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/sx.h> 48 49 #include <vm/vm.h> 50 #include <vm/vm_object.h> 51 #include <vm/vm_page.h> 52 #include <vm/vm_pager.h> 53 #include <vm/uma.h> 54 55 static void dev_pager_init(void); 56 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 57 vm_ooffset_t, struct ucred *); 58 static void dev_pager_dealloc(vm_object_t); 59 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int); 60 static void dev_pager_putpages(vm_object_t, vm_page_t *, int, 61 boolean_t, int *); 62 static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, 63 int *); 64 65 /* list of device pager objects */ 66 static struct pagerlst dev_pager_object_list; 67 /* protect list manipulation */ 68 static struct mtx dev_pager_mtx; 69 70 struct pagerops devicepagerops = { 71 .pgo_init = dev_pager_init, 72 .pgo_alloc = dev_pager_alloc, 73 .pgo_dealloc = dev_pager_dealloc, 74 .pgo_getpages = dev_pager_getpages, 75 .pgo_putpages = dev_pager_putpages, 76 .pgo_haspage = dev_pager_haspage, 77 }; 78 79 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 80 vm_ooffset_t foff, struct ucred *cred, u_short *color); 81 static void old_dev_pager_dtor(void *handle); 82 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, 83 int prot, vm_page_t *mres); 84 85 static struct cdev_pager_ops old_dev_pager_ops = { 86 .cdev_pg_ctor = old_dev_pager_ctor, 87 .cdev_pg_dtor = old_dev_pager_dtor, 88 .cdev_pg_fault = old_dev_pager_fault 89 }; 90 91 static void 92 dev_pager_init() 93 { 94 TAILQ_INIT(&dev_pager_object_list); 95 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF); 96 } 97 98 vm_object_t 99 cdev_pager_lookup(void *handle) 100 { 101 vm_object_t object; 102 103 mtx_lock(&dev_pager_mtx); 104 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 105 vm_object_reference(object); 106 mtx_unlock(&dev_pager_mtx); 107 return (object); 108 } 109 110 vm_object_t 111 cdev_pager_allocate(void *handle, enum obj_type tp, struct cdev_pager_ops *ops, 112 vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred) 113 { 114 vm_object_t object, object1; 115 vm_pindex_t pindex; 116 u_short color; 117 118 if (tp != OBJT_DEVICE) 119 return (NULL); 120 121 /* 122 * Offset should be page aligned. 123 */ 124 if (foff & PAGE_MASK) 125 return (NULL); 126 127 size = round_page(size); 128 pindex = OFF_TO_IDX(foff + size); 129 130 if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0) 131 return (NULL); 132 mtx_lock(&dev_pager_mtx); 133 134 /* 135 * Look up pager, creating as necessary. 136 */ 137 object1 = NULL; 138 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 139 if (object == NULL) { 140 /* 141 * Allocate object and associate it with the pager. Initialize 142 * the object's pg_color based upon the physical address of the 143 * device's memory. 144 */ 145 mtx_unlock(&dev_pager_mtx); 146 object1 = vm_object_allocate(tp, pindex); 147 object1->flags |= OBJ_COLORED; 148 object1->pg_color = color; 149 object1->handle = handle; 150 object1->un_pager.devp.ops = ops; 151 TAILQ_INIT(&object1->un_pager.devp.devp_pglist); 152 mtx_lock(&dev_pager_mtx); 153 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 154 if (object != NULL) { 155 /* 156 * We raced with other thread while allocating object. 157 */ 158 if (pindex > object->size) 159 object->size = pindex; 160 } else { 161 object = object1; 162 object1 = NULL; 163 object->handle = handle; 164 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 165 pager_object_list); 166 KASSERT(object->type == tp, 167 ("Inconsistent device pager type %p %d", object, tp)); 168 } 169 } else { 170 if (pindex > object->size) 171 object->size = pindex; 172 } 173 mtx_unlock(&dev_pager_mtx); 174 if (object1 != NULL) { 175 object1->handle = object1; 176 mtx_lock(&dev_pager_mtx); 177 TAILQ_INSERT_TAIL(&dev_pager_object_list, object1, 178 pager_object_list); 179 mtx_unlock(&dev_pager_mtx); 180 vm_object_deallocate(object1); 181 } 182 return (object); 183 } 184 185 static vm_object_t 186 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 187 vm_ooffset_t foff, struct ucred *cred) 188 { 189 190 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops, 191 size, prot, foff, cred)); 192 } 193 194 void 195 cdev_pager_free_page(vm_object_t object, vm_page_t m) 196 { 197 198 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 199 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 200 vm_page_putfake(m); 201 } 202 203 static void 204 dev_pager_dealloc(object) 205 vm_object_t object; 206 { 207 vm_page_t m; 208 209 VM_OBJECT_UNLOCK(object); 210 object->un_pager.devp.ops->cdev_pg_dtor(object->handle); 211 212 mtx_lock(&dev_pager_mtx); 213 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 214 mtx_unlock(&dev_pager_mtx); 215 VM_OBJECT_LOCK(object); 216 /* 217 * Free up our fake pages. 