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 71 static uma_zone_t fakepg_zone; 72 73 static vm_page_t dev_pager_getfake(vm_paddr_t, vm_memattr_t); 74 static void dev_pager_putfake(vm_page_t); 75 static void dev_pager_updatefake(vm_page_t, vm_paddr_t, vm_memattr_t); 76 77 struct pagerops devicepagerops = { 78 .pgo_init = dev_pager_init, 79 .pgo_alloc = dev_pager_alloc, 80 .pgo_dealloc = dev_pager_dealloc, 81 .pgo_getpages = dev_pager_getpages, 82 .pgo_putpages = dev_pager_putpages, 83 .pgo_haspage = dev_pager_haspage, 84 }; 85 86 static void 87 dev_pager_init() 88 { 89 TAILQ_INIT(&dev_pager_object_list); 90 mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF); 91 fakepg_zone = uma_zcreate("DP fakepg", sizeof(struct vm_page), 92 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 93 UMA_ZONE_NOFREE|UMA_ZONE_VM); 94 } 95 96 /* 97 * MPSAFE 98 */ 99 static vm_object_t 100 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 101 vm_ooffset_t foff, struct ucred *cred) 102 { 103 struct cdev *dev; 104 vm_object_t object, object1; 105 vm_pindex_t pindex; 106 unsigned int npages; 107 vm_paddr_t paddr; 108 vm_ooffset_t off; 109 vm_memattr_t dummy; 110 struct cdevsw *csw; 111 112 /* 113 * Offset should be page aligned. 114 */ 115 if (foff & PAGE_MASK) 116 return (NULL); 117 118 size = round_page(size); 119 pindex = OFF_TO_IDX(foff + size); 120 121 /* 122 * Make sure this device can be mapped. 123 */ 124 dev = handle; 125 csw = dev_refthread(dev); 126 if (csw == NULL) 127 return (NULL); 128 129 /* 130 * Check that the specified range of the device allows the desired 131 * protection. 132 * 133 * XXX assumes VM_PROT_* == PROT_* 134 */ 135 npages = OFF_TO_IDX(size); 136 for (off = foff; npages--; off += PAGE_SIZE) 137 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 138 dev_relthread(dev); 139 return (NULL); 140 } 141 142 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(OBJT_DEVICE, pindex); 157 object1->flags |= OBJ_COLORED; 158 object1->pg_color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 159 mtx_lock(&dev_pager_mtx); 160 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 161 if (object != NULL) { 162 /* 163 * We raced with other thread while allocating object. 164 */ 165 if (pindex > object->size) 166 object->size = pindex; 167 } else { 168 object = object1; 169 object1 = NULL; 170 object->handle = handle; 171 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 172 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 173 pager_object_list); 174 } 175 } else { 176 if (pindex > object->size) 177 object->size = pindex; 178 } 179 mtx_unlock(&dev_pager_mtx); 180 dev_relthread(dev); 181 vm_object_deallocate(object1); 182 return (object); 183 } 184 185 static void 186 dev_pager_dealloc(object) 187 vm_object_t object; 188 { 189 vm_page_t m; 190 191 VM_OBJECT_UNLOCK(object); 192 mtx_lock(&dev_pager_mtx); 193 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 194 mtx_unlock(&dev_pager_mtx); 195 VM_OBJECT_LOCK(object); 196 /* 197 * Free up our fake pages. 198 */ 199 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != