[apple/xnu.git] / osfmk / vm / vm_page.h

/*
 * Copyright (c) 2000-2005 Apple Computer, 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
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989,1988 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.h
 *	Author:	Avadis Tevanian, Jr., Michael Wayne Young
 *	Date:	1985
 *
 *	Resident memory system definitions.
 */

#ifndef	_VM_VM_PAGE_H_
#define _VM_VM_PAGE_H_

#include <debug.h>

#include <mach/boolean.h>
#include <mach/vm_prot.h>
#include <mach/vm_param.h>
#include <vm/vm_object.h>
#include <kern/queue.h>
#include <kern/lock.h>

#include <kern/macro_help.h>

/* 
 * Each page entered on the inactive queue obtains a ticket from a
 * particular ticket roll.  Pages granted tickets from a particular 
 * roll  generally flow through the queue as a group.  In this way when a
 * page with a ticket from a particular roll is pulled from the top of the
 * queue it is extremely likely that the pages near the top will have tickets
 * from the same or adjacent rolls.  In this way the proximity to the top
 * of the queue can be loosely ascertained by determining the identity of
 * the roll the pages ticket came from. 
 */


extern unsigned int	vm_page_ticket_roll;
extern unsigned int	vm_page_ticket;


#define VM_PAGE_TICKETS_IN_ROLL  512
#define VM_PAGE_TICKET_ROLL_IDS  16

/*
 *	Management of resident (logical) pages.
 *
 *	A small structure is kept for each resident
 *	page, indexed by page number.  Each structure
 *	is an element of several lists:
 *
 *		A hash table bucket used to quickly
 *		perform object/offset lookups
 *
 *		A list of all pages for a given object,
 *		so they can be quickly deactivated at
 *		time of deallocation.
 *
 *		An ordered list of pages due for pageout.
 *
 *	In addition, the structure contains the object
 *	and offset to which this page belongs (for pageout),
 *	and sundry status bits.
 *
 *	Fields in this structure are locked either by the lock on the
 *	object that the page belongs to (O) or by the lock on the page
 *	queues (P).  [Some fields require that both locks be held to
 *	change that field; holding either lock is sufficient to read.]
 */

struct vm_page {
	queue_chain_t	pageq;		/* queue info for FIFO
					 * queue or free list (P) */
	queue_chain_t	listq;		/* all pages in same object (O) */
	struct vm_page	*next;		/* VP bucket link (O) */

	vm_object_t	object;		/* which object am I in (O&P) */
	vm_object_offset_t offset;	/* offset into that object (O,P) */

	/*
	 * The following word of flags is protected
	 * by the "page queues" lock.
	 */
	unsigned int	wire_count:16,	/* how many wired down maps use me? (O&P) */
			page_ticket:4,	/* age of the page on the       */
					/* inactive queue.		    */
	/* boolean_t */	inactive:1,	/* page is in inactive list (P) */
			active:1,	/* page is in active list (P) */
			pageout_queue:1,/* page is on queue for pageout (P) */
			laundry:1,	/* page is being cleaned now (P)*/
			free:1,		/* page is on free list (P) */
			reference:1,	/* page has been used (P) */
			pageout:1,	/* page wired & busy for pageout (P) */
			gobbled:1,      /* page used internally (P) */
			private:1,	/* Page should not be returned to
					 *  the free list (P) */
			zero_fill:1,
			:0;

