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