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_radix.h> 55 #include <vm/vm_phys.h> 56 #include <vm/vm_radix.h> 57 #include <vm/uma.h> 58 59 static void dev_pager_init(void); 60 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 61 vm_ooffset_t, struct ucred *); 62 static void dev_pager_dealloc(vm_object_t); 63 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); 64 static void dev_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 65 static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 66 static void dev_pager_free_page(vm_object_t object, vm_page_t m); 67 static int dev_pager_populate(vm_object_t object, vm_pindex_t pidx, 68 int fault_type, vm_prot_t, vm_pindex_t *first, vm_pindex_t *last); 69 70 /* list of device pager objects */ 71 static struct pagerlst dev_pager_object_list; 72 /* protect list manipulation */ 73 static struct mtx dev_pager_mtx; 74 75 const struct pagerops devicepagerops = { 76 .pgo_kvme_type = KVME_TYPE_DEVICE, 77 .pgo_init = dev_pager_init, 78 .pgo_alloc = dev_pager_alloc, 79 .pgo_dealloc = dev_pager_dealloc, 80 .pgo_getpages = dev_pager_getpages, 81 .pgo_putpages = dev_pager_putpages, 82 .pgo_haspage = dev_pager_haspage, 83 }; 84 85 const struct pagerops mgtdevicepagerops = { 86 .pgo_kvme_type = KVME_TYPE_MGTDEVICE, 87 .pgo_alloc = dev_pager_alloc, 88 .pgo_dealloc = dev_pager_dealloc, 89 .pgo_getpages = dev_pager_getpages, 90 .pgo_putpages = dev_pager_putpages, 91 .pgo_haspage = dev_pager_haspage, 92 .pgo_populate = dev_pager_populate, 93 }; 94 95 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 96 vm_ooffset_t foff, struct ucred *cred, u_short *color); 97 static void old_dev_pager_dtor(void *handle); 98 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, 99 int prot, vm_page_t *mres); 100 static void old_dev_pager_path(void *handle, char *path, size_t len); 101 102 static const struct cdev_pager_ops old_dev_pager_ops = { 103 .cdev_pg_ctor = old_dev_pager_ctor, 104 .cdev_pg_dtor = old_dev_pager_dtor, 105 .cdev_pg_fault = old_dev_pager_fault, 106 .cdev_pg_path = old_dev_pager_path 107 }; 108 109 static void 110 dev_pager_init(void) 111 { 112 113 TAILQ_INIT(&dev_pager_object_list); 114 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF); 115 } 116 117 vm_object_t 118 cdev_pager_lookup(void *handle) 119 { 120 vm_object_t object; 121 122 again: 123 mtx_lock(&dev_pager_mtx); 124 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 125 if (object != NULL && object->un_pager.devp.handle == NULL) { 126 msleep(&object->un_pager.devp.handle, &dev_pager_mtx, 127 PVM | PDROP, "cdplkp", 0); 128 vm_object_deallocate(object); 129 goto again; 130 } 131 mtx_unlock(&dev_pager_mtx); 132 return (object); 133 } 134 135 vm_object_t 136 cdev_pager_allocate(void *handle, enum obj_type tp, 137 const struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot, 138 vm_ooffset_t foff, struct ucred *cred) 139 { 140 vm_object_t object; 141 vm_pindex_t pindex; 142 143 KASSERT(handle != NULL, ("device pager with NULL handle")); 144 145 if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE) 146 return (NULL); 147 KASSERT(tp == OBJT_MGTDEVICE || ops->cdev_pg_populate == NULL, 148 ("populate on unmanaged device pager")); 149 150 /* 151 * Offset should be page aligned. 