NULL) { 200 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 201 dev_pager_putfake(m); 202 } 203 } 204 205 static int 206 dev_pager_getpages(object, m, count, reqpage) 207 vm_object_t object; 208 vm_page_t *m; 209 int count; 210 int reqpage; 211 { 212 vm_pindex_t offset; 213 vm_paddr_t paddr; 214 vm_page_t m_paddr, page; 215 vm_memattr_t memattr; 216 struct cdev *dev; 217 int i, ret; 218 struct cdevsw *csw; 219 struct thread *td; 220 struct file *fpop; 221 222 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 223 dev = object->handle; 224 page = m[reqpage]; 225 offset = page->pindex; 226 memattr = object->memattr; 227 VM_OBJECT_UNLOCK(object); 228 csw = dev_refthread(dev); 229 if (csw == NULL) 230 panic("dev_pager_getpage: no cdevsw"); 231 td = curthread; 232 fpop = td->td_fpop; 233 td->td_fpop = NULL; 234 ret = csw->d_mmap(dev, (vm_ooffset_t)offset << PAGE_SHIFT, &paddr, 235 PROT_READ, &memattr); 236 KASSERT(ret == 0, ("dev_pager_getpage: map function returns error")); 237 td->td_fpop = fpop; 238 dev_relthread(dev); 239 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 240 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 241 pmap_page_get_memattr(m_paddr) != memattr) { 242 memattr = pmap_page_get_memattr(m_paddr); 243 printf( 244 "WARNING: A device driver has set \"memattr\" inconsistently.\n"); 245 } 246 if ((page->flags & PG_FICTITIOUS) != 0) { 247 /* 248 * If the passed in reqpage page is a fake page, update it with 249 * the new physical address. 250 */ 251 VM_OBJECT_LOCK(object); 252 dev_pager_updatefake(page, paddr, memattr); 253 if (count > 1) { 254 255 for (i = 0; i < count; i++) { 256 if (i != reqpage) { 257 vm_page_lock(m[i]); 258 vm_page_free(m[i]); 259 vm_page_unlock(m[i]); 260 } 261 } 262 } 263 } else { 264 /* 265 * Replace the passed in reqpage page with our own fake page and 266 * free up the all of the original pages. 267 */ 268 page = dev_pager_getfake(paddr, memattr); 269 VM_OBJECT_LOCK(object); 270 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 271 for (i = 0; i < count; i++) { 272 vm_page_lock(m[i]); 273 vm_page_free(m[i]); 274 vm_page_unlock(m[i]); 275 } 276 vm_page_insert(page, object, offset); 277 m[reqpage] = page; 278 } 279 page->valid = VM_PAGE_BITS_ALL; 280 return (VM_PAGER_OK); 281 } 282 283 static void 284 dev_pager_putpages(object, m, count, sync, rtvals) 285 vm_object_t object; 286 vm_page_t *m; 287 int count; 288 boolean_t sync; 289 int *rtvals; 290 { 291 panic("dev_pager_putpage called"); 292 } 293 294 static boolean_t 295 dev_pager_haspage(object, pindex, before, after) 296 vm_object_t object; 297 vm_pindex_t pindex; 298 int *before; 299 int *after; 300 { 301 if (before != NULL) 302 *before = 0; 303 if (after != NULL) 304 *after = 0; 305 return (TRUE); 306 } 307 308 /* 309 * Create a fictitious page with the specified physical address and memory 310 * attribute. The memory attribute is the only the machine-dependent aspect 311 * of a fictitious page that must be initialized. 312 */ 313 static vm_page_t 314 dev_pager_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 315 { 316 vm_page_t m; 317 318 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 319 m->phys_addr = paddr; 320 /* Fictitious pages don't use "segind". */ 321 m->flags = PG_FICTITIOUS; 322 /* Fictitious pages don't use "order" or "pool". */ 323 m->oflags = VPO_BUSY; 324 m->wire_count = 1; 325 pmap_page_set_memattr(m, memattr); 326 return (m); 327 } 328 329 /* 330 * Release a fictitious page. 331 */ 332 static void 333 dev_pager_putfake(vm_page_t m) 334 { 335 336 if (!(m->flags & PG_FICTITIOUS)) 337 panic("dev_pager_putfake: bad page"); 338 uma_zfree(fakepg_zone, m); 339 } 340 341 /* 342 * Update the given fictitious page to the specified physical address and 343 * memory attribute. 344 */ 345 static void 346 dev_pager_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 347 { 348 349 if (!(m->flags & PG_FICTITIOUS)) 350 panic("dev_pager_updatefake: bad page"); 351 m->phys_addr = paddr; 352 pmap_page_set_memattr(m, memattr); 353 } 354