	/*
	 * The following word of flags is protected
	 * by the "VM object" lock.
	 */
	unsigned int
	                page_error:8,   /* error from I/O operations */
	/* boolean_t */	busy:1,		/* page is in transit (O) */
			wanted:1,	/* someone is waiting for page (O) */
			tabled:1,	/* page is in VP table (O) */
			fictitious:1,	/* Physical page doesn't exist (O) */
			no_isync:1,     /* page has not been instruction synced */
			absent:1,	/* Data has been requested, but is
					 *  not yet available (O) */
			error:1,	/* Data manager was unable to provide
					 *  data due to error (O) */
			dirty:1,	/* Page must be cleaned (O) */
			cleaning:1,	/* Page clean has begun (O) */
			precious:1,	/* Page is precious; data must be
					 *  returned even if clean (O) */
			clustered:1,	/* page is not the faulted page (O) */
			overwriting:1,  /* Request to unlock has been made
					 * without having data. (O)
					 * [See vm_fault_page_overwrite] */
			restart:1,	/* Page was pushed higher in shadow
					   chain by copy_call-related pagers;
					   start again at top of chain */
			lock_supplied:1,/* protection supplied by pager (O) */
	/* vm_prot_t */	page_lock:3,	/* Uses prohibited by pager (O) */
	/* vm_prot_t */	unlock_request:3,/* Outstanding unlock request (O) */
			unusual:1,	/* Page is absent, error, restart or
					   page locked */
			encrypted:1,	/* encrypted for secure swap (O) */
			list_req_pending:1, /* pagein/pageout alt mechanism */
					    /* allows creation of list      */
					    /* requests on pages that are   */
					    /* actively being paged.        */
			dump_cleaning:1;   /* set by the pageout daemon when */
					   /* a page being cleaned is       */
					   /* encountered and targeted as   */
					   /* a pageout candidate           */
        /* we've used up all 32 bits */

	ppnum_t		phys_page;	/* Physical address of page, passed
					 *  to pmap_enter (read-only) */
};

#define DEBUG_ENCRYPTED_SWAP	1
#if DEBUG_ENCRYPTED_SWAP
#define ASSERT_PAGE_DECRYPTED(page) 					\
	MACRO_BEGIN							\
	if ((page)->encrypted) {					\
		panic("VM page %p should not be encrypted here\n",	\
		      (page));						\
	}								\
	MACRO_END
#else	/* DEBUG_ENCRYPTED_SWAP */
#define ASSERT_PAGE_DECRYPTED(page) assert(!(page)->encrypted)
#endif	/* DEBUG_ENCRYPTED_SWAP */

typedef struct vm_page	*vm_page_t;

#define VM_PAGE_NULL		((vm_page_t) 0)
#define NEXT_PAGE(m)		((vm_page_t) (m)->pageq.next)
#define NEXT_PAGE_PTR(m)	((vm_page_t *) &(m)->pageq.next)

/*
 * XXX	The unusual bit should not be necessary.  Most of the bit
 * XXX	fields above really want to be masks.
 */

/*
 *	For debugging, this macro can be defined to perform
 *	some useful check on a page structure.
 */

#define VM_PAGE_CHECK(mem)

/*
 *	Each pageable resident page falls into one of three lists:
 *
 *	free	
 *		Available for allocation now.
 *	inactive
 *		Not referenced in any map, but still has an
 *		object/offset-page mapping, and may be dirty.
 *		This is the list of pages that should be
 *		paged out next.
 *	active
 *		A list of pages which have been placed in
 *		at least one physical map.  This list is
 *		ordered, in LRU-like fashion.
 */

extern
vm_page_t	vm_page_queue_free;	/* memory free queue */
extern
vm_page_t	vm_page_queue_fictitious;	/* fictitious free queue */
extern
queue_head_t	vm_page_queue_active;	/* active memory queue */
extern
queue_head_t	vm_page_queue_inactive;	/* inactive memory queue */
queue_head_t	vm_page_queue_zf;	/* inactive memory queue for zero fill */

extern
vm_offset_t	first_phys_addr;	/* physical address for first_page */
extern
vm_offset_t	last_phys_addr;		/* physical address for last_page */

extern
unsigned int	vm_page_free_count;	/* How many pages are free? */
extern
unsigned int	vm_page_fictitious_count;/* How many fictitious pages are free? */
extern
unsigned int	vm_page_active_count;	/* How many pages are active? */
extern
unsigned int	vm_page_inactive_count;	/* How many pages are inactive? */
extern
unsigned int	vm_page_wire_count;	/* How many pages are wired? */
extern
unsigned int	vm_page_free_target;	/* How many do we want free? */
extern
unsigned int	vm_page_free_min;	/* When to wakeup pageout */
extern
unsigned int	vm_page_inactive_target;/* How many do we want inactive? */
extern
unsigned int	vm_page_free_reserved;	/* How many pages reserved to do pageout */
extern
unsigned int	vm_page_throttled_count;/* Count of zero-fill allocations throttled */
extern
unsigned int	vm_page_gobble_count;

extern
unsigned int	vm_page_purgeable_count;/* How many pages are purgeable now ? */
extern
uint64_t	vm_page_purged_count;	/* How many pages got purged so far ? */

decl_mutex_data(,vm_page_queue_lock)
				/* lock on active and inactive page queues */
decl_mutex_data(,vm_page_queue_free_lock)
				/* lock on free page queue */

extern unsigned int	vm_page_free_wanted;
				/* how many threads are waiting for memory */

extern vm_offset_t	vm_page_fictitious_addr;
				/* (fake) phys_addr of fictitious pages */

extern boolean_t	vm_page_deactivate_hint;

