobbled) {
                if (!m->vmp_private && !m->vmp_fictitious) {
                        vm_page_wire_count--;
                }
                vm_page_gobble_count--;
                m->vmp_gobbled = FALSE;
        }
        /*
         * if this page is currently on the pageout queue, we can't do the
         * vm_page_queues_remove (which doesn't handle the pageout queue case)
         * and we can't remove it manually since we would need the object lock
         * (which is not required here) to decrement the activity_in_progress
         * reference which is held on the object while the page is in the pageout queue...
         * just let the normal laundry processing proceed
         */
        if (m->vmp_laundry || m->vmp_private || m->vmp_fictitious ||
            (m->vmp_q_state == VM_PAGE_ON_INACTIVE_CLEANED_Q) ||
            (m->vmp_q_state == VM_PAGE_ON_PAGEOUT_Q)) {
                return;
        }
        vm_page_queues_remove(m, FALSE);

        vm_page_check_pageable_safe(m);
        vm_page_queue_enter(&vm_page_queue_cleaned, m, vmp_pageq);
        m->vmp_q_state = VM_PAGE_ON_INACTIVE_CLEANED_Q;
        vm_page_cleaned_count++;

        vm_page_inactive_count++;
        if (m_object->internal) {
                vm_page_pageable_internal_count++;
        } else {
                vm_page_pageable_external_count++;
        }
#if CONFIG_BACKGROUND_QUEUE
        if (m->vmp_in_background) {
                vm_page_add_to_backgroundq(m, TRUE);
        }
#endif
        VM_PAGEOUT_DEBUG(vm_pageout_enqueued_cleaned, 1);
}

/*
 *      vm_page_activate:
 *
 *      Put the specified page on the active list (if appropriate).
 *
 *      The page queues must be locked.
 */

void
vm_page_activate(
        vm_page_t       m)
{
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(m);

        VM_PAGE_CHECK(m);
#ifdef  FIXME_4778297
        assert(m_object != kernel_object);
#endif
        assert(VM_PAGE_GET_PHYS_PAGE(m) != vm_page_guard_addr);
        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        assert( !(m->vmp_absent && !m->vmp_unusual));

        if (m->vmp_gobbled) {
                assert( !VM_PAGE_WIRED(m));
                if (!m->vmp_private && !m->vmp_fictitious) {
                        vm_page_wire_count--;
                }
                vm_page_gobble_count--;
                m->vmp_gobbled = FALSE;
        }
        /*
         * if this page is currently on the pageout queue, we can't do the
         * vm_page_queues_remove (which doesn't handle the pageout queue case)
         * and we can't remove it manually since we would need the object lock
         * (which is not required here) to decrement the activity_in_progress
         * reference which is held on the object while the page is in the pageout queue...
         * just let the normal laundry processing proceed
         */
        if (m->vmp_laundry || m->vmp_private || m->vmp_fictitious ||
            (m->vmp_q_state == VM_PAGE_USED_BY_COMPRESSOR) ||
            (m->vmp_q_state == VM_PAGE_ON_PAGEOUT_Q)) {
                return;
        }

#if DEBUG
        if (m->vmp_q_state == VM_PAGE_ON_ACTIVE_Q) {
                panic("vm_page_activate: already active");
        }
#endif

        if (m->vmp_q_state == VM_PAGE_ON_SPECULATIVE_Q) {
                DTRACE_VM2(pgrec, int, 1, (uint64_t *), NULL);
                DTRACE_VM2(pgfrec, int, 1, (uint64_t *), NULL);
        }

        vm_page_queues_remove(m, FALSE);

        if (!VM_PAGE_WIRED(m)) {
                vm_page_check_pageable_safe(m);
                if (!VM_DYNAMIC_PAGING_ENABLED() &&
                    m->vmp_dirty && m_object->internal &&
                    (m_object->purgable == VM_PURGABLE_DENY ||
                    m_object->purgable == VM_PURGABLE_NONVOLATILE ||
                    m_object->purgable == VM_PURGABLE_VOLATILE)) {
                        vm_page_queue_enter(&vm_page_queue_throttled, m, vmp_pageq);
                        m->vmp_q_state = VM_PAGE_ON_THROTTLED_Q;
                        vm_page_throttled_count++;
                } else {
#if CONFIG_SECLUDED_MEMORY
                        if (secluded_for_filecache &&
                            vm_page_secluded_target != 0 &&
                            num_tasks_can_use_secluded_mem == 0 &&
                            m_object->eligible_for_secluded) {
                                vm_page_queue_enter(&vm_page_queue_secluded, m, vmp_pageq);
                                m->vmp_q_state = VM_PAGE_ON_SECLUDED_Q;
                                vm_page_secluded_count++;
                                VM_PAGE_SECLUDED_COUNT_OVER_TARGET_UPDATE();
                                vm_page_secluded_count_inuse++;
                                assert(!m_object->internal);
//                              vm_page_pageable_external_count++;
                        } else
#endif /* CONFIG_SECLUDED_MEMORY */
                        vm_page_enqueue_active(m, FALSE);
                }
                m->vmp_reference = TRUE;
                m->vmp_no_cache = FALSE;
        }
        VM_PAGE_CHECK(m);
}


/*
 *      vm_page_speculate:
 *
 *      Put the specified page on the speculative list (if appropriate).
 *
 *      The page queues must be locked.
 */
void
vm_page_speculate(
        vm_page_t       m,
        boolean_t       new)
{
        struct vm_speculative_age_q     *aq;
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(m);

        VM_PAGE_CHECK(m);
        vm_page_check_pageable_safe(m);

        assert(VM_PAGE_GET_PHYS_PAGE(m) != vm_page_guard_addr);
        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        assert( !(m->vmp_absent && !m->vmp_unusual));
        assert(m_object->internal == FALSE);

        /*
         * if this page is currently on the pageout queue, we can't do the
         * vm_page_queues_remove (which doesn't handle the pageout queue case)
         * and we can't remove it manually since we would need the object lock
         * (which is not required here) to decrement the activity_in_progress
         * reference which is held on the object while the page is in the pageout queue...
         * just let the normal laundry processing proceed
         */
        if (m->vmp_laundry || m->vmp_private || m->vmp_fictitious ||
            (m->vmp_q_state == VM_PAGE_USED_BY_COMPRESSOR) ||
            (m->vmp_q_state == VM_PAGE_ON_PAGEOUT_Q)) {
                return;
        }

        vm_page_queues_remove(m, FALSE);

        if (!VM_PAGE_WIRED(m)) {
                mach_timespec_t         ts;
                clock_sec_t sec;
                clock_nsec_t nsec;

                clock_get_system_nanotime(&sec, &nsec);
                ts.tv_sec = (unsigned int) sec;
                ts.tv_nsec = nsec;

                if (vm_page_speculative_count == 0) {
                        speculative_age_index = VM_PAGE_MIN_SPECULATIVE_AGE_Q;
                        speculative_steal_index = VM_PAGE_MIN_SPECULATIVE_AGE_Q;

                        aq = &vm_page_queue_speculative[speculative_age_index];

                        /*
                         * set the timer to begin a new group
                         */
                        aq->age_ts.tv_sec = vm_pageout_state.vm_page_speculative_q_age_ms / 1000;
                        aq->age_ts.tv_nsec = (vm_pageout_state.vm_page_speculative_q_age_ms % 1000) * 1000 * NSEC_PER_USEC;

                        ADD_MACH_TIMESPEC(&aq->age_ts, &ts);
                } else {
                        aq = &vm_page_queue_speculative[speculative_age_index];

                        if (CMP_MACH_TIMESPEC(&ts, &aq->age_ts) >= 0) {
                                speculative_age_index++;

                                if (speculative_age_index > VM_PAGE_MAX_SPECULATIVE_AGE_Q) {
                                        speculative_age_index = VM_PAGE_MIN_SPECULATIVE_AGE_Q;
                                }
                                if (speculative_age_index == speculative_steal_index) {
                                        speculative_steal_index = speculative_age_index + 1;

                                        if (speculative_steal_index > VM_PAGE_MAX_SPECULATIVE_AGE_Q) {
                                                speculative_steal_index = VM_PAGE_MIN_SPECULATIVE_AGE_Q;
                                        }
                                }
                                aq = &vm_page_queue_speculative[speculative_age_index];

                                if (!vm_page_queue_empty(&aq->age_q)) {
                                        vm_page_speculate_ageit(aq);
                                }

                                aq->age_ts.tv_sec = vm_pageout_state.vm_page_speculative_q_age_ms / 1000;
                                aq->age_ts.tv_nsec = (vm_pageout_state.vm_page_speculative_q_age_ms % 1000) * 1000 * NSEC_PER_USEC;

                                ADD_MACH_TIMESPEC(&aq->age_ts, &ts);
                        }
                }
                vm_page_enqueue_tail(&aq->age_q, &m->vmp_pageq);
                m->vmp_q_state = VM_PAGE_ON_SPECULATIVE_Q;
                vm_page_speculative_count++;
                vm_page_pageable_external_count++;

                if (new == TRUE) {
                        vm_object_lock_assert_exclusive(m_object);

                        m_object->pages_created++;
#if DEVELOPMENT || DEBUG
                        vm_page_speculative_created++;
#endif
                }
        }
        VM_PAGE_CHECK(m);
}


/*
 * move pages from the specified aging bin to
 * the speculative bin that pageout_scan claims from
 *
 *      The page queues must be locked.
 */
void
vm_page_speculate_ageit(struct vm_speculative_age_q *aq)
{
        struct vm_speculative_age_q     *sq;
        vm_page_t       t;

        sq = &vm_page_queue_speculative[VM_PAGE_SPECULATIVE_AGED_Q];

        if (vm_page_queue_empty(&sq->age_q)) {
                sq->age_q.next = aq->age_q.next;
                sq->age_q.prev = aq->age_q.prev;

                t = (vm_page_t)VM_PAGE_UNPACK_PTR(sq->age_q.next);
                t->vmp_pageq.prev = VM_PAGE_PACK_PTR(&sq->age_q);

                t = (vm_page_t)VM_PAGE_UNPACK_PTR(sq->age_q.prev);
                t->vmp_pageq.next = VM_PAGE_PACK_PTR(&sq->age_q);
        } else {
                t = (vm_page_t)VM_PAGE_UNPACK_PTR(sq->age_q.prev);
                t->vmp_pageq.next = aq->age_q.next;

                t = (vm_page_t)VM_PAGE_UNPACK_PTR(aq->age_q.next);
                t->vmp_pageq.prev = sq->age_q.prev;

                t = (vm_page_t)VM_PAGE_UNPACK_PTR(aq->age_q.prev);
                t->vmp_pageq.next = VM_PAGE_PACK_PTR(&sq->age_q);

                sq->age_q.prev = aq->age_q.prev;
        }
        vm_page_queue_init(&aq->age_q);
}


void
vm_page_lru(
        vm_page_t       m)
{
        VM_PAGE_CHECK(m);
        assert(VM_PAGE_OBJECT(m) != kernel_object);
        assert(VM_PAGE_GET_PHYS_PAGE(m) != vm_page_guard_addr);

        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);

        if (m->vmp_q_state == VM_PAGE_ON_INACTIVE_EXTERNAL_Q) {
                /*
                 * we don't need to do all the other work that
                 * vm_page_queues_remove and vm_page_enqueue_inactive
                 * bring along for the ride
                 */
                assert(!m->vmp_laundry);
                assert(!m->vmp_private);

                m->vmp_no_cache = FALSE;

                vm_page_queue_remove(&vm_page_queue_inactive, m, vmp_pageq);
                vm_page_queue_enter(&vm_page_queue_inactive, m, vmp_pageq);

                return;
        }
        /*
         * if this page is currently on the pageout queue, we can't do the
         * vm_page_queues_remove (which doesn't handle the pageout queue case)
         * and we can't remove it manually since we would need the object lock
         * (which is not required here) to decrement the activity_in_progress
         * reference which is held on the object while the page is in the pageout queue...
         * just let the normal laundry processing proceed
         */
        if (m->vmp_laundry || m->vmp_private ||
            (m->vmp_q_state == VM_PAGE_USED_BY_COMPRESSOR) ||
            (m->vmp_q_state == VM_PAGE_ON_PAGEOUT_Q) ||
            VM_PAGE_WIRED(m)) {
                return;
        }

        m->vmp_no_cache = FALSE;

        vm_page_queues_remove(m, FALSE);

        vm_page_enqueue_inactive(m, FALSE);
}


void
vm_page_reactivate_all_throttled(void)
{
        vm_page_t       first_throttled, last_throttled;
        vm_page_t       first_active;
        vm_page_t       m;
        int             extra_active_count;
        int             extra_internal_count, extra_external_count;
        vm_object_t     m_object;

        if (!VM_DYNAMIC_PAGING_ENABLED()) {
                return;
        }

        extra_active_count = 0;
        extra_internal_count = 0;
        extra_external_count = 0;
        vm_page_lock_queues();
        if (!vm_page_queue_empty(&vm_page_queue_throttled)) {
                /*
                 * Switch "throttled" pages to "active".
                 */
                vm_page_queue_iterate(&vm_page_queue_throttled, m, vmp_pageq) {
                        VM_PAGE_CHECK(m);
                        assert(m->vmp_q_state == VM_PAGE_ON_THROTTLED_Q);

                        m_object = VM_PAGE_OBJECT(m);

                        extra_active_count++;
                        if (m_object->internal) {
                                extra_internal_count++;
                        } else {
                                extra_external_count++;
                        }

                        m->vmp_q_state = VM_PAGE_ON_ACTIVE_Q;
                        VM_PAGE_CHECK(m);
#if CONFIG_BACKGROUND_QUEUE
                        if (m->vmp_in_background) {
                                vm_page_add_to_backgroundq(m, FALSE);
                        }
#endif
                }

                /*
                 * Transfer the entire throttled queue to a regular LRU page queues.
                 * We insert it at the head of the active queue, so that these pages
                 * get re-evaluated by the LRU algorithm first, since they've been
                 * completely out of it until now.
                 */
                first_throttled = (vm_page_t) vm_page_queue_first(&vm_page_queue_throttled);
                last_throttled = (vm_page_t) vm_page_queue_last(&vm_page_queue_throttled);
                first_active = (vm_page_t) vm_page_queue_first(&vm_page_queue_active);
                if (vm_page_queue_empty(&vm_page_queue_active)) {
                        vm_page_queue_active.prev = VM_PAGE_CONVERT_TO_QUEUE_ENTRY(last_throttled);
                } else {
                        first_active->vmp_pageq.prev = VM_PAGE_CONVERT_TO_QUEUE_ENTRY(last_throttled);
                }
                vm_page_queue_active.next = VM_PAGE_CONVERT_TO_QUEUE_ENTRY(first_throttled);
                first_throttled->vmp_pageq.prev = VM_PAGE_CONVERT_TO_QUEUE_ENTRY(&vm_page_queue_active);
                last_throttled->vmp_pageq.next = VM_PAGE_CONVERT_TO_QUEUE_ENTRY(first_active);

#if DEBUG
                printf("reactivated %d throttled pages\n", vm_page_throttled_count);
#endif
                vm_page_queue_init(&vm_page_queue_throttled);
                /*
                 * Adjust the global page counts.
                 */
                vm_page_active_count += extra_active_count;
                vm_page_pageable_internal_count += extra_internal_count;
                vm_page_pageable_external_count += extra_external_count;
                vm_page_throttled_count = 0;
        }
        assert(vm_page_throttled_count == 0);
        assert(vm_page_queue_empty(&vm_page_queue_throttled));
        vm_page_unlock_queues();
}


/*
 * move pages from the indicated local queue to the global active queue
 * its ok to fail if we're below the hard limit and force == FALSE
 * the nolocks == TRUE case is to allow this function to be run on
 * the hibernate path
 */

void
vm_page_reactivate_local(uint32_t lid, boolean_t force, boolean_t nolocks)
{
        struct vpl      *lq;
        vm_page_t       first_local, last_local;
        vm_page_t       first_active;
        vm_page_t       m;
        uint32_t        count = 0;

        if (vm_page_local_q == NULL) {
                return;
        }

        lq = &vm_page_local_q[lid].vpl_un.vpl;

        if (nolocks == FALSE) {
                if (lq->vpl_count < vm_page_local_q_hard_limit && force == FALSE) {
                        if (!vm_page_trylockspin_queues()) {
                                return;
                        }
                } else {
                        vm_page_lockspin_queues();
                }

                VPL_LOCK(&lq->vpl_lock);
        }
        if (lq->vpl_count) {
                /*
                 * Switch "local" pages to "active".
                 */
                assert(!vm_page_queue_empty(&lq->vpl_queue));

                vm_page_queue_iterate(&lq->vpl_queue, m, vmp_pageq) {
                        VM_PAGE_CHECK(m);
                        vm_page_check_pageable_safe(m);
                        assert(m->vmp_q_state == VM_PAGE_ON_ACTIVE_LOCAL_Q);
                        assert(!m->vmp_fictitious);

                        if (m->vmp_local_id != lid) {
                                panic("vm_page_reactivate_local: found vm_page_t(%p) with wrong cpuid", m);
                        }

                        m->vmp_local_id = 0;
                        m->vmp_q_state = VM_PAGE_ON_ACTIVE_Q;
                        VM_PAGE_CHECK(m);
#if CONFIG_BACKGROUND_QUEUE
                        if (m->vmp_in_background) {
                                vm_page_add_to_backgroundq(m, FALSE);
                        }
#endif
                        count++;
                }
                if (count != lq->vpl_count) {
                        panic("vm_page_reactivate_local: count = %d, vm_page_local_count = %d\n", count, lq->vpl_count);
                }

                /*
                 * Transfer the entire local queue to a regular LRU page queues.
                 */
                first_local = (vm_page_t) vm_page_queue_first(&lq->vpl_queue);
                last_local = (vm_page_t) vm_page_queue_last(&lq->vpl_queue);
                first_active = (vm_page_t) vm_page_queue_first(&vm_page_queue_active);

                if (vm_page_queue_empty(&vm_page_queue_active)) {
                        vm_page_queue_active.prev = VM_PAGE_CONVERT_TO_QUEUE_ENTRY(last_local);
                } else {
                        first_active->vmp_pageq.prev = VM_PAGE_CONVERT_TO_QUEUE_ENTRY(last_local);
                }
                vm_page_queue_active.next = VM_PAGE_CONVERT_TO_QUEUE_ENTRY(first_local);
                first_local->vmp_pageq.prev = VM_PAGE_CONVERT_TO_QUEUE_ENTRY(&vm_page_queue_active);
                last_local->vmp_pageq.next = VM_PAGE_CONVERT_TO_QUEUE_ENTRY(first_active);

                vm_page_queue_init(&lq->vpl_queue);
                /*
                 * Adjust the global page counts.
                 */
                vm_page_active_count += lq->vpl_count;
                vm_page_pageable_internal_count += lq->vpl_internal_count;
                vm_page_pageable_external_count += lq->vpl_external_count;
                lq->vpl_count = 0;
                lq->vpl_internal_count = 0;
                lq->vpl_external_count = 0;
        }
        assert(vm_page_queue_empty(&lq->vpl_queue));

        if (nolocks == FALSE) {
                VPL_UNLOCK(&lq->vpl_lock);

                vm_page_balance_inactive(count / 4);
                vm_page_unlock_queues();
        }
}

/*
 *      vm_page_part_zero_fill:
 *
 *      Zero-fill a part of the page.
 */
#define PMAP_ZERO_PART_PAGE_IMPLEMENTED
void
vm_page_part_zero_fill(
        vm_page_t       m,
        vm_offset_t     m_pa,
        vm_size_t       len)
{
#if 0
        /*
         * we don't hold the page queue lock
         * so this check isn't safe to make
         */
        VM_PAGE_CHECK(m);
#endif

#ifdef PMAP_ZERO_PART_PAGE_IMPLEMENTED
        pmap_zero_part_page(VM_PAGE_GET_PHYS_PAGE(m), m_pa, len);
#else
        vm_page_t       tmp;
        while (1) {
                tmp = vm_page_grab();
                if (tmp == VM_PAGE_NULL) {
                        vm_page_wait(THREAD_UNINT);
                        continue;
                }
                break;
        }
        vm_page_zero_fill(tmp);
        if (m_pa != 0) {
                vm_page_part_copy(m, 0, tmp, 0, m_pa);
        }
        if ((m_pa + len) < PAGE_SIZE) {
                vm_page_part_copy(m, m_pa + len, tmp,
                    m_pa + len, PAGE_SIZE - (m_pa + len));
        }
        vm_page_copy(tmp, m);
        VM_PAGE_FREE(tmp);
#endif
}

/*
 *      vm_page_zero_fill:
 *
 *      Zero-fill the specified page.
 */
void
vm_page_zero_fill(
        vm_page_t       m)
{
#if 0
        /*
         * we don't hold the page queue lock
         * so this check isn't safe to make
         */
        VM_PAGE_CHECK(m);
#endif

//      dbgTrace(0xAEAEAEAE, VM_PAGE_GET_PHYS_PAGE(m), 0);              /* (BRINGUP) */
        pmap_zero_page(VM_PAGE_GET_PHYS_PAGE(m));
}

