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 __FBSDID("$FreeBSD$"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/conf.h> 45 #include <sys/lock.h> 46 #include <sys/proc.h> 47 #include <sys/mutex.h> 48 #include <sys/mman.h> 49 #include <sys/rwlock.h> 50 #include <sys/sx.h> 51 #include <sys/user.h> 52 #include <sys/vmmeter.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_param.h> 56 #include <vm/vm_object.h> 57 #include <vm/vm_page.h> 58 #include <vm/vm_pager.h> 59 #include <vm/vm_phys.h> 60 #include <vm/uma.h> 61 62 static void dev_pager_init(void); 63 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 64 vm_ooffset_t, struct ucred *); 65 static void dev_pager_dealloc(vm_object_t); 66 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); 67 static void dev_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 68 static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 69 static void dev_pager_free_page(vm_object_t object, vm_page_t m); 70 static int dev_pager_populate(vm_object_t object, vm_pindex_t pidx, 71 int fault_type, vm_prot_t, vm_pindex_t *first, vm_pindex_t *last); 72 73 /* list of device pager objects */ 74 static struct pagerlst dev_pager_object_list; 75 /* protect list manipulation */ 76 static struct mtx dev_pager_mtx; 77 78 const struct pagerops devicepagerops = { 79 .pgo_kvme_type = KVME_TYPE_DEVICE, 80 .pgo_init = dev_pager_init, 81 .pgo_alloc = dev_pager_alloc, 82 .pgo_dealloc = dev_pager_dealloc, 83 .pgo_getpages = dev_pager_getpages, 84 .pgo_putpages = dev_pager_putpages, 85 .pgo_haspage = dev_pager_haspage, 86 }; 87 88 const struct pagerops mgtdevicepagerops = { 89 .pgo_kvme_type = KVME_TYPE_MGTDEVICE, 90 .pgo_alloc = dev_pager_alloc, 91 .pgo_dealloc = dev_pager_dealloc, 92 .pgo_getpages = dev_pager_getpages, 93 .pgo_putpages = dev_pager_putpages, 94 .pgo_haspage = dev_pager_haspage, 95 .pgo_populate = dev_pager_populate, 96 }; 97 98 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 99 vm_ooffset_t foff, struct ucred *cred, u_short *color); 100 static void old_dev_pager_dtor(void *handle); 101 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, 102 int prot, vm_page_t *mres); 103 104 static const struct cdev_pager_ops old_dev_pager_ops = { 105 .cdev_pg_ctor = old_dev_pager_ctor, 106 .cdev_pg_dtor = old_dev_pager_dtor, 107 .cdev_pg_fault = old_dev_pager_fault 108 }; 109 110 static void 111 dev_pager_init(void) 112 { 113 114 TAILQ_INIT(&dev_pager_object_list); 115 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF); 116 } 117 118 vm_object_t 119 cdev_pager_lookup(void *handle) 120 { 121 vm_object_t object; 122 123 mtx_lock(&dev_pager_mtx); 124 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 125 mtx_unlock(&dev_pager_mtx); 126 return (object); 127 } 128 129 vm_object_t 130 cdev_pager_allocate(void *handle, enum obj_type tp, 131 const struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot, 132 vm_ooffset_t foff, struct ucred *cred) 133 { 134 vm_object_t object, object1; 135 vm_pindex_t pindex; 136 u_short color; 137 138 if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE) 139 return (NULL); 140 KASSERT(tp == OBJT_MGTDEVICE || ops->cdev_pg_populate == NULL, 141 ("populate on unmanaged device pager")); 142 143 /* 144 * Offset should be page aligned. 145 */ 146 if (foff & PAGE_MASK) 147 return (NULL); 148 149 /* 150 * Treat the mmap(2) file offset as an unsigned value for a 151 * device mapping. This, in effect, allows a user to pass all 152 * possible off_t values as the mapping cookie to the driver. At 153 * this point, we know that both foff and size are a multiple 154 * of the page size. Do a check to avoid wrap. 155 */ 156 size = round_page(size); 157 pindex = OFF_TO_IDX(foff) + OFF_TO_IDX(size); 158 if (pindex > OBJ_MAX_SIZE || pindex < OFF_TO_IDX(foff) || 159 pindex < OFF_TO_IDX(size)) 160 return (NULL); 161 162 if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0) 163 return (NULL); 164 mtx_lock(&dev_pager_mtx); 165 166 /* 167 * Look up pager, creating as necessary. 