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 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 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 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 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 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, m); 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 280 cdev_mgtdev_pager_free_page(struct pctrie_iter *pages, vm_page_t m) 281 { 282 pmap_remove_all(m); 283 vm_page_iter_remove(pages, m); 284 } 285 286 void 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, m); 302 } 303 VM_OBJECT_WUNLOCK(object); 304 } 305 306 static void 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 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 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 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 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 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 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 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 530 old_dev_pager_dtor(void *handle) 531 { 532 533 dev_rel(handle); 534 } 535