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/vm_radix.h>
56 #include <vm/uma.h>
57
58 static void dev_pager_init(void);
59 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
60 vm_ooffset_t, struct ucred *);
61 static void dev_pager_dealloc(vm_object_t);
62 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *);
63 static void dev_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
64 static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
65 static void dev_pager_free_page(vm_object_t object, vm_page_t m);
66 static int dev_pager_populate(vm_object_t object, vm_pindex_t pidx,
67 int fault_type, vm_prot_t, vm_pindex_t *first, vm_pindex_t *last);
68
69 /* list of device pager objects */
70 static struct pagerlst dev_pager_object_list;
71 /* protect list manipulation */
72 static struct mtx dev_pager_mtx;
73
74 const struct pagerops devicepagerops = {
75 .pgo_kvme_type = KVME_TYPE_DEVICE,
76 .pgo_init = dev_pager_init,
77 .pgo_alloc = dev_pager_alloc,
78 .pgo_dealloc = dev_pager_dealloc,
79 .pgo_getpages = dev_pager_getpages,
80 .pgo_putpages = dev_pager_putpages,
81 .pgo_haspage = dev_pager_haspage,
82 };
83
84 const struct pagerops mgtdevicepagerops = {
85 .pgo_kvme_type = KVME_TYPE_MGTDEVICE,
86 .pgo_alloc = dev_pager_alloc,
87 .pgo_dealloc = dev_pager_dealloc,
88 .pgo_getpages = dev_pager_getpages,
89 .pgo_putpages = dev_pager_putpages,
90 .pgo_haspage = dev_pager_haspage,
91 .pgo_populate = dev_pager_populate,
92 };
93
94 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
95 vm_ooffset_t foff, struct ucred *cred, u_short *color);
96 static void old_dev_pager_dtor(void *handle);
97 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset,
98 int prot, vm_page_t *mres);
99
100 static const struct cdev_pager_ops old_dev_pager_ops = {
101 .cdev_pg_ctor = old_dev_pager_ctor,
102 .cdev_pg_dtor = old_dev_pager_dtor,
103 .cdev_pg_fault = old_dev_pager_fault
104 };
105
106 static void
dev_pager_init(void)107 dev_pager_init(void)
108 {
109
110 TAILQ_INIT(&dev_pager_object_list);
111 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF);
112 }
113
114 vm_object_t
cdev_pager_lookup(void * handle)115 cdev_pager_lookup(void *handle)
116 {
117 vm_object_t object;
118
119 again:
120 mtx_lock(&dev_pager_mtx);
121 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
122 if (object != NULL && object->un_pager.devp.handle == NULL) {
123 msleep(&object->un_pager.devp.handle, &dev_pager_mtx,
124 PVM | PDROP, "cdplkp", 0);
125 vm_object_deallocate(object);
126 goto again;
127 }
128 mtx_unlock(&dev_pager_mtx);
129 return (object);
130 }
131
132 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)133 cdev_pager_allocate(void *handle, enum obj_type tp,
134 const struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot,
135 vm_ooffset_t foff, struct ucred *cred)
136 {
137 vm_object_t object;
138 vm_pindex_t pindex;
139
140 if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE)
141 return (NULL);
142 KASSERT(tp == OBJT_MGTDEVICE || ops->cdev_pg_populate == NULL,
143 ("populate on unmanaged device pager"));
144
145 /*
146 * Offset should be page aligned.
147 */
148 if (foff & PAGE_MASK)
149 return (NULL);
150
151 /*
152 * Treat the mmap(2) file offset as an unsigned value for a
153 * device mapping. This, in effect, allows a user to pass all
154 * possible off_t values as the mapping cookie to the driver. At
155 * this point, we know that both foff and size are a multiple
156 * of the page size. Do a check to avoid wrap.
157 */
158 size = round_page(size);
159 pindex = OFF_TO_IDX(foff) + OFF_TO_IDX(size);
160 if (pindex > OBJ_MAX_SIZE || pindex < OFF_TO_IDX(foff) ||
161 pindex < OFF_TO_IDX(size))
162 return (NULL);
163
164 again:
165 mtx_lock(&dev_pager_mtx);
166
167 /*
168 * Look up pager, creating as necessary.