168 */ 169 object1 = NULL; 170 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 171 if (object == NULL) { 172 /* 173 * Allocate object and associate it with the pager. Initialize 174 * the object's pg_color based upon the physical address of the 175 * device's memory. 176 */ 177 mtx_unlock(&dev_pager_mtx); 178 object1 = vm_object_allocate(tp, pindex); 179 object1->flags |= OBJ_COLORED; 180 object1->pg_color = color; 181 object1->handle = handle; 182 object1->un_pager.devp.ops = ops; 183 object1->un_pager.devp.dev = handle; 184 TAILQ_INIT(&object1->un_pager.devp.devp_pglist); 185 mtx_lock(&dev_pager_mtx); 186 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 187 if (object != NULL) { 188 /* 189 * We raced with other thread while allocating object. 190 */ 191 if (pindex > object->size) 192 object->size = pindex; 193 KASSERT(object->type == tp, 194 ("Inconsistent device pager type %p %d", 195 object, tp)); 196 KASSERT(object->un_pager.devp.ops == ops, 197 ("Inconsistent devops %p %p", object, ops)); 198 } else { 199 object = object1; 200 object1 = NULL; 201 object->handle = handle; 202 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 203 pager_object_list); 204 if (ops->cdev_pg_populate != NULL) 205 vm_object_set_flag(object, OBJ_POPULATE); 206 } 207 } else { 208 if (pindex > object->size) 209 object->size = pindex; 210 KASSERT(object->type == tp, 211 ("Inconsistent device pager type %p %d", object, tp)); 212 } 213 mtx_unlock(&dev_pager_mtx); 214 if (object1 != NULL) { 215 object1->handle = object1; 216 mtx_lock(&dev_pager_mtx); 217 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1, 218 pager_object_list); 219 mtx_unlock(&dev_pager_mtx); 220 vm_object_deallocate(object1); 221 } 222 return (object); 223 } 224 225 static vm_object_t 226 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 227 vm_ooffset_t foff, struct ucred *cred) 228 { 229 230 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops, 231 size, prot, foff, cred)); 232 } 233 234 void 235 cdev_pager_free_page(vm_object_t object, vm_page_t m) 236 { 237 238 VM_OBJECT_ASSERT_WLOCKED(object); 239 if (object->type == OBJT_MGTDEVICE) { 240 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m)); 241 pmap_remove_all(m); 242 (void)vm_page_remove(m); 243 } else if (object->type == OBJT_DEVICE) 244 dev_pager_free_page(object, m); 245 } 246 247 static void 248 dev_pager_free_page(vm_object_t object, vm_page_t m) 249 { 250 251 VM_OBJECT_ASSERT_WLOCKED(object); 252 KASSERT((object->type == OBJT_DEVICE && 253 (m->oflags & VPO_UNMANAGED) != 0), 254 ("Managed device or page obj %p m %p", object, m)); 255 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q); 256 vm_page_putfake(m); 257 } 258 259 static void 260 dev_pager_dealloc(vm_object_t object) 261 { 262 vm_page_t m; 263 264 VM_OBJECT_WUNLOCK(object); 265 object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev); 266 267 mtx_lock(&dev_pager_mtx); 268 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 269 mtx_unlock(&dev_pager_mtx); 270 VM_OBJECT_WLOCK(object); 271 272 if (object->type == OBJT_DEVICE) { 273 /* 274 * Free up our fake pages. 275 */ 276 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) 277 != NULL) { 278 if (vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL) == 0) 279 continue; 280 281 dev_pager_free_page(object, m); 282 } 283 } 284 object->handle = NULL; 285 object->type = OBJT_DEAD; 286 } 287 288 static int 289 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind, 290 int *rahead) 291 { 292 int error; 293 294 /* Since our haspage reports zero after/before, the count is 1. */ 295 KASSERT(count == 1, ("%s: count %d", __func__, count)); 296 if (object->un_pager.devp.ops->cdev_pg_fault == NULL) 297 return (VM_PAGER_FAIL); 298 VM_OBJECT_WLOCK(object); 299 error = object->un_pager.devp.ops->cdev_pg_fault(object, 300 IDX_TO_OFF(ma[0]->pindex), PROT_READ, &ma[0]); 301 302 VM_OBJECT_ASSERT_WLOCKED(object); 303 304 if (error == VM_PAGER_OK) { 305 KASSERT((object->type == OBJT_DEVICE && 306 (ma[0]->oflags & VPO_UNMANAGED) != 0) || 307 (object->type == OBJT_MGTDEVICE && 308 (ma[0]->oflags & VPO_UNMANAGED) == 0), 309 ("Wrong page type %p %p", ma[0], object)); 310 if (object->type == OBJT_DEVICE) { 311 