summaryrefslogtreecommitdiffstats
path: root/sys/vm/vm_page.h
blob: b67c9a565301deb81d39489011b37f801a1da4ef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
/*
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * The Mach Operating System project at Carnegie-Mellon University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)vm_page.h	8.2 (Berkeley) 12/13/93
 *
 *
 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
 *
 * 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 the
 * rights to redistribute these changes.
 *
 * $Id: vm_page.h,v 1.23 1995/12/11 04:58:26 dyson Exp $
 */

/*
 *	Resident memory system definitions.
 */

#ifndef	_VM_PAGE_
#define	_VM_PAGE_

#include <vm/pmap.h>
/*
 *	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).
 */

TAILQ_HEAD(pglist, vm_page);

struct vm_page {
	TAILQ_ENTRY(vm_page) pageq;	/* queue info for FIFO queue or free list (P) */
	TAILQ_ENTRY(vm_page) hashq;	/* hash table links (O) */
	TAILQ_ENTRY(vm_page) listq;	/* pages in same object (O) */

	vm_object_t object;		/* which object am I in (O,P) */
	vm_pindex_t pindex;		/* offset into object (O,P) */
	vm_offset_t phys_addr;		/* physical address of page */
	u_short	queue:4,		/* page queue index */
		flags:12;		/* see below */
	u_short wire_count;		/* wired down maps refs (P) */
	short hold_count;		/* page hold count */
	u_char	act_count;		/* page usage count */
	u_char	busy;			/* page busy count */
	/* NOTE that these must support one bit per DEV_BSIZE in a page!!! */
	/* so, on normal X86 kernels, they must be at least 8 bits wide */
	u_char	valid;			/* map of valid DEV_BSIZE chunks */
	u_char	dirty;			/* map of dirty DEV_BSIZE chunks */
};

#define PQ_NONE 0
#define PQ_FREE	1
#define PQ_ZERO 2
#define PQ_INACTIVE 3
#define PQ_ACTIVE 4
#define PQ_CACHE 5

/*
 * These are the flags defined for vm_page.
 *
 * Note: PG_FILLED and PG_DIRTY are added for the filesystems.
 */
#define	PG_BUSY		0x01		/* page is in transit (O) */
#define	PG_WANTED	0x02		/* someone is waiting for page (O) */
#define	PG_TABLED	0x04		/* page is in VP table (O) */
#define	PG_FICTITIOUS	0x08		/* physical page doesn't exist (O) */
#define	PG_WRITEABLE	0x10		/* page is mapped writeable */
#define PG_MAPPED	0x20		/* page is mapped */
#define	PG_ZERO		0x40		/* page is zeroed */
#define PG_REFERENCED	0x80		/* page has been referenced */
#define PG_CLEANCHK	0x100		/* page has been checked for cleaning */

/*
 * Misc constants.
 */

#define ACT_DECLINE		1
#define ACT_ADVANCE		3
#define ACT_MAX			100
#define PFCLUSTER_BEHIND	3
#define PFCLUSTER_AHEAD		3

#ifdef KERNEL
/*
 * Each pageable resident page falls into one of four lists:
 *
 *	free
 *		Available for allocation now.
 *
 * The following are all LRU sorted:
 *
 *	cache
 *		Almost available for allocation. Still in an
 *		object, but clean and immediately freeable at
 *		non-interrupt times.
 *
 *	inactive
 *		Low activity, candidates for reclaimation.
 *		This is the list of pages that should be
 *		paged out next.
 *
 *	active
 *		Pages that are "active" i.e. they have been
 *		recently referenced.
 *
 *	zero
 *		Pages that are really free and have been pre-zeroed
 *
 */

extern struct pglist vm_page_queue_free;	/* memory free queue */
extern struct pglist vm_page_queue_zero;	/* zeroed memory free queue */
extern struct pglist vm_page_queue_active;	/* active memory queue */
extern struct pglist vm_page_queue_inactive;	/* inactive memory queue */
extern struct pglist vm_page_queue_cache;	/* cache memory queue */

extern int vm_page_zero_count;

extern vm_page_t vm_page_array;		/* First resident page in table */
extern long first_page;			/* first physical page number */