/*
 * Prototypes for functions exported by this module.
 */
extern void		vm_page_bootstrap(
					vm_offset_t	*startp,
					vm_offset_t	*endp);

extern void		vm_page_module_init(void);

extern void		vm_page_create(
					ppnum_t		start,
					ppnum_t		end);

extern vm_page_t	vm_page_lookup(
					vm_object_t		object,
					vm_object_offset_t	offset);

extern vm_page_t	vm_page_grab_fictitious(void);

extern void		vm_page_release_fictitious(
					vm_page_t page);

extern boolean_t	vm_page_convert(
					vm_page_t	page);

extern void		vm_page_more_fictitious(void);

extern int		vm_pool_low(void);

extern vm_page_t	vm_page_grab(void);

extern void		vm_page_release(
					vm_page_t	page);

extern boolean_t	vm_page_wait(
					int		interruptible );

extern vm_page_t	vm_page_alloc(
					vm_object_t		object,
					vm_object_offset_t	offset);

extern void		vm_page_init(
					vm_page_t	page,
					ppnum_t		phys_page);

extern void		vm_page_free(
					vm_page_t	page);

extern void		vm_page_activate(
					vm_page_t	page);

extern void		vm_page_deactivate(
					vm_page_t	page);

extern void		vm_page_rename(
					vm_page_t		page,
					vm_object_t		new_object,
					vm_object_offset_t	new_offset);

extern void		vm_page_insert(
					vm_page_t		page,
					vm_object_t		object,
					vm_object_offset_t	offset);

extern void		vm_page_replace(
					vm_page_t		mem,
					vm_object_t		object,
					vm_object_offset_t	offset);

extern void		vm_page_remove(
					vm_page_t	page);

extern void		vm_page_zero_fill(
					vm_page_t	page);

extern void		vm_page_part_zero_fill(
					vm_page_t	m,
					vm_offset_t	m_pa,
					vm_size_t	len);

extern void		vm_page_copy(
					vm_page_t	src_page,
					vm_page_t	dest_page);

extern 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);

extern void		vm_page_wire(
					vm_page_t	page);

extern void		vm_page_unwire(
					vm_page_t	page);

extern void		vm_set_page_size(void);

extern void		vm_page_gobble(
				        vm_page_t      page);

/*
 *	Functions implemented as macros. m->wanted and m->busy are
 *	protected by the object lock.
 */

#define PAGE_ASSERT_WAIT(m, interruptible)			\
		(((m)->wanted = TRUE),				\
		 assert_wait((event_t) (m), (interruptible)))

#define PAGE_SLEEP(o, m, interruptible)				\
		(((m)->wanted = TRUE),				\
		 thread_sleep_vm_object((o), (m), (interruptible)))

#define PAGE_WAKEUP_DONE(m)					\
		MACRO_BEGIN					\
		(m)->busy = FALSE;				\
		if ((m)->wanted) {				\
			(m)->wanted = FALSE;			\
			thread_wakeup((event_t) (m));		\
		}						\
		MACRO_END

#define PAGE_WAKEUP(m)						\
		MACRO_BEGIN					\
		if ((m)->wanted) {				\
			(m)->wanted = FALSE;			\
			thread_wakeup((event_t) (m));		\
		}						\
		MACRO_END

#define VM_PAGE_FREE(p) 			\
		MACRO_BEGIN			\
		vm_page_lock_queues();		\
		vm_page_free(p);		\
		vm_page_unlock_queues();	\
		MACRO_END

