[apple/xnu.git] / osfmk / i386 / pmap_internal.h

/*
 * Copyright (c) 2000-2012 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
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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 */


#ifndef _I386_PMAP_INTERNAL_
#define _I386_PMAP_INTERNAL_
#ifdef MACH_KERNEL_PRIVATE

#include <vm/pmap.h>
#include <sys/kdebug.h>
#include <kern/ledger.h>
#include <kern/simple_lock.h>
#include <i386/bit_routines.h>

/*
 * pmap locking
 */

static inline void
PMAP_LOCK_EXCLUSIVE(pmap_t p)
{
        mp_disable_preemption();
        lck_rw_lock_exclusive(&p->pmap_rwl);
}

static inline void
PMAP_LOCK_SHARED(pmap_t p)
{
        mp_disable_preemption();
        lck_rw_lock_shared(&p->pmap_rwl);
}

static inline void
PMAP_LOCK_SHARED_TO_EXCLUSIVE(pmap_t p)
{
        lck_rw_lock_shared_to_exclusive(&p->pmap_rwl);
}

static inline void
PMAP_LOCK_EXCLUSIVE_TO_SHARED(pmap_t p)
{
        lck_rw_lock_exclusive_to_shared(&p->pmap_rwl);
}

static inline void
PMAP_UNLOCK_EXCLUSIVE(pmap_t p)
{
        lck_rw_unlock_exclusive(&p->pmap_rwl);
        mp_enable_preemption();
}

static inline void
PMAP_UNLOCK_SHARED(pmap_t p)
{
        lck_rw_unlock_shared(&p->pmap_rwl);
        mp_enable_preemption();
}

#define iswired(pte)    ((pte) & INTEL_PTE_WIRED)

#ifdef  PMAP_TRACES
extern  boolean_t       pmap_trace;
#define PMAP_TRACE(...) \
        if (pmap_trace) { \
                KDBG_RELEASE(__VA_ARGS__); \
        }
#else
#define PMAP_TRACE(...) KDBG_DEBUG(__VA_ARGS__)
#endif /* PMAP_TRACES */

#define PMAP_TRACE_CONSTANT(...) KDBG_RELEASE(__VA_ARGS__)

kern_return_t   pmap_expand_pml4(
        pmap_t          map,
        vm_map_offset_t v,
        unsigned int options);

kern_return_t   pmap_expand_pdpt(
        pmap_t          map,
        vm_map_offset_t v,
        unsigned int options);

void            phys_attribute_set(
        ppnum_t         phys,
        int             bits);

void            pmap_set_reference(
        ppnum_t pn);

boolean_t       phys_page_exists(
        ppnum_t pn);

void
    pmap_flush_tlbs(pmap_t, vm_map_offset_t, vm_map_offset_t, int, pmap_flush_context *);

void
    pmap_update_cache_attributes_locked(ppnum_t, unsigned);


static inline void
PMAP_UPDATE_TLBS(pmap_t fp, addr64_t s, addr64_t e)
{
        pmap_flush_tlbs(fp, s, e, 0, NULL);
}

#define PMAP_DELAY_TLB_FLUSH            0x01

static inline void
PMAP_UPDATE_TLBS_DELAYED(pmap_t fp, addr64_t s, addr64_t e, pmap_flush_context *pfc)
{
        pmap_flush_tlbs(fp, s, e, PMAP_DELAY_TLB_FLUSH, pfc);
}

/*
 *      Private data structures.
 */

/*
 *      For each vm_page_t, there is a list of all currently
 *      valid virtual mappings of that page.  An entry is
 *      a pv_rooted_entry_t; the list is the pv_table.
 *
 *      N.B.  with the new combo rooted/hashed scheme it is
 *      only possibly to remove individual non-rooted entries
 *      if they are found via the hashed chains as there is no
 *      way to unlink the singly linked hashed entries if navigated to
 *      via the queue list off the rooted entries.  Think of it as
 *      hash/walk/pull, keeping track of the prev pointer while walking
 *      the singly linked hash list.  All of this is to save memory and
 *      keep both types of pv_entries as small as possible.
 */

/*
 *
 *  PV HASHING Changes - JK 1/2007
 *
 *  Pve's establish physical to virtual mappings.  These are used for aliasing of a
 *  physical page to (potentially many) virtual addresses within pmaps. In the
 *  previous implementation the structure of the pv_entries (each 16 bytes in size) was
 *
 *  typedef struct pv_entry {
 *   struct pv_entry_t    next;
 *   pmap_t                    pmap;
 *   vm_map_offset_t   va;
 *  } *pv_entry_t;
 *
 *  An initial array of these is created at boot time, one per physical page of
 *  memory, indexed by the physical page number. Additionally, a pool of entries
 *  is created from a pv_zone to be used as needed by pmap_enter() when it is
 *  creating new mappings.  Originally, we kept this pool around because the code
 *  in pmap_enter() was unable to block if it needed an entry and none were
 *  available - we'd panic.  Some time ago I restructured the pmap_enter() code
 *  so that for user pmaps it can block while zalloc'ing a pv structure and restart,
 *  removing a panic from the code (in the case of the kernel pmap we cannot block
 *  and still panic, so, we keep a separate hot pool for use only on kernel pmaps).
 *  The pool has not been removed since there is a large performance gain keeping
 *  freed pv's around for reuse and not suffering the overhead of zalloc for every
 *  new pv we need.
 *
 *  As pmap_enter() created new mappings it linked the new pve's for them off the
 *  fixed pv array for that ppn (off the next pointer).  These pve's are accessed
 *  for several operations, one of them being address space teardown. In that case,
 *  we basically do this
 *
 *       for (every page/pte in the space) {
 *               calc pve_ptr from the ppn in the pte
 *               for (every pv in the list for the ppn) {
 *                       if (this pv is for this pmap/vaddr) {
 *                               do housekeeping
 *                               unlink/free the pv
 *                       }
 *               }
 *       }
 *
 *  The problem arose when we were running, say 8000 (or even 2000) apache or
 *  other processes and one or all terminate. The list hanging off each pv array
 *  entry could have thousands of entries.  We were continuously linearly searching
 *  each of these lists as we stepped through the address space we were tearing
 *  down.  Because of the locks we hold, likely taking a cache miss for each node,
 *  and interrupt disabling for MP issues the system became completely unresponsive
 *  for many seconds while we did this.
 *
 *  Realizing that pve's are accessed in two distinct ways (linearly running the
 *  list by ppn for operations like pmap_page_protect and finding and
 *  modifying/removing a single pve as part of pmap_enter processing) has led to
 *  modifying the pve structures and databases.
 *
 *  There are now two types of pve structures.  A "rooted" structure which is
 *  basically the original structure accessed in an array by ppn, and a ''hashed''
 *  structure accessed on a hash list via a hash of [pmap, vaddr]. These have been
 *  designed with the two goals of minimizing wired memory and making the lookup of
 *  a ppn faster.  Since a vast majority of pages in the system are not aliased
 *  and hence represented by a single pv entry I've kept the rooted entry size as
 *  small as possible because there is one of these dedicated for every physical
 *  page of memory.  The hashed pve's are larger due to the addition of the hash
 *  link and the ppn entry needed for matching while running the hash list to find
 *  the entry we are looking for.  This way, only systems that have lots of
 *  aliasing (like 2000+ httpd procs) will pay the extra memory price. Both
 *  structures have the same first three fields allowing some simplification in
 *  the code.
 *
 *  They have these shapes
 *
 *  typedef struct pv_rooted_entry {
 *       queue_head_t           qlink;
 *       vm_map_offset_t                va;
 *       pmap_t                 pmap;
 *  } *pv_rooted_entry_t;
 *
 *
 *  typedef struct pv_hashed_entry {
 *       queue_head_t           qlink;
 *       vm_map_offset_t                va;
 *       pmap_t                 pmap;
 *       ppnum_t                ppn;
 *       struct pv_hashed_entry *nexth;
 *  } *pv_hashed_entry_t;
 *
 *  The main flow difference is that the code is now aware of the rooted entry and
 *  the hashed entries.  Code that runs the pv list still starts with the rooted
 *  entry and then continues down the qlink onto the hashed entries.  Code that is
 *  looking up a specific pv entry first checks the rooted entry and then hashes
 *  and runs the hash list for the match. The hash list lengths are much smaller
 *  than the original pv lists that contained all aliases for the specific ppn.
 *
 */

