1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990 University of Utah.
5 * Copyright (c) 1991, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
10 * Science Department.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/conf.h>
40 #include <sys/lock.h>
41 #include <sys/proc.h>
42 #include <sys/mutex.h>
43 #include <sys/mman.h>
44 #include <sys/rwlock.h>
45 #include <sys/sx.h>
46 #include <sys/user.h>
47 #include <sys/vmmeter.h>
48
49 #include <vm/vm.h>
50 #include <vm/vm_param.h>
51 #include <vm/vm_object.h>
52 #include <vm/vm_page.h>
53 #include <vm/vm_pager.h>
54 #include <vm/vm_phys.h>
55 #include <vm/uma.h>
56
57 static void dev_pager_init(void);
58 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
59 vm_ooffset_t, struct ucred *);
60 static void dev_pager_dealloc(vm_object_t);
61 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *);
62 static void dev_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
63 static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
64 static void dev_pager_free_page(vm_object_t object, vm_page_t m);
65 static int dev_pager_populate(vm_object_t object, vm_pindex_t pidx,
66 int fault_type, vm_prot_t, vm_pindex_t *first, vm_pindex_t *last);
67
68 /* list of device pager objects */
69 static struct pagerlst dev_pager_object_list;
70 /* protect list manipulation */
71 static struct mtx dev_pager_mtx;
72
73 const struct pagerops devicepagerops = {
74 .pgo_kvme_type = KVME_TYPE_DEVICE,
75 .pgo_init = dev_pager_init,
76 .pgo_alloc = dev_pager_alloc,
77 .pgo_dealloc = dev_pager_dealloc,
78 .pgo_getpages = dev_pager_getpages,
79 .pgo_putpages = dev_pager_putpages,
80 .pgo_haspage = dev_pager_haspage,
81 };
82
83 const struct pagerops mgtdevicepagerops = {
84 .pgo_kvme_type = KVME_TYPE_MGTDEVICE,
85 .pgo_alloc = dev_pager_alloc,
86 .pgo_dealloc = dev_pager_dealloc,
87 .pgo_getpages = dev_pager_getpages,
88 .pgo_putpages = dev_pager_putpages,
89 .pgo_haspage = dev_pager_haspage,
90 .pgo_populate = dev_pager_populate,
91 };
92
93 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
94 vm_ooffset_t foff, struct ucred *cred, u_short *color);
95 static void old_dev_pager_dtor(void *handle);
96 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset,
97 int prot, vm_page_t *mres);
98
99 static const struct cdev_pager_ops old_dev_pager_ops = {
100 .cdev_pg_ctor = old_dev_pager_ctor,
101 .cdev_pg_dtor = old_dev_pager_dtor,
102 .cdev_pg_fault = old_dev_pager_fault
103 };
104
105 static void
dev_pager_init(void)106 dev_pager_init(void)
107 {
108
109 TAILQ_INIT(&dev_pager_object_list);
110 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF);
111 }
112
113 vm_object_t
cdev_pager_lookup(void * handle)114 cdev_pager_lookup(void *handle)
115 {
116 vm_object_t object;
117
118 mtx_lock(&dev_pager_mtx);
119 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
120 mtx_unlock(&dev_pager_mtx);
121 return (object);
122 }
123
124 vm_object_t
cdev_pager_allocate(void * handle,enum obj_type tp,const struct cdev_pager_ops * ops,vm_ooffset_t size,vm_prot_t prot,vm_ooffset_t foff,struct ucred * cred)125 cdev_pager_allocate(void *handle, enum obj_type tp,
126 const struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
127 vm_ooffset_t foff, struct ucred *cred)
128 {
129 vm_object_t object, object1;
130 vm_pindex_t pindex;
131 u_short color;
132
133 if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE)
134 return (NULL);
135 KASSERT(tp == OBJT_MGTDEVICE || ops->cdev_pg_populate == NULL,
136 ("populate on unmanaged device pager"));
137
138 /*
139 * Offset should be page aligned.
140 */
141 if (foff & PAGE_MASK)
142 return (NULL);
143
144 /*
145 * Treat the mmap(2) file offset as an unsigned value for a
146 * device mapping. This, in effect, allows a user to pass all
147 * possible off_t values as the mapping cookie to the driver. At
148 * this point, we know that both foff and size are a multiple
149 * of the page size. Do a check to avoid wrap.
150 */
151 size = round_page(size);
152 pindex = OFF_TO_IDX(foff) + OFF_TO_IDX(size);
153 if (pindex > OBJ_MAX_SIZE || pindex < OFF_TO_IDX(foff) ||
154 pindex < OFF_TO_IDX(size))
155 return (NULL);
156
157 if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0)
158 return (NULL);
159 mtx_lock(&dev_pager_mtx);
160
161 /*
162 * Look up pager, creating as necessary.
163 */
164 object1 = NULL;
165 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
166 if (object == NULL) {
167 /*
168 * Allocate object and associate it with the pager. Initialize
169 * the object's pg_color based upon the physical address of the
170 * device's memory.