/*
 *      vm_page_part_copy:
 *
 *      copy part of one page to another
 */

void
vm_page_part_copy(
        vm_page_t       src_m,
        vm_offset_t     src_pa,
        vm_page_t       dst_m,
        vm_offset_t     dst_pa,
        vm_size_t       len)
{
#if 0
        /*
         * we don't hold the page queue lock
         * so this check isn't safe to make
         */
        VM_PAGE_CHECK(src_m);
        VM_PAGE_CHECK(dst_m);
#endif
        pmap_copy_part_page(VM_PAGE_GET_PHYS_PAGE(src_m), src_pa,
            VM_PAGE_GET_PHYS_PAGE(dst_m), dst_pa, len);
}

/*
 *      vm_page_copy:
 *
 *      Copy one page to another
 */

int vm_page_copy_cs_validations = 0;
int vm_page_copy_cs_tainted = 0;

void
vm_page_copy(
        vm_page_t       src_m,
        vm_page_t       dest_m)
{
        vm_object_t     src_m_object;

        src_m_object = VM_PAGE_OBJECT(src_m);

#if 0
        /*
         * we don't hold the page queue lock
         * so this check isn't safe to make
         */
        VM_PAGE_CHECK(src_m);
        VM_PAGE_CHECK(dest_m);
#endif
        vm_object_lock_assert_held(src_m_object);

        if (src_m_object != VM_OBJECT_NULL &&
            src_m_object->code_signed) {
                /*
                 * We're copying a page from a code-signed object.
                 * Whoever ends up mapping the copy page might care about
                 * the original page's integrity, so let's validate the
                 * source page now.
                 */
                vm_page_copy_cs_validations++;
                vm_page_validate_cs(src_m);
#if DEVELOPMENT || DEBUG
                DTRACE_VM4(codesigned_copy,
                    vm_object_t, src_m_object,
                    vm_object_offset_t, src_m->vmp_offset,
                    int, src_m->vmp_cs_validated,
                    int, src_m->vmp_cs_tainted);
#endif /* DEVELOPMENT || DEBUG */
        }

        /*
         * Propagate the cs_tainted bit to the copy page. Do not propagate
         * the cs_validated bit.
         */
        dest_m->vmp_cs_tainted = src_m->vmp_cs_tainted;
        if (dest_m->vmp_cs_tainted) {
                vm_page_copy_cs_tainted++;
        }
        dest_m->vmp_error = src_m->vmp_error; /* sliding src_m might have failed... */
        pmap_copy_page(VM_PAGE_GET_PHYS_PAGE(src_m), VM_PAGE_GET_PHYS_PAGE(dest_m));
}

#if MACH_ASSERT
static void
_vm_page_print(
        vm_page_t       p)
{
        printf("vm_page %p: \n", p);
        printf("  pageq: next=%p prev=%p\n",
            (vm_page_t)VM_PAGE_UNPACK_PTR(p->vmp_pageq.next),
            (vm_page_t)VM_PAGE_UNPACK_PTR(p->vmp_pageq.prev));
        printf("  listq: next=%p prev=%p\n",
            (vm_page_t)(VM_PAGE_UNPACK_PTR(p->vmp_listq.next)),
            (vm_page_t)(VM_PAGE_UNPACK_PTR(p->vmp_listq.prev)));
        printf("  next=%p\n", (vm_page_t)(VM_PAGE_UNPACK_PTR(p->vmp_next_m)));
        printf("  object=%p offset=0x%llx\n", VM_PAGE_OBJECT(p), p->vmp_offset);
        printf("  wire_count=%u\n", p->vmp_wire_count);
        printf("  q_state=%u\n", p->vmp_q_state);

        printf("  %slaundry, %sref, %sgobbled, %sprivate\n",
            (p->vmp_laundry ? "" : "!"),
            (p->vmp_reference ? "" : "!"),
            (p->vmp_gobbled ? "" : "!"),
            (p->vmp_private ? "" : "!"));
        printf("  %sbusy, %swanted, %stabled, %sfictitious, %spmapped, %swpmapped\n",
            (p->vmp_busy ? "" : "!"),
            (p->vmp_wanted ? "" : "!"),
            (p->vmp_tabled ? "" : "!"),
            (p->vmp_fictitious ? "" : "!"),
            (p->vmp_pmapped ? "" : "!"),
            (p->vmp_wpmapped ? "" : "!"));
        printf("  %sfree_when_done, %sabsent, %serror, %sdirty, %scleaning, %sprecious, %sclustered\n",
            (p->vmp_free_when_done ? "" : "!"),
            (p->vmp_absent ? "" : "!"),
            (p->vmp_error ? "" : "!"),
            (p->vmp_dirty ? "" : "!"),
            (p->vmp_cleaning ? "" : "!"),
            (p->vmp_precious ? "" : "!"),
            (p->vmp_clustered ? "" : "!"));
        printf("  %soverwriting, %srestart, %sunusual\n",
            (p->vmp_overwriting ? "" : "!"),
            (p->vmp_restart ? "" : "!"),
            (p->vmp_unusual ? "" : "!"));
        printf("  %scs_validated, %scs_tainted, %scs_nx, %sno_cache\n",
            (p->vmp_cs_validated ? "" : "!"),
            (p->vmp_cs_tainted ? "" : "!"),
            (p->vmp_cs_nx ? "" : "!"),
            (p->vmp_no_cache ? "" : "!"));

        printf("phys_page=0x%x\n", VM_PAGE_GET_PHYS_PAGE(p));
}

/*
 *      Check that the list of pages is ordered by
 *      ascending physical address and has no holes.
 */
static int
vm_page_verify_contiguous(
        vm_page_t       pages,
        unsigned int    npages)
{
        vm_page_t               m;
        unsigned int            page_count;
        vm_offset_t             prev_addr;

        prev_addr = VM_PAGE_GET_PHYS_PAGE(pages);
        page_count = 1;
        for (m = NEXT_PAGE(pages); m != VM_PAGE_NULL; m = NEXT_PAGE(m)) {
                if (VM_PAGE_GET_PHYS_PAGE(m) != prev_addr + 1) {
                        printf("m %p prev_addr 0x%lx, current addr 0x%x\n",
                            m, (long)prev_addr, VM_PAGE_GET_PHYS_PAGE(m));
                        printf("pages %p page_count %d npages %d\n", pages, page_count, npages);
                        panic("vm_page_verify_contiguous:  not contiguous!");
                }
                prev_addr = VM_PAGE_GET_PHYS_PAGE(m);
                ++page_count;
        }
        if (page_count != npages) {
                printf("pages %p actual count 0x%x but requested 0x%x\n",
                    pages, page_count, npages);
                panic("vm_page_verify_contiguous:  count error");
        }
        return 1;
}


/*
 *      Check the free lists for proper length etc.
 */
static boolean_t vm_page_verify_this_free_list_enabled = FALSE;
static unsigned int
vm_page_verify_free_list(
        vm_page_queue_head_t    *vm_page_queue,
        unsigned int    color,
        vm_page_t       look_for_page,
        boolean_t       expect_page)
{
        unsigned int    npages;
        vm_page_t       m;
        vm_page_t       prev_m;
        boolean_t       found_page;

        if (!vm_page_verify_this_free_list_enabled) {
                return 0;
        }

        found_page = FALSE;
        npages = 0;
        prev_m = (vm_page_t)((uintptr_t)vm_page_queue);

        vm_page_queue_iterate(vm_page_queue, m, vmp_pageq) {
                if (m == look_for_page) {
                        found_page = TRUE;
                }
                if ((vm_page_t)VM_PAGE_UNPACK_PTR(m->vmp_pageq.prev) != prev_m) {
                        panic("vm_page_verify_free_list(color=%u, npages=%u): page %p corrupted prev ptr %p instead of %p\n",
                            color, npages, m, (vm_page_t)VM_PAGE_UNPACK_PTR(m->vmp_pageq.prev), prev_m);
                }
                if (!m->vmp_busy) {
                        panic("vm_page_verify_free_list(color=%u, npages=%u): page %p not busy\n",
                            color, npages, m);
                }
                if (color != (unsigned int) -1) {
                        if (VM_PAGE_GET_COLOR(m) != color) {
                                panic("vm_page_verify_free_list(color=%u, npages=%u): page %p wrong color %u instead of %u\n",
                                    color, npages, m, VM_PAGE_GET_COLOR(m), color);
                        }
                        if (m->vmp_q_state != VM_PAGE_ON_FREE_Q) {
                                panic("vm_page_verify_free_list(color=%u, npages=%u): page %p - expecting q_state == VM_PAGE_ON_FREE_Q, found %d\n",
                                    color, npages, m, m->vmp_q_state);
                        }
                } else {
                        if (m->vmp_q_state != VM_PAGE_ON_FREE_LOCAL_Q) {
                                panic("vm_page_verify_free_list(npages=%u): local page %p - expecting q_state == VM_PAGE_ON_FREE_LOCAL_Q, found %d\n",
                                    npages, m, m->vmp_q_state);
                        }
                }
                ++npages;
                prev_m = m;
        }
        if (look_for_page != VM_PAGE_NULL) {
                unsigned int other_color;

                if (expect_page && !found_page) {
                        printf("vm_page_verify_free_list(color=%u, npages=%u): page %p not found phys=%u\n",
                            color, npages, look_for_page, VM_PAGE_GET_PHYS_PAGE(look_for_page));
                        _vm_page_print(look_for_page);
                        for (other_color = 0;
                            other_color < vm_colors;
                            other_color++) {
                                if (other_color == color) {
                                        continue;
                                }
                                vm_page_verify_free_list(&vm_page_queue_free[other_color].qhead,
                                    other_color, look_for_page, FALSE);
                        }
                        if (color == (unsigned int) -1) {
                                vm_page_verify_free_list(&vm_lopage_queue_free,
                                    (unsigned int) -1, look_for_page, FALSE);
                        }
                        panic("vm_page_verify_free_list(color=%u)\n", color);
                }
                if (!expect_page && found_page) {
                        printf("vm_page_verify_free_list(color=%u, npages=%u): page %p found phys=%u\n",
                            color, npages, look_for_page, VM_PAGE_GET_PHYS_PAGE(look_for_page));
                }
        }
        return npages;
}

static boolean_t vm_page_verify_all_free_lists_enabled = FALSE;
static void
vm_page_verify_free_lists( void )
{
        unsigned int    color, npages, nlopages;
        boolean_t       toggle = TRUE;

        if (!vm_page_verify_all_free_lists_enabled) {
                return;
        }

        npages = 0;

        lck_mtx_lock(&vm_page_queue_free_lock);

        if (vm_page_verify_this_free_list_enabled == TRUE) {
                /*
                 * This variable has been set globally for extra checking of
                 * each free list Q. Since we didn't set it, we don't own it
                 * and we shouldn't toggle it.
                 */
                toggle = FALSE;
        }

        if (toggle == TRUE) {
                vm_page_verify_this_free_list_enabled = TRUE;
        }

        for (color = 0; color < vm_colors; color++) {
                npages += vm_page_verify_free_list(&vm_page_queue_free[color].qhead,
                    color, VM_PAGE_NULL, FALSE);
        }
        nlopages = vm_page_verify_free_list(&vm_lopage_queue_free,
            (unsigned int) -1,
            VM_PAGE_NULL, FALSE);
        if (npages != vm_page_free_count || nlopages != vm_lopage_free_count) {
                panic("vm_page_verify_free_lists:  "
                    "npages %u free_count %d nlopages %u lo_free_count %u",
                    npages, vm_page_free_count, nlopages, vm_lopage_free_count);
        }

        if (toggle == TRUE) {
                vm_page_verify_this_free_list_enabled = FALSE;
        }

        lck_mtx_unlock(&vm_page_queue_free_lock);
}

#endif  /* MACH_ASSERT */


extern boolean_t(*volatile consider_buffer_cache_collect)(int);

/*
 *      CONTIGUOUS PAGE ALLOCATION
 *
 *      Find a region large enough to contain at least n pages
 *      of contiguous physical memory.
 *
 *      This is done by traversing the vm_page_t array in a linear fashion
 *      we assume that the vm_page_t array has the avaiable physical pages in an
 *      ordered, ascending list... this is currently true of all our implementations
 *      and must remain so... there can be 'holes' in the array...  we also can
 *      no longer tolerate the vm_page_t's in the list being 'freed' and reclaimed
 *      which use to happen via 'vm_page_convert'... that function was no longer
 *      being called and was removed...
 *
 *      The basic flow consists of stabilizing some of the interesting state of
 *      a vm_page_t behind the vm_page_queue and vm_page_free locks... we start our
 *      sweep at the beginning of the array looking for pages that meet our criterea
 *      for a 'stealable' page... currently we are pretty conservative... if the page
 *      meets this criterea and is physically contiguous to the previous page in the 'run'
 *      we keep developing it.  If we hit a page that doesn't fit, we reset our state
 *      and start to develop a new run... if at this point we've already considered
 *      at least MAX_CONSIDERED_BEFORE_YIELD pages, we'll drop the 2 locks we hold,
 *      and mutex_pause (which will yield the processor), to keep the latency low w/r
 *      to other threads trying to acquire free pages (or move pages from q to q),
 *      and then continue from the spot we left off... we only make 1 pass through the
 *      array.  Once we have a 'run' that is long enough, we'll go into the loop which
 *      which steals the pages from the queues they're currently on... pages on the free
 *      queue can be stolen directly... pages that are on any of the other queues
 *      must be removed from the object they are tabled on... this requires taking the
 *      object lock... we do this as a 'try' to prevent deadlocks... if the 'try' fails
 *      or if the state of the page behind the vm_object lock is no longer viable, we'll
 *      dump the pages we've currently stolen back to the free list, and pick up our
 *      scan from the point where we aborted the 'current' run.
 *
 *
 *      Requirements:
 *              - neither vm_page_queue nor vm_free_list lock can be held on entry
 *
 *      Returns a pointer to a list of gobbled/wired pages or VM_PAGE_NULL.
 *
 * Algorithm:
 */

#define MAX_CONSIDERED_BEFORE_YIELD     1000


#define RESET_STATE_OF_RUN()    \
        MACRO_BEGIN             \
        prevcontaddr = -2;      \
        start_pnum = -1;        \
        free_considered = 0;    \
        substitute_needed = 0;  \
        npages = 0;             \
        MACRO_END

/*
 * Can we steal in-use (i.e. not free) pages when searching for
 * physically-contiguous pages ?
 */
#define VM_PAGE_FIND_CONTIGUOUS_CAN_STEAL 1

static unsigned int vm_page_find_contiguous_last_idx = 0, vm_page_lomem_find_contiguous_last_idx = 0;
#if DEBUG
int vm_page_find_contig_debug = 0;
#endif

static vm_page_t
vm_page_find_contiguous(
        unsigned int    contig_pages,
        ppnum_t         max_pnum,
        ppnum_t     pnum_mask,
        boolean_t       wire,
        int             flags)
{
        vm_page_t       m = NULL;
        ppnum_t         prevcontaddr = 0;
        ppnum_t         start_pnum = 0;
        unsigned int    npages = 0, considered = 0, scanned = 0;
        unsigned int    page_idx = 0, start_idx = 0, last_idx = 0, orig_last_idx = 0;
        unsigned int    idx_last_contig_page_found = 0;
        int             free_considered = 0, free_available = 0;
        int             substitute_needed = 0;
        boolean_t       wrapped, zone_gc_called = FALSE;
        kern_return_t   kr;
#if DEBUG
        clock_sec_t     tv_start_sec = 0, tv_end_sec = 0;
        clock_usec_t    tv_start_usec = 0, tv_end_usec = 0;
#endif

        int             yielded = 0;
        int             dumped_run = 0;
        int             stolen_pages = 0;
        int             compressed_pages = 0;


        if (contig_pages == 0) {
                return VM_PAGE_NULL;
        }

full_scan_again:

#if MACH_ASSERT
        vm_page_verify_free_lists();
#endif
#if DEBUG
        clock_get_system_microtime(&tv_start_sec, &tv_start_usec);
#endif
        PAGE_REPLACEMENT_ALLOWED(TRUE);

        /*
         * If there are still delayed pages, try to free up some that match.
         */
        if (__improbable(vm_delayed_count != 0 && contig_pages != 0)) {
                vm_free_delayed_pages_contig(contig_pages, max_pnum, pnum_mask);
        }

        vm_page_lock_queues();
        lck_mtx_lock(&vm_page_queue_free_lock);

        RESET_STATE_OF_RUN();

        scanned = 0;
        considered = 0;
        free_available = vm_page_free_count - vm_page_free_reserved;

        wrapped = FALSE;

        if (flags & KMA_LOMEM) {
                idx_last_contig_page_found = vm_page_lomem_find_contiguous_last_idx;
        } else {
                idx_last_contig_page_found =  vm_page_find_contiguous_last_idx;
        }

        orig_last_idx = idx_last_contig_page_found;
        last_idx = orig_last_idx;

        for (page_idx = last_idx, start_idx = last_idx;
            npages < contig_pages && page_idx < vm_pages_count;
            page_idx++) {
retry:
                if (wrapped &&
                    npages == 0 &&
                    page_idx >= orig_last_idx) {
                        /*
                         * We're back where we started and we haven't
                         * found any suitable contiguous range.  Let's
                         * give up.
                         */
                        break;
                }
                scanned++;
                m = &vm_pages[page_idx];

                assert(!m->vmp_fictitious);
                assert(!m->vmp_private);

                if (max_pnum && VM_PAGE_GET_PHYS_PAGE(m) > max_pnum) {
                        /* no more low pages... */
                        break;
                }
                if (!npages & ((VM_PAGE_GET_PHYS_PAGE(m) & pnum_mask) != 0)) {
                        /*
                         * not aligned
                         */
                        RESET_STATE_OF_RUN();
                } else if (VM_PAGE_WIRED(m) || m->vmp_gobbled ||
                    m->vmp_laundry || m->vmp_wanted ||
                    m->vmp_cleaning || m->vmp_overwriting || m->vmp_free_when_done) {
                        /*
                         * page is in a transient state
                         * or a state we don't want to deal
                         * with, so don't consider it which
                         * means starting a new run
                         */
                        RESET_STATE_OF_RUN();
                } else if ((m->vmp_q_state == VM_PAGE_NOT_ON_Q) ||
                    (m->vmp_q_state == VM_PAGE_ON_FREE_LOCAL_Q) ||
                    (m->vmp_q_state == VM_PAGE_ON_FREE_LOPAGE_Q) ||
                    (m->vmp_q_state == VM_PAGE_ON_PAGEOUT_Q)) {
                        /*
                         * page needs to be on one of our queues (other then the pageout or special free queues)
                         * or it needs to belong to the compressor pool (which is now indicated
                         * by vmp_q_state == VM_PAGE_USED_BY_COMPRESSOR and falls out
                         * from the check for VM_PAGE_NOT_ON_Q)
                         * in order for it to be stable behind the
                         * locks we hold at this point...
                         * if not, don't consider it which
                         * means starting a new run
                         */
                        RESET_STATE_OF_RUN();
                } else if ((m->vmp_q_state != VM_PAGE_ON_FREE_Q) && (!m->vmp_tabled || m->vmp_busy)) {
                        /*
                         * pages on the free list are always 'busy'
                         * so we couldn't test for 'busy' in the check
                         * for the transient states... pages that are
                         * 'free' are never 'tabled', so we also couldn't
                         * test for 'tabled'.  So we check here to make
                         * sure that a non-free page is not busy and is
                         * tabled on an object...
                         * if not, don't consider it which
                         * means starting a new run
                         */
                        RESET_STATE_OF_RUN();
                } else {
                        if (VM_PAGE_GET_PHYS_PAGE(m) != prevcontaddr + 1) {
                                if ((VM_PAGE_GET_PHYS_PAGE(m) & pnum_mask) != 0) {
                                        RESET_STATE_OF_RUN();
                                        goto did_consider;
                                } else {
                                        npages = 1;
                                        start_idx = page_idx;
                                        start_pnum = VM_PAGE_GET_PHYS_PAGE(m);
                                }
                        } else {
                                npages++;
                        }
                        prevcontaddr = VM_PAGE_GET_PHYS_PAGE(m);

                        VM_PAGE_CHECK(m);
                        if (m->vmp_q_state == VM_PAGE_ON_FREE_Q) {
                                free_considered++;
                        } else {
                                /*
                                 * This page is not free.
                                 * If we can't steal used pages,
                                 * we have to give up this run
                                 * and keep looking.
                                 * Otherwise, we might need to
                                 * move the contents of this page
                                 * into a substitute page.
                                 */
#if VM_PAGE_FIND_CONTIGUOUS_CAN_STEAL
                                if (m->vmp_pmapped || m->vmp_dirty || m->vmp_precious) {
                                        substitute_needed++;
                                }
#else
                                RESET_STATE_OF_RUN();
#endif
                        }

                        if ((free_considered + substitute_needed) > free_available) {
                                /*
                                 * if we let this run continue
                                 * we will end up dropping the vm_page_free_count
                                 * below the reserve limit... we need to abort
                                 * this run, but we can at least re-consider this
                                 * page... thus the jump back to 'retry'
                                 */
                                RESET_STATE_OF_RUN();

                                if (free_available && considered <= MAX_CONSIDERED_BEFORE_YIELD) {
                                        considered++;
                                        goto retry;
                                }
                                /*
                                 * free_available == 0
                                 * so can't consider any free pages... if
                                 * we went to retry in this case, we'd
                                 * get stuck looking at the same page
                                 * w/o making any forward progress
                                 * we also want to take this path if we've already
                                 * reached our limit that controls the lock latency
                                 */
                        }
                }
did_consider:
                if (considered > MAX_CONSIDERED_BEFORE_YIELD && npages <= 1) {
                        PAGE_REPLACEMENT_ALLOWED(FALSE);

                        lck_mtx_unlock(&vm_page_queue_free_lock);
                        vm_page_unlock_queues();