typedef struct pv_rooted_entry {
        /* first three entries must match pv_hashed_entry_t */
        queue_head_t            qlink;
        vm_map_offset_t         va_and_flags;   /* virtual address for mapping */
        pmap_t                  pmap;   /* pmap where mapping lies */
} *pv_rooted_entry_t;

#define PV_ROOTED_ENTRY_NULL    ((pv_rooted_entry_t) 0)

typedef struct pv_hashed_entry {
        /* first three entries must match pv_rooted_entry_t */
        queue_head_t            qlink;
        vm_map_offset_t         va_and_flags;
        pmap_t                  pmap;
        ppnum_t                 ppn;
        struct pv_hashed_entry  *nexth;
} *pv_hashed_entry_t;

#define PV_HASHED_ENTRY_NULL ((pv_hashed_entry_t)0)

#define PVE_VA(pve) ((pve)->va_and_flags & ~PAGE_MASK)
#define PVE_FLAGS(pve) ((pve)->va_and_flags & PAGE_MASK)
#define PVE_IS_ALTACCT 0x001
#define PVE_IS_ALTACCT_PAGE(pve) \
        (((pve)->va_and_flags & PVE_IS_ALTACCT) ? TRUE : FALSE)

//#define PV_DEBUG 1   /* uncomment to enable some PV debugging code */
#ifdef PV_DEBUG
#define CHK_NPVHASH() if(0 == npvhashmask) panic("npvhash uninitialized");
#else
#define CHK_NPVHASH(x)
#endif

#define NPVHASHBUCKETS (4096)
#define NPVHASHMASK ((NPVHASHBUCKETS) - 1) /* MUST BE 2^N - 1 */
#define PV_HASHED_LOW_WATER_MARK_DEFAULT 5000
#define PV_HASHED_KERN_LOW_WATER_MARK_DEFAULT 2000
#define PV_HASHED_ALLOC_CHUNK_INITIAL 2000
#define PV_HASHED_KERN_ALLOC_CHUNK_INITIAL 200

extern volatile uint32_t        mappingrecurse;
extern uint32_t  pv_hashed_low_water_mark, pv_hashed_kern_low_water_mark;

/*
 * PV hash locking
 */

#define LOCK_PV_HASH(hash)      lock_hash_hash(hash)
#define UNLOCK_PV_HASH(hash)    unlock_hash_hash(hash)
extern uint32_t npvhashmask;
extern pv_hashed_entry_t        *pv_hash_table;  /* hash lists */
extern pv_hashed_entry_t        pv_hashed_free_list;
extern pv_hashed_entry_t        pv_hashed_kern_free_list;
decl_simple_lock_data(extern, pv_hashed_free_list_lock)
decl_simple_lock_data(extern, pv_hashed_kern_free_list_lock)
decl_simple_lock_data(extern, pv_hash_table_lock)
decl_simple_lock_data(extern, phys_backup_lock)

extern zone_t           pv_hashed_list_zone;    /* zone of pv_hashed_entry
                                                 * structures */

extern uint32_t         pv_hashed_free_count;
extern uint32_t         pv_hashed_kern_free_count;
/*
 *      Each entry in the pv_head_table is locked by a bit in the
 *      pv_lock_table.  The lock bits are accessed by the address of
 *      the frame they lock.
 */
#define pv_lock_table_size(n)   (((n)+BYTE_SIZE-1)/BYTE_SIZE)
#define pv_hash_lock_table_size(n)  (((n)+BYTE_SIZE-1)/BYTE_SIZE)
extern char             *pv_lock_table;         /* pointer to array of bits */
extern char             *pv_hash_lock_table;
extern pv_rooted_entry_t pv_head_table; /* array of entries, one per page */

extern event_t mapping_replenish_event;

static inline void
PV_HASHED_ALLOC(pv_hashed_entry_t *pvh_ep)
{
        pmap_assert(*pvh_ep == PV_HASHED_ENTRY_NULL);
        simple_lock(&pv_hashed_free_list_lock, LCK_GRP_NULL);
        /* If the kernel reserved pool is low, let non-kernel mappings allocate
         * synchronously, possibly subject to a throttle.
         */
        if ((pv_hashed_kern_free_count > pv_hashed_kern_low_water_mark) && ((*pvh_ep = pv_hashed_free_list) != 0)) {
                pv_hashed_free_list = (pv_hashed_entry_t)(*pvh_ep)->qlink.next;
                pv_hashed_free_count--;
        }