169 */
170 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
171 if (object == NULL) {
172 vm_object_t object1;
173
174 /*
175 * Allocate object and associate it with the pager. Initialize
176 * the object's pg_color based upon the physical address of the
177 * device's memory.
178 */
179 mtx_unlock(&dev_pager_mtx);
180 object1 = vm_object_allocate(tp, pindex);
181 mtx_lock(&dev_pager_mtx);
182 object = vm_pager_object_lookup(&dev_pager_object_list, handle);
183 if (object != NULL) {
184 object1->type = OBJT_DEAD;
185 vm_object_deallocate(object1);
186 object1 = NULL;
187 if (object->un_pager.devp.handle == NULL) {
188 msleep(&object->un_pager.devp.handle,
189 &dev_pager_mtx, PVM | PDROP, "cdplkp", 0);
190 vm_object_deallocate(object);
191 goto again;
192 }
193
194 /*
195 * We raced with other thread while allocating object.
196 */
197 if (pindex > object->size)
198 object->size = pindex;
199 KASSERT(object->type == tp,
200 ("Inconsistent device pager type %p %d",
201 object, tp));
202 KASSERT(object->un_pager.devp.ops == ops,
203 ("Inconsistent devops %p %p", object, ops));
204 } else {
205 u_short color;
206
207 object = object1;
208 object1 = NULL;
209 object->handle = handle;
210 object->un_pager.devp.ops = ops;
211 TAILQ_INIT(&object->un_pager.devp.devp_pglist);
212 TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
213 pager_object_list);
214 mtx_unlock(&dev_pager_mtx);
215 if (ops->cdev_pg_populate != NULL)
216 vm_object_set_flag(object, OBJ_POPULATE);
217 if (ops->cdev_pg_ctor(handle, size, prot, foff,
218 cred, &color) != 0) {
219 mtx_lock(&dev_pager_mtx);
220 TAILQ_REMOVE(&dev_pager_object_list, object,
221 pager_object_list);
222 wakeup(&object->un_pager.devp.handle);
223 mtx_unlock(&dev_pager_mtx);
224 object->type = OBJT_DEAD;
225 vm_object_deallocate(object);
226 object = NULL;
227 mtx_lock(&dev_pager_mtx);
228 } else {
229 mtx_lock(&dev_pager_mtx);
230 object->flags |= OBJ_COLORED;
231 object->pg_color = color;
232 object->un_pager.devp.handle = handle;
233 wakeup(&object->un_pager.devp.handle);
234 }
235 }
236 MPASS(object1 == NULL);
237 } else {
238 if (object->un_pager.devp.handle == NULL) {
239 msleep(&object->un_pager.devp.handle,
240 &dev_pager_mtx, PVM | PDROP, "cdplkp", 0);
241 vm_object_deallocate(object);
242 goto again;
243 }
244 if (pindex > object->size)
245 object->size = pindex;
246 KASSERT(object->type == tp,
247 ("Inconsistent device pager type %p %d", object, tp));
248 }
249 mtx_unlock(&dev_pager_mtx);
250 return (object);
251 }
252
253 static vm_object_t
dev_pager_alloc(void * handle,vm_ooffset_t size,vm_prot_t prot,vm_ooffset_t foff,struct ucred * cred)254 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
255 vm_ooffset_t foff, struct ucred *cred)
256 {
257
258 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops,
259 size, prot, foff, cred));
260 }
261
262 void
cdev_pager_free_page(vm_object_t object,vm_page_t m)263 cdev_pager_free_page(vm_object_t object, vm_page_t m)
264 {
265
266 if (object->type == OBJT_MGTDEVICE) {
267 struct pctrie_iter pages;
268
269 vm_page_iter_init(&pages, object);
270 vm_page_iter_lookup(&pages, m->pindex);
271 cdev_mgtdev_pager_free_page(&pages);
272 } else if (object->type == OBJT_DEVICE)
273 dev_pager_free_page(object, m);
274 else
275 KASSERT(false,
276 ("Invalid device type obj %p m %p", object, m));
277 }
278
279 void
cdev_mgtdev_pager_free_page(struct pctrie_iter * pages)280 cdev_mgtdev_pager_free_page(struct pctrie_iter *pages)
281 {
282 pmap_remove_all(vm_radix_iter_page(pages));
283 vm_page_iter_remove(pages);
284 }
