| 1 | /* |
| 2 | * (MPSAFE) |
| 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 | * $FreeBSD: src/sys/vm/device_pager.c,v 1.46.2.1 2000/08/02 21:54:37 peter Exp $ |
| 38 | */ |
| 39 | |
| 40 | #include <sys/param.h> |
| 41 | #include <sys/systm.h> |
| 42 | #include <sys/kernel.h> |
| 43 | #include <sys/conf.h> |
| 44 | #include <sys/mman.h> |
| 45 | #include <sys/device.h> |
| 46 | #include <sys/queue.h> |
| 47 | #include <sys/malloc.h> |
| 48 | #include <sys/mutex2.h> |
| 49 | |
| 50 | #include <vm/vm.h> |
| 51 | #include <vm/vm_object.h> |
| 52 | #include <vm/vm_page.h> |
| 53 | #include <vm/vm_pager.h> |
| 54 | #include <vm/vm_zone.h> |
| 55 | #include <vm/vm_page2.h> |
| 56 | |
| 57 | static pgo_dealloc_t dev_pager_dealloc; |
| 58 | static pgo_getpage_t dev_pager_getpage; |
| 59 | static pgo_putpages_t dev_pager_putpages; |
| 60 | static pgo_haspage_t dev_pager_haspage; |
| 61 | |
| 62 | struct pagerops devicepagerops = { |
| 63 | .pgo_dealloc = dev_pager_dealloc, |
| 64 | .pgo_getpage = dev_pager_getpage, |
| 65 | .pgo_putpages = dev_pager_putpages, |
| 66 | .pgo_haspage = dev_pager_haspage |
| 67 | }; |
| 68 | |
| 69 | /* list of device pager objects */ |
| 70 | static TAILQ_HEAD(, vm_page) dev_freepages_list = |
| 71 | TAILQ_HEAD_INITIALIZER(dev_freepages_list); |
| 72 | static MALLOC_DEFINE(M_FICTITIOUS_PAGES, "device-mapped pages", |
| 73 | "Device mapped pages"); |
| 74 | |
| 75 | static vm_page_t dev_pager_getfake (vm_paddr_t, int); |
| 76 | static void dev_pager_putfake (vm_page_t); |
| 77 | |
| 78 | /* list of device pager objects */ |
| 79 | static struct pagerlst dev_pager_object_list = |
| 80 | TAILQ_HEAD_INITIALIZER(dev_pager_object_list); |
| 81 | /* protect list manipulation */ |
| 82 | static struct mtx dev_pager_mtx = MTX_INITIALIZER("devpgr"); |
| 83 | |
| 84 | static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, |
| 85 | vm_ooffset_t foff, struct ucred *cred, u_short *pg_color); |
| 86 | static void old_dev_pager_dtor(void *handle); |
| 87 | static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, |
| 88 | int prot, vm_page_t *mres); |
| 89 | |
| 90 | static struct cdev_pager_ops old_dev_pager_ops = { |
| 91 | .cdev_pg_ctor = old_dev_pager_ctor, |
| 92 | .cdev_pg_dtor = old_dev_pager_dtor, |
| 93 | .cdev_pg_fault = old_dev_pager_fault |
| 94 | }; |
| 95 | |
| 96 | vm_object_t |
| 97 | cdev_pager_lookup(void *handle) |
| 98 | { |
| 99 | vm_object_t object; |
| 100 | |
| 101 | mtx_lock(&dev_pager_mtx); |
| 102 | object = vm_pager_object_lookup(&dev_pager_object_list, handle); |
| 103 | mtx_unlock(&dev_pager_mtx); |
| 104 | |
| 105 | return (object); |
| 106 | } |
| 107 | |
| 108 | vm_object_t |
| 109 | cdev_pager_allocate(void *handle, enum obj_type tp, struct cdev_pager_ops *ops, |
| 110 | vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred) |
| 111 | { |
| 112 | cdev_t dev; |
| 113 | vm_object_t object; |
| 114 | u_short color; |
| 115 | |
| 116 | /* |
| 117 | * Offset should be page aligned. |
| 118 | */ |
| 119 | if (foff & PAGE_MASK) |
| 120 | return (NULL); |
| 121 | |
| 122 | size = round_page64(size); |
| 123 | |
| 124 | if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0) |
| 125 | return (NULL); |
| 126 | |
| 127 | /* |
| 128 | * Look up pager, creating as necessary. |
| 129 | */ |
| 130 | mtx_lock(&dev_pager_mtx); |
| 131 | object = vm_pager_object_lookup(&dev_pager_object_list, handle); |
| 132 | if (object == NULL) { |
| 133 | /* |
| 134 | * Allocate object and associate it with the pager. |
| 135 | */ |
| 136 | object = vm_object_allocate_hold(tp, |
| 137 | OFF_TO_IDX(foff + size)); |
| 138 | object->handle = handle; |
| 139 | object->un_pager.devp.ops = ops; |
| 140 | object->un_pager.devp.dev = handle; |
| 141 | TAILQ_INIT(&object->un_pager.devp.devp_pglist); |