 /* ... represented in vm_page_array */
extern long last_page;			/* last physical page number */

 /* ... represented in vm_page_array */
 /* [INCLUSIVE] */
extern vm_offset_t first_phys_addr;	/* physical address for first_page */
extern vm_offset_t last_phys_addr;	/* physical address for last_page */

#define VM_PAGE_TO_PHYS(entry)	((entry)->phys_addr)

#define IS_VM_PHYSADDR(pa) \
		((pa) >= first_phys_addr && (pa) <= last_phys_addr)

#define PHYS_TO_VM_PAGE(pa) \
		(&vm_page_array[atop(pa) - first_page ])

/*
 *	Functions implemented as macros
 */

#define PAGE_ASSERT_WAIT(m, interruptible)	{ \
				(m)->flags |= PG_WANTED; \
				assert_wait((int) (m), (interruptible)); \
			}

#define PAGE_WAKEUP(m)	{ \
				(m)->flags &= ~PG_BUSY; \
				if ((m)->flags & PG_WANTED) { \
					(m)->flags &= ~PG_WANTED; \
					wakeup((caddr_t) (m)); \
				} \
			}

#if PAGE_SIZE == 4096
#define VM_PAGE_BITS_ALL 0xff
#endif

#if PAGE_SIZE == 8192
#define VM_PAGE_BITS_ALL 0xffff
#endif

#define VM_ALLOC_NORMAL 0
#define VM_ALLOC_INTERRUPT 1
#define VM_ALLOC_SYSTEM 2
#define	VM_ALLOC_ZERO	3

void vm_page_activate __P((vm_page_t));
vm_page_t vm_page_alloc __P((vm_object_t, vm_pindex_t, int));
void vm_page_cache __P((register vm_page_t));
void vm_page_copy __P((vm_page_t, vm_page_t));
void vm_page_deactivate __P((vm_page_t));
void vm_page_free __P((vm_page_t));
void vm_page_insert __P((vm_page_t, vm_object_t, vm_pindex_t));
vm_page_t vm_page_lookup __P((vm_object_t, vm_pindex_t));
void vm_page_remove __P((vm_page_t));
void vm_page_rename __P((vm_page_t, vm_object_t, vm_pindex_t));
vm_offset_t vm_page_startup __P((vm_offset_t, vm_offset_t, vm_offset_t));
void vm_page_unwire __P((vm_page_t));
void vm_page_wire __P((vm_page_t));
boolean_t vm_page_zero_fill __P((vm_page_t));
void vm_page_set_validclean __P((vm_page_t, int, int));
void vm_page_set_invalid __P((vm_page_t, int, int));
int vm_page_is_valid __P((vm_page_t, int, int));
void vm_page_test_dirty __P((vm_page_t));
int vm_page_bits __P((int, int));


/*
 * Keep page from being freed by the page daemon
 * much of the same effect as wiring, except much lower
 * overhead and should be used only for *very* temporary
 * holding ("wiring").
 */
static __inline void
vm_page_hold(vm_page_t mem)
{
	mem->hold_count++;
}

#ifdef DIAGNOSTIC
#include <sys/systm.h>		/* make GCC shut up */
#endif

static __inline void
vm_page_unhold(vm_page_t mem)
{
#ifdef DIAGNOSTIC
	if (--mem->hold_count < 0)
		panic("vm_page_unhold: hold count < 0!!!");
#else
	--mem->hold_count;
#endif
}

static __inline void
vm_page_protect(vm_page_t mem, int prot)
{
	if (prot == VM_PROT_NONE) {
		if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) {
			pmap_page_protect(VM_PAGE_TO_PHYS(mem), prot);
			mem->flags &= ~(PG_WRITEABLE|PG_MAPPED);
		}
	} else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) {
		pmap_page_protect(VM_PAGE_TO_PHYS(mem), prot);
		mem->flags &= ~PG_WRITEABLE;
	}
}


#endif				/* KERNEL */
#endif				/* !_VM_PAGE_ */
OpenPOWER on IntegriCloud