VFS messaging/interfacing work stage 8/99: Major reworking of the vnode
[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 $
377d4740 26 * $DragonFly: src/sys/vm/phys_pager.c,v 1.3 2003/07/19 21:14:53 dillon Exp $
984263bc
MD
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
42/* list of device pager objects */
43static struct pagerlst phys_pager_object_list;
44
45static int phys_pager_alloc_lock, phys_pager_alloc_lock_want;
46
47static void
48phys_pager_init(void)
49{
50
51 TAILQ_INIT(&phys_pager_object_list);
52}
53
54static vm_object_t
55phys_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
56 vm_ooffset_t foff)
57{
58 vm_object_t object;
59
60 /*
61 * Offset should be page aligned.
62 */
63 if (foff & PAGE_MASK)
64 return (NULL);
65
66 size = round_page(size);
67
68 if (handle != NULL) {
69 /*
70 * Lock to prevent object creation race condition.
71 */
72 while (phys_pager_alloc_lock) {
73 phys_pager_alloc_lock_want++;
377d4740 74 tsleep(&phys_pager_alloc_lock, 0, "ppall", 0);
984263bc
MD
75 phys_pager_alloc_lock_want--;
76 }
77 phys_pager_alloc_lock = 1;
78
79 /*
80 * Look up pager, creating as necessary.
81 */
82 object = vm_pager_object_lookup(&phys_pager_object_list, handle);
83 if (object == NULL) {
84 /*
85 * Allocate object and associate it with the pager.
86 */
87 object = vm_object_allocate(OBJT_PHYS,
88 OFF_TO_IDX(foff + size));
89 object->handle = handle;
90 TAILQ_INSERT_TAIL(&phys_pager_object_list, object,
91 pager_object_list);
92 } else {
93 /*
94 * Gain a reference to the object.
95 */
96 vm_object_reference(object);
97 if (OFF_TO_IDX(foff + size) > object->size)
98 object->size = OFF_TO_IDX(foff + size);
99 }
100 phys_pager_alloc_lock = 0;
101 if (phys_pager_alloc_lock_want)
102 wakeup(&phys_pager_alloc_lock);
103 } else {
104 object = vm_object_allocate(OBJT_PHYS,
105 OFF_TO_IDX(foff + size));
106 }
107
108 return (object);
109}
110
111static void
112phys_pager_dealloc(vm_object_t object)
113{
114
115 if (object->handle != NULL)
116 TAILQ_REMOVE(&phys_pager_object_list, object, pager_object_list);
117}
118
119static int
120phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
121{
122 int i, s;
123
124 s = splvm();
125 /*
126 * Fill as many pages as vm_fault has allocated for us.
127 */
128 for (i = 0; i < count; i++) {
129 if ((m[i]->flags & PG_ZERO) == 0)
130 vm_page_zero_fill(m[i]);
131 vm_page_flag_set(m[i], PG_ZERO);
132 /* Switch off pv_entries */
133 vm_page_unmanage(m[i]);
134 m[i]->valid = VM_PAGE_BITS_ALL;
135 m[i]->dirty = 0;
136 /* The requested page must remain busy, the others not. */
137 if (reqpage != i) {
138 vm_page_flag_clear(m[i], PG_BUSY);
139 m[i]->busy = 0;
140 }
141 }
142 splx(s);
143
144 return (VM_PAGER_OK);
145}
146
147static void
148phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync,
149 int *rtvals)
150{
151
152 panic("phys_pager_putpage called");
153}
154
155/*
156 * Implement a pretty aggressive clustered getpages strategy. Hint that
157 * everything in an entire 4MB window should be prefaulted at once.
158 *
159 * XXX 4MB (1024 slots per page table page) is convenient for x86,
160 * but may not be for other arches.
161 */
162#ifndef PHYSCLUSTER
163#define PHYSCLUSTER 1024
164#endif
165static boolean_t
166phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
167 int *after)
168{
169 vm_pindex_t base, end;
170
171 base = pindex & (~(PHYSCLUSTER - 1));
172 end = base + (PHYSCLUSTER - 1);
173 if (before != NULL)
174 *before = pindex - base;
175 if (after != NULL)
176 *after = end - pindex;
177 return (TRUE);
178}
179
180struct pagerops physpagerops = {
181 phys_pager_init,
182 phys_pager_alloc,
183 phys_pager_dealloc,
184 phys_pager_getpages,
185 phys_pager_putpages,
186 phys_pager_haspage,
187 NULL
188};