                        mutex_pause(0);

                        PAGE_REPLACEMENT_ALLOWED(TRUE);

                        vm_page_lock_queues();
                        lck_mtx_lock(&vm_page_queue_free_lock);

                        RESET_STATE_OF_RUN();
                        /*
                         * reset our free page limit since we
                         * dropped the lock protecting the vm_page_free_queue
                         */
                        free_available = vm_page_free_count - vm_page_free_reserved;
                        considered = 0;

                        yielded++;

                        goto retry;
                }
                considered++;
        }
        m = VM_PAGE_NULL;

        if (npages != contig_pages) {
                if (!wrapped) {
                        /*
                         * We didn't find a contiguous range but we didn't
                         * start from the very first page.
                         * Start again from the very first page.
                         */
                        RESET_STATE_OF_RUN();
                        if (flags & KMA_LOMEM) {
                                idx_last_contig_page_found  = vm_page_lomem_find_contiguous_last_idx = 0;
                        } else {
                                idx_last_contig_page_found = vm_page_find_contiguous_last_idx = 0;
                        }
                        last_idx = 0;
                        page_idx = last_idx;
                        wrapped = TRUE;
                        goto retry;
                }
                lck_mtx_unlock(&vm_page_queue_free_lock);
        } else {
                vm_page_t       m1;
                vm_page_t       m2;
                unsigned int    cur_idx;
                unsigned int    tmp_start_idx;
                vm_object_t     locked_object = VM_OBJECT_NULL;
                boolean_t       abort_run = FALSE;

                assert(page_idx - start_idx == contig_pages);

                tmp_start_idx = start_idx;

                /*
                 * first pass through to pull the free pages
                 * off of the free queue so that in case we
                 * need substitute pages, we won't grab any
                 * of the free pages in the run... we'll clear
                 * the 'free' bit in the 2nd pass, and even in
                 * an abort_run case, we'll collect all of the
                 * free pages in this run and return them to the free list
                 */
                while (start_idx < page_idx) {
                        m1 = &vm_pages[start_idx++];

#if !VM_PAGE_FIND_CONTIGUOUS_CAN_STEAL
                        assert(m1->vmp_q_state == VM_PAGE_ON_FREE_Q);
#endif

                        if (m1->vmp_q_state == VM_PAGE_ON_FREE_Q) {
                                unsigned int color;

                                color = VM_PAGE_GET_COLOR(m1);
#if MACH_ASSERT
                                vm_page_verify_free_list(&vm_page_queue_free[color].qhead, color, m1, TRUE);
#endif
                                vm_page_queue_remove(&vm_page_queue_free[color].qhead, m1, vmp_pageq);

                                VM_PAGE_ZERO_PAGEQ_ENTRY(m1);
#if MACH_ASSERT
                                vm_page_verify_free_list(&vm_page_queue_free[color].qhead, color, VM_PAGE_NULL, FALSE);
#endif
                                /*
                                 * Clear the "free" bit so that this page
                                 * does not get considered for another
                                 * concurrent physically-contiguous allocation.
                                 */
                                m1->vmp_q_state = VM_PAGE_NOT_ON_Q;
                                assert(m1->vmp_busy);

                                vm_page_free_count--;
                        }
                }
                if (flags & KMA_LOMEM) {
                        vm_page_lomem_find_contiguous_last_idx = page_idx;
                } else {
                        vm_page_find_contiguous_last_idx = page_idx;
                }

                /*
                 * we can drop the free queue lock at this point since
                 * we've pulled any 'free' candidates off of the list
                 * we need it dropped so that we can do a vm_page_grab
                 * when substituing for pmapped/dirty pages
                 */
                lck_mtx_unlock(&vm_page_queue_free_lock);

                start_idx = tmp_start_idx;
                cur_idx = page_idx - 1;

                while (start_idx++ < page_idx) {
                        /*
                         * must go through the list from back to front
                         * so that the page list is created in the
                         * correct order - low -> high phys addresses
                         */
                        m1 = &vm_pages[cur_idx--];

                        if (m1->vmp_object == 0) {
                                /*
                                 * page has already been removed from
                                 * the free list in the 1st pass
                                 */
                                assert(m1->vmp_q_state == VM_PAGE_NOT_ON_Q);
                                assert(m1->vmp_offset == (vm_object_offset_t) -1);
                                assert(m1->vmp_busy);
                                assert(!m1->vmp_wanted);
                                assert(!m1->vmp_laundry);
                        } else {
                                vm_object_t object;
                                int refmod;
                                boolean_t disconnected, reusable;

                                if (abort_run == TRUE) {
                                        continue;
                                }

                                assert(m1->vmp_q_state != VM_PAGE_NOT_ON_Q);

                                object = VM_PAGE_OBJECT(m1);

                                if (object != locked_object) {
                                        if (locked_object) {
                                                vm_object_unlock(locked_object);
                                                locked_object = VM_OBJECT_NULL;
                                        }
                                        if (vm_object_lock_try(object)) {
                                                locked_object = object;
                                        }
                                }
                                if (locked_object == VM_OBJECT_NULL ||
                                    (VM_PAGE_WIRED(m1) || m1->vmp_gobbled ||
                                    m1->vmp_laundry || m1->vmp_wanted ||
                                    m1->vmp_cleaning || m1->vmp_overwriting || m1->vmp_free_when_done || m1->vmp_busy) ||
                                    (m1->vmp_q_state == VM_PAGE_ON_PAGEOUT_Q)) {
                                        if (locked_object) {
                                                vm_object_unlock(locked_object);
                                                locked_object = VM_OBJECT_NULL;
                                        }
                                        tmp_start_idx = cur_idx;
                                        abort_run = TRUE;
                                        continue;
                                }

                                disconnected = FALSE;
                                reusable = FALSE;

                                if ((m1->vmp_reusable ||
                                    object->all_reusable) &&
                                    (m1->vmp_q_state == VM_PAGE_ON_INACTIVE_INTERNAL_Q) &&
                                    !m1->vmp_dirty &&
                                    !m1->vmp_reference) {
                                        /* reusable page... */
                                        refmod = pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(m1));
                                        disconnected = TRUE;
                                        if (refmod == 0) {
                                                /*
                                                 * ... not reused: can steal
                                                 * without relocating contents.
                                                 */
                                                reusable = TRUE;
                                        }
                                }

                                if ((m1->vmp_pmapped &&
                                    !reusable) ||
                                    m1->vmp_dirty ||
                                    m1->vmp_precious) {
                                        vm_object_offset_t offset;

                                        m2 = vm_page_grab_options(VM_PAGE_GRAB_Q_LOCK_HELD);

                                        if (m2 == VM_PAGE_NULL) {
                                                if (locked_object) {
                                                        vm_object_unlock(locked_object);
                                                        locked_object = VM_OBJECT_NULL;
                                                }
                                                tmp_start_idx = cur_idx;
                                                abort_run = TRUE;
                                                continue;
                                        }
                                        if (!disconnected) {
                                                if (m1->vmp_pmapped) {
                                                        refmod = pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(m1));
                                                } else {
                                                        refmod = 0;
                                                }
                                        }

                                        /* copy the page's contents */
                                        pmap_copy_page(VM_PAGE_GET_PHYS_PAGE(m1), VM_PAGE_GET_PHYS_PAGE(m2));
                                        /* copy the page's state */
                                        assert(!VM_PAGE_WIRED(m1));
                                        assert(m1->vmp_q_state != VM_PAGE_ON_FREE_Q);
                                        assert(m1->vmp_q_state != VM_PAGE_ON_PAGEOUT_Q);
                                        assert(!m1->vmp_laundry);
                                        m2->vmp_reference       = m1->vmp_reference;
                                        assert(!m1->vmp_gobbled);
                                        assert(!m1->vmp_private);
                                        m2->vmp_no_cache        = m1->vmp_no_cache;
                                        m2->vmp_xpmapped        = 0;
                                        assert(!m1->vmp_busy);
                                        assert(!m1->vmp_wanted);
                                        assert(!m1->vmp_fictitious);
                                        m2->vmp_pmapped = m1->vmp_pmapped; /* should flush cache ? */
                                        m2->vmp_wpmapped        = m1->vmp_wpmapped;
                                        assert(!m1->vmp_free_when_done);
                                        m2->vmp_absent  = m1->vmp_absent;
                                        m2->vmp_error   = m1->vmp_error;
                                        m2->vmp_dirty   = m1->vmp_dirty;
                                        assert(!m1->vmp_cleaning);
                                        m2->vmp_precious        = m1->vmp_precious;
                                        m2->vmp_clustered       = m1->vmp_clustered;
                                        assert(!m1->vmp_overwriting);
                                        m2->vmp_restart = m1->vmp_restart;
                                        m2->vmp_unusual = m1->vmp_unusual;
                                        m2->vmp_cs_validated = m1->vmp_cs_validated;
                                        m2->vmp_cs_tainted      = m1->vmp_cs_tainted;
                                        m2->vmp_cs_nx   = m1->vmp_cs_nx;

                                        /*
                                         * If m1 had really been reusable,
                                         * we would have just stolen it, so
                                         * let's not propagate it's "reusable"
                                         * bit and assert that m2 is not
                                         * marked as "reusable".
                                         */
                                        // m2->vmp_reusable     = m1->vmp_reusable;
                                        assert(!m2->vmp_reusable);

                                        // assert(!m1->vmp_lopage);

                                        if (m1->vmp_q_state == VM_PAGE_USED_BY_COMPRESSOR) {
                                                m2->vmp_q_state = VM_PAGE_USED_BY_COMPRESSOR;
                                        }

                                        /*
                                         * page may need to be flushed if
                                         * it is marshalled into a UPL
                                         * that is going to be used by a device
                                         * that doesn't support coherency
                                         */
                                        m2->vmp_written_by_kernel = TRUE;

                                        /*
                                         * make sure we clear the ref/mod state
                                         * from the pmap layer... else we risk
                                         * inheriting state from the last time
                                         * this page was used...
                                         */
                                        pmap_clear_refmod(VM_PAGE_GET_PHYS_PAGE(m2), VM_MEM_MODIFIED | VM_MEM_REFERENCED);

                                        if (refmod & VM_MEM_REFERENCED) {
                                                m2->vmp_reference = TRUE;
                                        }
                                        if (refmod & VM_MEM_MODIFIED) {
                                                SET_PAGE_DIRTY(m2, TRUE);
                                        }
                                        offset = m1->vmp_offset;

                                        /*
                                         * completely cleans up the state
                                         * of the page so that it is ready
                                         * to be put onto the free list, or
                                         * for this purpose it looks like it
                                         * just came off of the free list
                                         */
                                        vm_page_free_prepare(m1);

                                        /*
                                         * now put the substitute page
                                         * on the object
                                         */
                                        vm_page_insert_internal(m2, locked_object, offset, VM_KERN_MEMORY_NONE, TRUE, TRUE, FALSE, FALSE, NULL);

                                        if (m2->vmp_q_state == VM_PAGE_USED_BY_COMPRESSOR) {
                                                m2->vmp_pmapped = TRUE;
                                                m2->vmp_wpmapped = TRUE;

                                                PMAP_ENTER(kernel_pmap, m2->vmp_offset, m2,
                                                    VM_PROT_READ | VM_PROT_WRITE, VM_PROT_NONE, 0, TRUE, kr);

                                                assert(kr == KERN_SUCCESS);

                                                compressed_pages++;
                                        } else {
                                                if (m2->vmp_reference) {
                                                        vm_page_activate(m2);
                                                } else {
                                                        vm_page_deactivate(m2);
                                                }
                                        }
                                        PAGE_WAKEUP_DONE(m2);
                                } else {
                                        assert(m1->vmp_q_state != VM_PAGE_USED_BY_COMPRESSOR);

                                        /*
                                         * completely cleans up the state
                                         * of the page so that it is ready
                                         * to be put onto the free list, or
                                         * for this purpose it looks like it
                                         * just came off of the free list
                                         */
                                        vm_page_free_prepare(m1);
                                }

                                stolen_pages++;
                        }
#if CONFIG_BACKGROUND_QUEUE
                        vm_page_assign_background_state(m1);
#endif
                        VM_PAGE_ZERO_PAGEQ_ENTRY(m1);
                        m1->vmp_snext = m;
                        m = m1;
                }
                if (locked_object) {
                        vm_object_unlock(locked_object);
                        locked_object = VM_OBJECT_NULL;
                }

                if (abort_run == TRUE) {
                        /*
                         * want the index of the last
                         * page in this run that was
                         * successfully 'stolen', so back
                         * it up 1 for the auto-decrement on use
                         * and 1 more to bump back over this page
                         */
                        page_idx = tmp_start_idx + 2;
                        if (page_idx >= vm_pages_count) {
                                if (wrapped) {
                                        if (m != VM_PAGE_NULL) {
                                                vm_page_unlock_queues();
                                                vm_page_free_list(m, FALSE);
                                                vm_page_lock_queues();
                                                m = VM_PAGE_NULL;
                                        }
                                        dumped_run++;
                                        goto done_scanning;
                                }
                                page_idx = last_idx = 0;
                                wrapped = TRUE;
                        }
                        abort_run = FALSE;

                        /*
                         * We didn't find a contiguous range but we didn't
                         * start from the very first page.
                         * Start again from the very first page.
                         */
                        RESET_STATE_OF_RUN();

                        if (flags & KMA_LOMEM) {
                                idx_last_contig_page_found  = vm_page_lomem_find_contiguous_last_idx = page_idx;
                        } else {
                                idx_last_contig_page_found = vm_page_find_contiguous_last_idx = page_idx;
                        }

                        last_idx = page_idx;

                        if (m != VM_PAGE_NULL) {
                                vm_page_unlock_queues();
                                vm_page_free_list(m, FALSE);
                                vm_page_lock_queues();
                                m = VM_PAGE_NULL;
                        }
                        dumped_run++;

                        lck_mtx_lock(&vm_page_queue_free_lock);
                        /*
                         * reset our free page limit since we
                         * dropped the lock protecting the vm_page_free_queue
                         */
                        free_available = vm_page_free_count - vm_page_free_reserved;
                        goto retry;
                }

                for (m1 = m; m1 != VM_PAGE_NULL; m1 = NEXT_PAGE(m1)) {
                        assert(m1->vmp_q_state == VM_PAGE_NOT_ON_Q);
                        assert(m1->vmp_wire_count == 0);

                        if (wire == TRUE) {
                                m1->vmp_wire_count++;
                                m1->vmp_q_state = VM_PAGE_IS_WIRED;
                        } else {
                                m1->vmp_gobbled = TRUE;
                        }
                }
                if (wire == FALSE) {
                        vm_page_gobble_count += npages;
                }

                /*
                 * gobbled pages are also counted as wired pages
                 */
                vm_page_wire_count += npages;

                assert(vm_page_verify_contiguous(m, npages));
        }
done_scanning:
        PAGE_REPLACEMENT_ALLOWED(FALSE);

        vm_page_unlock_queues();

#if DEBUG
        clock_get_system_microtime(&tv_end_sec, &tv_end_usec);

        tv_end_sec -= tv_start_sec;
        if (tv_end_usec < tv_start_usec) {
                tv_end_sec--;
                tv_end_usec += 1000000;
        }
        tv_end_usec -= tv_start_usec;
        if (tv_end_usec >= 1000000) {
                tv_end_sec++;
                tv_end_sec -= 1000000;
        }
        if (vm_page_find_contig_debug) {
                printf("%s(num=%d,low=%d): found %d pages at 0x%llx in %ld.%06ds...  started at %d...  scanned %d pages...  yielded %d times...  dumped run %d times... stole %d pages... stole %d compressed pages\n",
                    __func__, contig_pages, max_pnum, npages, (vm_object_offset_t)start_pnum << PAGE_SHIFT,
                    (long)tv_end_sec, tv_end_usec, orig_last_idx,
                        scanned, yielded, dumped_run, stolen_pages, compressed_pages);
        }

#endif
#if MACH_ASSERT
        vm_page_verify_free_lists();
#endif
        if (m == NULL && zone_gc_called == FALSE) {
                printf("%s(num=%d,low=%d): found %d pages at 0x%llx...scanned %d pages...  yielded %d times...  dumped run %d times... stole %d pages... stole %d compressed pages... wired count is %d\n",
                    __func__, contig_pages, max_pnum, npages, (vm_object_offset_t)start_pnum << PAGE_SHIFT,
                        scanned, yielded, dumped_run, stolen_pages, compressed_pages, vm_page_wire_count);

                if (consider_buffer_cache_collect != NULL) {
                        (void)(*consider_buffer_cache_collect)(1);
                }

                consider_zone_gc(FALSE);

                zone_gc_called = TRUE;

                printf("vm_page_find_contiguous: zone_gc called... wired count is %d\n", vm_page_wire_count);
                goto full_scan_again;
        }

        return m;
}

/*
 *      Allocate a list of contiguous, wired pages.
 */
kern_return_t
cpm_allocate(
        vm_size_t       size,
        vm_page_t       *list,
        ppnum_t         max_pnum,
        ppnum_t         pnum_mask,
        boolean_t       wire,
        int             flags)
{
        vm_page_t               pages;
        unsigned int            npages;

        if (size % PAGE_SIZE != 0) {
                return KERN_INVALID_ARGUMENT;
        }

        npages = (unsigned int) (size / PAGE_SIZE);
        if (npages != size / PAGE_SIZE) {
                /* 32-bit overflow */
                return KERN_INVALID_ARGUMENT;
        }

        /*
         *      Obtain a pointer to a subset of the free
         *      list large enough to satisfy the request;
         *      the region will be physically contiguous.
         */
        pages = vm_page_find_contiguous(npages, max_pnum, pnum_mask, wire, flags);

        if (pages == VM_PAGE_NULL) {
                return KERN_NO_SPACE;
        }
        /*
         * determine need for wakeups
         */
        if (vm_page_free_count < vm_page_free_min) {
                lck_mtx_lock(&vm_page_queue_free_lock);
                if (vm_pageout_running == FALSE) {
                        lck_mtx_unlock(&vm_page_queue_free_lock);
                        thread_wakeup((event_t) &vm_page_free_wanted);
                } else {
                        lck_mtx_unlock(&vm_page_queue_free_lock);
                }
        }

        VM_CHECK_MEMORYSTATUS;

        /*
         *      The CPM pages should now be available and
         *      ordered by ascending physical address.
         */
        assert(vm_page_verify_contiguous(pages, npages));

        *list = pages;
        return KERN_SUCCESS;
}


unsigned int vm_max_delayed_work_limit = DEFAULT_DELAYED_WORK_LIMIT;

/*
 * when working on a 'run' of pages, it is necessary to hold
 * the vm_page_queue_lock (a hot global lock) for certain operations
 * on the page... however, the majority of the work can be done
 * while merely holding the object lock... in fact there are certain
 * collections of pages that don't require any work brokered by the
 * vm_page_queue_lock... to mitigate the time spent behind the global
 * lock, go to a 2 pass algorithm... collect pages up to DELAYED_WORK_LIMIT
 * while doing all of the work that doesn't require the vm_page_queue_lock...
 * then call vm_page_do_delayed_work to acquire the vm_page_queue_lock and do the
 * necessary work for each page... we will grab the busy bit on the page
 * if it's not already held so that vm_page_do_delayed_work can drop the object lock
 * if it can't immediately take the vm_page_queue_lock in order to compete
 * for the locks in the same order that vm_pageout_scan takes them.
 * the operation names are modeled after the names of the routines that
 * need to be called in order to make the changes very obvious in the
 * original loop
 */

void
vm_page_do_delayed_work(
        vm_object_t     object,
        vm_tag_t        tag,
        struct vm_page_delayed_work *dwp,
        int             dw_count)
{
        int             j;
        vm_page_t       m;
        vm_page_t       local_free_q = VM_PAGE_NULL;

        /*
         * pageout_scan takes the vm_page_lock_queues first
         * then tries for the object lock... to avoid what
         * is effectively a lock inversion, we'll go to the
         * trouble of taking them in that same order... otherwise
         * if this object contains the majority of the pages resident
         * in the UBC (or a small set of large objects actively being
         * worked on contain the majority of the pages), we could
         * cause the pageout_scan thread to 'starve' in its attempt
         * to find pages to move to the free queue, since it has to
         * successfully acquire the object lock of any candidate page
         * before it can steal/clean it.
         */
        if (!vm_page_trylockspin_queues()) {
                vm_object_unlock(object);

                /*
                 * "Turnstile enabled vm_pageout_scan" can be runnable
                 * for a very long time without getting on a core.
                 * If this is a higher priority thread it could be
                 * waiting here for a very long time respecting the fact
                 * that pageout_scan would like its object after VPS does
                 * a mutex_pause(0).
                 * So we cap the number of yields in the vm_object_lock_avoid()
                 * case to a single mutex_pause(0) which will give vm_pageout_scan
                 * 10us to run and grab the object if needed.
                 */
                vm_page_lockspin_queues();

                for (j = 0;; j++) {
                        if ((!vm_object_lock_avoid(object) ||
                            (vps_dynamic_priority_enabled && (j > 0))) &&
                            _vm_object_lock_try(object)) {
                                break;
                        }
                        vm_page_unlock_queues();
                        mutex_pause(j);
                        vm_page_lockspin_queues();
                }
        }
        for (j = 0; j < dw_count; j++, dwp++) {
                m = dwp->dw_m;

                if (dwp->dw_mask & DW_vm_pageout_throttle_up) {
                        vm_pageout_throttle_up(m);
                }
#if CONFIG_PHANTOM_CACHE
                if (dwp->dw_mask & DW_vm_phantom_cache_update) {
                        vm_phantom_cache_update(m);
                }
#endif
                if (dwp->dw_mask & DW_vm_page_wire) {
                        vm_page_wire(m, tag, FALSE);
                } else if (dwp->dw_mask & DW_vm_page_unwire) {
                        boolean_t       queueit;

