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 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/conf.h> 40 #include <sys/lock.h> 41 #include <sys/proc.h> 42 #include <sys/mutex.h> 43 #include <sys/mman.h> 44 #include <sys/rwlock.h> 45 #include <sys/sx.h> 46 #include <sys/user.h> 47 #include <sys/vmmeter.h> 48 49 #include <vm/vm.h> 50 #include <vm/vm_param.h> 51 #include <vm/vm_object.h> 52 #include <vm/vm_page.h> 53 #include <vm/vm_pager.h> 54 #include <vm/vm_phys.h> 55 #include <vm/uma.h> 56 57 static void dev_pager_init(void); 58 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 59 vm_ooffset_t, struct ucred *); 60 static void dev_pager_dealloc(vm_object_t); 61 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *); 62 static void dev_pager_putpages(vm_object_t, vm_page_t *, int, int, int *); 63 static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, int *); 64 static void dev_pager_free_page(vm_object_t object, vm_page_t m); 65 static int dev_pager_populate(vm_object_t object, vm_pindex_t pidx, 66 int fault_type, vm_prot_t, vm_pindex_t *first, vm_pindex_t *last); 67 68 /* list of device pager objects */ 69 static struct pagerlst dev_pager_object_list; 70 /* protect list manipulation */ 71 static struct mtx dev_pager_mtx; 72 73 const struct pagerops devicepagerops = { 74 .pgo_kvme_type = KVME_TYPE_DEVICE, 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 const struct pagerops mgtdevicepagerops = { 84 .pgo_kvme_type = KVME_TYPE_MGTDEVICE, 85 .pgo_alloc = dev_pager_alloc, 86 .pgo_dealloc = dev_pager_dealloc, 87 .pgo_getpages = dev_pager_getpages, 88 .pgo_putpages = dev_pager_putpages, 89 .pgo_haspage = dev_pager_haspage, 90 .pgo_populate = dev_pager_populate, 91 }; 92 93 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 94 vm_ooffset_t foff, struct ucred *cred, u_short *color); 95 static void old_dev_pager_dtor(void *handle); 96 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, 97 int prot, vm_page_t *mres); 98 99 static const struct cdev_pager_ops old_dev_pager_ops = { 100 .cdev_pg_ctor = old_dev_pager_ctor, 101 .cdev_pg_dtor = old_dev_pager_dtor, 102 .cdev_pg_fault = old_dev_pager_fault 103 }; 104 105 static void 106 dev_pager_init(void) 107 { 108 109 TAILQ_INIT(&dev_pager_object_list); 110 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF); 111 } 112 113 vm_object_t 114 cdev_pager_lookup(void *handle) 115 { 116 vm_object_t object; 117 118 mtx_lock(&dev_pager_mtx); 119 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 120 mtx_unlock(&dev_pager_mtx); 121 return (object); 122 } 123 124 vm_object_t 125 cdev_pager_allocate(void *handle, enum obj_type tp, 126 const struct cdev_pager_ops *ops, vm_ooffset_t size, vm_prot_t prot, 127 vm_ooffset_t foff, struct ucred *cred) 128 { 129 vm_object_t object, object1; 130 vm_pindex_t pindex; 131 u_short color; 132 133 if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE) 134 return (NULL); 135 KASSERT(tp == OBJT_MGTDEVICE || ops->cdev_pg_populate == NULL, 136 ("populate on unmanaged device pager")); 137 138 /* 139 * Offset should be page aligned. 140 */ 141 if (foff & PAGE_MASK) 142 return (NULL); 143 144 /* 145 * Treat the mmap(2) file offset as an unsigned value for a 146 * device mapping. This, in effect, allows a user to pass all 147 * possible off_t values as the mapping cookie to the driver. At 148 * this point, we know that both foff and size are a multiple 149 * of the page size. Do a check to avoid wrap. 150 */ 151 size = round_page(size); 152 pindex = OFF_TO_IDX(foff) + OFF_TO_IDX(size); 153 if (pindex > OBJ_MAX_SIZE || pindex < OFF_TO_IDX(foff) || 154 pindex < OFF_TO_IDX(size)) 155 return (NULL); 156 157 if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0) 158 return (NULL); 159 mtx_lock(&dev_pager_mtx); 160 161 /* 162 * Look up pager, creating as necessary. 