152 */ 153 if (foff & PAGE_MASK) 154 return (NULL); 155 156 /* 157 * Treat the mmap(2) file offset as an unsigned value for a 158 * device mapping. This, in effect, allows a user to pass all 159 * possible off_t values as the mapping cookie to the driver. At 160 * this point, we know that both foff and size are a multiple 161 * of the page size. Do a check to avoid wrap. 162 */ 163 size = round_page(size); 164 pindex = OFF_TO_IDX(foff) + OFF_TO_IDX(size); 165 if (pindex > OBJ_MAX_SIZE || pindex < OFF_TO_IDX(foff) || 166 pindex < OFF_TO_IDX(size)) 167 return (NULL); 168 169 again: 170 mtx_lock(&dev_pager_mtx); 171 172 /* 173 * Look up pager, creating as necessary. 174 */ 175 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 176 if (object == NULL) { 177 vm_object_t object1; 178 179 /* 180 * Allocate object and associate it with the pager. Initialize 181 * the object's pg_color based upon the physical address of the 182 * device's memory. 183 */ 184 mtx_unlock(&dev_pager_mtx); 185 object1 = vm_object_allocate(tp, pindex); 186 mtx_lock(&dev_pager_mtx); 187 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 188 if (object != NULL) { 189 object1->type = OBJT_DEAD; 190 vm_object_deallocate(object1); 191 object1 = NULL; 192 if (object->un_pager.devp.handle == NULL) { 193 msleep(&object->un_pager.devp.handle, 194 &dev_pager_mtx, PVM | PDROP, "cdplkp", 0); 195 vm_object_deallocate(object); 196 goto again; 197 } 198 199 /* 200 * We raced with other thread while allocating object. 201 */ 202 if (pindex > object->size) 203 object->size = pindex; 204 KASSERT(object->type == tp, 205 ("Inconsistent device pager type %p %d", 206 object, tp)); 207 KASSERT(object->un_pager.devp.ops == ops, 208 ("Inconsistent devops %p %p", object, ops)); 209 } else { 210 u_short color; 211 212 object = object1; 213 object1 = NULL; 214 object->handle = handle; 215 object->un_pager.devp.ops = ops; 216 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 217 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 218 pager_object_list); 219 mtx_unlock(&dev_pager_mtx); 220 if (ops->cdev_pg_populate != NULL) 221 vm_object_set_flag(object, OBJ_POPULATE); 222 if (ops->cdev_pg_ctor(handle, size, prot, foff, 223 cred, &color) != 0) { 224 mtx_lock(&dev_pager_mtx); 225 TAILQ_REMOVE(&dev_pager_object_list, object, 226 pager_object_list); 227 wakeup(&object->un_pager.devp.handle); 228 mtx_unlock(&dev_pager_mtx); 229 object->type = OBJT_DEAD; 230 vm_object_deallocate(object); 231 object = NULL; 232 mtx_lock(&dev_pager_mtx); 233 } else { 234 mtx_lock(&dev_pager_mtx); 235 object->flags |= OBJ_COLORED; 236 object->pg_color = color; 237 object->un_pager.devp.handle = handle; 238 wakeup(&object->un_pager.devp.handle); 239 } 240 } 241 MPASS(object1 == NULL); 242 } else { 243 if (object->un_pager.devp.handle == NULL) { 244 msleep(&object->un_pager.devp.handle, 245 &dev_pager_mtx, PVM | PDROP, "cdplkp", 0); 246 vm_object_deallocate(object); 247 goto again; 248 } 249 if (pindex > object->size) 250 object->size = pindex; 251 KASSERT(object->type == tp, 252 ("Inconsistent device pager type %p %d", object, tp)); 253 } 254 mtx_unlock(&dev_pager_mtx); 255 return (object); 256 } 257 258 static vm_object_t 259 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 260 vm_ooffset_t foff, struct ucred *cred) 261 { 262 263 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops, 264 size, prot, foff, cred)); 265 } 266 267 void 268 cdev_pager_get_path(vm_object_t object, char *path, size_t sz) 269 { 270 if (object->un_pager.devp.ops->cdev_pg_path != NULL) 271 object->un_pager.devp.ops->cdev_pg_path( 272 object->un_pager.devp.handle, path, sz); 273 } 274 275 void 276 cdev_pager_free_page(vm_object_t object, vm_page_t m) 277 { 278 279 if (object->type == OBJT_MGTDEVICE) { 280 struct pctrie_iter pages; 281 282 vm_page_iter_init(&pages, object); 283 