kernel - add spinlock to syscons console write path
[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 $
57f7b636 26 * $DragonFly: src/sys/vm/phys_pager.c,v 1.5 2006/03/27 01:54:18 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
57f7b636 57phys_pager_alloc(void *handle, off_t size, vm_prot_t prot, off_t foff)
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58{
59 vm_object_t object;
60
61 /*
62 * Offset should be page aligned.
63 */
64 if (foff & PAGE_MASK)
65 return (NULL);
66
67 size = round_page(size);
68
69 if (handle != NULL) {
70 /*
71 * Lock to prevent object creation race condition.
72 */
73 while (phys_pager_alloc_lock) {
74 phys_pager_alloc_lock_want++;
377d4740 75 tsleep(&phys_pager_alloc_lock, 0, "ppall", 0);
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76 phys_pager_alloc_lock_want--;
77 }
78 phys_pager_alloc_lock = 1;
79
80 /*
81 * Look up pager, creating as necessary.
82 */
83 object = vm_pager_object_lookup(&phys_pager_object_list, handle);
84 if (object == NULL) {
85 /*
86 * Allocate object and associate it with the pager.
87 */
88 object = vm_object_allocate(OBJT_PHYS,
89 OFF_TO_IDX(foff + size));
90 object->handle = handle;
91 TAILQ_INSERT_TAIL(&phys_pager_object_list, object,
92 pager_object_list);
93 } else {
94 /*
95 * Gain a reference to the object.
96 */
97 vm_object_reference(object);
98 if (OFF_TO_IDX(foff + size) > object->size)
99 object->size = OFF_TO_IDX(foff + size);
100 }
101 phys_pager_alloc_lock = 0;
102 if (phys_pager_alloc_lock_want)
103 wakeup(&phys_pager_alloc_lock);
104 } else {
105 object = vm_object_allocate(OBJT_PHYS,
106 OFF_TO_IDX(foff + size));
107 }
108
109 return (object);
110}
111
112static void
113phys_pager_dealloc(vm_object_t object)
114{
115
116 if (object->handle != NULL)
117 TAILQ_REMOVE(&phys_pager_object_list, object, pager_object_list);
118}
119
120static int
121phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
122{
654a39f0 123 int i;
984263bc 124
654a39f0 125 crit_enter();
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126 /*
127 * Fill as many pages as vm_fault has allocated for us.
128 */
129 for (i = 0; i < count; i++) {
130 if ((m[i]->flags & PG_ZERO) == 0)
131 vm_page_zero_fill(m[i]);
132 vm_page_flag_set(m[i], PG_ZERO);
133 /* Switch off pv_entries */
134 vm_page_unmanage(m[i]);
135 m[i]->valid = VM_PAGE_BITS_ALL;
136 m[i]->dirty = 0;
137 /* The requested page must remain busy, the others not. */
138 if (reqpage != i) {
139 vm_page_flag_clear(m[i], PG_BUSY);
140 m[i]->busy = 0;
141 }
142 }
654a39f0 143 crit_exit();
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144
145 return (VM_PAGER_OK);
146}
147
148static void
149phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync,
150 int *rtvals)
151{
152
153 panic("phys_pager_putpage called");
154}
155
156/*
157 * Implement a pretty aggressive clustered getpages strategy. Hint that
158 * everything in an entire 4MB window should be prefaulted at once.
159 *
160 * XXX 4MB (1024 slots per page table page) is convenient for x86,
161 * but may not be for other arches.
162 */
163#ifndef PHYSCLUSTER
164#define PHYSCLUSTER 1024
165#endif
166static boolean_t
167phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
168 int *after)
169{
170 vm_pindex_t base, end;
171
172 base = pindex & (~(PHYSCLUSTER - 1));
173 end = base + (PHYSCLUSTER - 1);
174 if (before != NULL)
175 *before = pindex - base;
176 if (after != NULL)
177 *after = end - pindex;
178 return (TRUE);
179}
180
181struct pagerops physpagerops = {
182 phys_pager_init,
183 phys_pager_alloc,
184 phys_pager_dealloc,
185 phys_pager_getpages,
186 phys_pager_putpages,
187 phys_pager_haspage,
188 NULL
189};