                        queueit = (dwp->dw_mask & (DW_vm_page_free | DW_vm_page_deactivate_internal)) ? FALSE : TRUE;

                        vm_page_unwire(m, queueit);
                }
                if (dwp->dw_mask & DW_vm_page_free) {
                        vm_page_free_prepare_queues(m);

                        assert(m->vmp_pageq.next == 0 && m->vmp_pageq.prev == 0);
                        /*
                         * Add this page to our list of reclaimed pages,
                         * to be freed later.
                         */
                        m->vmp_snext = local_free_q;
                        local_free_q = m;
                } else {
                        if (dwp->dw_mask & DW_vm_page_deactivate_internal) {
                                vm_page_deactivate_internal(m, FALSE);
                        } else if (dwp->dw_mask & DW_vm_page_activate) {
                                if (m->vmp_q_state != VM_PAGE_ON_ACTIVE_Q) {
                                        vm_page_activate(m);
                                }
                        } else if (dwp->dw_mask & DW_vm_page_speculate) {
                                vm_page_speculate(m, TRUE);
                        } else if (dwp->dw_mask & DW_enqueue_cleaned) {
                                /*
                                 * if we didn't hold the object lock and did this,
                                 * we might disconnect the page, then someone might
                                 * soft fault it back in, then we would put it on the
                                 * cleaned queue, and so we would have a referenced (maybe even dirty)
                                 * page on that queue, which we don't want
                                 */
                                int refmod_state = pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(m));

                                if ((refmod_state & VM_MEM_REFERENCED)) {
                                        /*
                                         * this page has been touched since it got cleaned; let's activate it
                                         * if it hasn't already been
                                         */
                                        VM_PAGEOUT_DEBUG(vm_pageout_enqueued_cleaned, 1);
                                        VM_PAGEOUT_DEBUG(vm_pageout_cleaned_reactivated, 1);

                                        if (m->vmp_q_state != VM_PAGE_ON_ACTIVE_Q) {
                                                vm_page_activate(m);
                                        }
                                } else {
                                        m->vmp_reference = FALSE;
                                        vm_page_enqueue_cleaned(m);
                                }
                        } else if (dwp->dw_mask & DW_vm_page_lru) {
                                vm_page_lru(m);
                        } else if (dwp->dw_mask & DW_VM_PAGE_QUEUES_REMOVE) {
                                if (m->vmp_q_state != VM_PAGE_ON_PAGEOUT_Q) {
                                        vm_page_queues_remove(m, TRUE);
                                }
                        }
                        if (dwp->dw_mask & DW_set_reference) {
                                m->vmp_reference = TRUE;
                        } else if (dwp->dw_mask & DW_clear_reference) {
                                m->vmp_reference = FALSE;
                        }

                        if (dwp->dw_mask & DW_move_page) {
                                if (m->vmp_q_state != VM_PAGE_ON_PAGEOUT_Q) {
                                        vm_page_queues_remove(m, FALSE);

                                        assert(VM_PAGE_OBJECT(m) != kernel_object);

                                        vm_page_enqueue_inactive(m, FALSE);
                                }
                        }
                        if (dwp->dw_mask & DW_clear_busy) {
                                m->vmp_busy = FALSE;
                        }

                        if (dwp->dw_mask & DW_PAGE_WAKEUP) {
                                PAGE_WAKEUP(m);
                        }
                }
        }
        vm_page_unlock_queues();

        if (local_free_q) {
                vm_page_free_list(local_free_q, TRUE);
        }

        VM_CHECK_MEMORYSTATUS;
}

kern_return_t
vm_page_alloc_list(
        int     page_count,
        int     flags,
        vm_page_t *list)
{
        vm_page_t       lo_page_list = VM_PAGE_NULL;
        vm_page_t       mem;
        int             i;

        if (!(flags & KMA_LOMEM)) {
                panic("vm_page_alloc_list: called w/o KMA_LOMEM");
        }

        for (i = 0; i < page_count; i++) {
                mem = vm_page_grablo();

                if (mem == VM_PAGE_NULL) {
                        if (lo_page_list) {
                                vm_page_free_list(lo_page_list, FALSE);
                        }

                        *list = VM_PAGE_NULL;

                        return KERN_RESOURCE_SHORTAGE;
                }
                mem->vmp_snext = lo_page_list;
                lo_page_list = mem;
        }
        *list = lo_page_list;

        return KERN_SUCCESS;
}

void
vm_page_set_offset(vm_page_t page, vm_object_offset_t offset)
{
        page->vmp_offset = offset;
}

vm_page_t
vm_page_get_next(vm_page_t page)
{
        return page->vmp_snext;
}

vm_object_offset_t
vm_page_get_offset(vm_page_t page)
{
        return page->vmp_offset;
}

ppnum_t
vm_page_get_phys_page(vm_page_t page)
{
        return VM_PAGE_GET_PHYS_PAGE(page);
}


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#if HIBERNATION

static vm_page_t hibernate_gobble_queue;

static int  hibernate_drain_pageout_queue(struct vm_pageout_queue *);
static int  hibernate_flush_dirty_pages(int);
static int  hibernate_flush_queue(vm_page_queue_head_t *, int);

void hibernate_flush_wait(void);
void hibernate_mark_in_progress(void);
void hibernate_clear_in_progress(void);

void            hibernate_free_range(int, int);
void            hibernate_hash_insert_page(vm_page_t);
uint32_t        hibernate_mark_as_unneeded(addr64_t, addr64_t, hibernate_page_list_t *, hibernate_page_list_t *);
void            hibernate_rebuild_vm_structs(void);
uint32_t        hibernate_teardown_vm_structs(hibernate_page_list_t *, hibernate_page_list_t *);
ppnum_t         hibernate_lookup_paddr(unsigned int);

struct hibernate_statistics {
        int hibernate_considered;
        int hibernate_reentered_on_q;
        int hibernate_found_dirty;
        int hibernate_skipped_cleaning;
        int hibernate_skipped_transient;
        int hibernate_skipped_precious;
        int hibernate_skipped_external;
        int hibernate_queue_nolock;
        int hibernate_queue_paused;
        int hibernate_throttled;
        int hibernate_throttle_timeout;
        int hibernate_drained;
        int hibernate_drain_timeout;
        int cd_lock_failed;
        int cd_found_precious;
        int cd_found_wired;
        int cd_found_busy;
        int cd_found_unusual;
        int cd_found_cleaning;
        int cd_found_laundry;
        int cd_found_dirty;
        int cd_found_xpmapped;
        int cd_skipped_xpmapped;
        int cd_local_free;
        int cd_total_free;
        int cd_vm_page_wire_count;
        int cd_vm_struct_pages_unneeded;
        int cd_pages;
        int cd_discarded;
        int cd_count_wire;
} hibernate_stats;


/*
 * clamp the number of 'xpmapped' pages we'll sweep into the hibernation image
 * so that we don't overrun the estimated image size, which would
 * result in a hibernation failure.
 */
#define HIBERNATE_XPMAPPED_LIMIT        40000


static int
hibernate_drain_pageout_queue(struct vm_pageout_queue *q)
{
        wait_result_t   wait_result;

        vm_page_lock_queues();

        while (!vm_page_queue_empty(&q->pgo_pending)) {
                q->pgo_draining = TRUE;

                assert_wait_timeout((event_t) (&q->pgo_laundry + 1), THREAD_INTERRUPTIBLE, 5000, 1000 * NSEC_PER_USEC);

                vm_page_unlock_queues();

                wait_result = thread_block(THREAD_CONTINUE_NULL);

                if (wait_result == THREAD_TIMED_OUT && !vm_page_queue_empty(&q->pgo_pending)) {
                        hibernate_stats.hibernate_drain_timeout++;

                        if (q == &vm_pageout_queue_external) {
                                return 0;
                        }

                        return 1;
                }
                vm_page_lock_queues();

                hibernate_stats.hibernate_drained++;
        }
        vm_page_unlock_queues();

        return 0;
}


boolean_t hibernate_skip_external = FALSE;

static int
hibernate_flush_queue(vm_page_queue_head_t *q, int qcount)
{
        vm_page_t       m;
        vm_object_t     l_object = NULL;
        vm_object_t     m_object = NULL;
        int             refmod_state = 0;
        int             try_failed_count = 0;
        int             retval = 0;
        int             current_run = 0;
        struct  vm_pageout_queue *iq;
        struct  vm_pageout_queue *eq;
        struct  vm_pageout_queue *tq;

        KDBG(IOKDBG_CODE(DBG_HIBERNATE, 4) | DBG_FUNC_START,
            VM_KERNEL_UNSLIDE_OR_PERM(q), qcount);

        iq = &vm_pageout_queue_internal;
        eq = &vm_pageout_queue_external;

        vm_page_lock_queues();

        while (qcount && !vm_page_queue_empty(q)) {
                if (current_run++ == 1000) {
                        if (hibernate_should_abort()) {
                                retval = 1;
                                break;
                        }
                        current_run = 0;
                }

                m = (vm_page_t) vm_page_queue_first(q);
                m_object = VM_PAGE_OBJECT(m);

                /*
                 * check to see if we currently are working
                 * with the same object... if so, we've
                 * already got the lock
                 */
                if (m_object != l_object) {
                        /*
                         * the object associated with candidate page is
                         * different from the one we were just working
                         * with... dump the lock if we still own it
                         */
                        if (l_object != NULL) {
                                vm_object_unlock(l_object);
                                l_object = NULL;
                        }
                        /*
                         * Try to lock object; since we've alread got the
                         * page queues lock, we can only 'try' for this one.
                         * if the 'try' fails, we need to do a mutex_pause
                         * to allow the owner of the object lock a chance to
                         * run...
                         */
                        if (!vm_object_lock_try_scan(m_object)) {
                                if (try_failed_count > 20) {
                                        hibernate_stats.hibernate_queue_nolock++;

                                        goto reenter_pg_on_q;
                                }

                                vm_page_unlock_queues();
                                mutex_pause(try_failed_count++);
                                vm_page_lock_queues();

                                hibernate_stats.hibernate_queue_paused++;
                                continue;
                        } else {
                                l_object = m_object;
                        }
                }
                if (!m_object->alive || m->vmp_cleaning || m->vmp_laundry || m->vmp_busy || m->vmp_absent || m->vmp_error) {
                        /*
                         * page is not to be cleaned
                         * put it back on the head of its queue
                         */
                        if (m->vmp_cleaning) {
                                hibernate_stats.hibernate_skipped_cleaning++;
                        } else {
                                hibernate_stats.hibernate_skipped_transient++;
                        }

                        goto reenter_pg_on_q;
                }
                if (m_object->copy == VM_OBJECT_NULL) {
                        if (m_object->purgable == VM_PURGABLE_VOLATILE || m_object->purgable == VM_PURGABLE_EMPTY) {
                                /*
                                 * let the normal hibernate image path
                                 * deal with these
                                 */
                                goto reenter_pg_on_q;
                        }
                }
                if (!m->vmp_dirty && m->vmp_pmapped) {
                        refmod_state = pmap_get_refmod(VM_PAGE_GET_PHYS_PAGE(m));

                        if ((refmod_state & VM_MEM_MODIFIED)) {
                                SET_PAGE_DIRTY(m, FALSE);
                        }
                } else {
                        refmod_state = 0;
                }

                if (!m->vmp_dirty) {
                        /*
                         * page is not to be cleaned
                         * put it back on the head of its queue
                         */
                        if (m->vmp_precious) {
                                hibernate_stats.hibernate_skipped_precious++;
                        }

                        goto reenter_pg_on_q;
                }

                if (hibernate_skip_external == TRUE && !m_object->internal) {
                        hibernate_stats.hibernate_skipped_external++;

                        goto reenter_pg_on_q;
                }
                tq = NULL;

                if (m_object->internal) {
                        if (VM_PAGE_Q_THROTTLED(iq)) {
                                tq = iq;
                        }
                } else if (VM_PAGE_Q_THROTTLED(eq)) {
                        tq = eq;
                }

                if (tq != NULL) {
                        wait_result_t   wait_result;
                        int             wait_count = 5;

                        if (l_object != NULL) {
                                vm_object_unlock(l_object);
                                l_object = NULL;
                        }

                        while (retval == 0) {
                                tq->pgo_throttled = TRUE;

                                assert_wait_timeout((event_t) &tq->pgo_laundry, THREAD_INTERRUPTIBLE, 1000, 1000 * NSEC_PER_USEC);

                                vm_page_unlock_queues();

                                wait_result = thread_block(THREAD_CONTINUE_NULL);

                                vm_page_lock_queues();

                                if (wait_result != THREAD_TIMED_OUT) {
                                        break;
                                }
                                if (!VM_PAGE_Q_THROTTLED(tq)) {
                                        break;
                                }

                                if (hibernate_should_abort()) {
                                        retval = 1;
                                }

                                if (--wait_count == 0) {
                                        hibernate_stats.hibernate_throttle_timeout++;

                                        if (tq == eq) {
                                                hibernate_skip_external = TRUE;
                                                break;
                                        }
                                        retval = 1;
                                }
                        }
                        if (retval) {
                                break;
                        }

                        hibernate_stats.hibernate_throttled++;

                        continue;
                }
                /*
                 * we've already factored out pages in the laundry which
                 * means this page can't be on the pageout queue so it's
                 * safe to do the vm_page_queues_remove
                 */
                vm_page_queues_remove(m, TRUE);

                if (m_object->internal == TRUE) {
                        pmap_disconnect_options(VM_PAGE_GET_PHYS_PAGE(m), PMAP_OPTIONS_COMPRESSOR, NULL);
                }

                vm_pageout_cluster(m);

                hibernate_stats.hibernate_found_dirty++;

                goto next_pg;

reenter_pg_on_q:
                vm_page_queue_remove(q, m, vmp_pageq);
                vm_page_queue_enter(q, m, vmp_pageq);

                hibernate_stats.hibernate_reentered_on_q++;
next_pg:
                hibernate_stats.hibernate_considered++;

                qcount--;
                try_failed_count = 0;
        }
        if (l_object != NULL) {
                vm_object_unlock(l_object);
                l_object = NULL;
        }

        vm_page_unlock_queues();

        KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 4) | DBG_FUNC_END, hibernate_stats.hibernate_found_dirty, retval, 0, 0, 0);

        return retval;
}


static int
hibernate_flush_dirty_pages(int pass)
{
        struct vm_speculative_age_q     *aq;
        uint32_t        i;

        if (vm_page_local_q) {
                for (i = 0; i < vm_page_local_q_count; i++) {
                        vm_page_reactivate_local(i, TRUE, FALSE);
                }
        }

        for (i = 0; i <= VM_PAGE_MAX_SPECULATIVE_AGE_Q; i++) {
                int             qcount;
                vm_page_t       m;

                aq = &vm_page_queue_speculative[i];

                if (vm_page_queue_empty(&aq->age_q)) {
                        continue;
                }
                qcount = 0;

                vm_page_lockspin_queues();

                vm_page_queue_iterate(&aq->age_q, m, vmp_pageq) {
                        qcount++;
                }
                vm_page_unlock_queues();

                if (qcount) {
                        if (hibernate_flush_queue(&aq->age_q, qcount)) {
                                return 1;
                        }
                }
        }
        if (hibernate_flush_queue(&vm_page_queue_inactive, vm_page_inactive_count - vm_page_anonymous_count - vm_page_cleaned_count)) {
                return 1;
        }
        /* XXX FBDP TODO: flush secluded queue */
        if (hibernate_flush_queue(&vm_page_queue_anonymous, vm_page_anonymous_count)) {
                return 1;
        }
        if (hibernate_flush_queue(&vm_page_queue_cleaned, vm_page_cleaned_count)) {
                return 1;
        }
        if (hibernate_drain_pageout_queue(&vm_pageout_queue_internal)) {
                return 1;
        }

        if (pass == 1) {
                vm_compressor_record_warmup_start();
        }

        if (hibernate_flush_queue(&vm_page_queue_active, vm_page_active_count)) {
                if (pass == 1) {
                        vm_compressor_record_warmup_end();
                }
                return 1;
        }
        if (hibernate_drain_pageout_queue(&vm_pageout_queue_internal)) {
                if (pass == 1) {
                        vm_compressor_record_warmup_end();
                }
                return 1;
        }
        if (pass == 1) {
                vm_compressor_record_warmup_end();
        }

        if (hibernate_skip_external == FALSE && hibernate_drain_pageout_queue(&vm_pageout_queue_external)) {
                return 1;
        }

        return 0;
}


void
hibernate_reset_stats()
{
        bzero(&hibernate_stats, sizeof(struct hibernate_statistics));
}


int
hibernate_flush_memory()
{
        int     retval;

        assert(VM_CONFIG_COMPRESSOR_IS_PRESENT);

        KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 3) | DBG_FUNC_START, vm_page_free_count, 0, 0, 0, 0);

        hibernate_cleaning_in_progress = TRUE;
        hibernate_skip_external = FALSE;

        if ((retval = hibernate_flush_dirty_pages(1)) == 0) {
                KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 10) | DBG_FUNC_START, VM_PAGE_COMPRESSOR_COUNT, 0, 0, 0, 0);

                vm_compressor_flush();

                KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 10) | DBG_FUNC_END, VM_PAGE_COMPRESSOR_COUNT, 0, 0, 0, 0);

                if (consider_buffer_cache_collect != NULL) {
                        unsigned int orig_wire_count;

                        KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 7) | DBG_FUNC_START, 0, 0, 0, 0, 0);
                        orig_wire_count = vm_page_wire_count;

                        (void)(*consider_buffer_cache_collect)(1);
                        consider_zone_gc(FALSE);

                        HIBLOG("hibernate_flush_memory: buffer_cache_gc freed up %d wired pages\n", orig_wire_count - vm_page_wire_count);

                        KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 7) | DBG_FUNC_END, orig_wire_count - vm_page_wire_count, 0, 0, 0, 0);
                }
        }
        hibernate_cleaning_in_progress = FALSE;

        KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 3) | DBG_FUNC_END, vm_page_free_count, hibernate_stats.hibernate_found_dirty, retval, 0, 0);

        if (retval) {
                HIBLOG("hibernate_flush_memory() failed to finish - vm_page_compressor_count(%d)\n", VM_PAGE_COMPRESSOR_COUNT);
        }


        HIBPRINT("hibernate_flush_memory() considered(%d) reentered_on_q(%d) found_dirty(%d)\n",
            hibernate_stats.hibernate_considered,
            hibernate_stats.hibernate_reentered_on_q,
            hibernate_stats.hibernate_found_dirty);
        HIBPRINT("   skipped_cleaning(%d) skipped_transient(%d) skipped_precious(%d) skipped_external(%d) queue_nolock(%d)\n",
            hibernate_stats.hibernate_skipped_cleaning,
            hibernate_stats.hibernate_skipped_transient,
            hibernate_stats.hibernate_skipped_precious,
            hibernate_stats.hibernate_skipped_external,
            hibernate_stats.hibernate_queue_nolock);
        HIBPRINT("   queue_paused(%d) throttled(%d) throttle_timeout(%d) drained(%d) drain_timeout(%d)\n",
            hibernate_stats.hibernate_queue_paused,
            hibernate_stats.hibernate_throttled,
            hibernate_stats.hibernate_throttle_timeout,
            hibernate_stats.hibernate_drained,
            hibernate_stats.hibernate_drain_timeout);

        return retval;
}


static void
hibernate_page_list_zero(hibernate_page_list_t *list)
{
        uint32_t             bank;
        hibernate_bitmap_t * bitmap;

        bitmap = &list->bank_bitmap[0];
        for (bank = 0; bank < list->bank_count; bank++) {
                uint32_t last_bit;

                bzero((void *) &bitmap->bitmap[0], bitmap->bitmapwords << 2);
                // set out-of-bound bits at end of bitmap.
                last_bit = ((bitmap->last_page - bitmap->first_page + 1) & 31);
                if (last_bit) {
                        bitmap->bitmap[bitmap->bitmapwords - 1] = (0xFFFFFFFF >> last_bit);
                }

                bitmap = (hibernate_bitmap_t *) &bitmap->bitmap[bitmap->bitmapwords];
        }
}

void
hibernate_free_gobble_pages(void)
{
        vm_page_t m, next;
        uint32_t  count = 0;

        m = (vm_page_t) hibernate_gobble_queue;
        while (m) {
                next = m->vmp_snext;
                vm_page_free(m);
                count++;
                m = next;
        }
        hibernate_gobble_queue = VM_PAGE_NULL;

        if (count) {
                HIBLOG("Freed %d pages\n", count);
        }
}

static boolean_t
hibernate_consider_discard(vm_page_t m, boolean_t preflight)
{
        vm_object_t object = NULL;
        int                  refmod_state;
        boolean_t            discard = FALSE;

        do{
                if (m->vmp_private) {
                        panic("hibernate_consider_discard: private");
                }

                object = VM_PAGE_OBJECT(m);

                if (!vm_object_lock_try(object)) {
                        object = NULL;
                        if (!preflight) {
                                hibernate_stats.cd_lock_failed++;
                        }
                        break;
                }
                if (VM_PAGE_WIRED(m)) {
                        if (!preflight) {
                                hibernate_stats.cd_found_wired++;
                        }
                        break;
                }
                if (m->vmp_precious) {
                        if (!preflight) {
                                hibernate_stats.cd_found_precious++;
                        }
                        break;
                }
                if (m->vmp_busy || !object->alive) {
                        /*
                         *      Somebody is playing with this page.
                         */
                        if (!preflight) {
                                hibernate_stats.cd_found_busy++;
                        }
                        break;
                }
                if (m->vmp_absent || m->vmp_unusual || m->vmp_error) {
                        /*
                         * If it's unusual in anyway, ignore it
                         */
                        if (!preflight) {
                                hibernate_stats.cd_found_unusual++;
                        }
                        break;
                }
                if (m->vmp_cleaning) {
                        if (!preflight) {
                                hibernate_stats.cd_found_cleaning++;
                        }
                        break;
                }
                if (m->vmp_laundry) {
                        if (!preflight) {
                                hibernate_stats.cd_found_laundry++;
                        }
                        break;
                }
                if (!m->vmp_dirty) {
                        refmod_state = pmap_get_refmod(VM_PAGE_GET_PHYS_PAGE(m));

