Set valid bits when updating a fake page.
[dragonfly.git] / sys / vm / device_pager.c
CommitLineData
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1/*
2 * Copyright (c) 1990 University of Utah.
3 * Copyright (c) 1991, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)device_pager.c 8.1 (Berkeley) 6/11/93
39 * $FreeBSD: src/sys/vm/device_pager.c,v 1.46.2.1 2000/08/02 21:54:37 peter Exp $
1a6619ce 40 * $DragonFly: src/sys/vm/device_pager.c,v 1.13 2008/01/21 10:25:18 corecode Exp $
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41 */
42
43#include <sys/param.h>
44#include <sys/systm.h>
27db6797 45#include <sys/kernel.h>
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46#include <sys/conf.h>
47#include <sys/mman.h>
335dda38 48#include <sys/device.h>
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49#include <sys/queue.h>
50#include <sys/malloc.h>
2f1821ca 51#include <sys/thread2.h>
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52
53#include <vm/vm.h>
54#include <vm/vm_object.h>
55#include <vm/vm_page.h>
56#include <vm/vm_pager.h>
57#include <vm/vm_zone.h>
58
1388df65 59static void dev_pager_init (void);
57f7b636 60static vm_object_t dev_pager_alloc (void *, off_t, vm_prot_t, off_t);
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61static void dev_pager_dealloc (vm_object_t);
62static int dev_pager_getpages (vm_object_t, vm_page_t *, int, int);
63static void dev_pager_putpages (vm_object_t, vm_page_t *, int,
64 boolean_t, int *);
65static boolean_t dev_pager_haspage (vm_object_t, vm_pindex_t, int *,
66 int *);
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67
68/* list of device pager objects */
69static struct pagerlst dev_pager_object_list;
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70static TAILQ_HEAD(, vm_page) dev_freepages_list;
71static MALLOC_DEFINE(M_FICTITIOUS_PAGES, "device-mapped pages", "Device mapped pages");
984263bc 72
6ef943a3 73static vm_page_t dev_pager_getfake (vm_paddr_t);
1388df65 74static void dev_pager_putfake (vm_page_t);
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75
76static int dev_pager_alloc_lock, dev_pager_alloc_lock_want;
77
78struct pagerops devicepagerops = {
79 dev_pager_init,
80 dev_pager_alloc,
81 dev_pager_dealloc,
82 dev_pager_getpages,
83 dev_pager_putpages,
84 dev_pager_haspage,
85 NULL
86};
87
88static void
57e43348 89dev_pager_init(void)
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90{
91 TAILQ_INIT(&dev_pager_object_list);
27db6797 92 TAILQ_INIT(&dev_freepages_list);
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93}
94
95static vm_object_t
57f7b636 96dev_pager_alloc(void *handle, off_t size, vm_prot_t prot, off_t foff)
984263bc 97{
b13267a5 98 cdev_t dev;
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99 vm_object_t object;
100 unsigned int npages;
101 vm_offset_t off;
102
103 /*
104 * Make sure this device can be mapped.
105 */
106 dev = handle;
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107
108 /*
109 * Offset should be page aligned.
110 */
111 if (foff & PAGE_MASK)
112 return (NULL);
113
114 size = round_page(size);
115
116 /*
117 * Check that the specified range of the device allows the desired
118 * protection.
119 *
120 * XXX assumes VM_PROT_* == PROT_*
121 */
122 npages = OFF_TO_IDX(size);
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123 for (off = foff; npages--; off += PAGE_SIZE) {
124 if (dev_dmmap(dev, off, (int)prot) == -1)
984263bc 125 return (NULL);
335dda38 126 }
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127
128 /*
129 * Lock to prevent object creation race condition.
130 */
131 while (dev_pager_alloc_lock) {
132 dev_pager_alloc_lock_want++;
377d4740 133 tsleep(&dev_pager_alloc_lock, 0, "dvpall", 0);
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134 dev_pager_alloc_lock_want--;
135 }
136 dev_pager_alloc_lock = 1;
137
138 /*
139 * Look up pager, creating as necessary.
140 */
141 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
142 if (object == NULL) {
143 /*
144 * Allocate object and associate it with the pager.