#define VM_PAGE_GRAB_FICTITIOUS(M)					\
		MACRO_BEGIN						\
		while ((M = vm_page_grab_fictitious()) == VM_PAGE_NULL)	\
			vm_page_more_fictitious();			\
		MACRO_END

#define VM_PAGE_THROTTLED()						\
		(vm_page_free_count < vm_page_free_min &&		\
		 !(current_thread()->options & TH_OPT_VMPRIV) && 			\
		 ++vm_page_throttled_count)

#define	VM_PAGE_WAIT()		((void)vm_page_wait(THREAD_UNINT))

#define vm_page_lock_queues()	mutex_lock(&vm_page_queue_lock)
#define vm_page_unlock_queues()	mutex_unlock(&vm_page_queue_lock)

#define VM_PAGE_QUEUES_REMOVE(mem)				\
	MACRO_BEGIN						\
	assert(!mem->laundry);					\
	if (mem->active) {					\
		assert(mem->object != kernel_object);		\
		assert(!mem->inactive);				\
		queue_remove(&vm_page_queue_active,		\
			mem, vm_page_t, pageq);			\
		mem->pageq.next = NULL;				\
		mem->pageq.prev = NULL;			       	\
		mem->active = FALSE;				\
		if (!mem->fictitious)				\
			vm_page_active_count--;			\
	}							\
								\
	if (mem->inactive) {					\
		assert(mem->object != kernel_object);		\
		assert(!mem->active);				\
		if (mem->zero_fill) {				\
			queue_remove(&vm_page_queue_zf,		\
			mem, vm_page_t, pageq);			\
		} else {					\
			queue_remove(&vm_page_queue_inactive,	\
			mem, vm_page_t, pageq);			\
		}						\
		mem->pageq.next = NULL;				\
		mem->pageq.prev = NULL;			       	\
		mem->inactive = FALSE;				\
		if (!mem->fictitious)				\
			vm_page_inactive_count--;		\
	}							\
	MACRO_END