                        if (refmod_state & VM_MEM_REFERENCED) {
                                m->vmp_reference = TRUE;
                        }
                        if (refmod_state & VM_MEM_MODIFIED) {
                                SET_PAGE_DIRTY(m, FALSE);
                        }
                }

                /*
                 * If it's clean or purgeable we can discard the page on wakeup.
                 */
                discard = (!m->vmp_dirty)
                    || (VM_PURGABLE_VOLATILE == object->purgable)
                    || (VM_PURGABLE_EMPTY == object->purgable);


                if (discard == FALSE) {
                        if (!preflight) {
                                hibernate_stats.cd_found_dirty++;
                        }
                } else if (m->vmp_xpmapped && m->vmp_reference && !object->internal) {
                        if (hibernate_stats.cd_found_xpmapped < HIBERNATE_XPMAPPED_LIMIT) {
                                if (!preflight) {
                                        hibernate_stats.cd_found_xpmapped++;
                                }
                                discard = FALSE;
                        } else {
                                if (!preflight) {
                                        hibernate_stats.cd_skipped_xpmapped++;
                                }
                        }
                }
        }while (FALSE);

        if (object) {
                vm_object_unlock(object);
        }

        return discard;
}


static void
hibernate_discard_page(vm_page_t m)
{
        vm_object_t m_object;

        if (m->vmp_absent || m->vmp_unusual || m->vmp_error) {
                /*
                 * If it's unusual in anyway, ignore
                 */
                return;
        }

        m_object = VM_PAGE_OBJECT(m);

#if MACH_ASSERT || DEBUG
        if (!vm_object_lock_try(m_object)) {
                panic("hibernate_discard_page(%p) !vm_object_lock_try", m);
        }
#else
        /* No need to lock page queue for token delete, hibernate_vm_unlock()
         *  makes sure these locks are uncontended before sleep */
#endif /* MACH_ASSERT || DEBUG */

        if (m->vmp_pmapped == TRUE) {
                __unused int refmod_state = pmap_disconnect(VM_PAGE_GET_PHYS_PAGE(m));
        }

        if (m->vmp_laundry) {
                panic("hibernate_discard_page(%p) laundry", m);
        }
        if (m->vmp_private) {
                panic("hibernate_discard_page(%p) private", m);
        }
        if (m->vmp_fictitious) {
                panic("hibernate_discard_page(%p) fictitious", m);
        }

        if (VM_PURGABLE_VOLATILE == m_object->purgable) {
                /* object should be on a queue */
                assert((m_object->objq.next != NULL) && (m_object->objq.prev != NULL));
                purgeable_q_t old_queue = vm_purgeable_object_remove(m_object);
                assert(old_queue);
                if (m_object->purgeable_when_ripe) {
                        vm_purgeable_token_delete_first(old_queue);
                }
                vm_object_lock_assert_exclusive(m_object);
                m_object->purgable = VM_PURGABLE_EMPTY;

                /*
                 * Purgeable ledgers:  pages of VOLATILE and EMPTY objects are
                 * accounted in the "volatile" ledger, so no change here.
                 * We have to update vm_page_purgeable_count, though, since we're
                 * effectively purging this object.
                 */
                unsigned int delta;
                assert(m_object->resident_page_count >= m_object->wired_page_count);
                delta = (m_object->resident_page_count - m_object->wired_page_count);
                assert(vm_page_purgeable_count >= delta);
                assert(delta > 0);
                OSAddAtomic(-delta, (SInt32 *)&vm_page_purgeable_count);
        }

        vm_page_free(m);

#if MACH_ASSERT || DEBUG
        vm_object_unlock(m_object);
#endif  /* MACH_ASSERT || DEBUG */
}

/*
 *  Grab locks for hibernate_page_list_setall()
 */
void
hibernate_vm_lock_queues(void)
{
        vm_object_lock(compressor_object);
        vm_page_lock_queues();
        lck_mtx_lock(&vm_page_queue_free_lock);
        lck_mtx_lock(&vm_purgeable_queue_lock);

        if (vm_page_local_q) {
                uint32_t  i;
                for (i = 0; i < vm_page_local_q_count; i++) {
                        struct vpl  *lq;
                        lq = &vm_page_local_q[i].vpl_un.vpl;
                        VPL_LOCK(&lq->vpl_lock);
                }
        }
}

void
hibernate_vm_unlock_queues(void)
{
        if (vm_page_local_q) {
                uint32_t  i;
                for (i = 0; i < vm_page_local_q_count; i++) {
                        struct vpl  *lq;
                        lq = &vm_page_local_q[i].vpl_un.vpl;
                        VPL_UNLOCK(&lq->vpl_lock);
                }
        }
        lck_mtx_unlock(&vm_purgeable_queue_lock);
        lck_mtx_unlock(&vm_page_queue_free_lock);
        vm_page_unlock_queues();
        vm_object_unlock(compressor_object);
}

/*
 *  Bits zero in the bitmaps => page needs to be saved. All pages default to be saved,
 *  pages known to VM to not need saving are subtracted.
 *  Wired pages to be saved are present in page_list_wired, pageable in page_list.
 */

void
hibernate_page_list_setall(hibernate_page_list_t * page_list,
    hibernate_page_list_t * page_list_wired,
    hibernate_page_list_t * page_list_pal,
    boolean_t preflight,
    boolean_t will_discard,
    uint32_t * pagesOut)
{
        uint64_t start, end, nsec;
        vm_page_t m;
        vm_page_t next;
        uint32_t pages = page_list->page_count;
        uint32_t count_anonymous = 0, count_throttled = 0, count_compressor = 0;
        uint32_t count_inactive = 0, count_active = 0, count_speculative = 0, count_cleaned = 0;
        uint32_t count_wire = pages;
        uint32_t count_discard_active    = 0;
        uint32_t count_discard_inactive  = 0;
        uint32_t count_discard_cleaned   = 0;
        uint32_t count_discard_purgeable = 0;
        uint32_t count_discard_speculative = 0;
        uint32_t count_discard_vm_struct_pages = 0;
        uint32_t i;
        uint32_t             bank;
        hibernate_bitmap_t * bitmap;
        hibernate_bitmap_t * bitmap_wired;
        boolean_t                    discard_all;
        boolean_t            discard;

        HIBLOG("hibernate_page_list_setall(preflight %d) start\n", preflight);

        if (preflight) {
                page_list       = NULL;
                page_list_wired = NULL;
                page_list_pal   = NULL;
                discard_all     = FALSE;
        } else {
                discard_all     = will_discard;
        }

#if MACH_ASSERT || DEBUG
        if (!preflight) {
                assert(hibernate_vm_locks_are_safe());
                vm_page_lock_queues();
                if (vm_page_local_q) {
                        for (i = 0; i < vm_page_local_q_count; i++) {
                                struct vpl      *lq;
                                lq = &vm_page_local_q[i].vpl_un.vpl;
                                VPL_LOCK(&lq->vpl_lock);
                        }
                }
        }
#endif  /* MACH_ASSERT || DEBUG */


        KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 8) | DBG_FUNC_START, count_wire, 0, 0, 0, 0);

        clock_get_uptime(&start);

        if (!preflight) {
                hibernate_page_list_zero(page_list);
                hibernate_page_list_zero(page_list_wired);
                hibernate_page_list_zero(page_list_pal);

                hibernate_stats.cd_vm_page_wire_count = vm_page_wire_count;
                hibernate_stats.cd_pages = pages;
        }

        if (vm_page_local_q) {
                for (i = 0; i < vm_page_local_q_count; i++) {
                        vm_page_reactivate_local(i, TRUE, !preflight);
                }
        }

        if (preflight) {
                vm_object_lock(compressor_object);
                vm_page_lock_queues();
                lck_mtx_lock(&vm_page_queue_free_lock);
        }

        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);

        hibernation_vmqueues_inspection = TRUE;

        m = (vm_page_t) hibernate_gobble_queue;
        while (m) {
                pages--;
                count_wire--;
                if (!preflight) {
                        hibernate_page_bitset(page_list, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                        hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                }
                m = m->vmp_snext;
        }

        if (!preflight) {
                for (i = 0; i < real_ncpus; i++) {
                        if (cpu_data_ptr[i] && cpu_data_ptr[i]->cpu_processor) {
                                for (m = PROCESSOR_DATA(cpu_data_ptr[i]->cpu_processor, free_pages); m; m = m->vmp_snext) {
                                        assert(m->vmp_q_state == VM_PAGE_ON_FREE_LOCAL_Q);

                                        pages--;
                                        count_wire--;
                                        hibernate_page_bitset(page_list, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                                        hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));

                                        hibernate_stats.cd_local_free++;
                                        hibernate_stats.cd_total_free++;
                                }
                        }
                }
        }

        for (i = 0; i < vm_colors; i++) {
                vm_page_queue_iterate(&vm_page_queue_free[i].qhead, m, vmp_pageq) {
                        assert(m->vmp_q_state == VM_PAGE_ON_FREE_Q);

                        pages--;
                        count_wire--;
                        if (!preflight) {
                                hibernate_page_bitset(page_list, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                                hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));

                                hibernate_stats.cd_total_free++;
                        }
                }
        }

        vm_page_queue_iterate(&vm_lopage_queue_free, m, vmp_pageq) {
                assert(m->vmp_q_state == VM_PAGE_ON_FREE_LOPAGE_Q);

                pages--;
                count_wire--;
                if (!preflight) {
                        hibernate_page_bitset(page_list, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                        hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));

                        hibernate_stats.cd_total_free++;
                }
        }

        m = (vm_page_t) vm_page_queue_first(&vm_page_queue_throttled);
        while (m && !vm_page_queue_end(&vm_page_queue_throttled, (vm_page_queue_entry_t)m)) {
                assert(m->vmp_q_state == VM_PAGE_ON_THROTTLED_Q);

                next = (vm_page_t)VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                discard = FALSE;
                if ((kIOHibernateModeDiscardCleanInactive & gIOHibernateMode)
                    && hibernate_consider_discard(m, preflight)) {
                        if (!preflight) {
                                hibernate_page_bitset(page_list, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                        }
                        count_discard_inactive++;
                        discard = discard_all;
                } else {
                        count_throttled++;
                }
                count_wire--;
                if (!preflight) {
                        hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                }

                if (discard) {
                        hibernate_discard_page(m);
                }
                m = next;
        }

        m = (vm_page_t)vm_page_queue_first(&vm_page_queue_anonymous);
        while (m && !vm_page_queue_end(&vm_page_queue_anonymous, (vm_page_queue_entry_t)m)) {
                assert(m->vmp_q_state == VM_PAGE_ON_INACTIVE_INTERNAL_Q);

                next = (vm_page_t)VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                discard = FALSE;
                if ((kIOHibernateModeDiscardCleanInactive & gIOHibernateMode) &&
                    hibernate_consider_discard(m, preflight)) {
                        if (!preflight) {
                                hibernate_page_bitset(page_list, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                        }
                        if (m->vmp_dirty) {
                                count_discard_purgeable++;
                        } else {
                                count_discard_inactive++;
                        }
                        discard = discard_all;
                } else {
                        count_anonymous++;
                }
                count_wire--;
                if (!preflight) {
                        hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                }
                if (discard) {
                        hibernate_discard_page(m);
                }
                m = next;
        }

        m = (vm_page_t) vm_page_queue_first(&vm_page_queue_cleaned);
        while (m && !vm_page_queue_end(&vm_page_queue_cleaned, (vm_page_queue_entry_t)m)) {
                assert(m->vmp_q_state == VM_PAGE_ON_INACTIVE_CLEANED_Q);

                next = (vm_page_t)VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                discard = FALSE;
                if ((kIOHibernateModeDiscardCleanInactive & gIOHibernateMode) &&
                    hibernate_consider_discard(m, preflight)) {
                        if (!preflight) {
                                hibernate_page_bitset(page_list, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                        }
                        if (m->vmp_dirty) {
                                count_discard_purgeable++;
                        } else {
                                count_discard_cleaned++;
                        }
                        discard = discard_all;
                } else {
                        count_cleaned++;
                }
                count_wire--;
                if (!preflight) {
                        hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                }
                if (discard) {
                        hibernate_discard_page(m);
                }
                m = next;
        }

        m = (vm_page_t) vm_page_queue_first(&vm_page_queue_active);
        while (m && !vm_page_queue_end(&vm_page_queue_active, (vm_page_queue_entry_t)m)) {
                assert(m->vmp_q_state == VM_PAGE_ON_ACTIVE_Q);

                next = (vm_page_t)VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                discard = FALSE;
                if ((kIOHibernateModeDiscardCleanActive & gIOHibernateMode) &&
                    hibernate_consider_discard(m, preflight)) {
                        if (!preflight) {
                                hibernate_page_bitset(page_list, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                        }
                        if (m->vmp_dirty) {
                                count_discard_purgeable++;
                        } else {
                                count_discard_active++;
                        }
                        discard = discard_all;
                } else {
                        count_active++;
                }
                count_wire--;
                if (!preflight) {
                        hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                }
                if (discard) {
                        hibernate_discard_page(m);
                }
                m = next;
        }

        m = (vm_page_t) vm_page_queue_first(&vm_page_queue_inactive);
        while (m && !vm_page_queue_end(&vm_page_queue_inactive, (vm_page_queue_entry_t)m)) {
                assert(m->vmp_q_state == VM_PAGE_ON_INACTIVE_EXTERNAL_Q);

                next = (vm_page_t)VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                discard = FALSE;
                if ((kIOHibernateModeDiscardCleanInactive & gIOHibernateMode) &&
                    hibernate_consider_discard(m, preflight)) {
                        if (!preflight) {
                                hibernate_page_bitset(page_list, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                        }
                        if (m->vmp_dirty) {
                                count_discard_purgeable++;
                        } else {
                                count_discard_inactive++;
                        }
                        discard = discard_all;
                } else {
                        count_inactive++;
                }
                count_wire--;
                if (!preflight) {
                        hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                }
                if (discard) {
                        hibernate_discard_page(m);
                }
                m = next;
        }
        /* XXX FBDP TODO: secluded queue */

        for (i = 0; i <= VM_PAGE_MAX_SPECULATIVE_AGE_Q; i++) {
                m = (vm_page_t) vm_page_queue_first(&vm_page_queue_speculative[i].age_q);
                while (m && !vm_page_queue_end(&vm_page_queue_speculative[i].age_q, (vm_page_queue_entry_t)m)) {
                        assertf(m->vmp_q_state == VM_PAGE_ON_SPECULATIVE_Q,
                            "Bad page: %p (0x%x:0x%x) on queue %d has state: %d (Discard: %d, Preflight: %d)",
                            m, m->vmp_pageq.next, m->vmp_pageq.prev, i, m->vmp_q_state, discard, preflight);

                        next = (vm_page_t)VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                        discard = FALSE;
                        if ((kIOHibernateModeDiscardCleanInactive & gIOHibernateMode) &&
                            hibernate_consider_discard(m, preflight)) {
                                if (!preflight) {
                                        hibernate_page_bitset(page_list, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                                }
                                count_discard_speculative++;
                                discard = discard_all;
                        } else {
                                count_speculative++;
                        }
                        count_wire--;
                        if (!preflight) {
                                hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                        }
                        if (discard) {
                                hibernate_discard_page(m);
                        }
                        m = next;
                }
        }

        vm_page_queue_iterate(&compressor_object->memq, m, vmp_listq) {
                assert(m->vmp_q_state == VM_PAGE_USED_BY_COMPRESSOR);

                count_compressor++;
                count_wire--;
                if (!preflight) {
                        hibernate_page_bitset(page_list_wired, TRUE, VM_PAGE_GET_PHYS_PAGE(m));
                }
        }

        if (preflight == FALSE && discard_all == TRUE) {
                KDBG(IOKDBG_CODE(DBG_HIBERNATE, 12) | DBG_FUNC_START);

                HIBLOG("hibernate_teardown started\n");
                count_discard_vm_struct_pages = hibernate_teardown_vm_structs(page_list, page_list_wired);
                HIBLOG("hibernate_teardown completed - discarded %d\n", count_discard_vm_struct_pages);

                pages -= count_discard_vm_struct_pages;
                count_wire -= count_discard_vm_struct_pages;

                hibernate_stats.cd_vm_struct_pages_unneeded = count_discard_vm_struct_pages;

                KDBG(IOKDBG_CODE(DBG_HIBERNATE, 12) | DBG_FUNC_END);
        }

        if (!preflight) {
                // pull wired from hibernate_bitmap
                bitmap = &page_list->bank_bitmap[0];
                bitmap_wired = &page_list_wired->bank_bitmap[0];
                for (bank = 0; bank < page_list->bank_count; bank++) {
                        for (i = 0; i < bitmap->bitmapwords; i++) {
                                bitmap->bitmap[i] = bitmap->bitmap[i] | ~bitmap_wired->bitmap[i];
                        }
                        bitmap = (hibernate_bitmap_t *)&bitmap->bitmap[bitmap->bitmapwords];
                        bitmap_wired = (hibernate_bitmap_t *) &bitmap_wired->bitmap[bitmap_wired->bitmapwords];
                }
        }

        // machine dependent adjustments
        hibernate_page_list_setall_machine(page_list, page_list_wired, preflight, &pages);

        if (!preflight) {
                hibernate_stats.cd_count_wire = count_wire;
                hibernate_stats.cd_discarded = count_discard_active + count_discard_inactive + count_discard_purgeable +
                    count_discard_speculative + count_discard_cleaned + count_discard_vm_struct_pages;
        }

        clock_get_uptime(&end);
        absolutetime_to_nanoseconds(end - start, &nsec);
        HIBLOG("hibernate_page_list_setall time: %qd ms\n", nsec / 1000000ULL);

        HIBLOG("pages %d, wire %d, act %d, inact %d, cleaned %d spec %d, zf %d, throt %d, compr %d, xpmapped %d\n  %s discard act %d inact %d purgeable %d spec %d cleaned %d\n",
            pages, count_wire, count_active, count_inactive, count_cleaned, count_speculative, count_anonymous, count_throttled, count_compressor, hibernate_stats.cd_found_xpmapped,
            discard_all ? "did" : "could",
            count_discard_active, count_discard_inactive, count_discard_purgeable, count_discard_speculative, count_discard_cleaned);

        if (hibernate_stats.cd_skipped_xpmapped) {
                HIBLOG("WARNING: hibernate_page_list_setall skipped %d xpmapped pages\n", hibernate_stats.cd_skipped_xpmapped);
        }

        *pagesOut = pages - count_discard_active - count_discard_inactive - count_discard_purgeable - count_discard_speculative - count_discard_cleaned;

        if (preflight && will_discard) {
                *pagesOut -= count_compressor + count_throttled + count_anonymous + count_inactive + count_cleaned + count_speculative + count_active;
        }

        hibernation_vmqueues_inspection = FALSE;

#if MACH_ASSERT || DEBUG
        if (!preflight) {
                if (vm_page_local_q) {
                        for (i = 0; i < vm_page_local_q_count; i++) {
                                struct vpl      *lq;
                                lq = &vm_page_local_q[i].vpl_un.vpl;
                                VPL_UNLOCK(&lq->vpl_lock);
                        }
                }
                vm_page_unlock_queues();
        }
#endif  /* MACH_ASSERT || DEBUG */

        if (preflight) {
                lck_mtx_unlock(&vm_page_queue_free_lock);
                vm_page_unlock_queues();
                vm_object_unlock(compressor_object);
        }

        KERNEL_DEBUG_CONSTANT(IOKDBG_CODE(DBG_HIBERNATE, 8) | DBG_FUNC_END, count_wire, *pagesOut, 0, 0, 0);
}

void
hibernate_page_list_discard(hibernate_page_list_t * page_list)
{
        uint64_t  start, end, nsec;
        vm_page_t m;
        vm_page_t next;
        uint32_t  i;
        uint32_t  count_discard_active    = 0;
        uint32_t  count_discard_inactive  = 0;
        uint32_t  count_discard_purgeable = 0;
        uint32_t  count_discard_cleaned   = 0;
        uint32_t  count_discard_speculative = 0;


