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/thread2.h> 49 #include <sys/mutex2.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_object.h> 53 #include <vm/vm_page.h> 54 #include <vm/vm_pager.h> 55 #include <vm/vm_zone.h> 56 #include <vm/vm_page2.h> 57 58 static void dev_pager_dealloc (vm_object_t); 59 static int dev_pager_getpage (vm_object_t, vm_page_t *, 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); 63 64 /* list of device pager objects */ 65 static TAILQ_HEAD(, vm_page) dev_freepages_list = 66 TAILQ_HEAD_INITIALIZER(dev_freepages_list); 67 static MALLOC_DEFINE(M_FICTITIOUS_PAGES, "device-mapped pages", 68 "Device mapped pages"); 69 70 static vm_page_t dev_pager_getfake (vm_paddr_t, int); 71 static void dev_pager_putfake (vm_page_t); 72 73 struct pagerops devicepagerops = { 74 dev_pager_dealloc, 75 dev_pager_getpage, 76 dev_pager_putpages, 77 dev_pager_haspage 78 }; 79 80 /* list of device pager objects */ 81 static struct pagerlst dev_pager_object_list = 82 TAILQ_HEAD_INITIALIZER(dev_pager_object_list); 83 /* protect list manipulation */ 84 static struct mtx dev_pager_mtx = MTX_INITIALIZER; 85 86 static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 87 vm_ooffset_t foff, struct ucred *cred, u_short *pg_color); 88 static void old_dev_pager_dtor(void *handle); 89 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, 90 int prot, vm_page_t *mres); 91 92 static struct cdev_pager_ops old_dev_pager_ops = { 93 .cdev_pg_ctor = old_dev_pager_ctor, 94 .cdev_pg_dtor = old_dev_pager_dtor, 95 .cdev_pg_fault = old_dev_pager_fault 96 }; 97 98 vm_object_t 99 cdev_pager_lookup(void *handle) 100 { 101 vm_object_t object; 102 mtx_lock(&dev_pager_mtx); 103 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 104 mtx_unlock(&dev_pager_mtx); 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 dev = handle; 116 117 /* 118 * Offset should be page aligned. 119 */ 120 if (foff & PAGE_MASK) 121 return (NULL); 122 123 size = round_page64(size); 124 125 if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0) 126 return (NULL); 127 128 /* 129 * Look up pager, creating as necessary. 130 */ 131 mtx_lock(&dev_pager_mtx); 132 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 133 if (object == NULL) { 134 /* 135 * Allocate object and associate it with the pager. 136 */ 137 object = vm_object_allocate_hold(tp, 138 OFF_TO_IDX(foff + size)); 139 object->handle = handle; 140 object->un_pager.devp.ops = ops; 141 object->un_pager.devp.dev = handle; 142 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 143 dev->si_object = object; 144 145 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 146 pager_object_list); 147 148 vm_object_drop(object); 149 } else { 150 /* 151 * Gain a reference to the object. 152 */ 153 vm_object_hold(object); 154 vm_object_reference_locked(object); 155 if (OFF_TO_IDX(foff + size) > object->size) 156 object->size = OFF_TO_IDX(foff + size); 157 vm_object_drop(object); 158 } 159 mtx_unlock(&dev_pager_mtx); 160 161 return (object); 162 } 163 164 /* 165 * No requirements. 166 */ 167 vm_object_t 168 dev_pager_alloc(void *handle, off_t size, vm_prot_t prot, off_t foff) 169 { 170 return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops, 171 size, prot, foff, NULL)); 172 } 173 174 /* XXX */ 175 void 176 cdev_pager_free_page(vm_object_t object, vm_page_t m) 177 { 178 if (object->type == OBJT_MGTDEVICE) { 179 KKASSERT((m->flags & PG_FICTITIOUS) != 0); 180 pmap_page_protect(m, VM_PROT_NONE); 181 vm_page_remove(m); 182 vm_page_wakeup(m); 183 } else if (object->type == OBJT_DEVICE) { 184 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 185 dev_pager_putfake(m); 186 } 187 } 188 189 /* 190 * No requirements. 191 */ 192 static void 193 dev_pager_dealloc(vm_object_t object) 194 { 195 vm_page_t m; 196 197 mtx_lock(&dev_pager_mtx); 198 object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev); 199 200 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 201 202 if (object->type == OBJT_DEVICE) { 203 /* 204 * Free up our fake pages. 