285
286 void
cdev_mgtdev_pager_free_pages(vm_object_t object)287 cdev_mgtdev_pager_free_pages(vm_object_t object)
288 {
289 struct pctrie_iter pages;
290 vm_page_t m;
291
292 vm_page_iter_init(&pages, object);
293 VM_OBJECT_WLOCK(object);
294 retry:
295 for (m = vm_page_iter_lookup_ge(&pages, 0); m != NULL;
296 m = vm_radix_iter_step(&pages)) {
297 if (!vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL)) {
298 pctrie_iter_reset(&pages);
299 goto retry;
300 }
301 cdev_mgtdev_pager_free_page(&pages);
302 }
303 VM_OBJECT_WUNLOCK(object);
304 }
305
306 static void
dev_pager_free_page(vm_object_t object,vm_page_t m)307 dev_pager_free_page(vm_object_t object, vm_page_t m)
308 {
309
310 VM_OBJECT_ASSERT_WLOCKED(object);
311 KASSERT((object->type == OBJT_DEVICE &&
312 (m->oflags & VPO_UNMANAGED) != 0),
313 ("Managed device or page obj %p m %p", object, m));
314 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q);
315 vm_page_putfake(m);
316 }
317
318 static void
dev_pager_dealloc(vm_object_t object)319 dev_pager_dealloc(vm_object_t object)
320 {
321 vm_page_t m;
322
323 VM_OBJECT_WUNLOCK(object);
324 object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.handle);
325
326 mtx_lock(&dev_pager_mtx);
327 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
328 mtx_unlock(&dev_pager_mtx);
329 VM_OBJECT_WLOCK(object);
330
331 if (object->type == OBJT_DEVICE) {
332 /*
333 * Free up our fake pages.
334 */
335 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist))
336 != NULL) {
337 if (vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL) == 0)
338 continue;
339
340 dev_pager_free_page(object, m);
341 }
342 }
343 object->handle = NULL;
344 object->type = OBJT_DEAD;
345 }
346
347 static int
dev_pager_getpages(vm_object_t object,vm_page_t * ma,int count,int * rbehind,int * rahead)348 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind,
349 int *rahead)
350 {
351 int error;
352
353 /* Since our haspage reports zero after/before, the count is 1. */
354 KASSERT(count == 1, ("%s: count %d", __func__, count));
355 if (object->un_pager.devp.ops->cdev_pg_fault == NULL)
356 return (VM_PAGER_FAIL);
357 VM_OBJECT_WLOCK(object);
358 error = object->un_pager.devp.ops->cdev_pg_fault(object,
359 IDX_TO_OFF(ma[0]->pindex), PROT_READ, &ma[0]);
360
361 VM_OBJECT_ASSERT_WLOCKED(object);
362
363 if (error == VM_PAGER_OK) {
364 KASSERT((object->type == OBJT_DEVICE &&
365 (ma[0]->oflags & VPO_UNMANAGED) != 0) ||
366 (object->type == OBJT_MGTDEVICE &&
367 (ma[0]->oflags & VPO_UNMANAGED) == 0),
368 ("Wrong page type %p %p", ma[0], object));
369 if (object->type == OBJT_DEVICE) {
370 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist,
371 ma[0], plinks.q);
372 }
373 if (rbehind)
374 *rbehind = 0;
375 if (rahead)
376 *rahead = 0;
377 }
378 VM_OBJECT_WUNLOCK(object);
379
380 return (error);
381 }
382
383 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)384 dev_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type,
385 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
386 {
387
388 VM_OBJECT_ASSERT_WLOCKED(object);
389 if (object->un_pager.devp.ops->cdev_pg_populate == NULL)
390 return (VM_PAGER_FAIL);
391 return (object->un_pager.devp.ops->cdev_pg_populate(object, pidx,
392 fault_type, max_prot, first, last));
393 }
394
395 static int
old_dev_pager_fault(vm_object_t object,vm_ooffset_t offset,int prot,vm_page_t * mres)396 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot,
397 vm_page_t *mres)
398 {
399 vm_paddr_t paddr;
400 vm_page_t m_paddr, page;
401 struct cdev *dev;
402 struct cdevsw *csw;