#if MACH_ASSERT || DEBUG
        vm_page_lock_queues();
        if (vm_page_local_q) {
                for (i = 0; i < vm_page_local_q_count; i++) {
                        struct vpl      *lq;
                        lq = &vm_page_local_q[i].vpl_un.vpl;
                        VPL_LOCK(&lq->vpl_lock);
                }
        }
#endif  /* MACH_ASSERT || DEBUG */

        clock_get_uptime(&start);

        m = (vm_page_t) vm_page_queue_first(&vm_page_queue_anonymous);
        while (m && !vm_page_queue_end(&vm_page_queue_anonymous, (vm_page_queue_entry_t)m)) {
                assert(m->vmp_q_state == VM_PAGE_ON_INACTIVE_INTERNAL_Q);

                next = (vm_page_t) VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                if (hibernate_page_bittst(page_list, VM_PAGE_GET_PHYS_PAGE(m))) {
                        if (m->vmp_dirty) {
                                count_discard_purgeable++;
                        } else {
                                count_discard_inactive++;
                        }
                        hibernate_discard_page(m);
                }
                m = next;
        }

        for (i = 0; i <= VM_PAGE_MAX_SPECULATIVE_AGE_Q; i++) {
                m = (vm_page_t) vm_page_queue_first(&vm_page_queue_speculative[i].age_q);
                while (m && !vm_page_queue_end(&vm_page_queue_speculative[i].age_q, (vm_page_queue_entry_t)m)) {
                        assert(m->vmp_q_state == VM_PAGE_ON_SPECULATIVE_Q);

                        next = (vm_page_t) VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                        if (hibernate_page_bittst(page_list, VM_PAGE_GET_PHYS_PAGE(m))) {
                                count_discard_speculative++;
                                hibernate_discard_page(m);
                        }
                        m = next;
                }
        }

        m = (vm_page_t) vm_page_queue_first(&vm_page_queue_inactive);
        while (m && !vm_page_queue_end(&vm_page_queue_inactive, (vm_page_queue_entry_t)m)) {
                assert(m->vmp_q_state == VM_PAGE_ON_INACTIVE_EXTERNAL_Q);

                next = (vm_page_t) VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                if (hibernate_page_bittst(page_list, VM_PAGE_GET_PHYS_PAGE(m))) {
                        if (m->vmp_dirty) {
                                count_discard_purgeable++;
                        } else {
                                count_discard_inactive++;
                        }
                        hibernate_discard_page(m);
                }
                m = next;
        }
        /* XXX FBDP TODO: secluded queue */

        m = (vm_page_t) vm_page_queue_first(&vm_page_queue_active);
        while (m && !vm_page_queue_end(&vm_page_queue_active, (vm_page_queue_entry_t)m)) {
                assert(m->vmp_q_state == VM_PAGE_ON_ACTIVE_Q);

                next = (vm_page_t) VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                if (hibernate_page_bittst(page_list, VM_PAGE_GET_PHYS_PAGE(m))) {
                        if (m->vmp_dirty) {
                                count_discard_purgeable++;
                        } else {
                                count_discard_active++;
                        }
                        hibernate_discard_page(m);
                }
                m = next;
        }

        m = (vm_page_t) vm_page_queue_first(&vm_page_queue_cleaned);
        while (m && !vm_page_queue_end(&vm_page_queue_cleaned, (vm_page_queue_entry_t)m)) {
                assert(m->vmp_q_state == VM_PAGE_ON_INACTIVE_CLEANED_Q);

                next = (vm_page_t) VM_PAGE_UNPACK_PTR(m->vmp_pageq.next);
                if (hibernate_page_bittst(page_list, VM_PAGE_GET_PHYS_PAGE(m))) {
                        if (m->vmp_dirty) {
                                count_discard_purgeable++;
                        } else {
                                count_discard_cleaned++;
                        }
                        hibernate_discard_page(m);
                }
                m = next;
        }

#if MACH_ASSERT || DEBUG
        if (vm_page_local_q) {
                for (i = 0; i < vm_page_local_q_count; i++) {
                        struct vpl      *lq;
                        lq = &vm_page_local_q[i].vpl_un.vpl;
                        VPL_UNLOCK(&lq->vpl_lock);
                }
        }
        vm_page_unlock_queues();
#endif  /* MACH_ASSERT || DEBUG */

        clock_get_uptime(&end);
        absolutetime_to_nanoseconds(end - start, &nsec);
        HIBLOG("hibernate_page_list_discard time: %qd ms, discarded act %d inact %d purgeable %d spec %d cleaned %d\n",
            nsec / 1000000ULL,
            count_discard_active, count_discard_inactive, count_discard_purgeable, count_discard_speculative, count_discard_cleaned);
}

boolean_t       hibernate_paddr_map_inited = FALSE;
unsigned int    hibernate_teardown_last_valid_compact_indx = -1;
vm_page_t       hibernate_rebuild_hash_list = NULL;

unsigned int    hibernate_teardown_found_tabled_pages = 0;
unsigned int    hibernate_teardown_found_created_pages = 0;
unsigned int    hibernate_teardown_found_free_pages = 0;
unsigned int    hibernate_teardown_vm_page_free_count;


struct ppnum_mapping {
        struct ppnum_mapping    *ppnm_next;
        ppnum_t                 ppnm_base_paddr;
        unsigned int            ppnm_sindx;
        unsigned int            ppnm_eindx;
};

struct ppnum_mapping    *ppnm_head;
struct ppnum_mapping    *ppnm_last_found = NULL;


void
hibernate_create_paddr_map()
{
        unsigned int    i;
        ppnum_t         next_ppnum_in_run = 0;
        struct ppnum_mapping *ppnm = NULL;

        if (hibernate_paddr_map_inited == FALSE) {
                for (i = 0; i < vm_pages_count; i++) {
                        if (ppnm) {
                                ppnm->ppnm_eindx = i;
                        }

                        if (ppnm == NULL || VM_PAGE_GET_PHYS_PAGE(&vm_pages[i]) != next_ppnum_in_run) {
                                ppnm = kalloc(sizeof(struct ppnum_mapping));

                                ppnm->ppnm_next = ppnm_head;
                                ppnm_head = ppnm;

                                ppnm->ppnm_sindx = i;
                                ppnm->ppnm_base_paddr = VM_PAGE_GET_PHYS_PAGE(&vm_pages[i]);
                        }
                        next_ppnum_in_run = VM_PAGE_GET_PHYS_PAGE(&vm_pages[i]) + 1;
                }
                ppnm->ppnm_eindx++;

                hibernate_paddr_map_inited = TRUE;
        }
}

ppnum_t
hibernate_lookup_paddr(unsigned int indx)
{
        struct ppnum_mapping *ppnm = NULL;

        ppnm = ppnm_last_found;

        if (ppnm) {
                if (indx >= ppnm->ppnm_sindx && indx < ppnm->ppnm_eindx) {
                        goto done;
                }
        }
        for (ppnm = ppnm_head; ppnm; ppnm = ppnm->ppnm_next) {
                if (indx >= ppnm->ppnm_sindx && indx < ppnm->ppnm_eindx) {
                        ppnm_last_found = ppnm;
                        break;
                }
        }
        if (ppnm == NULL) {
                panic("hibernate_lookup_paddr of %d failed\n", indx);
        }
done:
        return ppnm->ppnm_base_paddr + (indx - ppnm->ppnm_sindx);
}


uint32_t
hibernate_mark_as_unneeded(addr64_t saddr, addr64_t eaddr, hibernate_page_list_t *page_list, hibernate_page_list_t *page_list_wired)
{
        addr64_t        saddr_aligned;
        addr64_t        eaddr_aligned;
        addr64_t        addr;
        ppnum_t         paddr;
        unsigned int    mark_as_unneeded_pages = 0;

        saddr_aligned = (saddr + PAGE_MASK_64) & ~PAGE_MASK_64;
        eaddr_aligned = eaddr & ~PAGE_MASK_64;

        for (addr = saddr_aligned; addr < eaddr_aligned; addr += PAGE_SIZE_64) {
                paddr = pmap_find_phys(kernel_pmap, addr);

                assert(paddr);

                hibernate_page_bitset(page_list, TRUE, paddr);
                hibernate_page_bitset(page_list_wired, TRUE, paddr);

                mark_as_unneeded_pages++;
        }
        return mark_as_unneeded_pages;
}


void
hibernate_hash_insert_page(vm_page_t mem)
{
        vm_page_bucket_t *bucket;
        int             hash_id;
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(mem);

        assert(mem->vmp_hashed);
        assert(m_object);
        assert(mem->vmp_offset != (vm_object_offset_t) -1);

        /*
         *      Insert it into the object_object/offset hash table
         */
        hash_id = vm_page_hash(m_object, mem->vmp_offset);
        bucket = &vm_page_buckets[hash_id];

        mem->vmp_next_m = bucket->page_list;
        bucket->page_list = VM_PAGE_PACK_PTR(mem);
}


void
hibernate_free_range(int sindx, int eindx)
{
        vm_page_t       mem;
        unsigned int    color;

        while (sindx < eindx) {
                mem = &vm_pages[sindx];

                vm_page_init(mem, hibernate_lookup_paddr(sindx), FALSE);

                mem->vmp_lopage = FALSE;
                mem->vmp_q_state = VM_PAGE_ON_FREE_Q;

                color = VM_PAGE_GET_COLOR(mem);
#if defined(__x86_64__)
                vm_page_queue_enter_clump(&vm_page_queue_free[color].qhead, mem);
#else
                vm_page_queue_enter(&vm_page_queue_free[color].qhead, mem, vmp_pageq);
#endif
                vm_page_free_count++;

                sindx++;
        }
}


extern void hibernate_rebuild_pmap_structs(void);

void
hibernate_rebuild_vm_structs(void)
{
        int             i, cindx, sindx, eindx;
        vm_page_t       mem, tmem, mem_next;
        AbsoluteTime    startTime, endTime;
        uint64_t        nsec;

        if (hibernate_rebuild_needed == FALSE) {
                return;
        }

        KDBG(IOKDBG_CODE(DBG_HIBERNATE, 13) | DBG_FUNC_START);
        HIBLOG("hibernate_rebuild started\n");

        clock_get_uptime(&startTime);

        hibernate_rebuild_pmap_structs();

        bzero(&vm_page_buckets[0], vm_page_bucket_count * sizeof(vm_page_bucket_t));
        eindx = vm_pages_count;

        /*
         * Mark all the vm_pages[] that have not been initialized yet as being
         * transient. This is needed to ensure that buddy page search is corrrect.
         * Without this random data in these vm_pages[] can trip the buddy search
         */
        for (i = hibernate_teardown_last_valid_compact_indx + 1; i < eindx; ++i) {
                vm_pages[i].vmp_q_state = VM_PAGE_NOT_ON_Q;
        }

        for (cindx = hibernate_teardown_last_valid_compact_indx; cindx >= 0; cindx--) {
                mem = &vm_pages[cindx];
                assert(mem->vmp_q_state != VM_PAGE_ON_FREE_Q);
                /*
                 * hibernate_teardown_vm_structs leaves the location where
                 * this vm_page_t must be located in "next".
                 */
                tmem = (vm_page_t)(VM_PAGE_UNPACK_PTR(mem->vmp_next_m));
                mem->vmp_next_m = VM_PAGE_PACK_PTR(NULL);

                sindx = (int)(tmem - &vm_pages[0]);

                if (mem != tmem) {
                        /*
                         * this vm_page_t was moved by hibernate_teardown_vm_structs,
                         * so move it back to its real location
                         */
                        *tmem = *mem;
                        mem = tmem;
                }
                if (mem->vmp_hashed) {
                        hibernate_hash_insert_page(mem);
                }
                /*
                 * the 'hole' between this vm_page_t and the previous
                 * vm_page_t we moved needs to be initialized as
                 * a range of free vm_page_t's
                 */
                hibernate_free_range(sindx + 1, eindx);

                eindx = sindx;
        }
        if (sindx) {
                hibernate_free_range(0, sindx);
        }

        assert(vm_page_free_count == hibernate_teardown_vm_page_free_count);

        /*
         * process the list of vm_page_t's that were entered in the hash,
         * but were not located in the vm_pages arrary... these are
         * vm_page_t's that were created on the fly (i.e. fictitious)
         */
        for (mem = hibernate_rebuild_hash_list; mem; mem = mem_next) {
                mem_next = (vm_page_t)(VM_PAGE_UNPACK_PTR(mem->vmp_next_m));

                mem->vmp_next_m = 0;
                hibernate_hash_insert_page(mem);
        }
        hibernate_rebuild_hash_list = NULL;

        clock_get_uptime(&endTime);
        SUB_ABSOLUTETIME(&endTime, &startTime);
        absolutetime_to_nanoseconds(endTime, &nsec);

        HIBLOG("hibernate_rebuild completed - took %qd msecs\n", nsec / 1000000ULL);

        hibernate_rebuild_needed = FALSE;

        KDBG(IOKDBG_CODE(DBG_HIBERNATE, 13) | DBG_FUNC_END);
}


extern void hibernate_teardown_pmap_structs(addr64_t *, addr64_t *);

uint32_t
hibernate_teardown_vm_structs(hibernate_page_list_t *page_list, hibernate_page_list_t *page_list_wired)
{
        unsigned int    i;
        unsigned int    compact_target_indx;
        vm_page_t       mem, mem_next;
        vm_page_bucket_t *bucket;
        unsigned int    mark_as_unneeded_pages = 0;
        unsigned int    unneeded_vm_page_bucket_pages = 0;
        unsigned int    unneeded_vm_pages_pages = 0;
        unsigned int    unneeded_pmap_pages = 0;
        addr64_t        start_of_unneeded = 0;
        addr64_t        end_of_unneeded = 0;


        if (hibernate_should_abort()) {
                return 0;
        }

        hibernate_rebuild_needed = TRUE;

        HIBLOG("hibernate_teardown: wired_pages %d, free_pages %d, active_pages %d, inactive_pages %d, speculative_pages %d, cleaned_pages %d, compressor_pages %d\n",
            vm_page_wire_count, vm_page_free_count, vm_page_active_count, vm_page_inactive_count, vm_page_speculative_count,
            vm_page_cleaned_count, compressor_object->resident_page_count);

        for (i = 0; i < vm_page_bucket_count; i++) {
                bucket = &vm_page_buckets[i];

                for (mem = (vm_page_t)(VM_PAGE_UNPACK_PTR(bucket->page_list)); mem != VM_PAGE_NULL; mem = mem_next) {
                        assert(mem->vmp_hashed);

                        mem_next = (vm_page_t)(VM_PAGE_UNPACK_PTR(mem->vmp_next_m));

                        if (mem < &vm_pages[0] || mem >= &vm_pages[vm_pages_count]) {
                                mem->vmp_next_m = VM_PAGE_PACK_PTR(hibernate_rebuild_hash_list);
                                hibernate_rebuild_hash_list = mem;
                        }
                }
        }
        unneeded_vm_page_bucket_pages = hibernate_mark_as_unneeded((addr64_t)&vm_page_buckets[0], (addr64_t)&vm_page_buckets[vm_page_bucket_count], page_list, page_list_wired);
        mark_as_unneeded_pages += unneeded_vm_page_bucket_pages;

        hibernate_teardown_vm_page_free_count = vm_page_free_count;

        compact_target_indx = 0;

        for (i = 0; i < vm_pages_count; i++) {
                mem = &vm_pages[i];

                if (mem->vmp_q_state == VM_PAGE_ON_FREE_Q) {
                        unsigned int color;

                        assert(mem->vmp_busy);
                        assert(!mem->vmp_lopage);

                        color = VM_PAGE_GET_COLOR(mem);

                        vm_page_queue_remove(&vm_page_queue_free[color].qhead, mem, vmp_pageq);

                        VM_PAGE_ZERO_PAGEQ_ENTRY(mem);

                        vm_page_free_count--;

                        hibernate_teardown_found_free_pages++;

                        if (vm_pages[compact_target_indx].vmp_q_state != VM_PAGE_ON_FREE_Q) {
                                compact_target_indx = i;
                        }
                } else {
                        /*
                         * record this vm_page_t's original location
                         * we need this even if it doesn't get moved
                         * as an indicator to the rebuild function that
                         * we don't have to move it
                         */
                        mem->vmp_next_m = VM_PAGE_PACK_PTR(mem);

                        if (vm_pages[compact_target_indx].vmp_q_state == VM_PAGE_ON_FREE_Q) {
                                /*
                                 * we've got a hole to fill, so
                                 * move this vm_page_t to it's new home
                                 */
                                vm_pages[compact_target_indx] = *mem;
                                mem->vmp_q_state = VM_PAGE_ON_FREE_Q;

                                hibernate_teardown_last_valid_compact_indx = compact_target_indx;
                                compact_target_indx++;
                        } else {
                                hibernate_teardown_last_valid_compact_indx = i;
                        }
                }
        }
        unneeded_vm_pages_pages = hibernate_mark_as_unneeded((addr64_t)&vm_pages[hibernate_teardown_last_valid_compact_indx + 1],
            (addr64_t)&vm_pages[vm_pages_count - 1], page_list, page_list_wired);
        mark_as_unneeded_pages += unneeded_vm_pages_pages;

        hibernate_teardown_pmap_structs(&start_of_unneeded, &end_of_unneeded);

        if (start_of_unneeded) {
                unneeded_pmap_pages = hibernate_mark_as_unneeded(start_of_unneeded, end_of_unneeded, page_list, page_list_wired);
                mark_as_unneeded_pages += unneeded_pmap_pages;
        }
        HIBLOG("hibernate_teardown: mark_as_unneeded_pages %d, %d, %d\n", unneeded_vm_page_bucket_pages, unneeded_vm_pages_pages, unneeded_pmap_pages);

        return mark_as_unneeded_pages;
}


#endif /* HIBERNATION */

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include <mach_vm_debug.h>
#if     MACH_VM_DEBUG

#include <mach_debug/hash_info.h>
#include <vm/vm_debug.h>

/*
 *      Routine:        vm_page_info
 *      Purpose:
 *              Return information about the global VP table.
 *              Fills the buffer with as much information as possible
 *              and returns the desired size of the buffer.
 *      Conditions:
 *              Nothing locked.  The caller should provide
 *              possibly-pageable memory.
 */

unsigned int
vm_page_info(
        hash_info_bucket_t *info,
        unsigned int count)
{
        unsigned int i;
        lck_spin_t      *bucket_lock;

        if (vm_page_bucket_count < count) {
                count = vm_page_bucket_count;
        }

        for (i = 0; i < count; i++) {
                vm_page_bucket_t *bucket = &vm_page_buckets[i];
                unsigned int bucket_count = 0;
                vm_page_t m;

                bucket_lock = &vm_page_bucket_locks[i / BUCKETS_PER_LOCK];
                lck_spin_lock_grp(bucket_lock, &vm_page_lck_grp_bucket);

                for (m = (vm_page_t)(VM_PAGE_UNPACK_PTR(bucket->page_list));
                    m != VM_PAGE_NULL;
                    m = (vm_page_t)(VM_PAGE_UNPACK_PTR(m->vmp_next_m))) {
                        bucket_count++;
                }

                lck_spin_unlock(bucket_lock);

                /* don't touch pageable memory while holding locks */
                info[i].hib_count = bucket_count;
        }

        return vm_page_bucket_count;
}
#endif  /* MACH_VM_DEBUG */

#if VM_PAGE_BUCKETS_CHECK
void
vm_page_buckets_check(void)
{
        unsigned int i;
        vm_page_t p;
        unsigned int p_hash;
        vm_page_bucket_t *bucket;
        lck_spin_t      *bucket_lock;

        if (!vm_page_buckets_check_ready) {
                return;
        }

#if HIBERNATION
        if (hibernate_rebuild_needed ||
            hibernate_rebuild_hash_list) {
                panic("BUCKET_CHECK: hibernation in progress: "
                    "rebuild_needed=%d rebuild_hash_list=%p\n",
                    hibernate_rebuild_needed,
                    hibernate_rebuild_hash_list);
        }
#endif /* HIBERNATION */

#if VM_PAGE_FAKE_BUCKETS
        char *cp;
        for (cp = (char *) vm_page_fake_buckets_start;
            cp < (char *) vm_page_fake_buckets_end;
            cp++) {
                if (*cp != 0x5a) {
                        panic("BUCKET_CHECK: corruption at %p in fake buckets "
                            "[0x%llx:0x%llx]\n",
                            cp,
                            (uint64_t) vm_page_fake_buckets_start,
                            (uint64_t) vm_page_fake_buckets_end);
                }
        }
#endif /* VM_PAGE_FAKE_BUCKETS */

        for (i = 0; i < vm_page_bucket_count; i++) {
                vm_object_t     p_object;

                bucket = &vm_page_buckets[i];
                if (!bucket->page_list) {
                        continue;
                }

                bucket_lock = &vm_page_bucket_locks[i / BUCKETS_PER_LOCK];
                lck_spin_lock_grp(bucket_lock, &vm_page_lck_grp_bucket);
                p = (vm_page_t)(VM_PAGE_UNPACK_PTR(bucket->page_list));

                while (p != VM_PAGE_NULL) {
                        p_object = VM_PAGE_OBJECT(p);

                        if (!p->vmp_hashed) {
                                panic("BUCKET_CHECK: page %p (%p,0x%llx) "
                                    "hash %d in bucket %d at %p "
                                    "is not hashed\n",
                                    p, p_object, p->vmp_offset,
                                    p_hash, i, bucket);
                        }
                        p_hash = vm_page_hash(p_object, p->vmp_offset);
                        if (p_hash != i) {
                                panic("BUCKET_CHECK: corruption in bucket %d "
                                    "at %p: page %p object %p offset 0x%llx "
                                    "hash %d\n",
                                    i, bucket, p, p_object, p->vmp_offset,
                                    p_hash);
                        }
                        p = (vm_page_t)(VM_PAGE_UNPACK_PTR(p->vmp_next_m));
                }
                lck_spin_unlock(bucket_lock);
        }