#endif	/* _VM_VM_PAGE_H_ */
Commit	Line	Data
1c79356b	1	/*
91447636	2	* Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
1c79356b	3	*
8f6c56a5	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
8f6c56a5 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
8ad349bb	24	* limitations under the License.
8f6c56a5 A	25	*
8f6c56a5 A	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/*
	29	* @OSF_COPYRIGHT@
	30	*/
	31	/*
	32	* Mach Operating System
	33	* Copyright (c) 1991,1990,1989,1988 Carnegie Mellon University
	34	* All Rights Reserved.
	35	*
	36	* Permission to use, copy, modify and distribute this software and its
	37	* documentation is hereby granted, provided that both the copyright
	38	* notice and this permission notice appear in all copies of the
	39	* software, derivative works or modified versions, and any portions
	40	* thereof, and that both notices appear in supporting documentation.
	41	*
	42	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	43	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	44	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	45	*
	46	* Carnegie Mellon requests users of this software to return to
	47	*
	48	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	49	* School of Computer Science
	50	* Carnegie Mellon University
	51	* Pittsburgh PA 15213-3890
	52	*
	53	* any improvements or extensions that they make and grant Carnegie Mellon
	54	* the rights to redistribute these changes.
	55	*/
	56	/*
	57	*/
	58	/*
	59	* File: vm/vm_page.h
	60	* Author: Avadis Tevanian, Jr., Michael Wayne Young
	61	* Date: 1985
	62	*
	63	* Resident memory system definitions.
	64	*/
	65
	66	#ifndef _VM_VM_PAGE_H_
	67	#define _VM_VM_PAGE_H_
	68
91447636 A	69	#include <debug.h>
91447636 A	70
1c79356b A	71	#include <mach/boolean.h>
	72	#include <mach/vm_prot.h>
	73	#include <mach/vm_param.h>
	74	#include <vm/vm_object.h>
	75	#include <kern/queue.h>
	76	#include <kern/lock.h>
	77
	78	#include <kern/macro_help.h>
	79
0b4e3aa0 A	80	/*
	81	* Each page entered on the inactive queue obtains a ticket from a
	82	* particular ticket roll. Pages granted tickets from a particular
	83	* roll generally flow through the queue as a group. In this way when a
	84	* page with a ticket from a particular roll is pulled from the top of the
	85	* queue it is extremely likely that the pages near the top will have tickets
	86	* from the same or adjacent rolls. In this way the proximity to the top
	87	* of the queue can be loosely ascertained by determining the identity of
	88	* the roll the pages ticket came from.
	89	*/
	90
	91
91447636 A	92	extern unsigned int vm_page_ticket_roll;
91447636 A	93	extern unsigned int vm_page_ticket;
0b4e3aa0	94
9bccf70c	95
0b4e3aa0 A	96	#define VM_PAGE_TICKETS_IN_ROLL 512
	97	#define VM_PAGE_TICKET_ROLL_IDS 16
	98
1c79356b A	99	/*
	100	* Management of resident (logical) pages.
	101	*
	102	* A small structure is kept for each resident
	103	* page, indexed by page number. Each structure
	104	* is an element of several lists:
	105	*
	106	* A hash table bucket used to quickly
	107	* perform object/offset lookups
	108	*
	109	* A list of all pages for a given object,
	110	* so they can be quickly deactivated at
	111	* time of deallocation.
	112	*
	113	* An ordered list of pages due for pageout.
	114	*
	115	* In addition, the structure contains the object
	116	* and offset to which this page belongs (for pageout),
	117	* and sundry status bits.
	118	*
	119	* Fields in this structure are locked either by the lock on the
	120	* object that the page belongs to (O) or by the lock on the page
	121	* queues (P). [Some fields require that both locks be held to
	122	* change that field; holding either lock is sufficient to read.]
	123	*/
	124
	125	struct vm_page {
	126	queue_chain_t pageq; /* queue info for FIFO
	127	* queue or free list (P) */
	128	queue_chain_t listq; /* all pages in same object (O) */
	129	struct vm_page next; / VP bucket link (O) */
	130