vm_radix_iter_lookup(&pages, m->pindex); 284 cdev_mgtdev_pager_free_page(&pages, m); 285 } else if (object->type == OBJT_DEVICE) 286 dev_pager_free_page(object, m); 287 else 288 KASSERT(false, 289 ("Invalid device type obj %p m %p", object, m)); 290 } 291 292 void 293 cdev_mgtdev_pager_free_page(struct pctrie_iter *pages, vm_page_t m) 294 { 295 pmap_remove_all(m); 296 vm_page_iter_remove(pages, m); 297 } 298 299 void 300 cdev_mgtdev_pager_free_pages(vm_object_t object) 301 { 302 struct pctrie_iter pages; 303 vm_page_t m; 304 305 vm_page_iter_init(&pages, object); 306 VM_OBJECT_WLOCK(object); 307 retry: 308 KASSERT(pctrie_iter_is_reset(&pages), 309 ("%s: pctrie_iter not reset for retry", __func__)); 310 VM_RADIX_FOREACH(m, &pages) { 311 if (!vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL)) { 312 pctrie_iter_reset(&pages); 313 goto retry; 314 } 315 cdev_mgtdev_pager_free_page(&pages, m); 316 } 317 VM_OBJECT_WUNLOCK(object); 318 } 319 320 static void 321 dev_pager_free_page(vm_object_t object, vm_page_t m) 322 { 323 324 VM_OBJECT_ASSERT_WLOCKED(object); 325 KASSERT((object->type == OBJT_DEVICE && 326 (m->oflags & VPO_UNMANAGED) != 0), 327 ("Managed device or page obj %p m %p", object, m)); 328 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q); 329 vm_page_putfake(m); 330 } 331 332 static void 333 dev_pager_dealloc(vm_object_t object) 334 { 335 vm_page_t m; 336 337 VM_OBJECT_WUNLOCK(object); 338 object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.handle); 339 340 mtx_lock(&dev_pager_mtx); 341 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 342 mtx_unlock(&dev_pager_mtx); 343 VM_OBJECT_WLOCK(object); 344 345 if (object->type == OBJT_DEVICE) { 346 /* 347 * Free up our fake pages. 348 */ 349 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) 350 != NULL) { 351 if (vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL) == 0) 352 continue; 353 354 dev_pager_free_page(object, m); 355 } 356 } 357 object->handle = NULL; 358 object->type = OBJT_DEAD; 359 } 360 361 static int 362 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind, 363 int *rahead) 364 { 365 int error; 366 367 /* Since our haspage reports zero after/before, the count is 1. */ 368 KASSERT(count == 1, ("%s: count %d", __func__, count)); 369 if (object->un_pager.devp.ops->cdev_pg_fault == NULL) 370 return (VM_PAGER_FAIL); 371 VM_OBJECT_WLOCK(object); 372 error = object->un_pager.devp.ops->cdev_pg_fault(object, 373 IDX_TO_OFF(ma[0]->pindex), PROT_READ, &ma[0]); 374 375 VM_OBJECT_ASSERT_WLOCKED(object); 376 377 if (error == VM_PAGER_OK) { 378 KASSERT((object->type == OBJT_DEVICE && 379 (ma[0]->oflags & VPO_UNMANAGED) != 0) || 380 (object->type == OBJT_MGTDEVICE && 381 (ma[0]->oflags & VPO_UNMANAGED) == 0), 382 ("Wrong page type %p %p", ma[0], object)); 383 if (object->type == OBJT_DEVICE) { 384 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, 385 ma[0], plinks.q); 386 } 387 if (rbehind) 388 *rbehind = 0; 389 if (rahead) 390 *rahead = 0; 391 } 392 VM_OBJECT_WUNLOCK(object); 393 394 return (error); 395 } 396 397 static int 398 dev_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type, 399 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last) 400 { 401 402 VM_OBJECT_ASSERT_WLOCKED(object); 403 if (object->un_pager.devp.ops->cdev_pg_populate == NULL) 404 return (VM_PAGER_FAIL); 405 return (object->un_pager.devp.ops->cdev_pg_populate(object, pidx, 406 fault_type, max_prot, first, last)); 407 } 408 409 static int 410 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, 411 vm_page_t *mres) 412 { 413 vm_paddr_t paddr; 