171 */
172 mtx_unlock(&dev_pager_mtx);
173 object1 = vm_object_allocate(tp, pindex);
174 object1->flags |= OBJ_COLORED;
175 object1->pg_color = color;
176 object1->handle = handle;
177 object1->un_pager.devp.ops = ops;
178 object1->un_pager.devp.dev = handle;
179 TAILQ_INIT(&object1->un_pager.devp.devp_pglist);
180 mtx_lock(&dev_pager_mtx);
181 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
182 if (object != NULL) {
183 /*
184 * We raced with other thread while allocating object.
185 */
186 if (pindex > object->size)
187 object->size = pindex;
188 KASSERT(object->type == tp,
189 ("Inconsistent device pager type %p %d",
190 object, tp));
191 KASSERT(object->un_pager.devp.ops == ops,
192 ("Inconsistent devops %p %p", object, ops));
193 } else {
194 object = object1;
195 object1 = NULL;
196 object->handle = handle;
197 TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
198 pager_object_list);
199 if (ops->cdev_pg_populate != NULL)
200 vm_object_set_flag(object, OBJ_POPULATE);
201 }
202 } else {
203 if (pindex > object->size)
204 object->size = pindex;
205 KASSERT(object->type == tp,
206 ("Inconsistent device pager type %p %d", object, tp));
207 }
208 mtx_unlock(&dev_pager_mtx);
209 if (object1 != NULL) {
210 object1->handle = object1;
211 mtx_lock(&dev_pager_mtx);
212 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1,
213 pager_object_list);
214 mtx_unlock(&dev_pager_mtx);
215 vm_object_deallocate(object1);
216 }
217 return (object);
218 }
219
220 static vm_object_t
dev_pager_alloc(void * handle,vm_ooffset_t size,vm_prot_t prot,vm_ooffset_t foff,struct ucred * cred)221 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
222 vm_ooffset_t foff, struct ucred *cred)
223 {
224
225 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops,
226 size, prot, foff, cred));
227 }
228
229 void
cdev_pager_free_page(vm_object_t object,vm_page_t m)230 cdev_pager_free_page(vm_object_t object, vm_page_t m)
231 {
232
233 VM_OBJECT_ASSERT_WLOCKED(object);
234 if (object->type == OBJT_MGTDEVICE) {
235 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m));
236 pmap_remove_all(m);
237 (void)vm_page_remove(m);
238 } else if (object->type == OBJT_DEVICE)
239 dev_pager_free_page(object, m);
240 }
241
242 static void
dev_pager_free_page(vm_object_t object,vm_page_t m)243 dev_pager_free_page(vm_object_t object, vm_page_t m)
244 {
245
246 VM_OBJECT_ASSERT_WLOCKED(object);
247 KASSERT((object->type == OBJT_DEVICE &&
248 (m->oflags & VPO_UNMANAGED) != 0),
249 ("Managed device or page obj %p m %p", object, m));
250 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q);
251 vm_page_putfake(m);
252 }
253
254 static void
dev_pager_dealloc(vm_object_t object)255 dev_pager_dealloc(vm_object_t object)
256 {
257 vm_page_t m;
258
259 VM_OBJECT_WUNLOCK(object);
260 object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev);
261
262 mtx_lock(&dev_pager_mtx);
263 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
264 mtx_unlock(&dev_pager_mtx);
265 VM_OBJECT_WLOCK(object);
266
267 if (object->type == OBJT_DEVICE) {
268 /*
269 * Free up our fake pages.
270 */
271 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist))
272 != NULL) {
273 if (vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL) == 0)
274 continue;
275
276 dev_pager_free_page(object, m);
277 }
278 }
279 object->handle = NULL;
280 object->type = OBJT_DEAD;
281 }
282
283 static int
dev_pager_getpages(vm_object_t object,vm_page_t * ma,int count,int * rbehind,int * rahead)284 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind,
285 int *rahead)
286 {
287 int error;
288
289 /* Since our haspage reports zero after/before, the count is 1. */
290 KASSERT(count == 1, ("%s: count %d", __func__, count));
291 if (object->un_pager.devp.ops->cdev_pg_fault == NULL)
292 return (VM_PAGER_FAIL);
293 VM_OBJECT_WLOCK(object);
294 error = object->un_pager.devp.ops->cdev_pg_fault(object,
295 IDX_TO_OFF(ma[0]->pindex), PROT_READ, &ma[0]);
296
297 VM_OBJECT_ASSERT_WLOCKED(object);
298
299 if (error == VM_PAGER_OK) {
300 KASSERT((object->type == OBJT_DEVICE &&
301 (ma[0]->oflags & VPO_UNMANAGED) != 0) ||
302 (object->type == OBJT_MGTDEVICE &&
303 (ma[0]->oflags & VPO_UNMANAGED) == 0),
304 ("Wrong page type %p %p", ma[0], object));
305 if (object->type == OBJT_DEVICE) {
306 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist,
307 ma[0], plinks.q);
308 }
309 if (rbehind)
310 *rbehind = 0;
311 if (rahead)
312 *rahead = 0;
313 }
314 VM_OBJECT_WUNLOCK(object);
315