        simple_unlock(&pv_hashed_free_list_lock);

        if (pv_hashed_free_count <= pv_hashed_low_water_mark) {
                if (!mappingrecurse && hw_compare_and_store(0, 1, &mappingrecurse)) {
                        thread_wakeup(&mapping_replenish_event);
                }
        }
}

static inline void
PV_HASHED_FREE_LIST(pv_hashed_entry_t pvh_eh, pv_hashed_entry_t pvh_et, int pv_cnt)
{
        simple_lock(&pv_hashed_free_list_lock, LCK_GRP_NULL);
        pvh_et->qlink.next = (queue_entry_t)pv_hashed_free_list;
        pv_hashed_free_list = pvh_eh;
        pv_hashed_free_count += pv_cnt;
        simple_unlock(&pv_hashed_free_list_lock);
}

extern unsigned pmap_kern_reserve_alloc_stat;

static inline void
PV_HASHED_KERN_ALLOC(pv_hashed_entry_t *pvh_e)
{
        pmap_assert(*pvh_e == PV_HASHED_ENTRY_NULL);
        simple_lock(&pv_hashed_kern_free_list_lock, LCK_GRP_NULL);

        if ((*pvh_e = pv_hashed_kern_free_list) != 0) {
                pv_hashed_kern_free_list = (pv_hashed_entry_t)(*pvh_e)->qlink.next;
                pv_hashed_kern_free_count--;
                pmap_kern_reserve_alloc_stat++;
        }

        simple_unlock(&pv_hashed_kern_free_list_lock);

        if (pv_hashed_kern_free_count < pv_hashed_kern_low_water_mark) {
                if (!mappingrecurse && hw_compare_and_store(0, 1, &mappingrecurse)) {
                        thread_wakeup(&mapping_replenish_event);
                }
        }
}

static inline void
PV_HASHED_KERN_FREE_LIST(pv_hashed_entry_t pvh_eh, pv_hashed_entry_t pvh_et, int pv_cnt)
{
        simple_lock(&pv_hashed_kern_free_list_lock, LCK_GRP_NULL);
        pvh_et->qlink.next = (queue_entry_t)pv_hashed_kern_free_list;
        pv_hashed_kern_free_list = pvh_eh;
        pv_hashed_kern_free_count += pv_cnt;
        simple_unlock(&pv_hashed_kern_free_list_lock);
}

extern uint64_t pmap_pv_throttle_stat, pmap_pv_throttled_waiters;
extern event_t pmap_user_pv_throttle_event;

static inline void
pmap_pv_throttle(__unused pmap_t p)
{
        pmap_assert(p != kernel_pmap);
        /* Apply throttle on non-kernel mappings */
        if (pv_hashed_kern_free_count < (pv_hashed_kern_low_water_mark / 2)) {
                pmap_pv_throttle_stat++;
                /* This doesn't need to be strictly accurate, merely a hint
                 * to eliminate the timeout when the reserve is replenished.
                 */
                pmap_pv_throttled_waiters++;
                assert_wait_timeout(&pmap_user_pv_throttle_event, THREAD_UNINT, 1, 1000 * NSEC_PER_USEC);
                thread_block(THREAD_CONTINUE_NULL);
        }
}

/*
 *      Index into pv_head table, its lock bits, and the modify/reference and managed bits
 */

#define pa_index(pa)            (i386_btop(pa))
#define ppn_to_pai(ppn)         ((int)ppn)

#define pai_to_pvh(pai)         (&pv_head_table[pai])
#define lock_pvh_pai(pai)       bit_lock(pai, (void *)pv_lock_table)
#define unlock_pvh_pai(pai)     bit_unlock(pai, (void *)pv_lock_table)
#define pvhash(idx)             (&pv_hash_table[idx])
#define lock_hash_hash(hash)    bit_lock(hash, (void *)pv_hash_lock_table)
#define unlock_hash_hash(hash)  bit_unlock(hash, (void *)pv_hash_lock_table)

#define IS_MANAGED_PAGE(x)                              \
        ((unsigned int)(x) <= last_managed_page &&      \
         (pmap_phys_attributes[x] & PHYS_MANAGED))
#define IS_INTERNAL_PAGE(x)                     \
        (IS_MANAGED_PAGE(x) && (pmap_phys_attributes[x] & PHYS_INTERNAL))
#define IS_REUSABLE_PAGE(x)                     \
        (IS_MANAGED_PAGE(x) && (pmap_phys_attributes[x] & PHYS_REUSABLE))
#define IS_ALTACCT_PAGE(x, pve)                          \
        (IS_MANAGED_PAGE((x)) &&                        \
         (PVE_IS_ALTACCT_PAGE((pve))))

/*
 *      Physical page attributes.  Copy bits from PTE definition.
 */
#define PHYS_MODIFIED   INTEL_PTE_MOD   /* page modified */
#define PHYS_REFERENCED INTEL_PTE_REF   /* page referenced */
#define PHYS_MANAGED    INTEL_PTE_VALID /* page is managed */
#define PHYS_NOENCRYPT  INTEL_PTE_USER  /* no need to encrypt this page in the hibernation image */
#define PHYS_NCACHE     INTEL_PTE_NCACHE
#define PHYS_PAT        INTEL_PTE_PAT
#define PHYS_CACHEABILITY_MASK (INTEL_PTE_PAT | INTEL_PTE_NCACHE)
#define PHYS_INTERNAL   INTEL_PTE_WTHRU /* page from internal object */
#define PHYS_REUSABLE   INTEL_PTE_WRITE /* page is "reusable" */

#if DEVELOPMENT || DEBUG
extern boolean_t        pmap_disable_kheap_nx;
extern boolean_t        pmap_disable_kstack_nx;
#endif