414 vm_page_t m_paddr, page; 415 struct cdev *dev; 416 struct cdevsw *csw; 417 struct file *fpop; 418 struct thread *td; 419 vm_memattr_t memattr, memattr1; 420 int ref, ret; 421 422 memattr = object->memattr; 423 424 VM_OBJECT_WUNLOCK(object); 425 426 dev = object->handle; 427 csw = dev_refthread(dev, &ref); 428 if (csw == NULL) { 429 VM_OBJECT_WLOCK(object); 430 return (VM_PAGER_FAIL); 431 } 432 td = curthread; 433 fpop = td->td_fpop; 434 td->td_fpop = NULL; 435 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr); 436 td->td_fpop = fpop; 437 dev_relthread(dev, ref); 438 if (ret != 0) { 439 printf( 440 "WARNING: dev_pager_getpage: map function returns error %d", ret); 441 VM_OBJECT_WLOCK(object); 442 return (VM_PAGER_FAIL); 443 } 444 445 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 446 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 447 (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) { 448 /* 449 * For the /dev/mem d_mmap routine to return the 450 * correct memattr, pmap_page_get_memattr() needs to 451 * be called, which we do there. 452 */ 453 if ((csw->d_flags & D_MEM) == 0) { 454 printf("WARNING: Device driver %s has set " 455 "\"memattr\" inconsistently (drv %u pmap %u).\n", 456 csw->d_name, memattr, memattr1); 457 } 458 memattr = memattr1; 459 } 460 if (((*mres)->flags & PG_FICTITIOUS) != 0) { 461 /* 462 * If the passed in result page is a fake page, update it with 463 * the new physical address. 464 */ 465 page = *mres; 466 VM_OBJECT_WLOCK(object); 467 vm_page_updatefake(page, paddr, memattr); 468 } else { 469 /* 470 * Replace the passed in reqpage page with our own fake page and 471 * free up the all of the original pages. 472 */ 473 page = vm_page_getfake(paddr, memattr); 474 VM_OBJECT_WLOCK(object); 475 vm_page_replace(page, object, (*mres)->pindex, *mres); 476 *mres = page; 477 } 478 vm_page_valid(page); 479 return (VM_PAGER_OK); 480 } 481 482 static void 483 dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags, 484 int *rtvals) 485 { 486 487 panic("dev_pager_putpage called"); 488 } 489 490 static boolean_t 491 dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 492 int *after) 493 { 494 495 if (before != NULL) 496 *before = 0; 497 if (after != NULL) 498 *after = 0; 499 return (TRUE); 500 } 501 502 static int 503 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 504 vm_ooffset_t foff, struct ucred *cred, u_short *color) 505 { 506 struct cdev *dev; 507 struct cdevsw *csw; 508 vm_memattr_t dummy; 509 vm_ooffset_t off; 510 vm_paddr_t paddr; 511 unsigned int npages; 512 int ref; 513 514 /* 515 * Make sure this device can be mapped. 516 */ 517 dev = handle; 518 csw = dev_refthread(dev, &ref); 519 if (csw == NULL) 520 return (ENXIO); 521 522 /* 523 * Check that the specified range of the device allows the desired 524 * protection. 525 * 526 * XXX assumes VM_PROT_* == PROT_* 527 */ 528 npages = OFF_TO_IDX(size); 529 paddr = 0; /* Make paddr initialized for the case of size == 0. */ 530 for (off = foff; npages--; off += PAGE_SIZE) { 531 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 532 dev_relthread(dev, ref); 533 return (EINVAL); 534 } 535 } 536 537 dev_ref(dev); 538 dev_relthread(dev, ref); 539 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 540 return (0); 541 } 542 543 static void 544 old_dev_pager_dtor(void *handle) 545 { 546 547 dev_rel(handle); 548 } 549 550 static void 551 old_dev_pager_path(void *handle, char *path, size_t len) 552 { 553 struct cdev *cdev = handle; 554 555 if (cdev != NULL) 556 dev_copyname(cdev, path, len); 557 } 558