	131	vm_object_t object; /* which object am I in (O&P) */
	132	vm_object_offset_t offset; /* offset into that object (O,P) */
	133
91447636 A	134	/*
	135	* The following word of flags is protected
	136	* by the "page queues" lock.
	137	*/
1c79356b	138	unsigned int wire_count:16, /* how many wired down maps use me? (O&P) */
0b4e3aa0 A	139	page_ticket:4, /* age of the page on the */
0b4e3aa0 A	140	/* inactive queue. */
1c79356b A	141	/* boolean_t / inactive:1, / page is in inactive list (P) */
1c79356b A	142	active:1, /* page is in active list (P) */
91447636	143	pageout_queue:1,/* page is on queue for pageout (P) */
1c79356b A	144	laundry:1, /* page is being cleaned now (P)*/
	145	free:1, /* page is on free list (P) */
	146	reference:1, /* page has been used (P) */
1c79356b	147	pageout:1, /* page wired & busy for pageout (P) */
0b4e3aa0 A	148	gobbled:1, /* page used internally (P) */
0b4e3aa0 A	149	private:1, /* Page should not be returned to
91447636	150	* the free list (P) */
9bccf70c	151	zero_fill:1,
0b4e3aa0	152	:0;
1c79356b	153
91447636 A	154	/*
	155	* The following word of flags is protected
	156	* by the "VM object" lock.
	157	*/
1c79356b	158	unsigned int
0b4e3aa0	159	page_error:8, /* error from I/O operations */
1c79356b A	160	/* boolean_t / busy:1, / page is in transit (O) */
	161	wanted:1, /* someone is waiting for page (O) */
	162	tabled:1, /* page is in VP table (O) */
	163	fictitious:1, /* Physical page doesn't exist (O) */
0b4e3aa0	164	no_isync:1, /* page has not been instruction synced */
1c79356b A	165	absent:1, /* Data has been requested, but is
	166	* not yet available (O) */
	167	error:1, /* Data manager was unable to provide
	168	* data due to error (O) */
	169	dirty:1, /* Page must be cleaned (O) */
	170	cleaning:1, /* Page clean has begun (O) */
	171	precious:1, /* Page is precious; data must be
	172	* returned even if clean (O) */
	173	clustered:1, /* page is not the faulted page (O) */
	174	overwriting:1, /* Request to unlock has been made
	175	* without having data. (O)
	176	* [See vm_fault_page_overwrite] */
	177	restart:1, /* Page was pushed higher in shadow
	178	chain by copy_call-related pagers;
	179	start again at top of chain */
	180	lock_supplied:1,/* protection supplied by pager (O) */
	181	/* vm_prot_t / page_lock:3, / Uses prohibited by pager (O) */
	182	/* vm_prot_t / unlock_request:3,/ Outstanding unlock request (O) */
	183	unusual:1, /* Page is absent, error, restart or
	184	page locked */
91447636	185	encrypted:1, /* encrypted for secure swap (O) */
1c79356b A	186	list_req_pending:1, /* pagein/pageout alt mechanism */
	187	/* allows creation of list */
	188	/* requests on pages that are */
	189	/* actively being paged. */
0b4e3aa0 A	190	dump_cleaning:1; /* set by the pageout daemon when */
	191	/* a page being cleaned is */
	192	/* encountered and targeted as */
	193	/* a pageout candidate */
	194	/* we've used up all 32 bits */
1c79356b	195
91447636	196	ppnum_t phys_page; /* Physical address of page, passed
1c79356b	197	* to pmap_enter (read-only) */
1c79356b A	198	};
1c79356b A	199
91447636 A	200	#define DEBUG_ENCRYPTED_SWAP 1
	201	#if DEBUG_ENCRYPTED_SWAP
	202	#define ASSERT_PAGE_DECRYPTED(page) \
	203	MACRO_BEGIN \
	204	if ((page)->encrypted) { \
	205	panic("VM page %p should not be encrypted here\n", \
	206	(page)); \
	207	} \
	208	MACRO_END
	209	#else /* DEBUG_ENCRYPTED_SWAP */
	210	#define ASSERT_PAGE_DECRYPTED(page) assert(!(page)->encrypted)
	211	#endif /* DEBUG_ENCRYPTED_SWAP */
	212
1c79356b A	213	typedef struct vm_page *vm_page_t;
1c79356b A	214
1c79356b	215	#define VM_PAGE_NULL ((vm_page_t) 0)
91447636	216	#define NEXT_PAGE(m) ((vm_page_t) (m)->pageq.next)
e5568f75	217	#define NEXT_PAGE_PTR(m) ((vm_page_t *) &(m)->pageq.next)
1c79356b A	218
	219	/*
	220	* XXX The unusual bit should not be necessary. Most of the bit
	221	* XXX fields above really want to be masks.
	222	*/
	223
	224	/*
	225	* For debugging, this macro can be defined to perform