| 142 | |
| 143 | /* |
| 144 | * handle is only a device for old_dev_pager_ctor. |
| 145 | */ |
| 146 | if (ops->cdev_pg_ctor == old_dev_pager_ctor) { |
| 147 | dev = handle; |
| 148 | dev->si_object = object; |
| 149 | } |
| 150 | |
| 151 | TAILQ_INSERT_TAIL(&dev_pager_object_list, object, |
| 152 | pager_object_entry); |
| 153 | |
| 154 | vm_object_drop(object); |
| 155 | } else { |
| 156 | /* |
| 157 | * Gain a reference to the object. |
| 158 | */ |
| 159 | vm_object_hold(object); |
| 160 | vm_object_reference_locked(object); |
| 161 | if (OFF_TO_IDX(foff + size) > object->size) |
| 162 | object->size = OFF_TO_IDX(foff + size); |
| 163 | vm_object_drop(object); |
| 164 | } |
| 165 | mtx_unlock(&dev_pager_mtx); |
| 166 | |
| 167 | return (object); |
| 168 | } |
| 169 | |
| 170 | /* |
| 171 | * No requirements. |
| 172 | */ |
| 173 | vm_object_t |
| 174 | dev_pager_alloc(void *handle, off_t size, vm_prot_t prot, off_t foff) |
| 175 | { |
| 176 | return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops, |
| 177 | size, prot, foff, NULL)); |
| 178 | } |
| 179 | |
| 180 | /* |
| 181 | * Caller must hold object lock. |
| 182 | */ |
| 183 | void |
| 184 | cdev_pager_free_page(vm_object_t object, vm_page_t m) |
| 185 | { |
| 186 | if (object->type == OBJT_MGTDEVICE) { |
| 187 | KKASSERT((m->flags & PG_FICTITIOUS) != 0); |
| 188 | pmap_page_protect(m, VM_PROT_NONE); |
| 189 | vm_page_remove(m); |
| 190 | vm_page_wakeup(m); |
| 191 | } else if (object->type == OBJT_DEVICE) { |
| 192 | TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); |
| 193 | dev_pager_putfake(m); |
| 194 | } |
| 195 | } |
| 196 | |
| 197 | /* |
| 198 | * No requirements. |
| 199 | */ |
| 200 | static void |
| 201 | dev_pager_dealloc(vm_object_t object) |
| 202 | { |
| 203 | vm_page_t m; |
| 204 | |
| 205 | /* |
| 206 | * NOTE: Callback may recurse into the device pager so do not |
| 207 | * obtain dev_pager_mtx until after it returns. |
| 208 | * |
| 209 | * The mutex should only be needed when manipulating the list. |
| 210 | */ |
| 211 | object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev); |
| 212 | |
| 213 | mtx_lock(&dev_pager_mtx); |
| 214 | TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_entry); |
| 215 | mtx_unlock(&dev_pager_mtx); |
| 216 | |
| 217 | if (object->type == OBJT_DEVICE) { |
| 218 | /* |
| 219 | * Free up our fake pages. |
| 220 | */ |
| 221 | while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != |
| 222 | NULL) { |
| 223 | TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, |
| 224 | m, pageq); |
| 225 | dev_pager_putfake(m); |
| 226 | } |
| 227 | } |
| 228 | } |
| 229 | |
| 230 | /* |
| 231 | * No requirements. |
| 232 | * |
| 233 | * WARNING! Do not obtain dev_pager_mtx here, doing so will cause a |
| 234 | * deadlock in DRMs VM paging code. |
| 235 | */ |
| 236 | static int |
| 237 | dev_pager_getpage(vm_object_t object, vm_pindex_t pindex, |
| 238 | vm_page_t *mpp, int seqaccess) |
| 239 | { |
| 240 | int error; |
| 241 | |
| 242 | error = object->un_pager.devp.ops->cdev_pg_fault( |
| 243 | object, IDX_TO_OFF(pindex), |
| 244 | PROT_READ, mpp); |
| 245 | |
| 246 | return (error); |
| 247 | } |
| 248 | |
| 249 | /* |
| 250 | * No requirements. |
| 251 | */ |
| 252 | static void |
| 253 | dev_pager_putpages(vm_object_t object, vm_page_t *m, |
| 254 | int count, int flags, int *rtvals) |
| 255 | { |
| 256 | panic("dev_pager_putpage called"); |
| 257 | } |
| 258 | |
| 259 | /* |
| 260 | * No requirements. |
| 261 | */ |
| 262 | static boolean_t |
| 263 | dev_pager_haspage(vm_object_t object, vm_pindex_t pindex) |
| 264 | { |
| 265 | return (TRUE); |
| 266 | } |
| 267 | |
| 268 | /* |
| 269 | * The caller does not need to hold dev_pager_mtx() but caller must ensure |
