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