316 return (error);
317 }
318
319 static int
dev_pager_populate(vm_object_t object,vm_pindex_t pidx,int fault_type,vm_prot_t max_prot,vm_pindex_t * first,vm_pindex_t * last)320 dev_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type,
321 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
322 {
323
324 VM_OBJECT_ASSERT_WLOCKED(object);
325 if (object->un_pager.devp.ops->cdev_pg_populate == NULL)
326 return (VM_PAGER_FAIL);
327 return (object->un_pager.devp.ops->cdev_pg_populate(object, pidx,
328 fault_type, max_prot, first, last));
329 }
330
331 static int
old_dev_pager_fault(vm_object_t object,vm_ooffset_t offset,int prot,vm_page_t * mres)332 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot,
333 vm_page_t *mres)
334 {
335 vm_paddr_t paddr;
336 vm_page_t m_paddr, page;
337 struct cdev *dev;
338 struct cdevsw *csw;
339 struct file *fpop;
340 struct thread *td;
341 vm_memattr_t memattr, memattr1;
342 int ref, ret;
343
344 memattr = object->memattr;
345
346 VM_OBJECT_WUNLOCK(object);
347
348 dev = object->handle;
349 csw = dev_refthread(dev, &ref);
350 if (csw == NULL) {
351 VM_OBJECT_WLOCK(object);
352 return (VM_PAGER_FAIL);
353 }
354 td = curthread;
355 fpop = td->td_fpop;
356 td->td_fpop = NULL;
357 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr);
358 td->td_fpop = fpop;
359 dev_relthread(dev, ref);
360 if (ret != 0) {
361 printf(
362 "WARNING: dev_pager_getpage: map function returns error %d", ret);
363 VM_OBJECT_WLOCK(object);
364 return (VM_PAGER_FAIL);
365 }
366
367 /* If "paddr" is a real page, perform a sanity check on "memattr". */
368 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL &&
369 (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) {
370 /*
371 * For the /dev/mem d_mmap routine to return the
372 * correct memattr, pmap_page_get_memattr() needs to
373 * be called, which we do there.
374 */
375 if ((csw->d_flags & D_MEM) == 0) {
376 printf("WARNING: Device driver %s has set "
377 "\"memattr\" inconsistently (drv %u pmap %u).\n",
378 csw->d_name, memattr, memattr1);
379 }
380 memattr = memattr1;
381 }
382 if (((*mres)->flags & PG_FICTITIOUS) != 0) {
383 /*
384 * If the passed in result page is a fake page, update it with
385 * the new physical address.
386 */
387 page = *mres;
388 VM_OBJECT_WLOCK(object);
389 vm_page_updatefake(page, paddr, memattr);
390 } else {
391 /*
392 * Replace the passed in reqpage page with our own fake page and
393 * free up the all of the original pages.
394 */
395 page = vm_page_getfake(paddr, memattr);
396 VM_OBJECT_WLOCK(object);
397 vm_page_replace(page, object, (*mres)->pindex, *mres);
398 *mres = page;
399 }
400 vm_page_valid(page);
401 return (VM_PAGER_OK);
402 }
403
404 static void
dev_pager_putpages(vm_object_t object,vm_page_t * m,int count,int flags,int * rtvals)405 dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags,
406 int *rtvals)
407 {
408
409 panic("dev_pager_putpage called");
410 }
411
412 static boolean_t
dev_pager_haspage(vm_object_t object,vm_pindex_t pindex,int * before,int * after)413 dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
414 int *after)
415 {
416
417 if (before != NULL)
418 *before = 0;
419 if (after != NULL)
420 *after = 0;
421 return (TRUE);
422 }
423
424 static int
old_dev_pager_ctor(void * handle,vm_ooffset_t size,vm_prot_t prot,vm_ooffset_t foff,struct ucred * cred,u_short * color)425 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
426 vm_ooffset_t foff, struct ucred *cred, u_short *color)
427 {
428 struct cdev *dev;
429 struct cdevsw *csw;
430 vm_memattr_t dummy;
431 vm_ooffset_t off;
432 vm_paddr_t paddr;
433 unsigned int npages;
434 int ref;
435
436 /*
437 * Make sure this device can be mapped.
438 */
439 dev = handle;
440 csw = dev_refthread(dev, &ref);
441 if (csw == NULL)
442 return (ENXIO);
443
444 /*
445 * Check that the specified range of the device allows the desired
446 * protection.
447 *
448 * XXX assumes VM_PROT_* == PROT_*
449 */
450 npages = OFF_TO_IDX(size);
451 paddr = 0; /* Make paddr initialized for the case of size == 0. */
452 for (off = foff; npages--; off += PAGE_SIZE) {
453 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) {
454 dev_relthread(dev, ref);
455 return (EINVAL);
456 }
457 }
458
459 dev_ref(dev);
460 dev_relthread(dev, ref);
461 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE);
462 return (0);
463 }
464
465 static void
old_dev_pager_dtor(void * handle)466 old_dev_pager_dtor(void *handle)
467 {
468
469 dev_rel(handle);
470 }
471