device_pager.c revision 291905
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: stable/10/sys/vm/device_pager.c 291905 2015-12-06 17:11:23Z kib $"); 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 58static void dev_pager_init(void); 59static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 60 vm_ooffset_t, struct ucred *); 61static void dev_pager_dealloc(vm_object_t); 62static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int); 63static void dev_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 64static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 65static void dev_pager_free_page(vm_object_t object, vm_page_t m); 66 67/* list of device pager objects */ 68static struct pagerlst dev_pager_object_list; 69/* protect list manipulation */ 70static struct mtx dev_pager_mtx; 71 72struct pagerops devicepagerops = { 73 .pgo_init = dev_pager_init, 74 .pgo_alloc = dev_pager_alloc, 75 .pgo_dealloc = dev_pager_dealloc, 76 .pgo_getpages = dev_pager_getpages, 77 .pgo_putpages = dev_pager_putpages, 78 .pgo_haspage = dev_pager_haspage, 79}; 80 81struct pagerops mgtdevicepagerops = { 82 .pgo_alloc = dev_pager_alloc, 83 .pgo_dealloc = dev_pager_dealloc, 84 .pgo_getpages = dev_pager_getpages, 85 .pgo_putpages = dev_pager_putpages, 86 .pgo_haspage = dev_pager_haspage, 87}; 88 89static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 90 vm_ooffset_t foff, struct ucred *cred, u_short *color); 91static void old_dev_pager_dtor(void *handle); 92static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, 93 int prot, vm_page_t *mres); 94 95static struct cdev_pager_ops old_dev_pager_ops = { 96 .cdev_pg_ctor = old_dev_pager_ctor, 97 .cdev_pg_dtor = old_dev_pager_dtor, 98 .cdev_pg_fault = old_dev_pager_fault 99}; 100 101static void 102dev_pager_init(void) 103{ 104 105 TAILQ_INIT(&dev_pager_object_list); 106 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF); 107} 108 109vm_object_t 110cdev_pager_lookup(void *handle) 111{ 112 vm_object_t object; 113 114 mtx_lock(&dev_pager_mtx); 115 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 116 mtx_unlock(&dev_pager_mtx); 117 return (object); 118} 119 120vm_object_t 121cdev_pager_allocate(void *handle, enum obj_type tp, struct cdev_pager_ops *ops, 122 vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred) 123{ 124 vm_object_t object, object1; 125 vm_pindex_t pindex; 126 u_short color; 127 128 if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE) 129 return (NULL); 130 131 /* 132 * Offset should be page aligned. 133 */ 134 if (foff & PAGE_MASK) 135 return (NULL); 136 137 size = round_page(size); 138 pindex = OFF_TO_IDX(foff + size); 139 140 if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0) 141 return (NULL); 142 mtx_lock(&dev_pager_mtx); 143 144 /* 145 * Look up pager, creating as necessary. 146 */ 147 object1 = NULL; 148 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 149 if (object == NULL) { 150 /* 151 * Allocate object and associate it with the pager. Initialize 152 * the object's pg_color based upon the physical address of the 153 * device's memory. 154 */ 155 mtx_unlock(&dev_pager_mtx); 156 object1 = vm_object_allocate(tp, pindex); 157 object1->flags |= OBJ_COLORED; 158 object1->pg_color = color; 159 object1->handle = handle; 160 object1->un_pager.devp.ops = ops; 161 object1->un_pager.devp.dev = handle; 162 TAILQ_INIT(&object1->un_pager.devp.devp_pglist); 163 mtx_lock(&dev_pager_mtx); 164 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 165 if (object != NULL) { 166 /* 167 * We raced with other thread while allocating object. 168 */ 169 if (pindex > object->size) 170 object->size = pindex; 171 } else { 172 object = object1; 173 object1 = NULL; 174 object->handle = handle; 175 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 176 pager_object_list); 177 KASSERT(object->type == tp, 178 ("Inconsistent device pager type %p %d", object, tp)); 179 } 180 } else { 181 if (pindex > object->size) 182 object->size = pindex; 183 } 184 mtx_unlock(&dev_pager_mtx); 185 if (object1 != NULL) { 186 object1->handle = object1; 187 mtx_lock(&dev_pager_mtx); 188 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1, 189 pager_object_list); 190 mtx_unlock(&dev_pager_mtx); 191 vm_object_deallocate(object1); 192 } 193 return (object); 194} 195 196static vm_object_t 197dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 198 vm_ooffset_t foff, struct ucred *cred) 199{ 200 201 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops, 202 size, prot, foff, cred)); 203} 204 205void 206cdev_pager_free_page(vm_object_t object, vm_page_t m) 207{ 208 209 VM_OBJECT_ASSERT_WLOCKED(object); 210 if (object->type == OBJT_MGTDEVICE) { 211 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m)); 212 pmap_remove_all(m); 213 vm_page_lock(m); 214 vm_page_remove(m); 215 vm_page_unlock(m); 216 } else if (object->type == OBJT_DEVICE) 217 dev_pager_free_page(object, m); 218} 219 220static void 221dev_pager_free_page(vm_object_t object, vm_page_t m) 222{ 223 224 VM_OBJECT_ASSERT_WLOCKED(object); 225 KASSERT((object->type == OBJT_DEVICE && 226 (m->oflags & VPO_UNMANAGED) != 0), 227 ("Managed device or page obj %p m %p", object, m)); 228 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q); 229 vm_page_putfake(m); 230} 231 232static void 233dev_pager_dealloc(vm_object_t object) 234{ 235 vm_page_t m; 236 237 VM_OBJECT_WUNLOCK(object); 238 object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev); 239 240 mtx_lock(&dev_pager_mtx); 241 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 242 mtx_unlock(&dev_pager_mtx); 243 VM_OBJECT_WLOCK(object); 244 245 if (object->type == OBJT_DEVICE) { 246 /* 247 * Free up our fake pages. 