#define PMAP_EXPAND_OPTIONS_NONE (0x0)
#define PMAP_EXPAND_OPTIONS_NOWAIT (PMAP_OPTIONS_NOWAIT)
#define PMAP_EXPAND_OPTIONS_NOENTER (PMAP_OPTIONS_NOENTER)
#define PMAP_EXPAND_OPTIONS_ALIASMAP (0x40000000U)
/*
 *      Amount of virtual memory mapped by one
 *      page-directory entry.
 */
#define PDE_MAPPED_SIZE         (pdetova(1))

/*
 *      Locking and TLB invalidation
 */

/*
 *      Locking Protocols: (changed 2/2007 JK)
 *
 *      There are two structures in the pmap module that need locking:
 *      the pmaps themselves, and the per-page pv_lists (which are locked
 *      by locking the pv_lock_table entry that corresponds to the pv_head
 *      for the list in question.)  Most routines want to lock a pmap and
 *      then do operations in it that require pv_list locking -- however
 *      pmap_remove_all and pmap_copy_on_write operate on a physical page
 *      basis and want to do the locking in the reverse order, i.e. lock
 *      a pv_list and then go through all the pmaps referenced by that list.
 *
 *      The system wide pmap lock has been removed. Now, paths take a lock
 *      on the pmap before changing its 'shape' and the reverse order lockers
 *      (coming in by phys ppn) take a lock on the corresponding pv and then
 *      retest to be sure nothing changed during the window before they locked
 *      and can then run up/down the pv lists holding the list lock. This also
 *      lets the pmap layer run (nearly completely) interrupt enabled, unlike
 *      previously.
 */

/*
 * PV locking
 */

#define LOCK_PVH(index) {               \
        mp_disable_preemption();        \
        lock_pvh_pai(index);            \
}

#define UNLOCK_PVH(index) {             \
        unlock_pvh_pai(index);          \
        mp_enable_preemption();         \
}

extern uint64_t pde_mapped_size;

extern char             *pmap_phys_attributes;
extern ppnum_t          last_managed_page;

extern ppnum_t  lowest_lo;
extern ppnum_t  lowest_hi;
extern ppnum_t  highest_hi;

/*
 * when spinning through pmap_remove
 * ensure that we don't spend too much
 * time with preemption disabled.
 * I'm setting the current threshold
 * to 20us
 */
#define MAX_PREEMPTION_LATENCY_NS 20000
extern uint64_t max_preemption_latency_tsc;

#if DEBUG
#define PMAP_INTR_DEBUG (1)
#endif

#if PMAP_INTR_DEBUG
#define pmap_intr_assert() {                                                    \
        if (processor_avail_count > 1 && !ml_get_interrupts_enabled())          \
                panic("pmap interrupt assert %d %s, %d", processor_avail_count, __FILE__, __LINE__); \
}
#else
#define pmap_intr_assert()
#endif
#if DEVELOPMENT || DEBUG
extern int              nx_enabled;
#endif
extern unsigned int    inuse_ptepages_count;

static inline uint32_t
pvhashidx(pmap_t pmap, vm_map_offset_t va)
{
        uint32_t hashidx = ((uint32_t)(uintptr_t)pmap ^
            ((uint32_t)(va >> PAGE_SHIFT) & 0xFFFFFFFF)) &
            npvhashmask;
        return hashidx;
}

/*
 * unlinks the pv_hashed_entry_t pvh from the singly linked hash chain.
 * properly deals with the anchor.
 * must be called with the hash locked, does not unlock it
 */
static inline void
pmap_pvh_unlink(pv_hashed_entry_t pvh)
{
        pv_hashed_entry_t       curh;
        pv_hashed_entry_t       *pprevh;
        int                     pvhash_idx;

        CHK_NPVHASH();
        pvhash_idx = pvhashidx(pvh->pmap, PVE_VA(pvh));

        pprevh = pvhash(pvhash_idx);

#if PV_DEBUG
        if (NULL == *pprevh) {
                panic("pvh_unlink null anchor"); /* JK DEBUG */
        }
#endif
        curh = *pprevh;

        while (PV_HASHED_ENTRY_NULL != curh) {
                if (pvh == curh) {
                        break;
                }
                pprevh = &curh->nexth;
                curh = curh->nexth;
        }
        if (PV_HASHED_ENTRY_NULL == curh) {
                panic("pmap_pvh_unlink no pvh");
        }
        *pprevh = pvh->nexth;
        return;
}

static inline void
pv_hash_add(pv_hashed_entry_t   pvh_e,
    pv_rooted_entry_t   pv_h)
{
        pv_hashed_entry_t       *hashp;
        int                     pvhash_idx;

        CHK_NPVHASH();
        pvhash_idx = pvhashidx(pvh_e->pmap, PVE_VA(pvh_e));
        LOCK_PV_HASH(pvhash_idx);
        insque(&pvh_e->qlink, &pv_h->qlink);
        hashp = pvhash(pvhash_idx);
#if PV_DEBUG
        if (NULL == hashp) {
                panic("pv_hash_add(%p) null hash bucket", pvh_e);
        }
#endif
        pvh_e->nexth = *hashp;
        *hashp = pvh_e;
        UNLOCK_PV_HASH(pvhash_idx);
}

static inline void
pv_hash_remove(pv_hashed_entry_t pvh_e)
{
        int                     pvhash_idx;

        CHK_NPVHASH();
        pvhash_idx = pvhashidx(pvh_e->pmap, PVE_VA(pvh_e));
        LOCK_PV_HASH(pvhash_idx);
        remque(&pvh_e->qlink);
        pmap_pvh_unlink(pvh_e);
        UNLOCK_PV_HASH(pvhash_idx);
}

static inline boolean_t
popcnt1(uint64_t distance)
{
        return (distance & (distance - 1)) == 0;
}

