xref: /freebsd/sys/vm/vm_page.h (revision 5ebc7e6281887681c3a348a5a4c902e262ccd656)
1 /*
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * The Mach Operating System project at Carnegie-Mellon University.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	from: @(#)vm_page.h	8.2 (Berkeley) 12/13/93
37  *
38  *
39  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
40  * All rights reserved.
41  *
42  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
43  *
44  * Permission to use, copy, modify and distribute this software and
45  * its documentation is hereby granted, provided that both the copyright
46  * notice and this permission notice appear in all copies of the
47  * software, derivative works or modified versions, and any portions
48  * thereof, and that both notices appear in supporting documentation.
49  *
50  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
51  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
52  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
53  *
54  * Carnegie Mellon requests users of this software to return to
55  *
56  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
57  *  School of Computer Science
58  *  Carnegie Mellon University
59  *  Pittsburgh PA 15213-3890
60  *
61  * any improvements or extensions that they make and grant Carnegie the
62  * rights to redistribute these changes.
63  *
64  * $Id: vm_page.h,v 1.17 1995/03/26 23:33:14 davidg Exp $
65  */
66 
67 /*
68  *	Resident memory system definitions.
69  */
70 
71 #ifndef	_VM_PAGE_
72 #define	_VM_PAGE_
73 
74 #include <vm/pmap.h>
75 /*
76  *	Management of resident (logical) pages.
77  *
78  *	A small structure is kept for each resident
79  *	page, indexed by page number.  Each structure
80  *	is an element of several lists:
81  *
82  *		A hash table bucket used to quickly
83  *		perform object/offset lookups
84  *
85  *		A list of all pages for a given object,
86  *		so they can be quickly deactivated at
87  *		time of deallocation.
88  *
89  *		An ordered list of pages due for pageout.
90  *
91  *	In addition, the structure contains the object
92  *	and offset to which this page belongs (for pageout),
93  *	and sundry status bits.
94  *
95  *	Fields in this structure are locked either by the lock on the
96  *	object that the page belongs to (O) or by the lock on the page
97  *	queues (P).
98  */
99 
100 TAILQ_HEAD(pglist, vm_page);
101 
102 struct vm_page {
103 	TAILQ_ENTRY(vm_page) pageq;	/* queue info for FIFO queue or free list (P) */
104 	TAILQ_ENTRY(vm_page) hashq;	/* hash table links (O) */
105 	TAILQ_ENTRY(vm_page) listq;	/* pages in same object (O) */
106 
107 	vm_object_t object;		/* which object am I in (O,P) */
108 	vm_offset_t offset;		/* offset into object (O,P) */
109 	vm_offset_t phys_addr;		/* physical address of page */
110 
111 	u_short wire_count;		/* wired down maps refs (P) */
112 	u_short flags;			/* see below */
113 	short hold_count;		/* page hold count */
114 	u_short act_count;		/* page usage count */
115 	u_short bmapped;		/* number of buffers mapped */
116 	u_short busy;			/* page busy count */
117 	u_short valid;			/* map of valid DEV_BSIZE chunks */
118 	u_short dirty;			/* map of dirty DEV_BSIZE chunks */
119 };
120 
121 /*
122  * These are the flags defined for vm_page.
123  *
124  * Note: PG_FILLED and PG_DIRTY are added for the filesystems.
125  */
126 #define	PG_INACTIVE	0x0001		/* page is in inactive list (P) */
127 #define	PG_ACTIVE	0x0002		/* page is in active list (P) */
128 #define	PG_BUSY		0x0010		/* page is in transit (O) */
129 #define	PG_WANTED	0x0020		/* someone is waiting for page (O) */
130 #define	PG_TABLED	0x0040		/* page is in VP table (O) */
131 #define	PG_COPYONWRITE	0x0080		/* must copy page before changing (O) */
132 #define	PG_FICTITIOUS	0x0100		/* physical page doesn't exist (O) */
133 #define	PG_WRITEABLE	0x0200		/* page is mapped writeable */
134 #define PG_MAPPED	0x0400		/* page is mapped */
135 #define PG_REFERENCED	0x1000		/* page has been referenced */
136 #define	PG_CACHE	0x4000		/* On VMIO cache */
137 #define	PG_FREE		0x8000		/* page is in free list */
138 
139 #if	VM_PAGE_DEBUG
140 #define	VM_PAGE_CHECK(mem) { \
141 	if ((((unsigned int) mem) < ((unsigned int) &vm_page_array[0])) || \
142 	    (((unsigned int) mem) > \
143 		((unsigned int) &vm_page_array[last_page-first_page])) || \
144 	    ((mem->flags & (PG_ACTIVE | PG_INACTIVE)) == \
145 		(PG_ACTIVE | PG_INACTIVE))) \
146 		panic("vm_page_check: not valid!"); \
147 }
148 #else				/* VM_PAGE_DEBUG */
149 #define	VM_PAGE_CHECK(mem)
150 #endif				/* VM_PAGE_DEBUG */
151 
152 #ifdef KERNEL
153 /*
154  *	Each pageable resident page falls into one of three lists:
155  *
156  *	free
157  *		Available for allocation now.
158  *	inactive
159  *		Not referenced in any map, but still has an
160  *		object/offset-page mapping, and may be dirty.
161  *		This is the list of pages that should be
162  *		paged out next.
163  *	active
164  *		A list of pages which have been placed in
165  *		at least one physical map.  This list is
166  *		ordered, in LRU-like fashion.
