Remove redundant .Pp macros right before .El, .Sh and .Ss.
[dragonfly.git] / sys / vm / phys_pager.c
CommitLineData
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1/*
2 * Copyright (c) 2000 Peter Wemm
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 * $FreeBSD: src/sys/vm/phys_pager.c,v 1.3.2.3 2000/12/17 02:05:41 alfred Exp $
654a39f0 26 * $DragonFly: src/sys/vm/phys_pager.c,v 1.4 2004/10/12 19:29:34 dillon Exp $
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27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/linker_set.h>
32#include <sys/conf.h>
33#include <sys/mman.h>
34#include <sys/sysctl.h>
35
36#include <vm/vm.h>
37#include <vm/vm_object.h>
38#include <vm/vm_page.h>
39#include <vm/vm_pager.h>
40#include <vm/vm_zone.h>
41
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42#include <sys/thread2.h>
43
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44/* list of device pager objects */
45static struct pagerlst phys_pager_object_list;
46
47static int phys_pager_alloc_lock, phys_pager_alloc_lock_want;
48
49static void
50phys_pager_init(void)
51{
52
53 TAILQ_INIT(&phys_pager_object_list);
54}
55
56static vm_object_t
57phys_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
58 vm_ooffset_t foff)
59{
60 vm_object_t object;
61
62 /*
63 * Offset should be page aligned.
64 */
65 if (foff & PAGE_MASK)
66 return (NULL);
67
68 size = round_page(size);
69
70 if (handle != NULL) {
71 /*
72 * Lock to prevent object creation race condition.
73 */
74 while (phys_pager_alloc_lock) {
75 phys_pager_alloc_lock_want++;
377d4740 76 tsleep(&phys_pager_alloc_lock, 0, "ppall", 0);
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77 phys_pager_alloc_lock_want--;
78 }
79 phys_pager_alloc_lock = 1;
80
81 /*
82 * Look up pager, creating as necessary.
83 */
84 object = vm_pager_object_lookup(&phys_pager_object_list, handle);
85 if (object == NULL) {
86 /*
87 * Allocate object and associate it with the pager.
88 */
89 object = vm_object_allocate(OBJT_PHYS,
90 OFF_TO_IDX(foff + size));
91 object->handle = handle;
92 TAILQ_INSERT_TAIL(&phys_pager_object_list, object,
93 pager_object_list);
94 } else {
95 /*
96 * Gain a reference to the object.
97 */
98 vm_object_reference(object);
99 if (OFF_TO_IDX(foff + size) > object->size)
100 object->size = OFF_TO_IDX(foff + size);
101 }
102 phys_pager_alloc_lock = 0;
103 if (phys_pager_alloc_lock_want)
104 wakeup(&phys_pager_alloc_lock);
105 } else {
106 object = vm_object_allocate(OBJT_PHYS,
107 OFF_TO_IDX(foff + size));
108 }
109
110 return (object);
111}
112
113static void
114phys_pager_dealloc(vm_object_t object)
115{
116
117 if (object->handle != NULL)
118 TAILQ_REMOVE(&phys_pager_object_list, object, pager_object_list);
119}
120
121static int
122phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
123{
654a39f0 124 int i;
984263bc 125
654a39f0 126 crit_enter();
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127 /*
128 * Fill as many pages as vm_fault has allocated for us.
129 */
130 for (i = 0; i < count; i++) {
131 if ((m[i]->flags & PG_ZERO) == 0)
132 vm_page_zero_fill(m[i]);
133 vm_page_flag_set(m[i], PG_ZERO);
134 /* Switch off pv_entries */
135 vm_page_unmanage(m[i]);
136 m[i]->valid = VM_PAGE_BITS_ALL;
137 m[i]->dirty = 0;
138 /* The requested page must remain busy, the others not. */
139 if (reqpage != i) {
140 vm_page_flag_clear(m[i], PG_BUSY);
141 m[i]->busy = 0;
142 }
143 }
654a39f0 144 crit_exit();
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145
146 return (VM_PAGER_OK);
147}
148
149static void
150phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync,
151 int *rtvals)
152{
153
154 panic("phys_pager_putpage called");
155}
156
157/*
158 * Implement a pretty aggressive clustered getpages strategy. Hint that
159 * everything in an entire 4MB window should be prefaulted at once.
160 *
161 * XXX 4MB (1024 slots per page table page) is convenient for x86,
162 * but may not be for other arches.
163 */
164#ifndef PHYSCLUSTER
165#define PHYSCLUSTER 1024
166#endif
167static boolean_t
168phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
169 int *after)
170{
171 vm_pindex_t base, end;
172
173 base = pindex & (~(PHYSCLUSTER - 1));
174 end = base + (PHYSCLUSTER - 1);
175 if (before != NULL)
176 *before = pindex - base;
177 if (after != NULL)
178 *after = end - pindex;
179 return (TRUE);
180}
181
182struct pagerops physpagerops = {
183 phys_pager_init,
184 phys_pager_alloc,
185 phys_pager_dealloc,
186 phys_pager_getpages,
187 phys_pager_putpages,
188 phys_pager_haspage,
189 NULL
190};