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 * @(#)device_pager.c 8.1 (Berkeley) 6/11/93 37 */ 38 39 #include <sys/cdefs.h> 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/conf.h> 43 #include <sys/lock.h> 44 #include <sys/proc.h> 45 #include <sys/mutex.h> 46 #include <sys/mman.h> 47 #include <sys/rwlock.h> 48 #include <sys/sx.h> 49 #include <sys/user.h> 50 #include <sys/vmmeter.h> 51 52 #include <vm/vm.h> 53 #include <vm/vm_param.h> 54 #include <vm/vm_object.h> 55 #include <vm/vm_page.h> 56 #include <vm/vm_pager.h> 57 #include <vm/vm_phys.h> 58 #include <vm/uma.h> 59 60 static void dev_pager_init(void); 61 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 62 vm_ooffset_t, struct ucred *); 63 static void dev_pager_dealloc(vm_object_t); 64 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); 65 static void dev_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 66 static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 67 static void dev_pager_free_page(vm_object_t object, vm_page_t m); 68 static int dev_pager_populate(vm_object_t object, vm_pindex_t pidx, 69 int fault_type, vm_prot_t, vm_pindex_t *first, vm_pindex_t *last); 70 71 /* list of device pager objects */ 72 static struct pagerlst dev_pager_object_list; 73 /* protect list manipulation */ 74 static struct mtx dev_pager_mtx; 75 76 const struct pagerops devicepagerops = { 77 .pgo_kvme_type = KVME_TYPE_DEVICE, 78 .pgo_init = dev_pager_init, 79 .pgo_alloc = dev_pager_alloc, 80 .pgo_dealloc = dev_pager_dealloc, 81 .pgo_getpages = dev_pager_getpages, 82 .pgo_putpages = dev_pager_putpages, 83 .pgo_haspage = dev_pager_haspage, 84 }; 85 86 const struct pagerops mgtdevicepagerops = { 87 .pgo_kvme_type = KVME_TYPE_MGTDEVICE, 88 .pgo_alloc = dev_pager_alloc, 89 .pgo_dealloc = dev_pager_dealloc, 90 .pgo_getpages = dev_pager_getpages, 91 .pgo_putpages = dev_pager_putpages, 92 .pgo_haspage = dev_pager_haspage, 93 .pgo_populate = dev_pager_populate, 94 }; 95 96 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 97 vm_ooffset_t foff, struct ucred *cred, u_short *color); 98 static void old_dev_pager_dtor(void *handle); 99 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, 100 int prot, vm_page_t *mres); 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 }; 107 108 static void 109 dev_pager_init(void) 110 { 111 112 TAILQ_INIT(&dev_pager_object_list); 113 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF); 114 } 115 116 vm_object_t 117 cdev_pager_lookup(void *handle) 118 { 119 vm_object_t object; 120 121 mtx_lock(&dev_pager_mtx); 122 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 123 mtx_unlock(&dev_pager_mtx); 124 return (object); 125 } 126 127 vm_object_t 128 cdev_pager_allocate(void *handle, enum obj_type tp, 129 const struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot, 130 vm_ooffset_t foff, struct ucred *cred) 131 { 132 vm_object_t object, object1; 133 vm_pindex_t pindex; 134 u_short color; 135 136 if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE) 137 return (NULL); 138 KASSERT(tp == OBJT_MGTDEVICE || ops->cdev_pg_populate == NULL, 139 ("populate on unmanaged device pager")); 140 141 /* 142 * Offset should be page aligned. 143 */ 144 if (foff & PAGE_MASK) 145 return (NULL); 146 147 /* 148 * Treat the mmap(2) file offset as an unsigned value for a 149 * device mapping. This, in effect, allows a user to pass all 150 * possible off_t values as the mapping cookie to the driver. At 151 * this point, we know that both foff and size are a multiple 152 * of the page size. Do a check to avoid wrap. 153 */ 154 size = round_page(size); 155 pindex = OFF_TO_IDX(foff) + OFF_TO_IDX(size); 156 if (pindex > OBJ_MAX_SIZE || pindex < OFF_TO_IDX(foff) || 157 pindex < OFF_TO_IDX(size)) 158 return (NULL); 159 160 if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0) 161 return (NULL); 162 mtx_lock(&dev_pager_mtx); 163 164 /* 165 * Look up pager, creating as necessary. 166 */ 167 object1 = NULL; 168 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 169 if (object == NULL) { 170 /* 171 * Allocate object and associate it with the pager. Initialize 172 * the object's pg_color based upon the physical address of the 173 * device's memory. 