167  */
168 
169 extern struct pglist vm_page_queue_free;	/* memory free queue */
170 extern struct pglist vm_page_queue_active;	/* active memory queue */
171 extern struct pglist vm_page_queue_inactive;	/* inactive memory queue */
172 extern struct pglist vm_page_queue_cache;	/* cache memory queue */
173 
174 extern vm_page_t vm_page_array;		/* First resident page in table */
175 extern long first_page;			/* first physical page number */
176 
177  /* ... represented in vm_page_array */
178 extern long last_page;			/* last physical page number */
179 
180  /* ... represented in vm_page_array */
181  /* [INCLUSIVE] */
182 extern vm_offset_t first_phys_addr;	/* physical address for first_page */
183 extern vm_offset_t last_phys_addr;	/* physical address for last_page */
184 
185 #define VM_PAGE_TO_PHYS(entry)	((entry)->phys_addr)
186 
187 #define IS_VM_PHYSADDR(pa) \
188 		((pa) >= first_phys_addr && (pa) <= last_phys_addr)
189 
190 #define PHYS_TO_VM_PAGE(pa) \
191 		(&vm_page_array[atop(pa) - first_page ])
192 
193 extern simple_lock_data_t vm_page_queue_lock;	/* lock on active and inactive page queues */
194 extern simple_lock_data_t vm_page_queue_free_lock; /* lock on free page queue */
195 
196 /*
197  *	Functions implemented as macros
198  */
199 
200 #define PAGE_ASSERT_WAIT(m, interruptible)	{ \
201 				(m)->flags |= PG_WANTED; \
202 				assert_wait((int) (m), (interruptible)); \
203 			}
204 
205 #define PAGE_WAKEUP(m)	{ \
206 				(m)->flags &= ~PG_BUSY; \
207 				if ((m)->flags & PG_WANTED) { \
208 					(m)->flags &= ~PG_WANTED; \
209 					wakeup((caddr_t) (m)); \
210 				} \
211 			}
212 
213 #define	vm_page_lock_queues()	simple_lock(&vm_page_queue_lock)
214 #define	vm_page_unlock_queues()	simple_unlock(&vm_page_queue_lock)
215 
216 #if PAGE_SIZE == 4096
217 #define VM_PAGE_BITS_ALL 0xff
218 #endif
219 
220 #if PAGE_SIZE == 8192
221 #define VM_PAGE_BITS_ALL 0xffff
222 #endif
223 
224 #define VM_ALLOC_NORMAL 0
225 #define VM_ALLOC_INTERRUPT 1
226 #define VM_ALLOC_SYSTEM 2
227 
228 void vm_page_activate __P((vm_page_t));
229 vm_page_t vm_page_alloc __P((vm_object_t, vm_offset_t, int));
230 void vm_page_cache __P((register vm_page_t));
231 void vm_page_copy __P((vm_page_t, vm_page_t));
232 void vm_page_deactivate __P((vm_page_t));
233 void vm_page_free __P((vm_page_t));
234 void vm_page_insert __P((vm_page_t, vm_object_t, vm_offset_t));
235 vm_page_t vm_page_lookup __P((vm_object_t, vm_offset_t));
236 void vm_page_remove __P((vm_page_t));
237 void vm_page_rename __P((vm_page_t, vm_object_t, vm_offset_t));
238 vm_offset_t vm_page_startup __P((vm_offset_t, vm_offset_t, vm_offset_t));
239 void vm_page_unwire __P((vm_page_t));
240 void vm_page_wire __P((vm_page_t));
241 boolean_t vm_page_zero_fill __P((vm_page_t));
242 void vm_page_set_dirty __P((vm_page_t, int, int));
243 void vm_page_set_clean __P((vm_page_t, int, int));
244 int vm_page_is_clean __P((vm_page_t, int, int));
245 void vm_page_set_valid __P((vm_page_t, int, int));
246 void vm_page_set_invalid __P((vm_page_t, int, int));
247 int vm_page_is_valid __P((vm_page_t, int, int));
248 void vm_page_test_dirty __P((vm_page_t));
249 void vm_page_unqueue __P((vm_page_t ));
250 int vm_page_bits __P((int, int));
251 
252 
253 /*
254  * Keep page from being freed by the page daemon
255  * much of the same effect as wiring, except much lower
256  * overhead and should be used only for *very* temporary
257  * holding ("wiring").
258  */
259 static __inline void
260 vm_page_hold(vm_page_t mem)
261 {
262 	mem->hold_count++;
263 }
264 
265 #ifdef DIAGNOSTIC
266 #include <sys/systm.h>		/* make GCC shut up */
267 #endif
268 
269 static __inline void
270 vm_page_unhold(vm_page_t mem)
271 {
272 #ifdef DIAGNOSTIC
273 	if (--mem->hold_count < 0)
274 		panic("vm_page_unhold: hold count < 0!!!");
275 #else
276 	--mem->hold_count;
277 #endif
278 }
279 
280 static __inline void
281 vm_page_protect(vm_page_t mem, int prot)
282 {
283 	if (prot == VM_PROT_NONE) {
284 		if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) {
285 			pmap_page_protect(VM_PAGE_TO_PHYS(mem), prot);
286 			mem->flags &= ~(PG_WRITEABLE|PG_MAPPED);
287 		}
288 	} else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) {
289 		pmap_page_protect(VM_PAGE_TO_PHYS(mem), prot);
290 		mem->flags &= ~PG_WRITEABLE;
291 	}
292 }
293 
294 
295 #endif				/* KERNEL */
296 
297 #define ACT_DECLINE	1
298 #define ACT_ADVANCE	3
299 #define ACT_MAX		100
300 
301 #endif				/* !_VM_PAGE_ */
302