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 67 /* list of device pager objects */ 68 static struct pagerlst dev_pager_object_list; 69 /* protect list manipulation */ 70 static struct mtx dev_pager_mtx; 71 72 struct 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 81 struct 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 89 static 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); 91 static void old_dev_pager_dtor(void *handle); 92 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, 93 int prot, vm_page_t *mres); 94 95 static 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 }; 100 101 static void 102 dev_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 } 108 109 vm_object_t 110 cdev_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 } 119 120 vm_object_t 121 cdev_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 KASSERT(object->type == tp, 172 ("Inconsistent device pager type %p %d", 173 object, tp)); 174 KASSERT(object->un_pager.devp.ops == ops, 175 ("Inconsistent devops %p %p", object, ops)); 176 } else { 177 object = object1; 178 object1 = NULL; 179 object->handle = handle; 180 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 181 pager_object_list); 182 } 183 } else { 184 if (pindex > object->size) 185 object->size = pindex; 186 KASSERT(object->type == tp, 187 ("Inconsistent device pager type %p %d", object, tp)); 188 } 189 mtx_unlock(&dev_pager_mtx); 190 if (object1 != NULL) { 191 object1->handle = object1; 192 mtx_lock(&dev_pager_mtx); 193 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1, 194 pager_object_list); 195 mtx_unlock(&dev_pager_mtx); 196 vm_object_deallocate(object1); 197 } 198 return (object); 199 } 200 201 static vm_object_t 202 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 203 vm_ooffset_t foff, struct ucred *cred) 204 { 205 206 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops, 207 size, prot, foff, cred)); 208 } 209 210 void 211 cdev_pager_free_page(vm_object_t object, vm_page_t m) 212 { 213 214 VM_OBJECT_ASSERT_WLOCKED(object); 215 if (object->type == OBJT_MGTDEVICE) { 216 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m)); 217 pmap_remove_all(m); 218 vm_page_lock(m); 219 vm_page_remove(m); 220 vm_page_unlock(m); 221 } else if (object->type == OBJT_DEVICE) 222 dev_pager_free_page(object, m); 223 } 224 225 static void 226 dev_pager_free_page(vm_object_t object, vm_page_t m) 227 { 228 229 VM_OBJECT_ASSERT_WLOCKED(object); 230 KASSERT((object->type == OBJT_DEVICE && 231 (m->oflags & VPO_UNMANAGED) != 0), 232 ("Managed device or page obj %p m %p", object, m)); 233 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q); 234 vm_page_putfake(m); 235 } 236 237 static void 238 dev_pager_dealloc(vm_object_t object) 239 { 240 vm_page_t m; 241 242 VM_OBJECT_WUNLOCK(object); 243 object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev); 244 245 mtx_lock(&dev_pager_mtx); 246 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 247 mtx_unlock(&dev_pager_mtx); 248 VM_OBJECT_WLOCK(object); 249 250 if (object->type == OBJT_DEVICE) { 251 /* 252 * Free up our fake pages. 253 */ 254 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) 255 != NULL) 256 dev_pager_free_page(object, m); 257 } 258 object->handle = NULL; 259 object->type = OBJT_DEAD; 260 } 261 262 static int 263 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind, 264 int *rahead) 265 { 266 int error; 267 268 /* Since our haspage reports zero after/before, the count is 1. */ 269 KASSERT(count == 1, ("%s: count %d", __func__, count)); 270 VM_OBJECT_ASSERT_WLOCKED(object); 271 error = object->un_pager.devp.ops->cdev_pg_fault(object, 272 IDX_TO_OFF(ma[0]->pindex), PROT_READ, &ma[0]); 273 274 VM_OBJECT_ASSERT_WLOCKED(object); 275 276 if (error == VM_PAGER_OK) { 277 KASSERT((object->type == OBJT_DEVICE && 278 (ma[0]->oflags & VPO_UNMANAGED) != 0) || 279 (object->type == OBJT_MGTDEVICE && 280 (ma[0]->oflags & VPO_UNMANAGED) == 0), 281 ("Wrong page type %p %p", ma[0], object)); 282 if (object->type == OBJT_DEVICE) { 283 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, 284 ma[0], plinks.q); 285 } 286 if (rbehind) 287 *rbehind = 0; 288 if (rahead) 289 *rahead = 0; 290 } 291 292 return (error); 293 } 294 295 static int 296 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, 297 vm_page_t *mres) 298 { 299 vm_paddr_t paddr; 300 vm_page_t m_paddr, page; 301 struct cdev *dev; 302 struct cdevsw *csw; 303 struct file *fpop; 304 struct thread *td; 305 vm_memattr_t memattr, memattr1; 306 int ref, ret; 307 308 memattr = object->memattr; 309 310 VM_OBJECT_WUNLOCK(object); 311 312 dev = object->handle; 313 csw = dev_refthread(dev, &ref); 314 if (csw == NULL) { 315 VM_OBJECT_WLOCK(object); 316 return (VM_PAGER_FAIL); 317 } 318 td = curthread; 319 fpop = td->td_fpop; 320 td->td_fpop = NULL; 321 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr); 322 td->td_fpop = fpop; 323 dev_relthread(dev, ref); 324 if (ret != 0) { 325 printf( 326 "WARNING: dev_pager_getpage: map function returns error %d", ret); 327 VM_OBJECT_WLOCK(object); 328 return (VM_PAGER_FAIL); 329 } 330 331 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 332 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 333 (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) { 334 /* 335 * For the /dev/mem d_mmap routine to return the 336 * correct memattr, pmap_page_get_memattr() needs to 337 * be called, which we do there. 338 */ 339 if ((csw->d_flags & D_MEM) == 0) { 340 printf("WARNING: Device driver %s has set " 341 "\"memattr\" inconsistently (drv %u pmap %u).\n", 342 csw->d_name, memattr, memattr1); 343 } 344 memattr = memattr1; 345 } 346 if (((*mres)->flags & PG_FICTITIOUS) != 0) { 347 /* 348 * If the passed in result page is a fake page, update it with 349 * the new physical address. 350 */ 351 page = *mres; 352 VM_OBJECT_WLOCK(object); 353 vm_page_updatefake(page, paddr, memattr); 354 } else { 355 /* 356 * Replace the passed in reqpage page with our own fake page and 357 * free up the all of the original pages. 358 */ 359 page = vm_page_getfake(paddr, memattr); 360 VM_OBJECT_WLOCK(object); 361 vm_page_replace_checked(page, object, (*mres)->pindex, *mres); 362 vm_page_lock(*mres); 363 vm_page_free(*mres); 364 vm_page_unlock(*mres); 365 *mres = page; 366 } 367 page->valid = VM_PAGE_BITS_ALL; 368 return (VM_PAGER_OK); 369 } 370 371 static void 372 dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags, 373 int *rtvals) 374 { 375 376 panic("dev_pager_putpage called"); 377 } 378 379 static boolean_t 380 dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 381 int *after) 382 { 383 384 if (before != NULL) 385 *before = 0; 386 if (after != NULL) 387 *after = 0; 388 return (TRUE); 389 } 390 391 static int 392 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 393 vm_ooffset_t foff, struct ucred *cred, u_short *color) 394 { 395 struct cdev *dev; 396 struct cdevsw *csw; 397 vm_memattr_t dummy; 398 vm_ooffset_t off; 399 vm_paddr_t paddr; 400 unsigned int npages; 401 int ref; 402 403 /* 404 * Make sure this device can be mapped. 405 */ 406 dev = handle; 407 csw = dev_refthread(dev, &ref); 408 if (csw == NULL) 409 return (ENXIO); 410 411 /* 412 * Check that the specified range of the device allows the desired 413 * protection. 414 * 415 * XXX assumes VM_PROT_* == PROT_* 416 */ 417 npages = OFF_TO_IDX(size); 418 paddr = 0; /* Make paddr initialized for the case of size == 0. */ 419 for (off = foff; npages--; off += PAGE_SIZE) { 420 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 421 dev_relthread(dev, ref); 422 return (EINVAL); 423 } 424 } 425 426 dev_ref(dev); 427 dev_relthread(dev, ref); 428 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 429 return (0); 430 } 431 432 static void 433 old_dev_pager_dtor(void *handle) 434 { 435 436 dev_rel(handle); 437 } 438