248 */ 249 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) 250 != NULL) 251 dev_pager_free_page(object, m); 252 } 253 object->handle = NULL; 254 object->type = OBJT_DEAD; 255} 256 257static int 258dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int reqpage) 259{ 260 int error, i; 261 262 VM_OBJECT_ASSERT_WLOCKED(object); 263 error = object->un_pager.devp.ops->cdev_pg_fault(object, 264 IDX_TO_OFF(ma[reqpage]->pindex), PROT_READ, &ma[reqpage]); 265 266 VM_OBJECT_ASSERT_WLOCKED(object); 267 268 for (i = 0; i < count; i++) { 269 if (i != reqpage) { 270 vm_page_lock(ma[i]); 271 vm_page_free(ma[i]); 272 vm_page_unlock(ma[i]); 273 } 274 } 275 276 if (error == VM_PAGER_OK) { 277 KASSERT((object->type == OBJT_DEVICE && 278 (ma[reqpage]->oflags & VPO_UNMANAGED) != 0) || 279 (object->type == OBJT_MGTDEVICE && 280 (ma[reqpage]->oflags & VPO_UNMANAGED) == 0), 281 ("Wrong page type %p %p", ma[reqpage], object)); 282 if (object->type == OBJT_DEVICE) { 283 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, 284 ma[reqpage], plinks.q); 285 } 286 } 287 288 return (error); 289} 290 291static int 292old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, 293 vm_page_t *mres) 294{ 295 vm_pindex_t pidx; 296 vm_paddr_t paddr; 297 vm_page_t m_paddr, page; 298 struct cdev *dev; 299 struct cdevsw *csw; 300 struct file *fpop; 301 struct thread *td; 302 vm_memattr_t memattr; 303 int ref, ret; 304 305 pidx = OFF_TO_IDX(offset); 306 memattr = object->memattr; 307 308 VM_OBJECT_WUNLOCK(object); 309 310 dev = object->handle; 311 csw = dev_refthread(dev, &ref); 312 if (csw == NULL) { 313 VM_OBJECT_WLOCK(object); 314 return (VM_PAGER_FAIL); 315 } 316 td = curthread; 317 fpop = td->td_fpop; 318 td->td_fpop = NULL; 319 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr); 320 td->td_fpop = fpop; 321 dev_relthread(dev, ref); 322 if (ret != 0) { 323 printf( 324 "WARNING: dev_pager_getpage: map function returns error %d", ret); 325 VM_OBJECT_WLOCK(object); 326 return (VM_PAGER_FAIL); 327 } 328 329 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 330 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 331 pmap_page_get_memattr(m_paddr) != memattr) { 332 memattr = pmap_page_get_memattr(m_paddr); 333 printf( 334 "WARNING: A device driver has set \"memattr\" inconsistently.\n"); 335 } 336 if (((*mres)->flags & PG_FICTITIOUS) != 0) { 337 /* 338 * If the passed in result page is a fake page, update it with 339 * the new physical address. 340 */ 341 page = *mres; 342 VM_OBJECT_WLOCK(object); 343 vm_page_updatefake(page, paddr, memattr); 344 } else { 345 /* 346 * Replace the passed in reqpage page with our own fake page and 347 * free up the all of the original pages. 348 */ 349 page = vm_page_getfake(paddr, memattr); 350 VM_OBJECT_WLOCK(object); 351 if (vm_page_replace(page, object, (*mres)->pindex) != *mres) 352 panic("old_dev_pager_fault: invalid page replacement"); 353 vm_page_lock(*mres); 354 vm_page_free(*mres); 355 vm_page_unlock(*mres); 356 *mres = page; 357 } 358 page->valid = VM_PAGE_BITS_ALL; 359 return (VM_PAGER_OK); 360} 361 362static void 363dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags, 364 int *rtvals) 365{ 366 367 panic("dev_pager_putpage called"); 368} 369 370static boolean_t 371dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 372 int *after) 373{ 374 375 if (before != NULL) 376 *before = 0; 377 if (after != NULL) 378 *after = 0; 379 return (TRUE); 380} 381 382static int 383old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 384 vm_ooffset_t foff, struct ucred *cred, u_short *color) 385{ 386 struct cdev *dev; 387 struct cdevsw *csw; 388 vm_memattr_t dummy; 389 vm_ooffset_t off; 390 vm_paddr_t paddr; 391 unsigned int npages; 392 int ref; 393 394 /* 395 * Make sure this device can be mapped. 396 */ 397 dev = handle; 398 csw = dev_refthread(dev, &ref); 399 if (csw == NULL) 400 return (ENXIO); 401 402 /* 403 * Check that the specified range of the device allows the desired 404 * protection. 405 * 406 * XXX assumes VM_PROT_* == PROT_* 407 */ 408 npages = OFF_TO_IDX(size); 409 paddr = 0; /* Make paddr initialized for the case of size == 0. */ 410 for (off = foff; npages--; off += PAGE_SIZE) { 411 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 412 dev_relthread(dev, ref); 413 return (EINVAL); 414 } 415 } 416 417 dev_ref(dev); 418 dev_relthread(dev, ref); 419 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 420 return (0); 421} 422 423static void 424old_dev_pager_dtor(void *handle) 425{ 426 427 dev_rel(handle); 428} 429