403 struct file *fpop;
404 struct thread *td;
405 vm_memattr_t memattr, memattr1;
406 int ref, ret;
407
408 memattr = object->memattr;
409
410 VM_OBJECT_WUNLOCK(object);
411
412 dev = object->handle;
413 csw = dev_refthread(dev, &ref);
414 if (csw == NULL) {
415 VM_OBJECT_WLOCK(object);
416 return (VM_PAGER_FAIL);
417 }
418 td = curthread;
419 fpop = td->td_fpop;
420 td->td_fpop = NULL;
421 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr);
422 td->td_fpop = fpop;
423 dev_relthread(dev, ref);
424 if (ret != 0) {
425 printf(
426 "WARNING: dev_pager_getpage: map function returns error %d", ret);
427 VM_OBJECT_WLOCK(object);
428 return (VM_PAGER_FAIL);
429 }
430
431 /* If "paddr" is a real page, perform a sanity check on "memattr". */
432 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL &&
433 (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) {
434 /*
435 * For the /dev/mem d_mmap routine to return the
436 * correct memattr, pmap_page_get_memattr() needs to
437 * be called, which we do there.
438 */
439 if ((csw->d_flags & D_MEM) == 0) {
440 printf("WARNING: Device driver %s has set "
441 "\"memattr\" inconsistently (drv %u pmap %u).\n",
442 csw->d_name, memattr, memattr1);
443 }
444 memattr = memattr1;
445 }
446 if (((*mres)->flags & PG_FICTITIOUS) != 0) {
447 /*
448 * If the passed in result page is a fake page, update it with
449 * the new physical address.
450 */
451 page = *mres;
452 VM_OBJECT_WLOCK(object);
453 vm_page_updatefake(page, paddr, memattr);
454 } else {
455 /*
456 * Replace the passed in reqpage page with our own fake page and
457 * free up the all of the original pages.
458 */
459 page = vm_page_getfake(paddr, memattr);
460 VM_OBJECT_WLOCK(object);
461 vm_page_replace(page, object, (*mres)->pindex, *mres);
462 *mres = page;
463 }
464 vm_page_valid(page);
465 return (VM_PAGER_OK);
466 }
467
468 static void
dev_pager_putpages(vm_object_t object,vm_page_t * m,int count,int flags,int * rtvals)469 dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags,
470 int *rtvals)
471 {
472
473 panic("dev_pager_putpage called");
474 }
475
476 static boolean_t
dev_pager_haspage(vm_object_t object,vm_pindex_t pindex,int * before,int * after)477 dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
478 int *after)
479 {
480
481 if (before != NULL)
482 *before = 0;
483 if (after != NULL)
484 *after = 0;
485 return (TRUE);
486 }
487
488 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)489 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
490 vm_ooffset_t foff, struct ucred *cred, u_short *color)
491 {
492 struct cdev *dev;
493 struct cdevsw *csw;
494 vm_memattr_t dummy;
495 vm_ooffset_t off;
496 vm_paddr_t paddr;
497 unsigned int npages;
498 int ref;
499
500 /*
501 * Make sure this device can be mapped.
502 */
503 dev = handle;
504 csw = dev_refthread(dev, &ref);
505 if (csw == NULL)
506 return (ENXIO);
507
508 /*
509 * Check that the specified range of the device allows the desired
510 * protection.
511 *
512 * XXX assumes VM_PROT_* == PROT_*
513 */
514 npages = OFF_TO_IDX(size);
515 paddr = 0; /* Make paddr initialized for the case of size == 0. */
516 for (off = foff; npages--; off += PAGE_SIZE) {
517 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) {
518 dev_relthread(dev, ref);
519 return (EINVAL);
520 }
521 }
522
523 dev_ref(dev);
524 dev_relthread(dev, ref);
525 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE);
526 return (0);
527 }
528
529 static void
old_dev_pager_dtor(void * handle)530 old_dev_pager_dtor(void *handle)
531 {
532
533 dev_rel(handle);
534 }
535