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;
71 static uma_zone_t fakepg_zone;
73 static vm_page_t dev_pager_getfake(vm_paddr_t, vm_memattr_t);
74 static void dev_pager_putfake(vm_page_t);
75 static void dev_pager_updatefake(vm_page_t, vm_paddr_t, vm_memattr_t);
77 struct pagerops devicepagerops = {
78 .pgo_init = dev_pager_init,
79 .pgo_alloc = dev_pager_alloc,
80 .pgo_dealloc = dev_pager_dealloc,
81 .pgo_getpages = dev_pager_getpages,
82 .pgo_putpages = dev_pager_putpages,
83 .pgo_haspage = dev_pager_haspage,
89 TAILQ_INIT(&dev_pager_object_list);
90 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF);
91 fakepg_zone = uma_zcreate("DP fakepg", sizeof(struct vm_page),
92 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
93 UMA_ZONE_NOFREE|UMA_ZONE_VM);
97 dev_mmap(struct cdevsw *csw, struct cdev *dev, vm_offset_t offset,
98 vm_paddr_t *paddr, int nprot, vm_memattr_t *memattr)
101 if (csw->d_flags & D_MMAP2)
102 return (csw->d_mmap2(dev, offset, paddr, nprot, memattr));
104 return (csw->d_mmap(dev, offset, paddr, nprot));
111 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
112 vm_ooffset_t foff, struct ucred *cred)
115 vm_object_t object, object1;
125 * Offset should be page aligned.
127 if (foff & PAGE_MASK)
130 size = round_page(size);
131 pindex = OFF_TO_IDX(foff + size);
134 * Make sure this device can be mapped.
137 csw = dev_refthread(dev, &ref);
142 * Check that the specified range of the device allows the desired
145 * XXX assumes VM_PROT_* == PROT_*
147 npages = OFF_TO_IDX(size);
148 for (off = foff; npages--; off += PAGE_SIZE)
149 if (dev_mmap(csw, dev, off, &paddr, (int)prot, &dummy) != 0) {
150 dev_relthread(dev, ref);
154 mtx_lock(&dev_pager_mtx);
157 * Look up pager, creating as necessary.
160 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
161 if (object == NULL) {
163 * Allocate object and associate it with the pager. Initialize
164 * the object's pg_color based upon the physical address of the
167 mtx_unlock(&dev_pager_mtx);
168 object1 = vm_object_allocate(OBJT_DEVICE, pindex);
169 object1->flags |= OBJ_COLORED;
170 object1->pg_color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE);
171 mtx_lock(&dev_pager_mtx);
172 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
173 if (object != NULL) {
175 * We raced with other thread while allocating object.
177 if (pindex > object->size)
178 object->size = pindex;
182 object->handle = handle;
183 TAILQ_INIT(&object->un_pager.devp.devp_pglist);
184 TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
188 if (pindex > object->size)
189 object->size = pindex;
191 mtx_unlock(&dev_pager_mtx);
192 dev_relthread(dev, ref);
193 vm_object_deallocate(object1);
198 dev_pager_dealloc(object)
203 VM_OBJECT_UNLOCK(object);
204 mtx_lock(&dev_pager_mtx);
205 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
206 mtx_unlock(&dev_pager_mtx);
207 VM_OBJECT_LOCK(object);
209 * Free up our fake pages.
211 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != NULL) {
212 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq);
213 dev_pager_putfake(m);
218 dev_pager_getpages(object, m, count, reqpage)
226 vm_page_t m_paddr, page;
227 vm_memattr_t memattr;
234 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
235 dev = object->handle;
237 offset = page->pindex;
238 memattr = object->memattr;
239 VM_OBJECT_UNLOCK(object);
240 csw = dev_refthread(dev, &ref);
242 panic("dev_pager_getpage: no cdevsw");
246 ret = dev_mmap(csw, dev, (vm_offset_t)offset << PAGE_SHIFT, &paddr,
247 PROT_READ, &memattr);
248 KASSERT(ret == 0, ("dev_pager_getpage: map function returns error"));
250 dev_relthread(dev, ref);
251 /* If "paddr" is a real page, perform a sanity check on "memattr". */
252 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL &&
253 pmap_page_get_memattr(m_paddr) != memattr) {
254 memattr = pmap_page_get_memattr(m_paddr);
256 "WARNING: A device driver has set \"memattr\" inconsistently.\n");
258 if ((page->flags & PG_FICTITIOUS) != 0) {
260 * If the passed in reqpage page is a fake page, update it with
261 * the new physical address.
263 VM_OBJECT_LOCK(object);
264 dev_pager_updatefake(page, paddr, memattr);
266 vm_page_lock_queues();
267 for (i = 0; i < count; i++) {
271 vm_page_unlock_queues();
275 * Replace the passed in reqpage page with our own fake page and
276 * free up the all of the original pages.
278 page = dev_pager_getfake(paddr, memattr);
279 VM_OBJECT_LOCK(object);
280 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq);
281 vm_page_lock_queues();
282 for (i = 0; i < count; i++)
284 vm_page_unlock_queues();
285 vm_page_insert(page, object, offset);
288 page->valid = VM_PAGE_BITS_ALL;
289 return (VM_PAGER_OK);
293 dev_pager_putpages(object, m, count, sync, rtvals)
300 panic("dev_pager_putpage called");
304 dev_pager_haspage(object, pindex, before, after)
318 * Create a fictitious page with the specified physical address and memory
319 * attribute. The memory attribute is the only the machine-dependent aspect
320 * of a fictitious page that must be initialized.
323 dev_pager_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
327 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO);
328 m->phys_addr = paddr;
329 /* Fictitious pages don't use "segind". */
330 m->flags = PG_FICTITIOUS;
331 /* Fictitious pages don't use "order" or "pool". */
332 m->oflags = VPO_BUSY;
334 pmap_page_set_memattr(m, memattr);
339 * Release a fictitious page.
342 dev_pager_putfake(vm_page_t m)
345 if (!(m->flags & PG_FICTITIOUS))
346 panic("dev_pager_putfake: bad page");
347 uma_zfree(fakepg_zone, m);
351 * Update the given fictitious page to the specified physical address and
355 dev_pager_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
358 if (!(m->flags & PG_FICTITIOUS))
359 panic("dev_pager_updatefake: bad page");
360 m->phys_addr = paddr;
361 pmap_page_set_memattr(m, memattr);