| 270 | * no page-use collision. |
| 271 | */ |
| 272 | static vm_page_t |
| 273 | dev_pager_getfake(vm_paddr_t paddr, int pat_mode) |
| 274 | { |
| 275 | vm_page_t m; |
| 276 | |
| 277 | m = kmalloc(sizeof(*m), M_FICTITIOUS_PAGES, M_WAITOK|M_ZERO); |
| 278 | |
| 279 | pmap_page_init(m); |
| 280 | |
| 281 | m->flags = PG_FICTITIOUS | PG_UNQUEUED; |
| 282 | m->valid = VM_PAGE_BITS_ALL; |
| 283 | m->dirty = 0; |
| 284 | m->queue = PQ_NONE; |
| 285 | m->object = NULL; |
| 286 | |
| 287 | m->busy_count = PBUSY_LOCKED; |
| 288 | m->wire_count = 1; |
| 289 | m->hold_count = 0; |
| 290 | m->phys_addr = paddr; |
| 291 | m->pat_mode = pat_mode; |
| 292 | |
| 293 | spin_init(&m->spin, "dev_page"); |
| 294 | |
| 295 | return (m); |
| 296 | } |
| 297 | |
| 298 | /* |
| 299 | * The caller does not need to hold dev_pager_mtx() but caller must ensure |
| 300 | * no page-use collision within the object. |
| 301 | */ |
| 302 | static void |
| 303 | dev_pager_putfake(vm_page_t m) |
| 304 | { |
| 305 | if (!(m->flags & PG_FICTITIOUS)) |
| 306 | panic("dev_pager_putfake: bad page"); |
| 307 | KKASSERT(m->object == NULL); |
| 308 | KKASSERT(m->hold_count == 0); |
| 309 | kfree(m, M_FICTITIOUS_PAGES); |
| 310 | } |
| 311 | |
| 312 | static int |
| 313 | old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, |
| 314 | vm_ooffset_t foff, struct ucred *cred, u_short *color) |
| 315 | { |
| 316 | unsigned int npages; |
| 317 | vm_offset_t off; |
| 318 | cdev_t dev; |
| 319 | |
| 320 | dev = handle; |
| 321 | |
| 322 | /* |
| 323 | * Check that the specified range of the device allows the desired |
| 324 | * protection. |
| 325 | * |
| 326 | * XXX assumes VM_PROT_* == PROT_* |
| 327 | */ |
| 328 | npages = OFF_TO_IDX(size); |
| 329 | for (off = foff; npages--; off += PAGE_SIZE) { |
| 330 | if (dev_dmmap(dev, off, (int)prot, NULL) == -1) |
| 331 | return (EINVAL); |
| 332 | } |
| 333 | |
| 334 | return (0); |
| 335 | } |
| 336 | |
| 337 | static void old_dev_pager_dtor(void *handle) |
| 338 | { |
| 339 | cdev_t dev; |
| 340 | |
| 341 | dev = handle; |
| 342 | if (dev != NULL) { |
| 343 | KKASSERT(dev->si_object); |
| 344 | dev->si_object = NULL; |
| 345 | } |
| 346 | } |
| 347 | |
| 348 | static int |
| 349 | old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, |
| 350 | int prot, vm_page_t *mres) |
| 351 | { |
| 352 | vm_paddr_t paddr; |
| 353 | vm_page_t page; |
| 354 | vm_offset_t pidx = OFF_TO_IDX(offset); |
| 355 | cdev_t dev; |
| 356 | |
| 357 | page = *mres; |
| 358 | dev = object->handle; |
| 359 | |
| 360 | paddr = pmap_phys_address(dev_dmmap(dev, offset, prot, NULL)); |
| 361 | KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); |
| 362 | KKASSERT(object->type == OBJT_DEVICE); |
| 363 | |
| 364 | if (page->flags & PG_FICTITIOUS) { |
| 365 | /* |
| 366 | * If the passed in reqpage page is already a fake page, |
| 367 | * update it with the new physical address. |
| 368 | */ |
| 369 | page->phys_addr = paddr; |
| 370 | page->valid = VM_PAGE_BITS_ALL; |
| 371 | } else { |
| 372 | /* |
| 373 | * Replace the passed in reqpage page with our own fake page |
| 374 | * and free up all the original pages. Object lock must be |
| 375 | * held when manipulating devp_pglist and inserting the |
| 376 | * page. |
| 377 | */ |
| 378 | page = dev_pager_getfake(paddr, object->memattr); |
| 379 | vm_object_hold(object); |
| 380 | TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, |
| 381 | page, pageq); |
| 382 | vm_page_free(*mres); |
| 383 | if (vm_page_insert(page, object, pidx) == FALSE) { |
| 384 | panic("dev_pager_getpage: page (%p,%016jx) exists", |
| 385 | object, (uintmax_t)pidx); |
| 386 | } |
| 387 | vm_object_drop(object); |
| 388 | } |
| 389 | return (VM_PAGER_OK); |
| 390 | } |
| 391 | |