	226	* some useful check on a page structure.
	227	*/
	228
	229	#define VM_PAGE_CHECK(mem)
	230
	231	/*
	232	* Each pageable resident page falls into one of three lists:
	233	*
	234	* free
	235	* Available for allocation now.
	236	* inactive
	237	* Not referenced in any map, but still has an
	238	* object/offset-page mapping, and may be dirty.
	239	* This is the list of pages that should be
	240	* paged out next.
	241	* active
	242	* A list of pages which have been placed in
	243	* at least one physical map. This list is
	244	* ordered, in LRU-like fashion.
	245	*/
	246
	247	extern
	248	vm_page_t vm_page_queue_free; /* memory free queue */
	249	extern
	250	vm_page_t vm_page_queue_fictitious; /* fictitious free queue */
	251	extern
	252	queue_head_t vm_page_queue_active; /* active memory queue */
	253	extern
	254	queue_head_t vm_page_queue_inactive; /* inactive memory queue */
9bccf70c	255	queue_head_t vm_page_queue_zf; /* inactive memory queue for zero fill */
1c79356b A	256
	257	extern
	258	vm_offset_t first_phys_addr; /* physical address for first_page */
	259	extern
	260	vm_offset_t last_phys_addr; /* physical address for last_page */
	261
	262	extern
91447636	263	unsigned int vm_page_free_count; /* How many pages are free? */
1c79356b	264	extern
91447636	265	unsigned int vm_page_fictitious_count;/* How many fictitious pages are free? */
1c79356b	266	extern
91447636	267	unsigned int vm_page_active_count; /* How many pages are active? */
1c79356b	268	extern
91447636	269	unsigned int vm_page_inactive_count; /* How many pages are inactive? */
1c79356b	270	extern
91447636	271	unsigned int vm_page_wire_count; /* How many pages are wired? */
1c79356b	272	extern
91447636	273	unsigned int vm_page_free_target; /* How many do we want free? */
1c79356b	274	extern
91447636	275	unsigned int vm_page_free_min; /* When to wakeup pageout */
1c79356b	276	extern
91447636	277	unsigned int vm_page_inactive_target;/* How many do we want inactive? */
1c79356b	278	extern
91447636	279	unsigned int vm_page_free_reserved; /* How many pages reserved to do pageout */
1c79356b	280	extern
91447636 A	281	unsigned int vm_page_throttled_count;/* Count of zero-fill allocations throttled */
	282	extern
	283	unsigned int vm_page_gobble_count;
	284
55e303ae	285	extern
91447636	286	unsigned int vm_page_purgeable_count;/* How many pages are purgeable now ? */
55e303ae	287	extern
91447636	288	uint64_t vm_page_purged_count; /* How many pages got purged so far ? */
1c79356b A	289
	290	decl_mutex_data(,vm_page_queue_lock)
	291	/* lock on active and inactive page queues */
	292	decl_mutex_data(,vm_page_queue_free_lock)
	293	/* lock on free page queue */
1c79356b A	294
	295	extern unsigned int vm_page_free_wanted;
	296	/* how many threads are waiting for memory */
	297
	298	extern vm_offset_t vm_page_fictitious_addr;
	299	/* (fake) phys_addr of fictitious pages */
	300
91447636 A	301	extern boolean_t vm_page_deactivate_hint;
91447636 A	302
1c79356b A	303	/*
	304	* Prototypes for functions exported by this module.
	305	*/
	306	extern void vm_page_bootstrap(
	307	vm_offset_t *startp,
	308	vm_offset_t *endp);
	309
	310	extern void vm_page_module_init(void);
	311
	312	extern void vm_page_create(
55e303ae A	313	ppnum_t start,
55e303ae A	314	ppnum_t end);
1c79356b A	315
	316	extern vm_page_t vm_page_lookup(
	317	vm_object_t object,
	318	vm_object_offset_t offset);
	319
	320	extern vm_page_t vm_page_grab_fictitious(void);
	321
	322	extern void vm_page_release_fictitious(
	323	vm_page_t page);
	324
	325	extern boolean_t vm_page_convert(
	326	vm_page_t page);
	327
	328	extern void vm_page_more_fictitious(void);
	329
	330	extern int vm_pool_low(void);
	331
	332	extern vm_page_t vm_page_grab(void);
	333
	334	extern void vm_page_release(
	335	vm_page_t page);
	336
1c79356b A	337	extern boolean_t vm_page_wait(
	338	int interruptible );
	339
	340	extern vm_page_t vm_page_alloc(
	341	vm_object_t object,
	342	vm_object_offset_t offset);
	343
	344	extern void vm_page_init(
