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 for (m = vm_radix_iter_lookup_ge(&pages, 0); m != NULL; 311 m = vm_radix_iter_step(&pages)) { 312 if (!vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL)) { 313 pctrie_iter_reset(&pages); 314 goto retry; 315 } 316 cdev_mgtdev_pager_free_page(&pages, m); 317 } 318 VM_OBJECT_WUNLOCK(object); 319 } 320 321 static void 322 dev_pager_free_page(vm_object_t object, vm_page_t m) 323 { 324 325 VM_OBJECT_ASSERT_WLOCKED(object); 326 KASSERT((object->type == OBJT_DEVICE && 327 (m->oflags & VPO_UNMANAGED) != 0), 328 ("Managed device or page obj %p m %p", object, m)); 329 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q); 330 vm_page_putfake(m); 331 } 332 333 static void 334 dev_pager_dealloc(vm_object_t object) 335 { 336 vm_page_t m; 337 338 VM_OBJECT_WUNLOCK(object); 339 object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.handle); 340 341 mtx_lock(&dev_pager_mtx); 342 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 343 mtx_unlock(&dev_pager_mtx); 344 VM_OBJECT_WLOCK(object); 345 346 if (object->type == OBJT_DEVICE) { 347 /* 348 * Free up our fake pages. 349 */ 350 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) 351 != NULL) { 352 if (vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL) == 0) 353 continue; 354 355 dev_pager_free_page(object, m); 356 } 357 } 358 object->handle = NULL; 359 object->type = OBJT_DEAD; 360 } 361 362 static int 363 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind, 364 int *rahead) 365 { 366 int error; 367 368 /* Since our haspage reports zero after/before, the count is 1. */ 369 KASSERT(count == 1, ("%s: count %d", __func__, count)); 370 if (object->un_pager.devp.ops->cdev_pg_fault == NULL) 371 return (VM_PAGER_FAIL); 372 VM_OBJECT_WLOCK(object); 373 error = object->un_pager.devp.ops->cdev_pg_fault(object, 374 IDX_TO_OFF(ma[0]->pindex), PROT_READ, &ma[0]); 375 376 VM_OBJECT_ASSERT_WLOCKED(object); 377 378 if (error == VM_PAGER_OK) { 379 KASSERT((object->type == OBJT_DEVICE && 380 (ma[0]->oflags & VPO_UNMANAGED) != 0) || 381 (object->type == OBJT_MGTDEVICE && 382 (ma[0]->oflags & VPO_UNMANAGED) == 0), 383 ("Wrong page type %p %p", ma[0], object)); 384 if (object->type == OBJT_DEVICE) { 385 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, 386 ma[0], plinks.q); 387 } 388 if (rbehind) 389 *rbehind = 0; 390 if (rahead) 391 *rahead = 0; 392 } 393 VM_OBJECT_WUNLOCK(object); 394 395 return (error); 396 } 397 398 static int 399 dev_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type, 400 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last) 401 { 402 403 VM_OBJECT_ASSERT_WLOCKED(object); 404 if (object->un_pager.devp.ops->cdev_pg_populate == NULL) 405 return (VM_PAGER_FAIL); 406 return (object->un_pager.devp.ops->cdev_pg_populate(object, pidx, 407 fault_type, max_prot, first, last)); 408 } 409 410 static int 411 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, 412 vm_page_t *mres) 413 { 414 vm_paddr_t paddr; 415 vm_page_t m_paddr, page; 416 struct cdev *dev; 417 struct cdevsw *csw; 418 struct file *fpop; 419 struct thread *td; 420 vm_memattr_t memattr, memattr1; 421 int ref, ret; 422 423 memattr = object->memattr; 424 425 VM_OBJECT_WUNLOCK(object); 426 427 dev = object->handle; 428 csw = dev_refthread(dev, &ref); 429 if (csw == NULL) { 430 VM_OBJECT_WLOCK(object); 431 return (VM_PAGER_FAIL); 432 } 433 td = curthread; 434 fpop = td->td_fpop; 435 td->td_fpop = NULL; 436 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr); 437 td->td_fpop = fpop; 438 dev_relthread(dev, ref); 439 if (ret != 0) { 440 printf( 441 "WARNING: dev_pager_getpage: map function returns error %d", ret); 442 VM_OBJECT_WLOCK(object); 443 return (VM_PAGER_FAIL); 444 } 445 446 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 447 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 448 (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) { 449 /* 450 * For the /dev/mem d_mmap routine to return the 451 * correct memattr, pmap_page_get_memattr() needs to 452 * be called, which we do there. 453 */ 454 if ((csw->d_flags & D_MEM) == 0) { 455 printf("WARNING: Device driver %s has set " 456 "\"memattr\" inconsistently (drv %u pmap %u).\n", 457 csw->d_name, memattr, memattr1); 458 } 459 memattr = memattr1; 460 } 461 if (((*mres)->flags & PG_FICTITIOUS) != 0) { 462 /* 463 * If the passed in result page is a fake page, update it with 464 * the new physical address. 465 */ 466 page = *mres; 467 VM_OBJECT_WLOCK(object); 468 vm_page_updatefake(page, paddr, memattr); 469 } else { 470 /* 471 * Replace the passed in reqpage page with our own fake page and 472 * free up the all of the original pages. 473 */ 474 page = vm_page_getfake(paddr, memattr); 475 VM_OBJECT_WLOCK(object); 476 vm_page_replace(page, object, (*mres)->pindex, *mres); 477 *mres = page; 478 } 479 vm_page_valid(page); 480 return (VM_PAGER_OK); 481 } 482 483 static void 484 dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags, 485 int *rtvals) 486 { 487 488 panic("dev_pager_putpage called"); 489 } 490 491 static boolean_t 492 dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 493 int *after) 494 { 495 496 if (before != NULL) 497 *before = 0; 498 if (after != NULL) 499 *after = 0; 500 return (TRUE); 501 } 502 503 static int 504 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 505 vm_ooffset_t foff, struct ucred *cred, u_short *color) 506 { 507 struct cdev *dev; 508 struct cdevsw *csw; 509 vm_memattr_t dummy; 510 vm_ooffset_t off; 511 vm_paddr_t paddr; 512 unsigned int npages; 513 int ref; 514 515 /* 516 * Make sure this device can be mapped. 517 */ 518 dev = handle; 519 csw = dev_refthread(dev, &ref); 520 if (csw == NULL) 521 return (ENXIO); 522 523 /* 524 * Check that the specified range of the device allows the desired 525 * protection. 526 * 527 * XXX assumes VM_PROT_* == PROT_* 528 */ 529 npages = OFF_TO_IDX(size); 530 paddr = 0; /* Make paddr initialized for the case of size == 0. */ 531 for (off = foff; npages--; off += PAGE_SIZE) { 532 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 533 dev_relthread(dev, ref); 534 return (EINVAL); 535 } 536 } 537 538 dev_ref(dev); 539 dev_relthread(dev, ref); 540 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 541 return (0); 542 } 543 544 static void 545 old_dev_pager_dtor(void *handle) 546 { 547 548 dev_rel(handle); 549 } 550 551 static void 552 old_dev_pager_path(void *handle, char *path, size_t len) 553 { 554 struct cdev *cdev = handle; 555 556 if (cdev != NULL) 557 dev_copyname(cdev, path, len); 558 } 559