Change the kernel dev_t, representing a pointer to a specinfo structure,
[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 $
b13267a5 40 * $DragonFly: src/sys/vm/device_pager.c,v 1.11 2006/09/10 01:26:41 dillon Exp $
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41 */
42
43#include <sys/param.h>
44#include <sys/systm.h>
45#include <sys/conf.h>
46#include <sys/mman.h>
335dda38 47#include <sys/device.h>
2f1821ca 48#include <sys/thread2.h>
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49
50#include <vm/vm.h>
51#include <vm/vm_object.h>
52#include <vm/vm_page.h>
53#include <vm/vm_pager.h>
54#include <vm/vm_zone.h>
55
1388df65 56static void dev_pager_init (void);
57f7b636 57static vm_object_t dev_pager_alloc (void *, off_t, vm_prot_t, off_t);
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58static void dev_pager_dealloc (vm_object_t);
59static int dev_pager_getpages (vm_object_t, vm_page_t *, int, int);
60static void dev_pager_putpages (vm_object_t, vm_page_t *, int,
61 boolean_t, int *);
62static boolean_t dev_pager_haspage (vm_object_t, vm_pindex_t, int *,
63 int *);
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64
65/* list of device pager objects */
66static struct pagerlst dev_pager_object_list;
67
68static vm_zone_t fakepg_zone;
69static struct vm_zone fakepg_zone_store;
70
6ef943a3 71static vm_page_t dev_pager_getfake (vm_paddr_t);
1388df65 72static void dev_pager_putfake (vm_page_t);
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73
74static int dev_pager_alloc_lock, dev_pager_alloc_lock_want;
75
76struct pagerops devicepagerops = {
77 dev_pager_init,
78 dev_pager_alloc,
79 dev_pager_dealloc,
80 dev_pager_getpages,
81 dev_pager_putpages,
82 dev_pager_haspage,
83 NULL
84};
85
86static void
57e43348 87dev_pager_init(void)
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88{
89 TAILQ_INIT(&dev_pager_object_list);
90 fakepg_zone = &fakepg_zone_store;
91 zinitna(fakepg_zone, NULL, "DP fakepg", sizeof(struct vm_page), 0, 0, 2);
92}
93
94static vm_object_t
57f7b636 95dev_pager_alloc(void *handle, off_t size, vm_prot_t prot, off_t foff)
984263bc 96{
b13267a5 97 cdev_t dev;
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98 vm_object_t object;
99 unsigned int npages;
100 vm_offset_t off;
101
102 /*
103 * Make sure this device can be mapped.
104 */
105 dev = handle;
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106
107 /*
108 * Offset should be page aligned.
109 */
110 if (foff & PAGE_MASK)
111 return (NULL);
112
113 size = round_page(size);
114
115 /*
116 * Check that the specified range of the device allows the desired
117 * protection.
118 *
119 * XXX assumes VM_PROT_* == PROT_*
120 */
121 npages = OFF_TO_IDX(size);
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122 for (off = foff; npages--; off += PAGE_SIZE) {
123 if (dev_dmmap(dev, off, (int)prot) == -1)
984263bc 124 return (NULL);
335dda38 125 }
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126
127 /*
128 * Lock to prevent object creation race condition.
129 */
130 while (dev_pager_alloc_lock) {
131 dev_pager_alloc_lock_want++;
377d4740 132 tsleep(&dev_pager_alloc_lock, 0, "dvpall", 0);
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133 dev_pager_alloc_lock_want--;
134 }
135 dev_pager_alloc_lock = 1;
136
137 /*
138 * Look up pager, creating as necessary.
139 */
140 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
141 if (object == NULL) {
142 /*
143 * Allocate object and associate it with the pager.
144 */
145 object = vm_object_allocate(OBJT_DEVICE,
146 OFF_TO_IDX(foff + size));
147 object->handle = handle;
148 TAILQ_INIT(&object->un_pager.devp.devp_pglist);
149 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list);
150 } else {
151 /*
152 * Gain a reference to the object.
153 */
154 vm_object_reference(object);
155 if (OFF_TO_IDX(foff + size) > object->size)
156 object->size = OFF_TO_IDX(foff + size);
157 }
158
159 dev_pager_alloc_lock = 0;
160 if (dev_pager_alloc_lock_want)
161 wakeup(&dev_pager_alloc_lock);
162
163 return (object);
164}
165
166static void
57e43348 167dev_pager_dealloc(vm_object_t object)
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168{
169 vm_page_t m;
170
171 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
172 /*
173 * Free up our fake pages.
174 */
175 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) {
176 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq);
177 dev_pager_putfake(m);
178 }
179}
180
181static int
57e43348 182dev_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage)
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183{
184 vm_offset_t offset;
6ef943a3 185 vm_paddr_t paddr;
984263bc 186 vm_page_t page;
b13267a5 187 cdev_t dev;
984263bc 188 int prot;
2f1821ca 189 int i;
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190
191 dev = object->handle;
192 offset = m[reqpage]->pindex;
193 prot = PROT_READ; /* XXX should pass in? */
984263bc 194
335dda38 195 paddr = pmap_phys_address(dev_dmmap(dev, (vm_offset_t) offset << PAGE_SHIFT, prot));
984263bc 196 KASSERT(paddr != -1,("dev_pager_getpage: map function returns error"));
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197
198 if (m[reqpage]->flags & PG_FICTITIOUS) {
199 /*
200 * If the passed in reqpage page is a fake page, update it
201 * with the new physical address.
202 */
203 m[reqpage]->phys_addr = paddr;
204 } else {
205 /*
206 * Replace the passed in reqpage page with our own fake page
207 * and free up all the original pages.
208 */
209 page = dev_pager_getfake(paddr);
210 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq);
211 crit_enter();
212 vm_page_free(m[reqpage]);
213 vm_page_insert(page, object, offset);
214 crit_exit();
215 }
984263bc 216 for (i = 0; i < count; i++) {
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217 if (i != reqpage)
218 vm_page_free(m[i]);
984263bc 219 }
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220 return (VM_PAGER_OK);
221}
222
223static void
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224dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync,
225 int *rtvals)
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226{
227 panic("dev_pager_putpage called");
228}
229
230static boolean_t
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231dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
232 int *after)
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233{
234 if (before != NULL)
235 *before = 0;
236 if (after != NULL)
237 *after = 0;
238 return (TRUE);
239}
240
241static vm_page_t
57e43348 242dev_pager_getfake(vm_paddr_t paddr)
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243{
244 vm_page_t m;
245
246 m = zalloc(fakepg_zone);
247
248 m->flags = PG_BUSY | PG_FICTITIOUS;
249 m->valid = VM_PAGE_BITS_ALL;
250 m->dirty = 0;
251 m->busy = 0;
252 m->queue = PQ_NONE;
253 m->object = NULL;
254
255 m->wire_count = 1;
256 m->hold_count = 0;
257 m->phys_addr = paddr;
258
259 return (m);
260}
261
262static void
57e43348 263dev_pager_putfake(vm_page_t m)
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264{
265 if (!(m->flags & PG_FICTITIOUS))
266 panic("dev_pager_putfake: bad page");
fad57d0e 267 KKASSERT(m->object == NULL);
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268 zfree(fakepg_zone, m);
269}
fad57d0e 270