218 */ 219 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != NULL) 220 cdev_pager_free_page(object, m); 221 } 222 223 static int 224 dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int reqpage) 225 { 226 int error, i; 227 228 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 229 error = object->un_pager.devp.ops->cdev_pg_fault(object, 230 IDX_TO_OFF(ma[reqpage]->pindex), PROT_READ, &ma[reqpage]); 231 232 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 233 234 for (i = 0; i < count; i++) { 235 if (i != reqpage) { 236 vm_page_lock(ma[i]); 237 vm_page_free(ma[i]); 238 vm_page_unlock(ma[i]); 239 } 240 } 241 242 if (error == VM_PAGER_OK) { 243 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, 244 ma[reqpage], pageq); 245 } 246 247 return (error); 248 } 249 250 static int 251 old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, 252 vm_page_t *mres) 253 { 254 vm_pindex_t pidx; 255 vm_paddr_t paddr; 256 vm_page_t m_paddr, page; 257 struct cdev *dev; 258 struct cdevsw *csw; 259 struct file *fpop; 260 struct thread *td; 261 vm_memattr_t memattr; 262 int ref, ret; 263 264 pidx = OFF_TO_IDX(offset); 265 memattr = object->memattr; 266 267 VM_OBJECT_UNLOCK(object); 268 269 dev = object->handle; 270 csw = dev_refthread(dev, &ref); 271 if (csw == NULL) { 272 VM_OBJECT_LOCK(object); 273 return (VM_PAGER_FAIL); 274 } 275 td = curthread; 276 fpop = td->td_fpop; 277 td->td_fpop = NULL; 278 ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr); 279 td->td_fpop = fpop; 280 dev_relthread(dev, ref); 281 if (ret != 0) { 282 printf( 283 "WARNING: dev_pager_getpage: map function returns error %d", ret); 284 VM_OBJECT_LOCK(object); 285 return (VM_PAGER_FAIL); 286 } 287 288 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 289 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 290 pmap_page_get_memattr(m_paddr) != memattr) { 291 memattr = pmap_page_get_memattr(m_paddr); 292 printf( 293 "WARNING: A device driver has set \"memattr\" inconsistently.\n"); 294 } 295 if (((*mres)->flags & PG_FICTITIOUS) != 0) { 296 /* 297 * If the passed in result page is a fake page, update it with 298 * the new physical address. 299 */ 300 page = *mres; 301 VM_OBJECT_LOCK(object); 302 vm_page_updatefake(page, paddr, memattr); 303 } else { 304 /* 305 * Replace the passed in reqpage page with our own fake page and 306 * free up the all of the original pages. 307 */ 308 page = vm_page_getfake(paddr, memattr); 309 VM_OBJECT_LOCK(object); 310 vm_page_lock(*mres); 311 vm_page_free(*mres); 312 vm_page_unlock(*mres); 313 *mres = page; 314 vm_page_insert(page, object, pidx); 315 } 316 page->valid = VM_PAGE_BITS_ALL; 317 return (VM_PAGER_OK); 318 } 319 320 static void 321 dev_pager_putpages(object, m, count, sync, rtvals) 322 vm_object_t object; 323 vm_page_t *m; 324 int count; 325 boolean_t sync; 326 int *rtvals; 327 { 328 329 panic("dev_pager_putpage called"); 330 } 331 332 static boolean_t 333 dev_pager_haspage(object, pindex, before, after) 334 vm_object_t object; 335 vm_pindex_t pindex; 336 int *before; 337 int *after; 338 { 339 if (before != NULL) 340 *before = 0; 341 if (after != NULL) 342 *after = 0; 343 return (TRUE); 344 } 345 346 static int 347 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 348 vm_ooffset_t foff, struct ucred *cred, u_short *color) 349 { 350 struct cdev *dev; 351 struct cdevsw *csw; 352 vm_memattr_t dummy; 353 vm_ooffset_t off; 354 vm_paddr_t paddr; 355 unsigned int npages; 356 int ref; 357 358 /* 359 * Make sure this device can be mapped. 360 */ 361 dev = handle; 362 csw = dev_refthread(dev, &ref); 363 if (csw == NULL) 364 return (ENXIO); 365 366 /* 367 * Check that the specified range of the device allows the desired 368 * protection. 369 * 370 * XXX assumes VM_PROT_* == PROT_* 371 */ 372 npages = OFF_TO_IDX(size); 373 for (off = foff; npages--; off += PAGE_SIZE) { 374 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 375 dev_relthread(dev, ref); 376 return (EINVAL); 377 } 378 } 379 380 dev_ref(dev); 381 dev_relthread(dev, ref); 382 *color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 383 return (0); 384 } 385 386 static void 387 old_dev_pager_dtor(void *handle) 388 { 389 390 dev_rel(handle); 391 } 392