174 */ 175 mtx_unlock(&dev_pager_mtx); 176 object1 = vm_object_allocate(tp, pindex); 177 object1->flags |= OBJ_COLORED; 178 object1->pg_color = color; 179 object1->handle = handle; 180 object1->un_pager.devp.ops = ops; 181 object1->un_pager.devp.dev = handle; 182 TAILQ_INIT(&object1->un_pager.devp.devp_pglist); 183 mtx_lock(&dev_pager_mtx); 184 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 185 if (object != NULL) { 186 /* 187 * We raced with other thread while allocating object. 188 */ 189 if (pindex > object->size) 190 object->size = pindex; 191 KASSERT(object->type == tp, 192 ("Inconsistent device pager type %p %d", 193 object, tp)); 194 KASSERT(object->un_pager.devp.ops == ops, 195 ("Inconsistent devops %p %p", object, ops)); 196 } else { 197 object = object1; 198 object1 = NULL; 199 object->handle = handle; 200 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 201 pager_object_list); 202 if (ops->cdev_pg_populate != NULL) 203 vm_object_set_flag(object, OBJ_POPULATE); 204 } 205 } else { 206 if (pindex > object->size) 207 object->size = pindex; 208 KASSERT(object->type == tp, 209 ("Inconsistent device pager type %p %d", object, tp)); 210 } 211 mtx_unlock(&dev_pager_mtx); 212 if (object1 != NULL) { 213 object1->handle = object1; 214 mtx_lock(&dev_pager_mtx); 215 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1, 216 pager_object_list); 217 mtx_unlock(&dev_pager_mtx); 218 vm_object_deallocate(object1); 219 } 220 return (object); 221 } 222 223 static vm_object_t 224 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 225 vm_ooffset_t foff, struct ucred *cred) 226 { 227 228 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops, 229 size, prot, foff, cred)); 230 } 231 232 void 233 cdev_pager_free_page(vm_object_t object, vm_page_t m) 234 { 235 236 VM_OBJECT_ASSERT_WLOCKED(object); 237 if (object->type == OBJT_MGTDEVICE) { 238 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m)); 239 pmap_remove_all(m); 240 (void)vm_page_remove(m); 241 } else if (object->type == OBJT_DEVICE) 242 dev_pager_free_page(object, m); 243 } 244 245 static void 246 dev_pager_free_page(vm_object_t object, vm_page_t m) 247 { 248 249 VM_OBJECT_ASSERT_WLOCKED(object); 250 KASSERT((object->type == OBJT_DEVICE && 251 (m->oflags & VPO_UNMANAGED) != 0), 252 ("Managed device or page obj %p m %p", object, m)); 253 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q); 254 vm_page_putfake(m); 255 } 256 257 static void 258 dev_pager_dealloc(vm_object_t object) 259 { 260 vm_page_t m; 261 262 VM_OBJECT_WUNLOCK(object); 263 object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev); 264 265 mtx_lock(&dev_pager_mtx); 266 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 267 mtx_unlock(&dev_pager_mtx); 268 VM_OBJECT_WLOCK(object); 269 270 if (object->type == OBJT_DEVICE) { 271 /* 272 * Free up our fake pages. 273 */ 274 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) 275 != NULL) { 276 if (vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL) == 0) 277 continue; 278 279 dev_pager_free_page(object, m); 280 } 281 } 282 object->handle = NULL; 283 object->type = OBJT_DEAD; 284 } 285 286 static int 287 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind, 288 int *rahead) 289 { 290 int error; 291 292 /* Since our haspage reports zero after/before, the count is 1. */ 293 KASSERT(count == 1, ("%s: count %d", __func__, count)); 294 if (object->un_pager.devp.ops->cdev_pg_fault == NULL) 295 return (VM_PAGER_FAIL); 296 VM_OBJECT_WLOCK(object); 297 error = object->un_pager.devp.ops->cdev_pg_fault(object, 298 IDX_TO_OFF(ma[0]->pindex), PROT_READ, &ma[0]); 299 300 VM_OBJECT_ASSERT_WLOCKED(object); 301 302 if (error == VM_PAGER_OK) { 303 KASSERT((object->type == OBJT_DEVICE && 304 (ma[0]->oflags & VPO_UNMANAGED) != 0) || 305 (object->type == OBJT_MGTDEVICE && 306 (ma[0]->oflags & VPO_UNMANAGED) == 0), 307 ("Wrong page type %p %p", ma[0], object)); 308 if (object->type == OBJT_DEVICE) { 309 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, 