/*
 * Routines to handle suppression of/recovery from some forms of pagetable corruption
 * incidents observed in the field. These can be either software induced (wild
 * stores to the mapwindows where applicable, use after free errors
 * (typically of pages addressed physically), mis-directed DMAs etc., or due
 * to DRAM/memory hierarchy/interconnect errors. Given the theoretical rarity of these errors,
 * the recording mechanism is deliberately not MP-safe. The overarching goal is to
 * still assert on potential software races, but attempt recovery from incidents
 * identifiable as occurring due to issues beyond the control of the pmap module.
 * The latter includes single-bit errors and malformed pagetable entries.
 * We currently limit ourselves to recovery/suppression of one incident per
 * PMAP_PAGETABLE_CORRUPTION_INTERVAL seconds, and details of the incident
 * are logged.
 * Assertions are not suppressed if kernel debugging is enabled. (DRK 09)
 */

typedef enum {
        PTE_VALID               = 0x0,
        PTE_INVALID             = 0x1,
        PTE_RSVD                = 0x2,
        PTE_SUPERVISOR          = 0x4,
        PTE_BITFLIP             = 0x8,
        PV_BITFLIP              = 0x10,
        PTE_INVALID_CACHEABILITY = 0x20
} pmap_pagetable_corruption_t;

typedef enum {
        ROOT_PRESENT = 0,
        ROOT_ABSENT = 1
} pmap_pv_assertion_t;

typedef enum {
        PMAP_ACTION_IGNORE      = 0x0,
        PMAP_ACTION_ASSERT      = 0x1,
        PMAP_ACTION_RETRY       = 0x2,
        PMAP_ACTION_RETRY_RELOCK = 0x4
} pmap_pagetable_corruption_action_t;

#define PMAP_PAGETABLE_CORRUPTION_INTERVAL (6ULL * 3600ULL)
extern uint64_t pmap_pagetable_corruption_interval_abstime;

extern uint32_t pmap_pagetable_corruption_incidents;
#define PMAP_PAGETABLE_CORRUPTION_MAX_LOG (8)
typedef struct {
        pmap_pv_assertion_t incident;
        pmap_pagetable_corruption_t reason;
        pmap_pagetable_corruption_action_t action;
        pmap_t  pmap;
        vm_map_offset_t vaddr;
        pt_entry_t pte;
        ppnum_t ppn;
        pmap_t pvpmap;
        vm_map_offset_t pvva;
        uint64_t abstime;
} pmap_pagetable_corruption_record_t;

extern pmap_pagetable_corruption_record_t pmap_pagetable_corruption_records[];
extern uint64_t pmap_pagetable_corruption_last_abstime;
extern thread_call_t    pmap_pagetable_corruption_log_call;
extern boolean_t pmap_pagetable_corruption_timeout;

static inline void
pmap_pagetable_corruption_log(pmap_pv_assertion_t incident, pmap_pagetable_corruption_t suppress_reason, pmap_pagetable_corruption_action_t action, pmap_t pmap, vm_map_offset_t vaddr, pt_entry_t *ptep, ppnum_t ppn, pmap_t pvpmap, vm_map_offset_t pvva)
{
        uint32_t pmap_pagetable_corruption_log_index;
        pmap_pagetable_corruption_log_index = pmap_pagetable_corruption_incidents++ % PMAP_PAGETABLE_CORRUPTION_MAX_LOG;
        pmap_pagetable_corruption_records[pmap_pagetable_corruption_log_index].incident = incident;
        pmap_pagetable_corruption_records[pmap_pagetable_corruption_log_index].reason = suppress_reason;
        pmap_pagetable_corruption_records[pmap_pagetable_corruption_log_index].action = action;
        pmap_pagetable_corruption_records[pmap_pagetable_corruption_log_index].pmap = pmap;
        pmap_pagetable_corruption_records[pmap_pagetable_corruption_log_index].vaddr = vaddr;
        pmap_pagetable_corruption_records[pmap_pagetable_corruption_log_index].pte = *ptep;
        pmap_pagetable_corruption_records[pmap_pagetable_corruption_log_index].ppn = ppn;
        pmap_pagetable_corruption_records[pmap_pagetable_corruption_log_index].pvpmap = pvpmap;
        pmap_pagetable_corruption_records[pmap_pagetable_corruption_log_index].pvva = pvva;
        pmap_pagetable_corruption_records[pmap_pagetable_corruption_log_index].abstime = mach_absolute_time();
        /* Asynchronously log */
        thread_call_enter(pmap_pagetable_corruption_log_call);
}

static inline pmap_pagetable_corruption_action_t
pmap_classify_pagetable_corruption(pmap_t pmap, vm_map_offset_t vaddr, ppnum_t *ppnp, pt_entry_t *ptep, pmap_pv_assertion_t incident)
{
        pmap_pagetable_corruption_action_t      action = PMAP_ACTION_ASSERT;
        pmap_pagetable_corruption_t     suppress_reason = PTE_VALID;
        ppnum_t                 suppress_ppn = 0;
        pt_entry_t cpte = *ptep;
        ppnum_t cpn = pa_index(pte_to_pa(cpte));
        ppnum_t ppn = *ppnp;
        pv_rooted_entry_t       pv_h = pai_to_pvh(ppn_to_pai(ppn));
        pv_rooted_entry_t       pv_e = pv_h;
        uint32_t        bitdex;
        pmap_t pvpmap = pv_h->pmap;
        vm_map_offset_t pvva = PVE_VA(pv_h);
        vm_map_offset_t pve_flags;
        boolean_t ppcd = FALSE;
        boolean_t is_ept;

        /* Ideally, we'd consult the Mach VM here to definitively determine
         * the nature of the mapping for this address space and address.
         * As that would be a layering violation in this context, we
         * use various heuristics to recover from single bit errors,
         * malformed pagetable entries etc. These are not intended
         * to be comprehensive.
         */

        /* As a precautionary measure, mark A+D */
        pmap_phys_attributes[ppn_to_pai(ppn)] |= (PHYS_MODIFIED | PHYS_REFERENCED);
        is_ept = is_ept_pmap(pmap);

        /*
         * Correct potential single bit errors in either (but not both) element
         * of the PV
         */
        do {
                if ((popcnt1((uintptr_t)pv_e->pmap ^ (uintptr_t)pmap) && PVE_VA(pv_e) == vaddr) ||
                    (pv_e->pmap == pmap && popcnt1(PVE_VA(pv_e) ^ vaddr))) {
                        pve_flags = PVE_FLAGS(pv_e);
                        pv_e->pmap = pmap;
                        pv_h->va_and_flags = vaddr | pve_flags;
                        suppress_reason = PV_BITFLIP;
                        action = PMAP_ACTION_RETRY;
                        goto pmap_cpc_exit;
                }
        } while (((pv_e = (pv_rooted_entry_t) queue_next(&pv_e->qlink))) && (pv_e != pv_h));