205 */ 206 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 207 NULL) { 208 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, 209 m, pageq); 210 dev_pager_putfake(m); 211 } 212 } 213 mtx_unlock(&dev_pager_mtx); 214 } 215 216 /* 217 * No requirements. 218 */ 219 static int 220 dev_pager_getpage(vm_object_t object, vm_page_t *mpp, int seqaccess) 221 { 222 vm_page_t page; 223 int error; 224 225 mtx_lock(&dev_pager_mtx); 226 227 page = *mpp; 228 229 error = object->un_pager.devp.ops->cdev_pg_fault(object, 230 IDX_TO_OFF(page->pindex), PROT_READ, mpp); 231 232 mtx_unlock(&dev_pager_mtx); 233 234 return (error); 235 } 236 237 /* 238 * No requirements. 239 */ 240 static void 241 dev_pager_putpages(vm_object_t object, vm_page_t *m, 242 int count, boolean_t sync, int *rtvals) 243 { 244 panic("dev_pager_putpage called"); 245 } 246 247 /* 248 * No requirements. 249 */ 250 static boolean_t 251 dev_pager_haspage(vm_object_t object, vm_pindex_t pindex) 252 { 253 return (TRUE); 254 } 255 256 /* 257 * The caller must hold dev_pager_mtx 258 */ 259 static vm_page_t 260 dev_pager_getfake(vm_paddr_t paddr, int pat_mode) 261 { 262 vm_page_t m; 263 264 m = kmalloc(sizeof(*m), M_FICTITIOUS_PAGES, M_WAITOK|M_ZERO); 265 266 pmap_page_init(m); 267 268 m->flags = PG_BUSY | PG_FICTITIOUS; 269 m->valid = VM_PAGE_BITS_ALL; 270 m->dirty = 0; 271 m->busy = 0; 272 m->queue = PQ_NONE; 273 m->object = NULL; 274 275 m->wire_count = 1; 276 m->hold_count = 0; 277 m->phys_addr = paddr; 278 m->pat_mode = pat_mode; 279 280 return (m); 281 } 282 283 /* 284 * Synthesized VM pages must be structurally stable for lockless lookups to 285 * work properly. 286 * 287 * The caller must hold dev_pager_mtx 288 */ 289 static void 290 dev_pager_putfake(vm_page_t m) 291 { 292 if (!(m->flags & PG_FICTITIOUS)) 293 panic("dev_pager_putfake: bad page"); 294 KKASSERT(m->object == NULL); 295 KKASSERT(m->hold_count == 0); 296 kfree(m, M_FICTITIOUS_PAGES); 297 } 298 299 static int 300 old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot, 301 vm_ooffset_t foff, struct ucred *cred, u_short *color) 302 { 303 unsigned int npages; 304 vm_offset_t off; 305 cdev_t dev; 306 307 dev = handle; 308 309 /* 310 * Check that the specified range of the device allows the desired 311 * protection. 312 * 313 * XXX assumes VM_PROT_* == PROT_* 314 */ 315 npages = OFF_TO_IDX(size); 316 for (off = foff; npages--; off += PAGE_SIZE) { 317 if (dev_dmmap(dev, off, (int)prot) == -1) 318 return (EINVAL); 319 } 320 321 return (0); 322 } 323 324 static void old_dev_pager_dtor(void *handle) 325 { 326 cdev_t dev; 327 328 dev = handle; 329 if (dev != NULL) { 330 KKASSERT(dev->si_object); 331 dev->si_object = NULL; 332 } 333 } 334 335 static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, 336 int prot, vm_page_t *mres) 337 { 338 vm_paddr_t paddr; 339 vm_page_t page; 340 vm_offset_t pidx = OFF_TO_IDX(offset); 341 cdev_t dev; 342 343 page = *mres; 344 dev = object->handle; 345 346 paddr = pmap_phys_address( 347 dev_dmmap(dev, offset, prot)); 348 KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); 349 KKASSERT(object->type == OBJT_DEVICE); 350 351 if (page->flags & PG_FICTITIOUS) { 352 /* 353 * If the passed in reqpage page is already a fake page, 354 * update it with the new physical address. 355 */ 356 page->phys_addr = paddr; 357 page->valid = VM_PAGE_BITS_ALL; 358 } else { 359 /* 360 * Replace the passed in reqpage page with our own fake page 361 * and free up all the original pages. 362 */ 363 page = dev_pager_getfake(paddr, object->memattr); 364 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, 365 page, pageq); 366 vm_object_hold(object); 367 vm_page_free(*mres); 368 if (vm_page_insert(page, object, pidx) == FALSE) { 369 panic("dev_pager_getpage: page (%p,%016jx) exists", 370 object, (uintmax_t)pidx); 371 } 372 vm_object_drop(object); 373 } 374 375 return (VM_PAGER_OK); 376 } 377 378