2 * Copyright (c) 1990 University of Utah.
3 * Copyright (c) 1991, 1993
4 * The Regents of the University of California. All rights reserved.
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * @(#)device_pager.c 8.1 (Berkeley) 6/11/93
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
40 #include <sys/param.h>
41 #include <sys/systm.h>
45 #include <sys/mutex.h>
50 #include <vm/vm_object.h>
51 #include <vm/vm_page.h>
52 #include <vm/vm_pager.h>
55 static void dev_pager_init(void);
56 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
57 vm_ooffset_t, struct ucred *);
58 static void dev_pager_dealloc(vm_object_t);
59 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int);
60 static void dev_pager_putpages(vm_object_t, vm_page_t *, int,
62 static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *,
65 /* list of device pager objects */
66 static struct pagerlst dev_pager_object_list;
67 /* protect list manipulation */
68 static struct mtx dev_pager_mtx;
70 struct pagerops devicepagerops = {
71 .pgo_init = dev_pager_init,
72 .pgo_alloc = dev_pager_alloc,
73 .pgo_dealloc = dev_pager_dealloc,
74 .pgo_getpages = dev_pager_getpages,
75 .pgo_putpages = dev_pager_putpages,
76 .pgo_haspage = dev_pager_haspage,
82 TAILQ_INIT(&dev_pager_object_list);
83 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF);
90 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
91 vm_ooffset_t foff, struct ucred *cred)
94 vm_object_t object, object1;
104 * Offset should be page aligned.
106 if (foff & PAGE_MASK)
109 size = round_page(size);
110 pindex = OFF_TO_IDX(foff + size);
113 * Make sure this device can be mapped.
116 csw = dev_refthread(dev, &ref);
121 * Check that the specified range of the device allows the desired
124 * XXX assumes VM_PROT_* == PROT_*
126 npages = OFF_TO_IDX(size);
127 for (off = foff; npages--; off += PAGE_SIZE)
128 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) {
129 dev_relthread(dev, ref);
133 mtx_lock(&dev_pager_mtx);
136 * Look up pager, creating as necessary.
139 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
140 if (object == NULL) {
142 * Allocate object and associate it with the pager. Initialize
143 * the object's pg_color based upon the physical address of the
146 mtx_unlock(&dev_pager_mtx);
147 object1 = vm_object_allocate(OBJT_DEVICE, pindex);
148 object1->flags |= OBJ_COLORED;
149 object1->pg_color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE);
150 TAILQ_INIT(&object1->un_pager.devp.devp_pglist);
151 mtx_lock(&dev_pager_mtx);
152 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
153 if (object != NULL) {
155 * We raced with other thread while allocating object.
157 if (pindex > object->size)
158 object->size = pindex;
162 object->handle = handle;
163 TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
167 if (pindex > object->size)
168 object->size = pindex;
170 mtx_unlock(&dev_pager_mtx);
171 dev_relthread(dev, ref);
172 if (object1 != NULL) {
173 object1->handle = object1;
174 mtx_lock(&dev_pager_mtx);
175 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1,
177 mtx_unlock(&dev_pager_mtx);
178 vm_object_deallocate(object1);
184 dev_pager_dealloc(object)
189 VM_OBJECT_UNLOCK(object);
190 mtx_lock(&dev_pager_mtx);
191 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
192 mtx_unlock(&dev_pager_mtx);
193 VM_OBJECT_LOCK(object);
195 * Free up our fake pages.
197 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != NULL) {
198 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq);
204 dev_pager_getpages(object, m, count, reqpage)
212 vm_page_t m_paddr, page;
213 vm_memattr_t memattr;
220 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
221 dev = object->handle;
223 offset = page->pindex;
224 memattr = object->memattr;
225 VM_OBJECT_UNLOCK(object);
226 csw = dev_refthread(dev, &ref);
228 VM_OBJECT_LOCK(object);
229 return (VM_PAGER_FAIL);
234 ret = csw->d_mmap(dev, (vm_ooffset_t)offset << PAGE_SHIFT, &paddr,
235 PROT_READ, &memattr);
236 KASSERT(ret == 0, ("dev_pager_getpage: map function returns error"));
238 dev_relthread(dev, ref);
239 /* If "paddr" is a real page, perform a sanity check on "memattr". */
240 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL &&
241 pmap_page_get_memattr(m_paddr) != memattr) {
242 memattr = pmap_page_get_memattr(m_paddr);
244 "WARNING: A device driver has set \"memattr\" inconsistently.\n");
246 if ((page->flags & PG_FICTITIOUS) != 0) {
248 * If the passed in reqpage page is a fake page, update it with
249 * the new physical address.
251 VM_OBJECT_LOCK(object);
252 vm_page_updatefake(page, paddr, memattr);
255 for (i = 0; i < count; i++) {
259 vm_page_unlock(m[i]);
265 * Replace the passed in reqpage page with our own fake page and
266 * free up the all of the original pages.
268 page = vm_page_getfake(paddr, memattr);
269 VM_OBJECT_LOCK(object);
270 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq);
271 for (i = 0; i < count; i++) {
274 vm_page_unlock(m[i]);
276 vm_page_insert(page, object, offset);
279 page->valid = VM_PAGE_BITS_ALL;
280 return (VM_PAGER_OK);
284 dev_pager_putpages(object, m, count, sync, rtvals)
291 panic("dev_pager_putpage called");
295 dev_pager_haspage(object, pindex, before, after)