        /* Discover root entries with a Hamming
         * distance of 1 from the supplied
         * physical page frame.
         */
        for (bitdex = 0; bitdex < (sizeof(ppnum_t) << 3); bitdex++) {
                ppnum_t npn = cpn ^ (ppnum_t) (1ULL << bitdex);
                if (IS_MANAGED_PAGE(npn)) {
                        pv_rooted_entry_t npv_h = pai_to_pvh(ppn_to_pai(npn));
                        if (PVE_VA(npv_h) == vaddr && npv_h->pmap == pmap) {
                                suppress_reason = PTE_BITFLIP;
                                suppress_ppn = npn;
                                action = PMAP_ACTION_RETRY_RELOCK;
                                UNLOCK_PVH(ppn_to_pai(ppn));
                                *ppnp = npn;
                                goto pmap_cpc_exit;
                        }
                }
        }

        if (pmap == kernel_pmap) {
                action = PMAP_ACTION_ASSERT;
                goto pmap_cpc_exit;
        }

        /*
         * Check for malformed/inconsistent entries.
         * The first check here isn't useful for EPT PTEs because INTEL_EPT_NCACHE == 0
         */
        if (!is_ept && ((cpte & (INTEL_PTE_NCACHE | INTEL_PTE_WTHRU | INTEL_PTE_PAT)) == (INTEL_PTE_NCACHE | INTEL_PTE_WTHRU))) {
                action = PMAP_ACTION_IGNORE;
                suppress_reason = PTE_INVALID_CACHEABILITY;
        } else if (cpte & INTEL_PTE_RSVD) {
                action = PMAP_ACTION_IGNORE;
                suppress_reason = PTE_RSVD;
        } else if ((pmap != kernel_pmap) && (!is_ept) && ((cpte & INTEL_PTE_USER) == 0)) {
                action = PMAP_ACTION_IGNORE;
                suppress_reason = PTE_SUPERVISOR;
        }
pmap_cpc_exit:
        PE_parse_boot_argn("-pmap_pagetable_corruption_deassert", &ppcd, sizeof(ppcd));

        if (debug_boot_arg && !ppcd) {
                action = PMAP_ACTION_ASSERT;
        }

        if ((mach_absolute_time() - pmap_pagetable_corruption_last_abstime) < pmap_pagetable_corruption_interval_abstime) {
                action = PMAP_ACTION_ASSERT;
                pmap_pagetable_corruption_timeout = TRUE;
        } else {
                pmap_pagetable_corruption_last_abstime = mach_absolute_time();
        }
        pmap_pagetable_corruption_log(incident, suppress_reason, action, pmap, vaddr, &cpte, *ppnp, pvpmap, pvva);
        return action;
}

/*
 * Remove pv list entry.
 * Called with pv_head_table entry locked.
 * Returns pv entry to be freed (or NULL).
 */
static inline __attribute__((always_inline)) pv_hashed_entry_t
pmap_pv_remove(pmap_t           pmap,
    vm_map_offset_t  vaddr,
    ppnum_t          *ppnp,
    pt_entry_t       *pte,
    boolean_t        *was_altacct)
{
        pv_hashed_entry_t       pvh_e;
        pv_rooted_entry_t       pv_h;
        pv_hashed_entry_t       *pprevh;
        int                     pvhash_idx;
        uint32_t                pv_cnt;
        ppnum_t                 ppn;

        *was_altacct = FALSE;
pmap_pv_remove_retry:
        ppn = *ppnp;
        pvh_e = PV_HASHED_ENTRY_NULL;
        pv_h = pai_to_pvh(ppn_to_pai(ppn));

        if (__improbable(pv_h->pmap == PMAP_NULL)) {
                pmap_pagetable_corruption_action_t pac = pmap_classify_pagetable_corruption(pmap, vaddr, ppnp, pte, ROOT_ABSENT);
                if (pac == PMAP_ACTION_IGNORE) {
                        goto pmap_pv_remove_exit;
                } else if (pac == PMAP_ACTION_ASSERT) {
                        panic("Possible memory corruption: pmap_pv_remove(%p,0x%llx,0x%x, 0x%llx, %p, %p): null pv_list, priors: %d", pmap, vaddr, ppn, *pte, ppnp, pte, pmap_pagetable_corruption_incidents);
                } else if (pac == PMAP_ACTION_RETRY_RELOCK) {
                        LOCK_PVH(ppn_to_pai(*ppnp));
                        pmap_phys_attributes[ppn_to_pai(*ppnp)] |= (PHYS_MODIFIED | PHYS_REFERENCED);
                        goto pmap_pv_remove_retry;
                } else if (pac == PMAP_ACTION_RETRY) {
                        goto pmap_pv_remove_retry;
                }
        }

        if (PVE_VA(pv_h) == vaddr && pv_h->pmap == pmap) {
                *was_altacct = IS_ALTACCT_PAGE(ppn_to_pai(*ppnp), pv_h);
                /*
                 * Header is the pv_rooted_entry.
                 * We can't free that. If there is a queued
                 * entry after this one we remove that
                 * from the ppn queue, we remove it from the hash chain
                 * and copy it to the rooted entry. Then free it instead.
                 */
                pvh_e = (pv_hashed_entry_t) queue_next(&pv_h->qlink);
                if (pv_h != (pv_rooted_entry_t) pvh_e) {
                        /*
                         * Entry queued to root, remove this from hash
                         * and install as new root.
                         */
                        CHK_NPVHASH();
                        pvhash_idx = pvhashidx(pvh_e->pmap, PVE_VA(pvh_e));
                        LOCK_PV_HASH(pvhash_idx);
                        remque(&pvh_e->qlink);
                        pprevh = pvhash(pvhash_idx);
                        if (PV_HASHED_ENTRY_NULL == *pprevh) {
                                panic("Possible memory corruption: pmap_pv_remove(%p,0x%llx,0x%x): "
                                    "empty hash, removing rooted, priors: %d",
                                    pmap, vaddr, ppn, pmap_pagetable_corruption_incidents);
                        }
                        pmap_pvh_unlink(pvh_e);
                        UNLOCK_PV_HASH(pvhash_idx);
                        pv_h->pmap = pvh_e->pmap;
                        pv_h->va_and_flags = pvh_e->va_and_flags;
                        /* dispose of pvh_e */
                } else {
                        /* none queued after rooted */
                        pv_h->pmap = PMAP_NULL;
                        pvh_e = PV_HASHED_ENTRY_NULL;
                }
        } else {
                /*
                 * not removing rooted pv. find it on hash chain, remove from
                 * ppn queue and hash chain and free it
                 */
                CHK_NPVHASH();
                pvhash_idx = pvhashidx(pmap, vaddr);
                LOCK_PV_HASH(pvhash_idx);
                pprevh = pvhash(pvhash_idx);
                if (PV_HASHED_ENTRY_NULL == *pprevh) {
                        panic("Possible memory corruption: pmap_pv_remove(%p,0x%llx,0x%x, 0x%llx, %p): empty hash, priors: %d",
                            pmap, vaddr, ppn, *pte, pte, pmap_pagetable_corruption_incidents);
                }
                pvh_e = *pprevh;
                pmap_pv_hashlist_walks++;
                pv_cnt = 0;
                while (PV_HASHED_ENTRY_NULL != pvh_e) {
                        pv_cnt++;
                        if (pvh_e->pmap == pmap &&
                            PVE_VA(pvh_e) == vaddr &&
                            pvh_e->ppn == ppn) {
                                break;
                        }
                        pprevh = &pvh_e->nexth;
                        pvh_e = pvh_e->nexth;
                }