310 ma[0], plinks.q); 311 } 312 if (rbehind) 313 *rbehind = 0; 314 if (rahead) 315 *rahead = 0; 316 } 317 VM_OBJECT_WUNLOCK(object); 318 319 return (error); 320 } 321 322 static int 323 dev_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type, 324 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last) 325 { 326 327 VM_OBJECT_ASSERT_WLOCKED(object); 328 if (object->un_pager.devp.ops->cdev_pg_populate == NULL) 329 return (VM_PAGER_FAIL); 330 return (object->un_pager.devp.ops->cdev_pg_populate(object, pidx, 331 fault_type, max_prot, first, last)); 332 } 333 334 static int 335 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, 336 vm_page_t *mres) 337 { 338 vm_paddr_t paddr; 339 vm_page_t m_paddr, page; 340 struct cdev *dev; 341 struct cdevsw *csw; 342 struct file *fpop; 343 struct thread *td; 344 vm_memattr_t memattr, memattr1; 345 int ref, ret; 346 347 memattr = object->memattr; 348 349 VM_OBJECT_WUNLOCK(object); 350 351 dev = object->handle; 352 csw = dev_refthread(dev, &ref); 353 if (csw == NULL) { 354 VM_OBJECT_WLOCK(object); 355 return (VM_PAGER_FAIL); 356 } 357 td = curthread; 358 fpop = td->td_fpop; 359 td->td_fpop = NULL; 360 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr); 361 td->td_fpop = fpop; 362 dev_relthread(dev, ref); 363 if (ret != 0) { 364 printf( 365 "WARNING: dev_pager_getpage: map function returns error %d", ret); 366 VM_OBJECT_WLOCK(object); 367 return (VM_PAGER_FAIL); 368 } 369 370 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 371 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 372 (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) { 373 /* 374 * For the /dev/mem d_mmap routine to return the 375 * correct memattr, pmap_page_get_memattr() needs to 376 * be called, which we do there. 377 */ 378 if ((csw->d_flags & D_MEM) == 0) { 379 printf("WARNING: Device driver %s has set " 380 "\"memattr\" inconsistently (drv %u pmap %u).\n", 381 csw->d_name, memattr, memattr1); 382 } 383 memattr = memattr1; 384 } 385 if (((*mres)->flags & PG_FICTITIOUS) != 0) { 386 /* 387 * If the passed in result page is a fake page, update it with 388 * the new physical address. 389 */ 390 page = *mres; 391 VM_OBJECT_WLOCK(object); 392 vm_page_updatefake(page, paddr, memattr); 393 } else { 394 /* 395 * Replace the passed in reqpage page with our own fake page and 396 * free up the all of the original pages. 397 */ 398 page = vm_page_getfake(paddr, memattr); 399 VM_OBJECT_WLOCK(object); 400 vm_page_replace(page, object, (*mres)->pindex, *mres); 401 *mres = page; 402 } 403 vm_page_valid(page); 404 return (VM_PAGER_OK); 405 } 406 407 static void 408 dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags, 409 int *rtvals) 410 { 411 412 panic("dev_pager_putpage called"); 413 } 414 415 static boolean_t 416 dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 417 int *after) 418 { 419 420 if (before != NULL) 421 *before = 0; 422 if (after != NULL) 423 *after = 0; 424 return (TRUE); 425 } 426 427 static int 428 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 429 vm_ooffset_t foff, struct ucred *cred, u_short *color) 430 { 431 struct cdev *dev; 432 struct cdevsw *csw; 433 vm_memattr_t dummy; 434 vm_ooffset_t off; 435 vm_paddr_t paddr; 436 unsigned int npages; 437 int ref; 438 439 /* 440 * Make sure this device can be mapped. 441 */ 442 dev = handle; 443 csw = dev_refthread(dev, &ref); 444 if (csw == NULL) 445 return (ENXIO); 446 447 /* 448 * Check that the specified range of the device allows the desired 449 * protection. 450 * 451 * XXX assumes VM_PROT_* == PROT_* 452 */ 453 npages = OFF_TO_IDX(size); 454 paddr = 0; /* Make paddr initialized for the case of size == 0. */ 455 for (off = foff; npages--; off += PAGE_SIZE) { 456 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 457 dev_relthread(dev, ref); 458 return (EINVAL); 459 } 460 } 461 462 dev_ref(dev); 463 dev_relthread(dev, ref); 464 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 465 return (0); 466 } 467 468 static void 469 old_dev_pager_dtor(void *handle) 470 { 471 472 dev_rel(handle); 473 } 474