1 /*- 2 * Copyright (c) 1990 University of Utah. 3 * Copyright (c) 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)device_pager.c 8.1 (Berkeley) 6/11/93 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 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 50 #include <vm/vm.h> 51 #include <vm/vm_param.h> 52 #include <vm/vm_object.h> 53 #include <vm/vm_page.h> 54 #include <vm/vm_pager.h> 55 #include <vm/vm_phys.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 struct pagerops devicepagerops = { 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 struct pagerops mgtdevicepagerops = { 84 .pgo_alloc = dev_pager_alloc, 85 .pgo_dealloc = dev_pager_dealloc, 86 .pgo_getpages = dev_pager_getpages, 87 .pgo_putpages = dev_pager_putpages, 88 .pgo_haspage = dev_pager_haspage, 89 .pgo_populate = dev_pager_populate, 90 }; 91 92 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 93 vm_ooffset_t foff, struct ucred *cred, u_short *color); 94 static void old_dev_pager_dtor(void *handle); 95 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, 96 int prot, vm_page_t *mres); 97 98 static struct cdev_pager_ops old_dev_pager_ops = { 99 .cdev_pg_ctor = old_dev_pager_ctor, 100 .cdev_pg_dtor = old_dev_pager_dtor, 101 .cdev_pg_fault = old_dev_pager_fault 102 }; 103 104 static void 105 dev_pager_init(void) 106 { 107 108 TAILQ_INIT(&dev_pager_object_list); 109 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF); 110 } 111 112 vm_object_t 113 cdev_pager_lookup(void *handle) 114 { 115 vm_object_t object; 116 117 mtx_lock(&dev_pager_mtx); 118 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 119 mtx_unlock(&dev_pager_mtx); 120 return (object); 121 } 122 123 vm_object_t 124 cdev_pager_allocate(void *handle, enum obj_type tp, struct cdev_pager_ops *ops, 125 vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred) 126 { 127 vm_object_t object, object1; 128 vm_pindex_t pindex; 129 u_short color; 130 131 if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE) 132 return (NULL); 133 KASSERT(tp == OBJT_MGTDEVICE || ops->cdev_pg_populate == NULL, 134 ("populate on unmanaged device pager")); 135 136 /* 137 * Offset should be page aligned. 138 */ 139 if (foff & PAGE_MASK) 140 return (NULL); 141 142 /* 143 * Treat the mmap(2) file offset as an unsigned value for a 144 * device mapping. This, in effect, allows a user to pass all 145 * possible off_t values as the mapping cookie to the driver. At 146 * this point, we know that both foff and size are a multiple 147 * of the page size. Do a check to avoid wrap. 148 */ 149 size = round_page(size); 150 pindex = UOFF_TO_IDX(foff) + UOFF_TO_IDX(size); 151 if (pindex > OBJ_MAX_SIZE || pindex < UOFF_TO_IDX(foff) || 152 pindex < UOFF_TO_IDX(size)) 153 return (NULL); 154 155 if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0) 156 return (NULL); 157 mtx_lock(&dev_pager_mtx); 158 159 /* 160 * Look up pager, creating as necessary. 161 */ 162 object1 = NULL; 163 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 164 if (object == NULL) { 165 /* 166 * Allocate object and associate it with the pager. Initialize 167 * the object's pg_color based upon the physical address of the 168 * device's memory. 169 */ 170 mtx_unlock(&dev_pager_mtx); 171 object1 = vm_object_allocate(tp, pindex); 172 object1->flags |= OBJ_COLORED; 173 object1->pg_color = color; 174 object1->handle = handle; 175 object1->un_pager.devp.ops = ops; 176 object1->un_pager.devp.dev = handle; 177 TAILQ_INIT(&object1->un_pager.devp.devp_pglist); 178 mtx_lock(&dev_pager_mtx); 179 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 180 if (object != NULL) { 181 /* 182 * We raced with other thread while allocating object. 