                if (PV_HASHED_ENTRY_NULL == pvh_e) {
                        pmap_pagetable_corruption_action_t pac = pmap_classify_pagetable_corruption(pmap, vaddr, ppnp, pte, ROOT_PRESENT);

                        if (pac == PMAP_ACTION_ASSERT) {
                                panic("Possible memory corruption: pmap_pv_remove(%p, 0x%llx, 0x%x, 0x%llx, %p, %p): pv not on hash, head: %p, 0x%llx, priors: %d", pmap, vaddr, ppn, *pte, ppnp, pte, pv_h->pmap, PVE_VA(pv_h), pmap_pagetable_corruption_incidents);
                        } else {
                                UNLOCK_PV_HASH(pvhash_idx);
                                if (pac == PMAP_ACTION_RETRY_RELOCK) {
                                        LOCK_PVH(ppn_to_pai(*ppnp));
                                        pmap_phys_attributes[ppn_to_pai(*ppnp)] |= (PHYS_MODIFIED | PHYS_REFERENCED);
                                        goto pmap_pv_remove_retry;
                                } else if (pac == PMAP_ACTION_RETRY) {
                                        goto pmap_pv_remove_retry;
                                } else if (pac == PMAP_ACTION_IGNORE) {
                                        goto pmap_pv_remove_exit;
                                }
                        }
                }

                *was_altacct = IS_ALTACCT_PAGE(ppn_to_pai(*ppnp), pvh_e);

                pmap_pv_hashlist_cnts += pv_cnt;
                if (pmap_pv_hashlist_max < pv_cnt) {
                        pmap_pv_hashlist_max = pv_cnt;
                }
                *pprevh = pvh_e->nexth;
                remque(&pvh_e->qlink);
                UNLOCK_PV_HASH(pvhash_idx);
        }
pmap_pv_remove_exit:
        return pvh_e;
}

static inline __attribute__((always_inline)) boolean_t
pmap_pv_is_altacct(
        pmap_t          pmap,
        vm_map_offset_t vaddr,
        ppnum_t         ppn)
{
        pv_hashed_entry_t       pvh_e;
        pv_rooted_entry_t       pv_h;
        int                     pvhash_idx;
        boolean_t               is_altacct;

        pvh_e = PV_HASHED_ENTRY_NULL;
        pv_h = pai_to_pvh(ppn_to_pai(ppn));

        if (__improbable(pv_h->pmap == PMAP_NULL)) {
                return FALSE;
        }

        if (PVE_VA(pv_h) == vaddr && pv_h->pmap == pmap) {
                /*
                 * Header is the pv_rooted_entry.
                 */
                return IS_ALTACCT_PAGE(ppn, pv_h);
        }

        CHK_NPVHASH();
        pvhash_idx = pvhashidx(pmap, vaddr);
        LOCK_PV_HASH(pvhash_idx);
        pvh_e = *(pvhash(pvhash_idx));
        while (PV_HASHED_ENTRY_NULL != pvh_e) {
                if (pvh_e->pmap == pmap &&
                    PVE_VA(pvh_e) == vaddr &&
                    pvh_e->ppn == ppn) {
                        break;
                }
                pvh_e = pvh_e->nexth;
        }
        if (PV_HASHED_ENTRY_NULL == pvh_e) {
                is_altacct = FALSE;
        } else {
                is_altacct = IS_ALTACCT_PAGE(ppn, pvh_e);
        }
        UNLOCK_PV_HASH(pvhash_idx);

        return is_altacct;
}

extern int      pt_fake_zone_index;
static inline void
PMAP_ZINFO_PALLOC(pmap_t pmap, vm_size_t bytes)
{
        pmap_ledger_credit(pmap, task_ledgers.tkm_private, bytes);
}

static inline void
PMAP_ZINFO_PFREE(pmap_t pmap, vm_size_t bytes)
{
        pmap_ledger_debit(pmap, task_ledgers.tkm_private, bytes);
}

static inline void
PMAP_ZINFO_SALLOC(pmap_t pmap, vm_size_t bytes)
{
        pmap_ledger_credit(pmap, task_ledgers.tkm_shared, bytes);
}

static inline void
PMAP_ZINFO_SFREE(pmap_t pmap, vm_size_t bytes)
{
        pmap_ledger_debit(pmap, task_ledgers.tkm_shared, bytes);
}

extern boolean_t        pmap_initialized;/* Has pmap_init completed? */
#define valid_page(x) (pmap_initialized && pmap_valid_page(x))

int             phys_attribute_test(
        ppnum_t         phys,
        int             bits);
void            phys_attribute_clear(
        ppnum_t         phys,
        int             bits,
        unsigned int    options,
        void            *arg);

//#define PCID_DEBUG 1
#if     PCID_DEBUG
#define pmap_pcid_log(fmt, args...)                                     \
        do {                                                            \
                kprintf(fmt, ##args);                                   \
                printf(fmt, ##args);                                    \
        } while(0)
#else
#define pmap_pcid_log(fmt, args...)
#endif
void    pmap_pcid_configure(void);