145 */
146 object = vm_object_allocate(OBJT_DEVICE,
147 OFF_TO_IDX(foff + size));
148 object->handle = handle;
149 TAILQ_INIT(&object->un_pager.devp.devp_pglist);
150 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list);
151 } else {
152 /*
153 * Gain a reference to the object.
154 */
155 vm_object_reference(object);
156 if (OFF_TO_IDX(foff + size) > object->size)
157 object->size = OFF_TO_IDX(foff + size);
158 }
159
160 dev_pager_alloc_lock = 0;
161 if (dev_pager_alloc_lock_want)
162 wakeup(&dev_pager_alloc_lock);
163
164 return (object);
165}
166
167static void
57e43348 168dev_pager_dealloc(vm_object_t object)
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169{
170 vm_page_t m;
171
172 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
173 /*
174 * Free up our fake pages.
175 */
176 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) {
177 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq);
178 dev_pager_putfake(m);
179 }
180}
181
182static int
57e43348 183dev_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
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184{
185 vm_offset_t offset;
6ef943a3 186 vm_paddr_t paddr;
984263bc 187 vm_page_t page;
b13267a5 188 cdev_t dev;
984263bc 189 int prot;
2f1821ca 190 int i;
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191
192 dev = object->handle;
193 offset = m[reqpage]->pindex;
194 prot = PROT_READ; /* XXX should pass in? */
984263bc 195
335dda38 196 paddr = pmap_phys_address(dev_dmmap(dev, (vm_offset_t) offset << PAGE_SHIFT, prot));
984263bc 197 KASSERT(paddr != -1,("dev_pager_getpage: map function returns error"));
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198
199 if (m[reqpage]->flags & PG_FICTITIOUS) {
200 /*
201 * If the passed in reqpage page is a fake page, update it
202 * with the new physical address.
203 */
204 m[reqpage]->phys_addr = paddr;
1a6619ce 205 m[reqpage]->valid = VM_PAGE_BITS_ALL;
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206 } else {
207 /*
208 * Replace the passed in reqpage page with our own fake page
209 * and free up all the original pages.
210 */
211 page = dev_pager_getfake(paddr);
212 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq);
213 crit_enter();
214 vm_page_free(m[reqpage]);
215 vm_page_insert(page, object, offset);
216 crit_exit();
217 }
984263bc 218 for (i = 0; i < count; i++) {
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219 if (i != reqpage)
220 vm_page_free(m[i]);
984263bc 221 }
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222 return (VM_PAGER_OK);
223}
224
225static void
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226dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync,
227 int *rtvals)
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228{
229 panic("dev_pager_putpage called");
230}
231
232static boolean_t
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233dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
234 int *after)
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235{
236 if (before != NULL)
237 *before = 0;
238 if (after != NULL)
239 *after = 0;
240 return (TRUE);
241}
242
243static vm_page_t
57e43348 244dev_pager_getfake(vm_paddr_t paddr)
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245{
246 vm_page_t m;
247
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248 if ((m = TAILQ_FIRST(&dev_freepages_list)) != NULL) {
249 TAILQ_REMOVE(&dev_freepages_list, m, pageq);
250 } else {
251 m = kmalloc(sizeof(*m), M_FICTITIOUS_PAGES, M_WAITOK);
252 }
253 bzero(m, sizeof(*m));
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254
255 m->flags = PG_BUSY | PG_FICTITIOUS;
256 m->valid = VM_PAGE_BITS_ALL;
257 m->dirty = 0;
258 m->busy = 0;
259 m->queue = PQ_NONE;
260 m->object = NULL;
261
262 m->wire_count = 1;
263 m->hold_count = 0;
264 m->phys_addr = paddr;
265
266 return (m);
267}
268
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269/*
270 * Synthesized VM pages must be structurally stable for lockless lookups to
271 * work properly.
272 */
984263bc 273static void
57e43348 274dev_pager_putfake(vm_page_t m)
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275{
276 if (!(m->flags & PG_FICTITIOUS))
277 panic("dev_pager_putfake: bad page");
fad57d0e 278 KKASSERT(m->object == NULL);
27db6797 279 TAILQ_INSERT_HEAD(&dev_freepages_list, m, pageq);
984263bc 280}
fad57d0e 281