163 */ 164 object1 = NULL; 165 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 166 if (object == NULL) { 167 /* 168 * Allocate object and associate it with the pager. Initialize 169 * the object's pg_color based upon the physical address of the 170 * device's memory. 171 */ 172 mtx_unlock(&dev_pager_mtx); 173 object1 = vm_object_allocate(tp, pindex); 174 object1->flags |= OBJ_COLORED; 175 object1->pg_color = color; 176 object1->handle = handle; 177 object1->un_pager.devp.ops = ops; 178 object1->un_pager.devp.dev = handle; 179 TAILQ_INIT(&object1->un_pager.devp.devp_pglist); 180 mtx_lock(&dev_pager_mtx); 181 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 182 if (object != NULL) { 183 /* 184 * We raced with other thread while allocating object. 185 */ 186 if (pindex > object->size) 187 object->size = pindex; 188 KASSERT(object->type == tp, 189 ("Inconsistent device pager type %p %d", 190 object, tp)); 191 KASSERT(object->un_pager.devp.ops == ops, 192 ("Inconsistent devops %p %p", object, ops)); 193 } else { 194 object = object1; 195 object1 = NULL; 196 object->handle = handle; 197 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 198 pager_object_list); 199 if (ops->cdev_pg_populate != NULL) 200 vm_object_set_flag(object, OBJ_POPULATE); 201 } 202 } else { 203 if (pindex > object->size) 204 object->size = pindex; 205 KASSERT(object->type == tp, 206 ("Inconsistent device pager type %p %d", object, tp)); 207 } 208 mtx_unlock(&dev_pager_mtx); 209 if (object1 != NULL) { 210 object1->handle = object1; 211 mtx_lock(&dev_pager_mtx); 212 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1, 213 pager_object_list); 214 mtx_unlock(&dev_pager_mtx); 215 vm_object_deallocate(object1); 216 } 217 return (object); 218 } 219 220 static vm_object_t 221 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 222 vm_ooffset_t foff, struct ucred *cred) 223 { 224 225 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops, 226 size, prot, foff, cred)); 227 } 228 229 void 230 cdev_pager_free_page(vm_object_t object, vm_page_t m) 231 { 232 233 VM_OBJECT_ASSERT_WLOCKED(object); 234 if (object->type == OBJT_MGTDEVICE) { 235 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m)); 236 pmap_remove_all(m); 237 (void)vm_page_remove(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 if (vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL) == 0) 274 continue; 275 276 dev_pager_free_page(object, m); 277 } 278 } 279 object->handle = NULL; 280 object->type = OBJT_DEAD; 281 } 282 283 static int 284 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind, 285 int *rahead) 286 { 287 int error; 288 289 /* Since our haspage reports zero after/before, the count is 1. */ 290 KASSERT(count == 1, ("%s: count %d", __func__, count)); 291 if (object->un_pager.devp.ops->cdev_pg_fault == NULL) 292 return (VM_PAGER_FAIL); 293 VM_OBJECT_WLOCK(object); 294 error = object->un_pager.devp.ops->cdev_pg_fault(object, 295 IDX_TO_OFF(ma[0]->pindex), PROT_READ, &ma[0]); 296 297 VM_OBJECT_ASSERT_WLOCKED(object); 298 299 if (error == VM_PAGER_OK) { 300 KASSERT((object->type == OBJT_DEVICE && 301 (ma[0]->oflags & VPO_UNMANAGED) != 0) || 302 (object->type == OBJT_MGTDEVICE && 303 (ma[0]->oflags & VPO_UNMANAGED) == 0), 304 ("Wrong page type %p %p", ma[0], object)); 305 if (object->type == OBJT_DEVICE) { 306 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, 307 ma[0], plinks.q); 308 } 309 if (rbehind) 310 *rbehind = 0; 311 if (rahead) 312 *rahead = 0; 313 } 314 VM_OBJECT_WUNLOCK(object); 315 316 return (error); 317 } 318 319 static int 320 dev_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type, 321 vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last) 