//      printf("BUCKET_CHECK: checked buckets\n");
}
#endif /* VM_PAGE_BUCKETS_CHECK */

/*
 * 'vm_fault_enter' will place newly created pages (zero-fill and COW) onto the
 * local queues if they exist... its the only spot in the system where we add pages
 * to those queues...  once on those queues, those pages can only move to one of the
 * global page queues or the free queues... they NEVER move from local q to local q.
 * the 'local' state is stable when vm_page_queues_remove is called since we're behind
 * the global vm_page_queue_lock at this point...  we still need to take the local lock
 * in case this operation is being run on a different CPU then the local queue's identity,
 * but we don't have to worry about the page moving to a global queue or becoming wired
 * while we're grabbing the local lock since those operations would require the global
 * vm_page_queue_lock to be held, and we already own it.
 *
 * this is why its safe to utilze the wire_count field in the vm_page_t as the local_id...
 * 'wired' and local are ALWAYS mutually exclusive conditions.
 */

#if CONFIG_BACKGROUND_QUEUE
void
vm_page_queues_remove(vm_page_t mem, boolean_t remove_from_backgroundq)
#else
void
vm_page_queues_remove(vm_page_t mem, boolean_t __unused remove_from_backgroundq)
#endif
{
        boolean_t       was_pageable = TRUE;
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(mem);

        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);

        if (mem->vmp_q_state == VM_PAGE_NOT_ON_Q) {
                assert(mem->vmp_pageq.next == 0 && mem->vmp_pageq.prev == 0);
#if CONFIG_BACKGROUND_QUEUE
                if (remove_from_backgroundq == TRUE) {
                        vm_page_remove_from_backgroundq(mem);
                }
                if (mem->vmp_on_backgroundq) {
                        assert(mem->vmp_backgroundq.next != 0);
                        assert(mem->vmp_backgroundq.prev != 0);
                } else {
                        assert(mem->vmp_backgroundq.next == 0);
                        assert(mem->vmp_backgroundq.prev == 0);
                }
#endif /* CONFIG_BACKGROUND_QUEUE */
                return;
        }

        if (mem->vmp_q_state == VM_PAGE_USED_BY_COMPRESSOR) {
                assert(mem->vmp_pageq.next == 0 && mem->vmp_pageq.prev == 0);
#if CONFIG_BACKGROUND_QUEUE
                assert(mem->vmp_backgroundq.next == 0 &&
                    mem->vmp_backgroundq.prev == 0 &&
                    mem->vmp_on_backgroundq == FALSE);
#endif
                return;
        }
        if (mem->vmp_q_state == VM_PAGE_IS_WIRED) {
                /*
                 * might put these guys on a list for debugging purposes
                 * if we do, we'll need to remove this assert
                 */
                assert(mem->vmp_pageq.next == 0 && mem->vmp_pageq.prev == 0);
#if CONFIG_BACKGROUND_QUEUE
                assert(mem->vmp_backgroundq.next == 0 &&
                    mem->vmp_backgroundq.prev == 0 &&
                    mem->vmp_on_backgroundq == FALSE);
#endif
                return;
        }

        assert(m_object != compressor_object);
        assert(m_object != kernel_object);
        assert(m_object != vm_submap_object);
        assert(!mem->vmp_fictitious);

        switch (mem->vmp_q_state) {
        case VM_PAGE_ON_ACTIVE_LOCAL_Q:
        {
                struct vpl      *lq;

                lq = &vm_page_local_q[mem->vmp_local_id].vpl_un.vpl;
                VPL_LOCK(&lq->vpl_lock);
                vm_page_queue_remove(&lq->vpl_queue, mem, vmp_pageq);
                mem->vmp_local_id = 0;
                lq->vpl_count--;
                if (m_object->internal) {
                        lq->vpl_internal_count--;
                } else {
                        lq->vpl_external_count--;
                }
                VPL_UNLOCK(&lq->vpl_lock);
                was_pageable = FALSE;
                break;
        }
        case VM_PAGE_ON_ACTIVE_Q:
        {
                vm_page_queue_remove(&vm_page_queue_active, mem, vmp_pageq);
                vm_page_active_count--;
                break;
        }

        case VM_PAGE_ON_INACTIVE_INTERNAL_Q:
        {
                assert(m_object->internal == TRUE);

                vm_page_inactive_count--;
                vm_page_queue_remove(&vm_page_queue_anonymous, mem, vmp_pageq);
                vm_page_anonymous_count--;

                vm_purgeable_q_advance_all();
                vm_page_balance_inactive(3);
                break;
        }

        case VM_PAGE_ON_INACTIVE_EXTERNAL_Q:
        {
                assert(m_object->internal == FALSE);

                vm_page_inactive_count--;
                vm_page_queue_remove(&vm_page_queue_inactive, mem, vmp_pageq);
                vm_purgeable_q_advance_all();
                vm_page_balance_inactive(3);
                break;
        }

        case VM_PAGE_ON_INACTIVE_CLEANED_Q:
        {
                assert(m_object->internal == FALSE);

                vm_page_inactive_count--;
                vm_page_queue_remove(&vm_page_queue_cleaned, mem, vmp_pageq);
                vm_page_cleaned_count--;
                vm_page_balance_inactive(3);
                break;
        }

        case VM_PAGE_ON_THROTTLED_Q:
        {
                assert(m_object->internal == TRUE);

                vm_page_queue_remove(&vm_page_queue_throttled, mem, vmp_pageq);
                vm_page_throttled_count--;
                was_pageable = FALSE;
                break;
        }

        case VM_PAGE_ON_SPECULATIVE_Q:
        {
                assert(m_object->internal == FALSE);

                vm_page_remque(&mem->vmp_pageq);
                vm_page_speculative_count--;
                vm_page_balance_inactive(3);
                break;
        }

#if CONFIG_SECLUDED_MEMORY
        case VM_PAGE_ON_SECLUDED_Q:
        {
                vm_page_queue_remove(&vm_page_queue_secluded, mem, vmp_pageq);
                vm_page_secluded_count--;
                VM_PAGE_SECLUDED_COUNT_OVER_TARGET_UPDATE();
                if (m_object == VM_OBJECT_NULL) {
                        vm_page_secluded_count_free--;
                        was_pageable = FALSE;
                } else {
                        assert(!m_object->internal);
                        vm_page_secluded_count_inuse--;
                        was_pageable = FALSE;
//                      was_pageable = TRUE;
                }
                break;
        }
#endif /* CONFIG_SECLUDED_MEMORY */

        default:
        {
                /*
                 *      if (mem->vmp_q_state == VM_PAGE_ON_PAGEOUT_Q)
                 *              NOTE: vm_page_queues_remove does not deal with removing pages from the pageout queue...
                 *              the caller is responsible for determing if the page is on that queue, and if so, must
                 *              either first remove it (it needs both the page queues lock and the object lock to do
                 *              this via vm_pageout_steal_laundry), or avoid the call to vm_page_queues_remove
                 *
                 *      we also don't expect to encounter VM_PAGE_ON_FREE_Q, VM_PAGE_ON_FREE_LOCAL_Q, VM_PAGE_ON_FREE_LOPAGE_Q
                 *      or any of the undefined states
                 */
                panic("vm_page_queues_remove - bad page q_state (%p, %d)\n", mem, mem->vmp_q_state);
                break;
        }
        }
        VM_PAGE_ZERO_PAGEQ_ENTRY(mem);
        mem->vmp_q_state = VM_PAGE_NOT_ON_Q;

#if CONFIG_BACKGROUND_QUEUE
        if (remove_from_backgroundq == TRUE) {
                vm_page_remove_from_backgroundq(mem);
        }
#endif
        if (was_pageable) {
                if (m_object->internal) {
                        vm_page_pageable_internal_count--;
                } else {
                        vm_page_pageable_external_count--;
                }
        }
}

void
vm_page_remove_internal(vm_page_t page)
{
        vm_object_t __object = VM_PAGE_OBJECT(page);
        if (page == __object->memq_hint) {
                vm_page_t       __new_hint;
                vm_page_queue_entry_t   __qe;
                __qe = (vm_page_queue_entry_t)vm_page_queue_next(&page->vmp_listq);
                if (vm_page_queue_end(&__object->memq, __qe)) {
                        __qe = (vm_page_queue_entry_t)vm_page_queue_prev(&page->vmp_listq);
                        if (vm_page_queue_end(&__object->memq, __qe)) {
                                __qe = NULL;
                        }
                }
                __new_hint = (vm_page_t)((uintptr_t) __qe);
                __object->memq_hint = __new_hint;
        }
        vm_page_queue_remove(&__object->memq, page, vmp_listq);
#if CONFIG_SECLUDED_MEMORY
        if (__object->eligible_for_secluded) {
                vm_page_secluded.eligible_for_secluded--;
        }
#endif /* CONFIG_SECLUDED_MEMORY */
}

void
vm_page_enqueue_inactive(vm_page_t mem, boolean_t first)
{
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(mem);

        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        assert(!mem->vmp_fictitious);
        assert(!mem->vmp_laundry);
        assert(mem->vmp_q_state == VM_PAGE_NOT_ON_Q);
        vm_page_check_pageable_safe(mem);

        if (m_object->internal) {
                mem->vmp_q_state = VM_PAGE_ON_INACTIVE_INTERNAL_Q;

                if (first == TRUE) {
                        vm_page_queue_enter_first(&vm_page_queue_anonymous, mem, vmp_pageq);
                } else {
                        vm_page_queue_enter(&vm_page_queue_anonymous, mem, vmp_pageq);
                }

                vm_page_anonymous_count++;
                vm_page_pageable_internal_count++;
        } else {
                mem->vmp_q_state = VM_PAGE_ON_INACTIVE_EXTERNAL_Q;

                if (first == TRUE) {
                        vm_page_queue_enter_first(&vm_page_queue_inactive, mem, vmp_pageq);
                } else {
                        vm_page_queue_enter(&vm_page_queue_inactive, mem, vmp_pageq);
                }

                vm_page_pageable_external_count++;
        }
        vm_page_inactive_count++;
        token_new_pagecount++;

#if CONFIG_BACKGROUND_QUEUE
        if (mem->vmp_in_background) {
                vm_page_add_to_backgroundq(mem, FALSE);
        }
#endif
}

void
vm_page_enqueue_active(vm_page_t mem, boolean_t first)
{
        vm_object_t     m_object;

        m_object = VM_PAGE_OBJECT(mem);

        LCK_MTX_ASSERT(&vm_page_queue_lock, LCK_MTX_ASSERT_OWNED);
        assert(!mem->vmp_fictitious);
        assert(!mem->vmp_laundry);
        assert(mem->vmp_q_state == VM_PAGE_NOT_ON_Q);
        vm_page_check_pageable_safe(mem);

        mem->vmp_q_state = VM_PAGE_ON_ACTIVE_Q;
        if (first == TRUE) {
                vm_page_queue_enter_first(&vm_page_queue_active, mem, vmp_pageq);
        } else {
                vm_page_queue_enter(&vm_page_queue_active, mem, vmp_pageq);
        }
        vm_page_active_count++;

        if (m_object->internal) {
                vm_page_pageable_internal_count++;
        } else {
                vm_page_pageable_external_count++;
        }

#if CONFIG_BACKGROUND_QUEUE
        if (mem->vmp_in_background) {
                vm_page_add_to_backgroundq(mem, FALSE);
        }
#endif
        vm_page_balance_inactive(3);
}

/*
 * Pages from special kernel objects shouldn't
 * be placed on pageable queues.
 */
void
vm_page_check_pageable_safe(vm_page_t page)
{
        vm_object_t     page_object;

        page_object = VM_PAGE_OBJECT(page);

        if (page_object == kernel_object) {
                panic("vm_page_check_pageable_safe: trying to add page" \
                    "from kernel object (%p) to pageable queue", kernel_object);
        }

        if (page_object == compressor_object) {
                panic("vm_page_check_pageable_safe: trying to add page" \
                    "from compressor object (%p) to pageable queue", compressor_object);
        }

        if (page_object == vm_submap_object) {
                panic("vm_page_check_pageable_safe: trying to add page" \
                    "from submap object (%p) to pageable queue", vm_submap_object);
        }
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* wired page diagnose
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include <libkern/OSKextLibPrivate.h>

#define KA_SIZE(namelen, subtotalscount)        \
        (sizeof(struct vm_allocation_site) + (namelen) + 1 + ((subtotalscount) * sizeof(struct vm_allocation_total)))

#define KA_NAME(alloc)  \
        ((char *)(&(alloc)->subtotals[(alloc->subtotalscount)]))

#define KA_NAME_LEN(alloc)      \
    (VM_TAG_NAME_LEN_MAX & (alloc->flags >> VM_TAG_NAME_LEN_SHIFT))

vm_tag_t
vm_tag_bt(void)
{
        uintptr_t* frameptr;
        uintptr_t* frameptr_next;
        uintptr_t retaddr;
        uintptr_t kstackb, kstackt;
        const vm_allocation_site_t * site;
        thread_t cthread;
        kern_allocation_name_t name;

        cthread = current_thread();
        if (__improbable(cthread == NULL)) {
                return VM_KERN_MEMORY_OSFMK;
        }

        if ((name = thread_get_kernel_state(cthread)->allocation_name)) {
                if (!name->tag) {
                        vm_tag_alloc(name);
                }
                return name->tag;
        }

        kstackb = cthread->kernel_stack;
        kstackt = kstackb + kernel_stack_size;

        /* Load stack frame pointer (EBP on x86) into frameptr */
        frameptr = __builtin_frame_address(0);
        site = NULL;
        while (frameptr != NULL) {
                /* Verify thread stack bounds */
                if (((uintptr_t)(frameptr + 2) > kstackt) || ((uintptr_t)frameptr < kstackb)) {
                        break;
                }

                /* Next frame pointer is pointed to by the previous one */
                frameptr_next = (uintptr_t*) *frameptr;

                /* Pull return address from one spot above the frame pointer */
                retaddr = *(frameptr + 1);

#if defined(HAS_APPLE_PAC)
                retaddr = (uintptr_t) ptrauth_strip((void *)retaddr, ptrauth_key_return_address);
#endif

                if (((retaddr < vm_kernel_builtinkmod_text_end) && (retaddr >= vm_kernel_builtinkmod_text))
                    || (retaddr < vm_kernel_stext) || (retaddr > vm_kernel_top)) {
                        site = OSKextGetAllocationSiteForCaller(retaddr);
                        break;
                }
                frameptr = frameptr_next;
        }

        return site ? site->tag : VM_KERN_MEMORY_NONE;
}

static uint64_t free_tag_bits[VM_MAX_TAG_VALUE / 64];

void
vm_tag_alloc_locked(vm_allocation_site_t * site, vm_allocation_site_t ** releasesiteP)
{
        vm_tag_t tag;
        uint64_t avail;
        uint32_t idx;
        vm_allocation_site_t * prev;

        if (site->tag) {
                return;
        }

        idx = 0;
        while (TRUE) {
                avail = free_tag_bits[idx];
                if (avail) {
                        tag = __builtin_clzll(avail);
                        avail &= ~(1ULL << (63 - tag));
                        free_tag_bits[idx] = avail;
                        tag += (idx << 6);
                        break;
                }
                idx++;
                if (idx >= ARRAY_COUNT(free_tag_bits)) {
                        for (idx = 0; idx < ARRAY_COUNT(vm_allocation_sites); idx++) {
                                prev = vm_allocation_sites[idx];
                                if (!prev) {
                                        continue;
                                }
                                if (!KA_NAME_LEN(prev)) {
                                        continue;
                                }
                                if (!prev->tag) {
                                        continue;
                                }
                                if (prev->total) {
                                        continue;
                                }
                                if (1 != prev->refcount) {
                                        continue;
                                }

                                assert(idx == prev->tag);
                                tag = idx;
                                prev->tag = VM_KERN_MEMORY_NONE;
                                *releasesiteP = prev;
                                break;
                        }
                        if (idx >= ARRAY_COUNT(vm_allocation_sites)) {
                                tag = VM_KERN_MEMORY_ANY;
                        }
                        break;
                }
        }
        site->tag = tag;

        OSAddAtomic16(1, &site->refcount);

        if (VM_KERN_MEMORY_ANY != tag) {
                vm_allocation_sites[tag] = site;
        }

        if (tag > vm_allocation_tag_highest) {
                vm_allocation_tag_highest = tag;
        }
}

static void
vm_tag_free_locked(vm_tag_t tag)
{
        uint64_t avail;
        uint32_t idx;
        uint64_t bit;

        if (VM_KERN_MEMORY_ANY == tag) {
                return;
        }

        idx = (tag >> 6);
        avail = free_tag_bits[idx];
        tag &= 63;
        bit = (1ULL << (63 - tag));
        assert(!(avail & bit));
        free_tag_bits[idx] = (avail | bit);
}

static void
vm_tag_init(void)
{
        vm_tag_t tag;
        for (tag = VM_KERN_MEMORY_FIRST_DYNAMIC; tag < VM_KERN_MEMORY_ANY; tag++) {
                vm_tag_free_locked(tag);
        }

        for (tag = VM_KERN_MEMORY_ANY + 1; tag < VM_MAX_TAG_VALUE; tag++) {
                vm_tag_free_locked(tag);
        }
}

vm_tag_t
vm_tag_alloc(vm_allocation_site_t * site)
{
        vm_tag_t tag;
        vm_allocation_site_t * releasesite;

        if (VM_TAG_BT & site->flags) {
                tag = vm_tag_bt();
                if (VM_KERN_MEMORY_NONE != tag) {
                        return tag;
                }
        }

        if (!site->tag) {
                releasesite = NULL;
                lck_spin_lock(&vm_allocation_sites_lock);
                vm_tag_alloc_locked(site, &releasesite);
                lck_spin_unlock(&vm_allocation_sites_lock);
                if (releasesite) {
                        kern_allocation_name_release(releasesite);
                }
        }

        return site->tag;
}

void
vm_tag_update_size(vm_tag_t tag, int64_t delta)
{
        vm_allocation_site_t * allocation;
        uint64_t prior;

        assert(VM_KERN_MEMORY_NONE != tag);
        assert(tag < VM_MAX_TAG_VALUE);

        allocation = vm_allocation_sites[tag];
        assert(allocation);

        if (delta < 0) {
                assertf(allocation->total >= ((uint64_t)-delta), "tag %d, site %p", tag, allocation);
        }
        prior = OSAddAtomic64(delta, &allocation->total);

#if DEBUG || DEVELOPMENT

        uint64_t new, peak;
        new = prior + delta;
        do{
                peak = allocation->peak;
                if (new <= peak) {
                        break;
                }
        }while (!OSCompareAndSwap64(peak, new, &allocation->peak));

#endif /* DEBUG || DEVELOPMENT */

        if (tag < VM_KERN_MEMORY_FIRST_DYNAMIC) {
                return;
        }

        if (!prior && !allocation->tag) {
                vm_tag_alloc(allocation);
        }
}

void
kern_allocation_update_size(kern_allocation_name_t allocation, int64_t delta)
{
        uint64_t prior;

        if (delta < 0) {
                assertf(allocation->total >= ((uint64_t)-delta), "name %p", allocation);
        }
        prior = OSAddAtomic64(delta, &allocation->total);

#if DEBUG || DEVELOPMENT

        uint64_t new, peak;
        new = prior + delta;
        do{
                peak = allocation->peak;
                if (new <= peak) {
                        break;
                }
        }while (!OSCompareAndSwap64(peak, new, &allocation->peak));

#endif /* DEBUG || DEVELOPMENT */

        if (!prior && !allocation->tag) {
                vm_tag_alloc(allocation);
        }
}

#if VM_MAX_TAG_ZONES

void
vm_allocation_zones_init(void)
{
        kern_return_t ret;
        vm_offset_t       addr;
        vm_size_t     size;

        size = VM_MAX_TAG_VALUE * sizeof(vm_allocation_zone_total_t * *)
            + 2 * VM_MAX_TAG_ZONES * sizeof(vm_allocation_zone_total_t);

        ret = kernel_memory_allocate(kernel_map,
            &addr, round_page(size), 0,
            KMA_ZERO, VM_KERN_MEMORY_DIAG);
        assert(KERN_SUCCESS == ret);

        vm_allocation_zone_totals = (vm_allocation_zone_total_t **) addr;
        addr += VM_MAX_TAG_VALUE * sizeof(vm_allocation_zone_total_t * *);

        // prepopulate VM_KERN_MEMORY_DIAG & VM_KERN_MEMORY_KALLOC so allocations
        // in vm_tag_update_zone_size() won't recurse
        vm_allocation_zone_totals[VM_KERN_MEMORY_DIAG]   = (vm_allocation_zone_total_t *) addr;
        addr += VM_MAX_TAG_ZONES * sizeof(vm_allocation_zone_total_t);
        vm_allocation_zone_totals[VM_KERN_MEMORY_KALLOC] = (vm_allocation_zone_total_t *) addr;
}

void
vm_tag_will_update_zone(vm_tag_t tag, uint32_t zidx)
{
        vm_allocation_zone_total_t * zone;

        assert(VM_KERN_MEMORY_NONE != tag);
        assert(tag < VM_MAX_TAG_VALUE);

        if (zidx >= VM_MAX_TAG_ZONES) {
                return;
        }

        zone = vm_allocation_zone_totals[tag];
        if (!zone) {
                zone = kalloc_tag(VM_MAX_TAG_ZONES * sizeof(*zone), VM_KERN_MEMORY_DIAG);
                if (!zone) {
                        return;
                }
                bzero(zone, VM_MAX_TAG_ZONES * sizeof(*zone));
                if (!OSCompareAndSwapPtr(NULL, zone, &vm_allocation_zone_totals[tag])) {
                        kfree(zone, VM_MAX_TAG_ZONES * sizeof(*zone));
                }
        }
}

void
vm_tag_update_zone_size(vm_tag_t tag, uint32_t zidx, int64_t delta, int64_t dwaste)
{
        vm_allocation_zone_total_t * zone;
        uint32_t new;

        assert(VM_KERN_MEMORY_NONE != tag);
        assert(tag < VM_MAX_TAG_VALUE);

        if (zidx >= VM_MAX_TAG_ZONES) {
                return;
        }

        zone = vm_allocation_zone_totals[tag];
        assert(zone);
        zone += zidx;