183 */ 184 if (pindex > object->size) 185 object->size = pindex; 186 KASSERT(object->type == tp, 187 ("Inconsistent device pager type %p %d", 188 object, tp)); 189 KASSERT(object->un_pager.devp.ops == ops, 190 ("Inconsistent devops %p %p", object, ops)); 191 } else { 192 object = object1; 193 object1 = NULL; 194 object->handle = handle; 195 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 196 pager_object_list); 197 if (ops->cdev_pg_populate != NULL) 198 vm_object_set_flag(object, OBJ_POPULATE); 199 } 200 } else { 201 if (pindex > object->size) 202 object->size = pindex; 203 KASSERT(object->type == tp, 204 ("Inconsistent device pager type %p %d", object, tp)); 205 } 206 mtx_unlock(&dev_pager_mtx); 207 if (object1 != NULL) { 208 object1->handle = object1; 209 mtx_lock(&dev_pager_mtx); 210 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1, 211 pager_object_list); 212 mtx_unlock(&dev_pager_mtx); 213 vm_object_deallocate(object1); 214 } 215 return (object); 216 } 217 218 static vm_object_t 219 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 220 vm_ooffset_t foff, struct ucred *cred) 221 { 222 223 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops, 224 size, prot, foff, cred)); 225 } 226 227 void 228 cdev_pager_free_page(vm_object_t object, vm_page_t m) 229 { 230 231 VM_OBJECT_ASSERT_WLOCKED(object); 232 if (object->type == OBJT_MGTDEVICE) { 233 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m)); 234 pmap_remove_all(m); 235 vm_page_lock(m); 236 vm_page_remove(m); 237 vm_page_unlock(m); 238 } else if (object->type == OBJT_DEVICE) 239 dev_pager_free_page(object, m); 240 } 241 242 static void 243 dev_pager_free_page(vm_object_t object, vm_page_t m) 244 { 245 246 VM_OBJECT_ASSERT_WLOCKED(object); 247 KASSERT((object->type == OBJT_DEVICE && 248 (m->oflags & VPO_UNMANAGED) != 0), 249 ("Managed device or page obj %p m %p", object, m)); 250 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q); 251 vm_page_putfake(m); 252 } 253 254 static void 255 dev_pager_dealloc(vm_object_t object) 256 { 257 vm_page_t m; 258 259 VM_OBJECT_WUNLOCK(object); 260 object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev); 261 262 mtx_lock(&dev_pager_mtx); 263 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 264 mtx_unlock(&dev_pager_mtx); 265 VM_OBJECT_WLOCK(object); 266 267 if (object->type == OBJT_DEVICE) { 268 /* 269 * Free up our fake pages. 270 */ 271 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) 272 != NULL) 273 dev_pager_free_page(object, m); 274 } 275 object->handle = NULL; 276 object->type = OBJT_DEAD; 277 } 278 279 static int 280 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind, 281 int *rahead) 282 { 283 int error; 284 285 /* Since our haspage reports zero after/before, the count is 1. */ 286 KASSERT(count == 1, ("%s: count %d", __func__, count)); 287 VM_OBJECT_ASSERT_WLOCKED(object); 288 if (object->un_pager.devp.ops->cdev_pg_fault == NULL) 289 return (VM_PAGER_FAIL); 290 error = object->un_pager.devp.ops->cdev_pg_fault(object, 291 IDX_TO_OFF(ma[0]->pindex), PROT_READ, &ma[0]); 292 293 VM_OBJECT_ASSERT_WLOCKED(object); 294 295 if (error == VM_PAGER_OK) { 296 KASSERT((object->type == OBJT_DEVICE && 297 (ma[0]->oflags & VPO_UNMANAGED) != 0) || 298 (object->type == OBJT_MGTDEVICE && 299 (ma[0]->oflags & VPO_UNMANAGED) == 0), 300 ("Wrong page type %p %p", ma[0], object)); 301 if (object->type == OBJT_DEVICE) { 302 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, 303 ma[0], plinks.q); 304 } 305 if (rbehind) 306 *rbehind = 0; 307 if (rahead) 308 *rahead = 0; 309 } 310 311 return (error); 312 } 313 314 static int 315 dev_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type, 316 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last) 317 { 318 319 VM_OBJECT_ASSERT_WLOCKED(object); 320 if (object->un_pager.devp.ops->cdev_pg_populate == NULL) 321 return (VM_PAGER_FAIL); 322 return (object->un_pager.devp.ops->cdev_pg_populate(object, pidx, 323 fault_type, max_prot, first, last)); 324 } 325 326 static int 327 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, 328 vm_page_t *mres) 329 { 330 vm_paddr_t paddr; 331 vm_page_t m_paddr, page; 332 struct cdev *dev; 333 struct cdevsw *csw; 334 struct file *fpop; 335 struct thread *td; 336 vm_memattr_t memattr, memattr1; 337 int ref, ret; 338 339 memattr = object->memattr; 340 341 VM_OBJECT_WUNLOCK(object); 342 343 dev = object->handle; 344 csw = dev_refthread(dev, &ref); 345 if (csw == NULL) { 346 VM_OBJECT_WLOCK(object); 347 return (VM_PAGER_FAIL); 348 } 349 td = curthread; 350 fpop = td->td_fpop; 351 td->td_fpop = NULL; 352 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr); 353 td->td_fpop = fpop; 354 dev_relthread(dev, ref); 355 if (ret != 0) { 356 printf( 357 "WARNING: dev_pager_getpage: map function returns error %d", ret); 358 VM_OBJECT_WLOCK(object); 359 return (VM_PAGER_FAIL); 360 } 361 362 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 363 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 364 (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) { 365 /* 366 * For the /dev/mem d_mmap routine to return the 367 * correct memattr, pmap_page_get_memattr() needs to 368 * be called, which we do there. 369 */ 370 if ((csw->d_flags & D_MEM) == 0) { 371 printf("WARNING: Device driver %s has set " 372 "\"memattr\" inconsistently (drv %u pmap %u).\n", 373 csw->d_name, memattr, memattr1); 374 } 375 memattr = memattr1; 376 } 377 if (((*mres)->flags & PG_FICTITIOUS) != 0) { 378 /* 379 * If the passed in result page is a fake page, update it with 380 * the new physical address. 381 */ 382 page = *mres; 383 VM_OBJECT_WLOCK(object); 384 vm_page_updatefake(page, paddr, memattr); 385 } else { 386 /* 387 * Replace the passed in reqpage page with our own fake page and 388 * free up the all of the original pages. 389 */ 390 page = vm_page_getfake(paddr, memattr); 391 VM_OBJECT_WLOCK(object); 392 vm_page_replace_checked(page, object, (*mres)->pindex, *mres); 393 vm_page_lock(*mres); 394 vm_page_free(*mres); 395 vm_page_unlock(*mres); 396 *mres = page; 397 } 398 page->valid = VM_PAGE_BITS_ALL; 399 return (VM_PAGER_OK); 400 } 401 402 static void 403 dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags, 404 int *rtvals) 405 { 406 407 panic("dev_pager_putpage called"); 408 } 409 410 static boolean_t 411 dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 412 int *after) 413 { 414 415 if (before != NULL) 416 *before = 0; 417 if (after != NULL) 418 *after = 0; 419 return (TRUE); 420 } 421 422 static int 423 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 424 vm_ooffset_t foff, struct ucred *cred, u_short *color) 425 { 426 struct cdev *dev; 427 struct cdevsw *csw; 428 vm_memattr_t dummy; 429 vm_ooffset_t off; 430 vm_paddr_t paddr; 431 unsigned int npages; 432 int ref; 433 434 /* 435 * Make sure this device can be mapped. 436 */ 437 dev = handle; 438 csw = dev_refthread(dev, &ref); 439 if (csw == NULL) 440 return (ENXIO); 441 442 /* 443 * Check that the specified range of the device allows the desired 444 * protection. 445 * 446 * XXX assumes VM_PROT_* == PROT_* 447 */ 448 npages = OFF_TO_IDX(size); 449 paddr = 0; /* Make paddr initialized for the case of size == 0. */ 450 for (off = foff; npages--; off += PAGE_SIZE) { 451 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 452 dev_relthread(dev, ref); 453 return (EINVAL); 454 } 455 } 456 457 dev_ref(dev); 458 dev_relthread(dev, ref); 459 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 460 return (0); 461 } 462 463 static void 464 old_dev_pager_dtor(void *handle) 465 { 466 467 dev_rel(handle); 468 } 469