	345	vm_page_t page,
55e303ae	346	ppnum_t phys_page);
1c79356b A	347
	348	extern void vm_page_free(
	349	vm_page_t page);
	350
	351	extern void vm_page_activate(
	352	vm_page_t page);
	353
	354	extern void vm_page_deactivate(
	355	vm_page_t page);
	356
	357	extern void vm_page_rename(
	358	vm_page_t page,
	359	vm_object_t new_object,
	360	vm_object_offset_t new_offset);
	361
	362	extern void vm_page_insert(
	363	vm_page_t page,
	364	vm_object_t object,
	365	vm_object_offset_t offset);
	366
	367	extern void vm_page_replace(
	368	vm_page_t mem,
	369	vm_object_t object,
	370	vm_object_offset_t offset);
	371
	372	extern void vm_page_remove(
	373	vm_page_t page);
	374
	375	extern void vm_page_zero_fill(
	376	vm_page_t page);
	377
	378	extern void vm_page_part_zero_fill(
	379	vm_page_t m,
	380	vm_offset_t m_pa,
	381	vm_size_t len);
	382
	383	extern void vm_page_copy(
	384	vm_page_t src_page,
	385	vm_page_t dest_page);
	386
	387	extern void vm_page_part_copy(
	388	vm_page_t src_m,
	389	vm_offset_t src_pa,
	390	vm_page_t dst_m,
	391	vm_offset_t dst_pa,
	392	vm_size_t len);
	393
	394	extern void vm_page_wire(
	395	vm_page_t page);
	396
	397	extern void vm_page_unwire(
	398	vm_page_t page);
	399
	400	extern void vm_set_page_size(void);
	401
	402	extern void vm_page_gobble(
	403	vm_page_t page);
	404
1c79356b A	405	/*
	406	* Functions implemented as macros. m->wanted and m->busy are
	407	* protected by the object lock.
	408	*/
	409
	410	#define PAGE_ASSERT_WAIT(m, interruptible) \
9bccf70c A	411	(((m)->wanted = TRUE), \
	412	assert_wait((event_t) (m), (interruptible)))
	413
	414	#define PAGE_SLEEP(o, m, interruptible) \
	415	(((m)->wanted = TRUE), \
	416	thread_sleep_vm_object((o), (m), (interruptible)))
1c79356b A	417
	418	#define PAGE_WAKEUP_DONE(m) \
	419	MACRO_BEGIN \
	420	(m)->busy = FALSE; \
	421	if ((m)->wanted) { \
	422	(m)->wanted = FALSE; \
	423	thread_wakeup((event_t) (m)); \
	424	} \
	425	MACRO_END
	426
	427	#define PAGE_WAKEUP(m) \
	428	MACRO_BEGIN \
	429	if ((m)->wanted) { \
	430	(m)->wanted = FALSE; \
	431	thread_wakeup((event_t) (m)); \
	432	} \
	433	MACRO_END
	434
	435	#define VM_PAGE_FREE(p) \
	436	MACRO_BEGIN \
	437	vm_page_lock_queues(); \
	438	vm_page_free(p); \
	439	vm_page_unlock_queues(); \
	440	MACRO_END
	441
	442	#define VM_PAGE_GRAB_FICTITIOUS(M) \
	443	MACRO_BEGIN \
	444	while ((M = vm_page_grab_fictitious()) == VM_PAGE_NULL) \
	445	vm_page_more_fictitious(); \
	446	MACRO_END
	447
	448	#define VM_PAGE_THROTTLED() \
55e303ae	449	(vm_page_free_count < vm_page_free_min && \
91447636	450	!(current_thread()->options & TH_OPT_VMPRIV) && \
55e303ae	451	++vm_page_throttled_count)
1c79356b A	452
	453	#define VM_PAGE_WAIT() ((void)vm_page_wait(THREAD_UNINT))
	454
	455	#define vm_page_lock_queues() mutex_lock(&vm_page_queue_lock)
	456	#define vm_page_unlock_queues() mutex_unlock(&vm_page_queue_lock)
1c79356b A	457
	458	#define VM_PAGE_QUEUES_REMOVE(mem) \
	459	MACRO_BEGIN \
91447636	460	assert(!mem->laundry); \
1c79356b	461	if (mem->active) { \
91447636	462	assert(mem->object != kernel_object); \
1c79356b A	463	assert(!mem->inactive); \
	464	queue_remove(&vm_page_queue_active, \
	465	mem, vm_page_t, pageq); \
91447636 A	466	mem->pageq.next = NULL; \
91447636 A	467	mem->pageq.prev = NULL; \
1c79356b A	468	mem->active = FALSE; \
	469	if (!mem->fictitious) \
	470	vm_page_active_count--; \
	471	} \
	472	\
	473	if (mem->inactive) { \
91447636	474	assert(mem->object != kernel_object); \
1c79356b	475	assert(!mem->active); \
9bccf70c A	476	if (mem->zero_fill) { \
	477	queue_remove(&vm_page_queue_zf, \
	478	mem, vm_page_t, pageq); \
	479	} else { \
	480	queue_remove(&vm_page_queue_inactive, \
1c79356b	481	mem, vm_page_t, pageq); \
9bccf70c	482	} \
91447636 A	483	mem->pageq.next = NULL; \
91447636 A	484	mem->pageq.prev = NULL; \
1c79356b A	485	mem->inactive = FALSE; \
	486	if (!mem->fictitious) \
	487	vm_page_inactive_count--; \
	488	} \
	489	MACRO_END
	490
	491	#endif /* _VM_VM_PAGE_H_ */