        /* the zone is locked */
        if (delta < 0) {
                assertf(zone->total >= ((uint64_t)-delta), "zidx %d, tag %d, %p", zidx, tag, zone);
                zone->total += delta;
        } else {
                zone->total += delta;
                if (zone->total > zone->peak) {
                        zone->peak = zone->total;
                }
                if (dwaste) {
                        new = zone->waste;
                        if (zone->wastediv < 65536) {
                                zone->wastediv++;
                        } else {
                                new -= (new >> 16);
                        }
                        __assert_only bool ov = os_add_overflow(new, dwaste, &new);
                        assert(!ov);
                        zone->waste = new;
                }
        }
}

#endif /* VM_MAX_TAG_ZONES */

void
kern_allocation_update_subtotal(kern_allocation_name_t allocation, uint32_t subtag, int64_t delta)
{
        kern_allocation_name_t other;
        struct vm_allocation_total * total;
        uint32_t subidx;

        subidx = 0;
        assert(VM_KERN_MEMORY_NONE != subtag);
        lck_spin_lock(&vm_allocation_sites_lock);
        for (; subidx < allocation->subtotalscount; subidx++) {
                if (VM_KERN_MEMORY_NONE == allocation->subtotals[subidx].tag) {
                        allocation->subtotals[subidx].tag = subtag;
                        break;
                }
                if (subtag == allocation->subtotals[subidx].tag) {
                        break;
                }
        }
        lck_spin_unlock(&vm_allocation_sites_lock);
        assert(subidx < allocation->subtotalscount);
        if (subidx >= allocation->subtotalscount) {
                return;
        }

        total = &allocation->subtotals[subidx];
        other = vm_allocation_sites[subtag];
        assert(other);

        if (delta < 0) {
                assertf(total->total >= ((uint64_t)-delta), "name %p", allocation);
                assertf(other->mapped >= ((uint64_t)-delta), "other %p", other);
        }
        OSAddAtomic64(delta, &other->mapped);
        OSAddAtomic64(delta, &total->total);
}

const char *
kern_allocation_get_name(kern_allocation_name_t allocation)
{
        return KA_NAME(allocation);
}

kern_allocation_name_t
kern_allocation_name_allocate(const char * name, uint32_t subtotalscount)
{
        uint32_t namelen;

        namelen = (uint32_t) strnlen(name, MACH_MEMORY_INFO_NAME_MAX_LEN - 1);

        kern_allocation_name_t allocation;
        allocation = kalloc(KA_SIZE(namelen, subtotalscount));
        bzero(allocation, KA_SIZE(namelen, subtotalscount));

        allocation->refcount       = 1;
        allocation->subtotalscount = subtotalscount;
        allocation->flags          = (namelen << VM_TAG_NAME_LEN_SHIFT);
        strlcpy(KA_NAME(allocation), name, namelen + 1);

        return allocation;
}

void
kern_allocation_name_release(kern_allocation_name_t allocation)
{
        assert(allocation->refcount > 0);
        if (1 == OSAddAtomic16(-1, &allocation->refcount)) {
                kfree(allocation, KA_SIZE(KA_NAME_LEN(allocation), allocation->subtotalscount));
        }
}

vm_tag_t
kern_allocation_name_get_vm_tag(kern_allocation_name_t allocation)
{
        return vm_tag_alloc(allocation);
}

#if !VM_TAG_ACTIVE_UPDATE
static void
vm_page_count_object(mach_memory_info_t * info, unsigned int __unused num_info, vm_object_t object)
{
        if (!object->wired_page_count) {
                return;
        }
        if (object != kernel_object) {
                assert(object->wire_tag < num_info);
                info[object->wire_tag].size += ptoa_64(object->wired_page_count);
        }
}

typedef void (*vm_page_iterate_proc)(mach_memory_info_t * info,
    unsigned int num_info, vm_object_t object);

static void
vm_page_iterate_purgeable_objects(mach_memory_info_t * info, unsigned int num_info,
    vm_page_iterate_proc proc, purgeable_q_t queue,
    int group)
{
        vm_object_t object;

        for (object = (vm_object_t) queue_first(&queue->objq[group]);
            !queue_end(&queue->objq[group], (queue_entry_t) object);
            object = (vm_object_t) queue_next(&object->objq)) {
                proc(info, num_info, object);
        }
}

static void
vm_page_iterate_objects(mach_memory_info_t * info, unsigned int num_info,
    vm_page_iterate_proc proc)
{
        vm_object_t     object;

        lck_spin_lock_grp(&vm_objects_wired_lock, &vm_page_lck_grp_bucket);
        queue_iterate(&vm_objects_wired,
            object,
            vm_object_t,
            wired_objq)
        {
                proc(info, num_info, object);
        }
        lck_spin_unlock(&vm_objects_wired_lock);
}
#endif /* ! VM_TAG_ACTIVE_UPDATE */

static uint64_t
process_account(mach_memory_info_t * info, unsigned int num_info, uint64_t zones_collectable_bytes, boolean_t iterated)
{
        size_t                 namelen;
        unsigned int           idx, count, nextinfo;
        vm_allocation_site_t * site;
        lck_spin_lock(&vm_allocation_sites_lock);

        for (idx = 0; idx <= vm_allocation_tag_highest; idx++) {
                site = vm_allocation_sites[idx];
                if (!site) {
                        continue;
                }
                info[idx].mapped = site->mapped;
                info[idx].tag    = site->tag;
                if (!iterated) {
                        info[idx].size = site->total;
#if DEBUG || DEVELOPMENT
                        info[idx].peak = site->peak;
#endif /* DEBUG || DEVELOPMENT */
                } else {
                        if (!site->subtotalscount && (site->total != info[idx].size)) {
                                printf("tag mismatch[%d] 0x%qx, iter 0x%qx\n", idx, site->total, info[idx].size);
                                info[idx].size = site->total;
                        }
                }
                info[idx].flags |= VM_KERN_SITE_WIRED;
                if (idx < VM_KERN_MEMORY_FIRST_DYNAMIC) {
                        info[idx].site   = idx;
                        info[idx].flags |= VM_KERN_SITE_TAG;
                        if (VM_KERN_MEMORY_ZONE == idx) {
                                info[idx].flags |= VM_KERN_SITE_HIDE;
                                info[idx].flags &= ~VM_KERN_SITE_WIRED;
                                info[idx].collectable_bytes = zones_collectable_bytes;
                        }
                } else if ((namelen = (VM_TAG_NAME_LEN_MAX & (site->flags >> VM_TAG_NAME_LEN_SHIFT)))) {
                        info[idx].site   = 0;
                        info[idx].flags |= VM_KERN_SITE_NAMED;
                        if (namelen > sizeof(info[idx].name)) {
                                namelen = sizeof(info[idx].name);
                        }
                        strncpy(&info[idx].name[0], KA_NAME(site), namelen);
                } else if (VM_TAG_KMOD & site->flags) {
                        info[idx].site   = OSKextGetKmodIDForSite(site, NULL, 0);
                        info[idx].flags |= VM_KERN_SITE_KMOD;
                } else {
                        info[idx].site   = VM_KERNEL_UNSLIDE(site);
                        info[idx].flags |= VM_KERN_SITE_KERNEL;
                }
        }

        nextinfo = (vm_allocation_tag_highest + 1);
        count    = nextinfo;
        if (count >= num_info) {
                count = num_info;
        }

        for (idx = 0; idx < count; idx++) {
                site = vm_allocation_sites[idx];
                if (!site) {
                        continue;
                }
#if VM_MAX_TAG_ZONES
                vm_allocation_zone_total_t * zone;
                unsigned int                 zidx;
                vm_size_t                    elem_size;

                if (vm_allocation_zone_totals
                    && (zone = vm_allocation_zone_totals[idx])
                    && (nextinfo < num_info)) {
                        for (zidx = 0; zidx < VM_MAX_TAG_ZONES; zidx++) {
                                if (!zone[zidx].peak) {
                                        continue;
                                }
                                info[nextinfo]                   = info[idx];
                                info[nextinfo].zone              = zone_index_from_tag_index(zidx, &elem_size);
                                info[nextinfo].flags            &= ~VM_KERN_SITE_WIRED;
                                info[nextinfo].flags            |= VM_KERN_SITE_ZONE;
                                info[nextinfo].size              = zone[zidx].total;
                                info[nextinfo].peak              = zone[zidx].peak;
                                info[nextinfo].mapped            = 0;
                                if (zone[zidx].wastediv) {
                                        info[nextinfo].collectable_bytes = ((zone[zidx].waste * zone[zidx].total / elem_size) / zone[zidx].wastediv);
                                }
                                nextinfo++;
                        }
                }
#endif /* VM_MAX_TAG_ZONES */
                if (site->subtotalscount) {
                        uint64_t mapped, mapcost, take;
                        uint32_t sub;
                        vm_tag_t alloctag;

                        info[idx].size = site->total;
                        mapped = info[idx].size;
                        info[idx].mapped = mapped;
                        mapcost = 0;
                        for (sub = 0; sub < site->subtotalscount; sub++) {
                                alloctag = site->subtotals[sub].tag;
                                assert(alloctag < num_info);
                                if (info[alloctag].name[0]) {
                                        continue;
                                }
                                take = site->subtotals[sub].total;
                                if (take > info[alloctag].size) {
                                        take = info[alloctag].size;
                                }
                                if (take > mapped) {
                                        take = mapped;
                                }
                                info[alloctag].mapped  -= take;
                                info[alloctag].size    -= take;
                                mapped                 -= take;
                                mapcost                += take;
                        }
                        info[idx].size = mapcost;
                }
        }
        lck_spin_unlock(&vm_allocation_sites_lock);

        return 0;
}

uint32_t
vm_page_diagnose_estimate(void)
{
        vm_allocation_site_t * site;
        uint32_t               count;
        uint32_t               idx;

        lck_spin_lock(&vm_allocation_sites_lock);
        for (count = idx = 0; idx < VM_MAX_TAG_VALUE; idx++) {
                site = vm_allocation_sites[idx];
                if (!site) {
                        continue;
                }
                count++;
#if VM_MAX_TAG_ZONES
                if (vm_allocation_zone_totals) {
                        vm_allocation_zone_total_t * zone;
                        zone = vm_allocation_zone_totals[idx];
                        if (!zone) {
                                continue;
                        }
                        for (uint32_t zidx = 0; zidx < VM_MAX_TAG_ZONES; zidx++) {
                                if (zone[zidx].peak) {
                                        count++;
                                }
                        }
                }
#endif
        }
        lck_spin_unlock(&vm_allocation_sites_lock);

        /* some slop for new tags created */
        count += 8;
        count += VM_KERN_COUNTER_COUNT;

        return count;
}

kern_return_t
vm_page_diagnose(mach_memory_info_t * info, unsigned int num_info, uint64_t zones_collectable_bytes)
{
        uint64_t                 wired_size;
        uint64_t                 wired_managed_size;
        uint64_t                 wired_reserved_size;
        boolean_t                iterate;
        mach_memory_info_t     * counts;

        bzero(info, num_info * sizeof(mach_memory_info_t));

        if (!vm_page_wire_count_initial) {
                return KERN_ABORTED;
        }

#if CONFIG_EMBEDDED
        wired_size          = ptoa_64(vm_page_wire_count);
        wired_reserved_size = ptoa_64(vm_page_wire_count_initial - vm_page_stolen_count);
#else
        wired_size          = ptoa_64(vm_page_wire_count + vm_lopage_free_count + vm_page_throttled_count);
        wired_reserved_size = ptoa_64(vm_page_wire_count_initial - vm_page_stolen_count + vm_page_throttled_count);
#endif
        wired_managed_size  = ptoa_64(vm_page_wire_count - vm_page_wire_count_initial);

        wired_size += booter_size;

        assert(num_info >= VM_KERN_COUNTER_COUNT);
        num_info -= VM_KERN_COUNTER_COUNT;
        counts = &info[num_info];

#define SET_COUNT(xcount, xsize, xflags)                        \
    counts[xcount].tag   = VM_MAX_TAG_VALUE + xcount;   \
    counts[xcount].site  = (xcount);                            \
    counts[xcount].size  = (xsize);                                 \
    counts[xcount].mapped  = (xsize);                           \
    counts[xcount].flags = VM_KERN_SITE_COUNTER | xflags;

        SET_COUNT(VM_KERN_COUNT_MANAGED, ptoa_64(vm_page_pages), 0);
        SET_COUNT(VM_KERN_COUNT_WIRED, wired_size, 0);
        SET_COUNT(VM_KERN_COUNT_WIRED_MANAGED, wired_managed_size, 0);
        SET_COUNT(VM_KERN_COUNT_RESERVED, wired_reserved_size, VM_KERN_SITE_WIRED);
        SET_COUNT(VM_KERN_COUNT_STOLEN, ptoa_64(vm_page_stolen_count), VM_KERN_SITE_WIRED);
        SET_COUNT(VM_KERN_COUNT_LOPAGE, ptoa_64(vm_lopage_free_count), VM_KERN_SITE_WIRED);
        SET_COUNT(VM_KERN_COUNT_WIRED_BOOT, ptoa_64(vm_page_wire_count_on_boot), 0);
        SET_COUNT(VM_KERN_COUNT_BOOT_STOLEN, booter_size, VM_KERN_SITE_WIRED);

#define SET_MAP(xcount, xsize, xfree, xlargest) \
    counts[xcount].site    = (xcount);                  \
    counts[xcount].size    = (xsize);                   \
    counts[xcount].mapped  = (xsize);                   \
    counts[xcount].free    = (xfree);                   \
    counts[xcount].largest = (xlargest);                \
    counts[xcount].flags   = VM_KERN_SITE_COUNTER;

        vm_map_size_t map_size, map_free, map_largest;

        vm_map_sizes(kernel_map, &map_size, &map_free, &map_largest);
        SET_MAP(VM_KERN_COUNT_MAP_KERNEL, map_size, map_free, map_largest);

        vm_map_sizes(zone_map, &map_size, &map_free, &map_largest);
        SET_MAP(VM_KERN_COUNT_MAP_ZONE, map_size, map_free, map_largest);

        vm_map_sizes(kalloc_map, &map_size, &map_free, &map_largest);
        SET_MAP(VM_KERN_COUNT_MAP_KALLOC, map_size, map_free, map_largest);

        iterate = !VM_TAG_ACTIVE_UPDATE;
        if (iterate) {
                enum                       { kMaxKernelDepth = 1 };
                vm_map_t                     maps[kMaxKernelDepth];
                vm_map_entry_t               entries[kMaxKernelDepth];
                vm_map_t                     map;
                vm_map_entry_t               entry;
                vm_object_offset_t           offset;
                vm_page_t                    page;
                int                          stackIdx, count;

#if !VM_TAG_ACTIVE_UPDATE
                vm_page_iterate_objects(info, num_info, &vm_page_count_object);
#endif /* ! VM_TAG_ACTIVE_UPDATE */

                map = kernel_map;
                stackIdx = 0;
                while (map) {
                        vm_map_lock(map);
                        for (entry = map->hdr.links.next; map; entry = entry->links.next) {
                                if (entry->is_sub_map) {
                                        assert(stackIdx < kMaxKernelDepth);
                                        maps[stackIdx] = map;
                                        entries[stackIdx] = entry;
                                        stackIdx++;
                                        map = VME_SUBMAP(entry);
                                        entry = NULL;
                                        break;
                                }
                                if (VME_OBJECT(entry) == kernel_object) {
                                        count = 0;
                                        vm_object_lock(VME_OBJECT(entry));
                                        for (offset = entry->links.start; offset < entry->links.end; offset += page_size) {
                                                page = vm_page_lookup(VME_OBJECT(entry), offset);
                                                if (page && VM_PAGE_WIRED(page)) {
                                                        count++;
                                                }
                                        }
                                        vm_object_unlock(VME_OBJECT(entry));

                                        if (count) {
                                                assert(VME_ALIAS(entry) != VM_KERN_MEMORY_NONE);
                                                assert(VME_ALIAS(entry) < num_info);
                                                info[VME_ALIAS(entry)].size += ptoa_64(count);
                                        }
                                }
                                while (map && (entry == vm_map_last_entry(map))) {
                                        vm_map_unlock(map);
                                        if (!stackIdx) {
                                                map = NULL;
                                        } else {
                                                --stackIdx;
                                                map = maps[stackIdx];
                                                entry = entries[stackIdx];
                                        }
                                }
                        }
                }
        }

        process_account(info, num_info, zones_collectable_bytes, iterate);

        return KERN_SUCCESS;
}

#if DEBUG || DEVELOPMENT

kern_return_t
vm_kern_allocation_info(uintptr_t addr, vm_size_t * size, vm_tag_t * tag, vm_size_t * zone_size)
{
        kern_return_t  ret;
        vm_size_t      zsize;
        vm_map_t       map;
        vm_map_entry_t entry;

        zsize = zone_element_info((void *) addr, tag);
        if (zsize) {
                *zone_size = *size = zsize;
                return KERN_SUCCESS;
        }

        *zone_size = 0;
        ret = KERN_INVALID_ADDRESS;
        for (map = kernel_map; map;) {
                vm_map_lock(map);
                if (!vm_map_lookup_entry(map, addr, &entry)) {
                        break;
                }
                if (entry->is_sub_map) {
                        if (map != kernel_map) {
                                break;
                        }
                        map = VME_SUBMAP(entry);
                        continue;
                }
                if (entry->vme_start != addr) {
                        break;
                }
                *tag = VME_ALIAS(entry);
                *size = (entry->vme_end - addr);
                ret = KERN_SUCCESS;
                break;
        }
        if (map != kernel_map) {
                vm_map_unlock(map);
        }
        vm_map_unlock(kernel_map);

        return ret;
}

#endif /* DEBUG || DEVELOPMENT */

uint32_t
vm_tag_get_kext(vm_tag_t tag, char * name, vm_size_t namelen)
{
        vm_allocation_site_t * site;
        uint32_t               kmodId;

        kmodId = 0;
        lck_spin_lock(&vm_allocation_sites_lock);
        if ((site = vm_allocation_sites[tag])) {
                if (VM_TAG_KMOD & site->flags) {
                        kmodId = OSKextGetKmodIDForSite(site, name, namelen);
                }
        }
        lck_spin_unlock(&vm_allocation_sites_lock);

        return kmodId;
}


#if CONFIG_SECLUDED_MEMORY
/*
 * Note that there's no locking around other accesses to vm_page_secluded_target.
 * That should be OK, since these are the only place where it can be changed after
 * initialization. Other users (like vm_pageout) may see the wrong value briefly,
 * but will eventually get the correct value. This brief mismatch is OK as pageout
 * and page freeing will auto-adjust the vm_page_secluded_count to match the target
 * over time.
 */
unsigned int vm_page_secluded_suppress_cnt = 0;
unsigned int vm_page_secluded_save_target;


lck_grp_attr_t  secluded_suppress_slock_grp_attr;
lck_grp_t       secluded_suppress_slock_grp;
lck_attr_t      secluded_suppress_slock_attr;
lck_spin_t      secluded_suppress_slock;

void
secluded_suppression_init(void)
{
        lck_grp_attr_setdefault(&secluded_suppress_slock_grp_attr);
        lck_grp_init(&secluded_suppress_slock_grp,
            "secluded_suppress_slock", &secluded_suppress_slock_grp_attr);
        lck_attr_setdefault(&secluded_suppress_slock_attr);
        lck_spin_init(&secluded_suppress_slock,
            &secluded_suppress_slock_grp, &secluded_suppress_slock_attr);
}

void
start_secluded_suppression(task_t task)
{
        if (task->task_suppressed_secluded) {
                return;
        }
        lck_spin_lock(&secluded_suppress_slock);
        if (!task->task_suppressed_secluded && vm_page_secluded_suppress_cnt++ == 0) {
                task->task_suppressed_secluded = TRUE;
                vm_page_secluded_save_target = vm_page_secluded_target;
                vm_page_secluded_target = 0;
                VM_PAGE_SECLUDED_COUNT_OVER_TARGET_UPDATE();
        }
        lck_spin_unlock(&secluded_suppress_slock);
}

void
stop_secluded_suppression(task_t task)
{
        lck_spin_lock(&secluded_suppress_slock);
        if (task->task_suppressed_secluded && --vm_page_secluded_suppress_cnt == 0) {
                task->task_suppressed_secluded = FALSE;
                vm_page_secluded_target = vm_page_secluded_save_target;
                VM_PAGE_SECLUDED_COUNT_OVER_TARGET_UPDATE();
        }
        lck_spin_unlock(&secluded_suppress_slock);
}

#endif /* CONFIG_SECLUDED_MEMORY */