322 { 323 324 VM_OBJECT_ASSERT_WLOCKED(object); 325 if (object->un_pager.devp.ops->cdev_pg_populate == NULL) 326 return (VM_PAGER_FAIL); 327 return (object->un_pager.devp.ops->cdev_pg_populate(object, pidx, 328 fault_type, max_prot, first, last)); 329 } 330 331 static int 332 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, 333 vm_page_t *mres) 334 { 335 vm_paddr_t paddr; 336 vm_page_t m_paddr, page; 337 struct cdev *dev; 338 struct cdevsw *csw; 339 struct file *fpop; 340 struct thread *td; 341 vm_memattr_t memattr, memattr1; 342 int ref, ret; 343 344 memattr = object->memattr; 345 346 VM_OBJECT_WUNLOCK(object); 347 348 dev = object->handle; 349 csw = dev_refthread(dev, &ref); 350 if (csw == NULL) { 351 VM_OBJECT_WLOCK(object); 352 return (VM_PAGER_FAIL); 353 } 354 td = curthread; 355 fpop = td->td_fpop; 356 td->td_fpop = NULL; 357 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr); 358 td->td_fpop = fpop; 359 dev_relthread(dev, ref); 360 if (ret != 0) { 361 printf( 362 "WARNING: dev_pager_getpage: map function returns error %d", ret); 363 VM_OBJECT_WLOCK(object); 364 return (VM_PAGER_FAIL); 365 } 366 367 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 368 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 369 (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) { 370 /* 371 * For the /dev/mem d_mmap routine to return the 372 * correct memattr, pmap_page_get_memattr() needs to 373 * be called, which we do there. 374 */ 375 if ((csw->d_flags & D_MEM) == 0) { 376 printf("WARNING: Device driver %s has set " 377 "\"memattr\" inconsistently (drv %u pmap %u).\n", 378 csw->d_name, memattr, memattr1); 379 } 380 memattr = memattr1; 381 } 382 if (((*mres)->flags & PG_FICTITIOUS) != 0) { 383 /* 384 * If the passed in result page is a fake page, update it with 385 * the new physical address. 386 */ 387 page = *mres; 388 VM_OBJECT_WLOCK(object); 389 vm_page_updatefake(page, paddr, memattr); 390 } else { 391 /* 392 * Replace the passed in reqpage page with our own fake page and 393 * free up the all of the original pages. 394 */ 395 page = vm_page_getfake(paddr, memattr); 396 VM_OBJECT_WLOCK(object); 397 vm_page_replace(page, object, (*mres)->pindex, *mres); 398 *mres = page; 399 } 400 vm_page_valid(page); 401 return (VM_PAGER_OK); 402 } 403 404 static void 405 dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags, 406 int *rtvals) 407 { 408 409 panic("dev_pager_putpage called"); 410 } 411 412 static boolean_t 413 dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 414 int *after) 415 { 416 417 if (before != NULL) 418 *before = 0; 419 if (after != NULL) 420 *after = 0; 421 return (TRUE); 422 } 423 424 static int 425 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 426 vm_ooffset_t foff, struct ucred *cred, u_short *color) 427 { 428 struct cdev *dev; 429 struct cdevsw *csw; 430 vm_memattr_t dummy; 431 vm_ooffset_t off; 432 vm_paddr_t paddr; 433 unsigned int npages; 434 int ref; 435 436 /* 437 * Make sure this device can be mapped. 438 */ 439 dev = handle; 440 csw = dev_refthread(dev, &ref); 441 if (csw == NULL) 442 return (ENXIO); 443 444 /* 445 * Check that the specified range of the device allows the desired 446 * protection. 447 * 448 * XXX assumes VM_PROT_* == PROT_* 449 */ 450 npages = OFF_TO_IDX(size); 451 paddr = 0; /* Make paddr initialized for the case of size == 0. */ 452 for (off = foff; npages--; off += PAGE_SIZE) { 453 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 454 dev_relthread(dev, ref); 455 return (EINVAL); 456 } 457 } 458 459 dev_ref(dev); 460 dev_relthread(dev, ref); 461 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 462 return (0); 463 } 464 465 static void 466 old_dev_pager_dtor(void *handle) 467 { 468 469 dev_rel(handle); 470 } 471