Initial import from FreeBSD RELENG_4:
[dragonfly.git] / sys / vm / phys_pager.c
CommitLineData
984263bc
MD
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 $
26 */
27
28#include <sys/param.h>
29#include <sys/systm.h>
30#include <sys/linker_set.h>
31#include <sys/conf.h>
32#include <sys/mman.h>
33#include <sys/sysctl.h>
34
35#include <vm/vm.h>
36#include <vm/vm_object.h>
37#include <vm/vm_page.h>
38#include <vm/vm_pager.h>
39#include <vm/vm_zone.h>
40
41/* list of device pager objects */
42static struct pagerlst phys_pager_object_list;
43
44static int phys_pager_alloc_lock, phys_pager_alloc_lock_want;
45
46static void
47phys_pager_init(void)
48{
49
50 TAILQ_INIT(&phys_pager_object_list);
51}
52
53static vm_object_t
54phys_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
55 vm_ooffset_t foff)
56{
57 vm_object_t object;
58
59 /*
60 * Offset should be page aligned.
61 */
62 if (foff & PAGE_MASK)
63 return (NULL);
64
65 size = round_page(size);
66
67 if (handle != NULL) {
68 /*
69 * Lock to prevent object creation race condition.
70 */
71 while (phys_pager_alloc_lock) {
72 phys_pager_alloc_lock_want++;
73 tsleep(&phys_pager_alloc_lock, PVM, "ppall", 0);
74 phys_pager_alloc_lock_want--;
75 }
76 phys_pager_alloc_lock = 1;
77
78 /*
79 * Look up pager, creating as necessary.
80 */
81 object = vm_pager_object_lookup(&phys_pager_object_list, handle);
82 if (object == NULL) {
83 /*
84 * Allocate object and associate it with the pager.
85 */
86 object = vm_object_allocate(OBJT_PHYS,
87 OFF_TO_IDX(foff + size));
88 object->handle = handle;
89 TAILQ_INSERT_TAIL(&phys_pager_object_list, object,
90 pager_object_list);
91 } else {
92 /*
93 * Gain a reference to the object.
94 */
95 vm_object_reference(object);
96 if (OFF_TO_IDX(foff + size) > object->size)
97 object->size = OFF_TO_IDX(foff + size);
98 }
99 phys_pager_alloc_lock = 0;
100 if (phys_pager_alloc_lock_want)
101 wakeup(&phys_pager_alloc_lock);
102 } else {
103 object = vm_object_allocate(OBJT_PHYS,
104 OFF_TO_IDX(foff + size));
105 }
106
107 return (object);
108}
109
110static void
111phys_pager_dealloc(vm_object_t object)
112{
113
114 if (object->handle != NULL)
115 TAILQ_REMOVE(&phys_pager_object_list, object, pager_object_list);
116}
117
118static int
119phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
120{
121 int i, s;
122
123 s = splvm();
124 /*
125 * Fill as many pages as vm_fault has allocated for us.
126 */
127 for (i = 0; i < count; i++) {
128 if ((m[i]->flags & PG_ZERO) == 0)
129 vm_page_zero_fill(m[i]);
130 vm_page_flag_set(m[i], PG_ZERO);
131 /* Switch off pv_entries */
132 vm_page_unmanage(m[i]);
133 m[i]->valid = VM_PAGE_BITS_ALL;
134 m[i]->dirty = 0;
135 /* The requested page must remain busy, the others not. */
136 if (reqpage != i) {
137 vm_page_flag_clear(m[i], PG_BUSY);
138 m[i]->busy = 0;
139 }
140 }
141 splx(s);
142
143 return (VM_PAGER_OK);
144}
145
146static void
147phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync,
148 int *rtvals)
149{
150
151 panic("phys_pager_putpage called");
152}
153
154/*
155 * Implement a pretty aggressive clustered getpages strategy. Hint that
156 * everything in an entire 4MB window should be prefaulted at once.
157 *
158 * XXX 4MB (1024 slots per page table page) is convenient for x86,
159 * but may not be for other arches.
160 */
161#ifndef PHYSCLUSTER
162#define PHYSCLUSTER 1024
163#endif
164static boolean_t
165phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
166 int *after)
167{
168 vm_pindex_t base, end;
169
170 base = pindex & (~(PHYSCLUSTER - 1));
171 end = base + (PHYSCLUSTER - 1);
172 if (before != NULL)
173 *before = pindex - base;
174 if (after != NULL)
175 *after = end - pindex;
176 return (TRUE);
177}
178
179struct pagerops physpagerops = {
180 phys_pager_init,
181 phys_pager_alloc,
182 phys_pager_dealloc,
183 phys_pager_getpages,
184 phys_pager_putpages,
185 phys_pager_haspage,
186 NULL
187};