/*
 * Atomic 64-bit compare and exchange of a page table entry.
 */

#include <machine/atomic.h>
static inline boolean_t
pmap_cmpx_pte(pt_entry_t *entryp, pt_entry_t old, pt_entry_t new)
{
        return __c11_atomic_compare_exchange_strong((_Atomic pt_entry_t *)entryp, &old, new,
                   memory_order_acq_rel_smp, memory_order_relaxed);
}

extern uint32_t pmap_update_clear_pte_count;

static inline void
pmap_update_pte(pt_entry_t *mptep, uint64_t pclear_bits, uint64_t pset_bits)
{
        pt_entry_t npte, opte;
        do {
                opte = *mptep;
                if (__improbable(opte == 0)) {
#if DEVELOPMENT || DEBUG
                        pmap_update_clear_pte_count++;
#endif
                        break;
                }
                npte = opte & ~(pclear_bits);
                npte |= pset_bits;
        }       while (!pmap_cmpx_pte(mptep, opte, npte));
}

/*
 * The single pml4 page per pmap is allocated at pmap create time and exists
 * for the duration of the pmap. we allocate this page in kernel vm.
 * this returns the address of the requested pml4 entry in the top level page.
 */
static inline
pml4_entry_t *
pmap64_pml4(pmap_t pmap, vm_map_offset_t vaddr)
{
        if (__improbable((vaddr > 0x00007FFFFFFFFFFFULL) &&
            (vaddr < 0xFFFF800000000000ULL))) {
                return NULL;
        }

#if     DEBUG
        return PHYSMAP_PTOV(&((pml4_entry_t *)pmap->pm_cr3)[(vaddr >> PML4SHIFT) & (NPML4PG - 1)]);
#else
        return &pmap->pm_pml4[(vaddr >> PML4SHIFT) & (NPML4PG - 1)];
#endif
}

static inline pml4_entry_t *
pmap64_user_pml4(pmap_t pmap, vm_map_offset_t vaddr)
{
        if (__improbable((vaddr > 0x00007FFFFFFFFFFFULL) &&
            (vaddr < 0xFFFF800000000000ULL))) {
                return NULL;
        }

#if     DEBUG
        return PHYSMAP_PTOV(&((pml4_entry_t *)pmap->pm_ucr3)[(vaddr >> PML4SHIFT) & (NPML4PG - 1)]);
#else
        return &pmap->pm_upml4[(vaddr >> PML4SHIFT) & (NPML4PG - 1)];
#endif
}

/*
 * Returns address of requested PDPT entry in the physmap.
 */
static inline pdpt_entry_t *
pmap64_pdpt(pmap_t pmap, vm_map_offset_t vaddr)
{
        pml4_entry_t    newpf;
        pml4_entry_t    *pml4;
        boolean_t       is_ept;

        pml4 = pmap64_pml4(pmap, vaddr);
        is_ept = is_ept_pmap(pmap);

        if (pml4 && (*pml4 & PTE_VALID_MASK(is_ept))) {
                newpf = *pml4 & PG_FRAME;
                return &((pdpt_entry_t *) PHYSMAP_PTOV(newpf))
                       [(vaddr >> PDPTSHIFT) & (NPDPTPG - 1)];
        }
        return NULL;
}
/*
 * Returns the address of the requested PDE entry in the physmap.
 */
static inline pd_entry_t *
pmap_pde_internal1(vm_map_offset_t vaddr, boolean_t is_ept, pdpt_entry_t *pdpte)
{
        if (*pdpte & PTE_VALID_MASK(is_ept)) {
                pdpt_entry_t    newpf = *pdpte & PG_FRAME;
                return &((pd_entry_t *) PHYSMAP_PTOV(newpf))
                       [(vaddr >> PDSHIFT) & (NPDPG - 1)];
        } else {
                return NULL;
        }
}

static inline pd_entry_t *
pmap_pde_internal0(pmap_t pmap, vm_map_offset_t vaddr, boolean_t is_ept)
{
        pdpt_entry_t    *pdpt;

        pdpt = pmap64_pdpt(pmap, vaddr);
        if (pdpt) {
                return pmap_pde_internal1(vaddr, is_ept, pdpt);
        } else {
                return NULL;
        }
}


static inline pd_entry_t *
pmap_pde(pmap_t pmap, vm_map_offset_t vaddr)
{
        pdpt_entry_t    *pdpt;
        boolean_t       is_ept;

        pdpt = pmap64_pdpt(pmap, vaddr);
        is_ept = is_ept_pmap(pmap);

        if (pdpt) {
                return pmap_pde_internal1(vaddr, is_ept, pdpt);
        } else {
                return NULL;
        }
}


/*
 * return address of mapped pte for vaddr va in pmap pmap.
 *
 * In case the pde maps a superpage, return the pde, which, in this case
 * is the actual page table entry.
 */


static inline pt_entry_t *
pmap_pte_internal(vm_map_offset_t vaddr, boolean_t is_ept, pd_entry_t *pde)
{
        if (*pde & PTE_VALID_MASK(is_ept)) {
                if (__improbable(*pde & PTE_PS)) {
                        return pde;
                }
                pd_entry_t      newpf = *pde & PG_FRAME;

                return &((pt_entry_t *)PHYSMAP_PTOV(newpf))
                       [i386_btop(vaddr) & (ppnum_t)(NPTEPG - 1)];
        } else {
                return NULL;
        }
}

static inline pt_entry_t *
pmap_pte(pmap_t pmap, vm_map_offset_t vaddr)
{
        pd_entry_t      *pde;

        boolean_t       is_ept;

        is_ept = is_ept_pmap(pmap);

        pde = pmap_pde_internal0(pmap, vaddr, is_ept);

        if (pde) {
                return pmap_pte_internal(vaddr, is_ept, pde);
        } else {
                return NULL;
        }
}

extern void     pmap_alias(
        vm_offset_t     ava,
        vm_map_offset_t start,
        vm_map_offset_t end,
        vm_prot_t       prot,
        unsigned int options);

#if     DEBUG
#define DPRINTF(x...)   kprintf(x)
#else
#define DPRINTF(x...)
#endif

#endif /* MACH_KERNEL_PRIVATE */
#endif /* _I386_PMAP_INTERNAL_ */