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, 312 ma[0], plinks.q); 313 } 314 if (rbehind) 315 *rbehind = 0; 316 if (rahead) 317 *rahead = 0; 318 } 319 VM_OBJECT_WUNLOCK(object); 320 321 return (error); 322 } 323 324 static int 325 dev_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type, 326 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last) 327 { 328 329 VM_OBJECT_ASSERT_WLOCKED(object); 330 if (object->un_pager.devp.ops->cdev_pg_populate == NULL) 331 return (VM_PAGER_FAIL); 332 return (object->un_pager.devp.ops->cdev_pg_populate(object, pidx, 333 fault_type, max_prot, first, last)); 334 } 335 336 static int 337 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, 338 vm_page_t *mres) 339 { 340 vm_paddr_t paddr; 341 vm_page_t m_paddr, page; 342 struct cdev *dev; 343 struct cdevsw *csw; 344 struct file *fpop; 345 struct thread *td; 346 vm_memattr_t memattr, memattr1; 347 int ref, ret; 348 349 memattr = object->memattr; 350 351 VM_OBJECT_WUNLOCK(object); 352 353 dev = object->handle; 354 csw = dev_refthread(dev, &ref); 355 if (csw == NULL) { 356 VM_OBJECT_WLOCK(object); 357 return (VM_PAGER_FAIL); 358 } 359 td = curthread; 360 fpop = td->td_fpop; 361 td->td_fpop = NULL; 362 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr); 363 td->td_fpop = fpop; 364 dev_relthread(dev, ref); 365 if (ret != 0) { 366 printf( 367 "WARNING: dev_pager_getpage: map function returns error %d", ret); 368 VM_OBJECT_WLOCK(object); 369 return (VM_PAGER_FAIL); 370 } 371 372 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 373 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 374 (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) { 375 /* 376 * For the /dev/mem d_mmap routine to return the 377 * correct memattr, pmap_page_get_memattr() needs to 378 * be called, which we do there. 379 */ 380 if ((csw->d_flags & D_MEM) == 0) { 381 printf("WARNING: Device driver %s has set " 382 "\"memattr\" inconsistently (drv %u pmap %u).\n", 383 csw->d_name, memattr, memattr1); 384 } 385 memattr = memattr1; 386 } 387 if (((*mres)->flags & PG_FICTITIOUS) != 0) { 388 /* 389 * If the passed in result page is a fake page, update it with 390 * the new physical address. 391 */ 392 page = *mres; 393 VM_OBJECT_WLOCK(object); 394 vm_page_updatefake(page, paddr, memattr); 395 } else { 396 /* 397 * Replace the passed in reqpage page with our own fake page and 398 * free up the all of the original pages. 399 */ 400 page = vm_page_getfake(paddr, memattr); 401 VM_OBJECT_WLOCK(object); 402 vm_page_replace(page, object, (*mres)->pindex, *mres); 403 *mres = page; 404 } 405 vm_page_valid(page); 406 return (VM_PAGER_OK); 407 } 408 409 static void 410 dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags, 411 int *rtvals) 412 { 413 414 panic("dev_pager_putpage called"); 415 } 416 417 static boolean_t 418 dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 419 int *after) 420 { 421 422 if (before != NULL) 423 *before = 0; 424 if (after != NULL) 425 *after = 0; 426 return (TRUE); 427 } 428 429 static int 430 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 431 vm_ooffset_t foff, struct ucred *cred, u_short *color) 432 { 433 struct cdev *dev; 434 struct cdevsw *csw; 435 vm_memattr_t dummy; 436 vm_ooffset_t off; 437 vm_paddr_t paddr; 438 unsigned int npages; 439 int ref; 440 441 /* 442 * Make sure this device can be mapped. 443 */ 444 dev = handle; 445 csw = dev_refthread(dev, &ref); 446 if (csw == NULL) 447 return (ENXIO); 448 449 /* 450 * Check that the specified range of the device allows the desired 451 * protection. 452 * 453 * XXX assumes VM_PROT_* == PROT_* 454 */ 455 npages = OFF_TO_IDX(size); 456 paddr = 0; /* Make paddr initialized for the case of size == 0. */ 457 for (off = foff; npages--; off += PAGE_SIZE) { 458 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 459 dev_relthread(dev, ref); 460 return (EINVAL); 461 } 462 } 463 464 dev_ref(dev); 465 dev_relthread(dev, ref); 466 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 467 return (0); 468 } 469 470 static void 471 old_dev_pager_dtor(void *handle) 472 { 473 474 dev_rel(handle); 475 } 476