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 int ref; 112 113 /* 114 * Offset should be page aligned. 115 */ 116 if (foff & PAGE_MASK) 117 return (NULL); 118 119 size = round_page(size); 120 pindex = OFF_TO_IDX(foff + size); 121 122 /* 123 * Make sure this device can be mapped. 124 */ 125 dev = handle; 126 csw = dev_refthread(dev, &ref); 127 if (csw == NULL) 128 return (NULL); 129 130 /* 131 * Check that the specified range of the device allows the desired 132 * protection. 133 * 134 * XXX assumes VM_PROT_* == PROT_* 135 */ 136 npages = OFF_TO_IDX(size); 137 for (off = foff; npages--; off += PAGE_SIZE) 138 if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) { 139 dev_relthread(dev, ref); 140 return (NULL); 141 } 142 143 mtx_lock(&dev_pager_mtx); 144 145 /* 146 * Look up pager, creating as necessary. 147 */ 148 object1 = NULL; 149 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 150 if (object == NULL) { 151 /* 152 * Allocate object and associate it with the pager. Initialize 153 * the object's pg_color based upon the physical address of the 154 * device's memory. 155 */ 156 mtx_unlock(&dev_pager_mtx); 157 object1 = vm_object_allocate(OBJT_DEVICE, pindex); 158 object1->flags |= OBJ_COLORED; 159 object1->pg_color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 160 mtx_lock(&dev_pager_mtx); 161 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 162 if (object != NULL) { 163 /* 164 * We raced with other thread while allocating object. 165 */ 166 if (pindex > object->size) 167 object->size = pindex; 168 } else { 169 object = object1; 170 object1 = NULL; 171 object->handle = handle; 172 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 173 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 174 pager_object_list); 175 } 176 } else { 177 if (pindex > object->size) 178 object->size = pindex; 179 } 180 mtx_unlock(&dev_pager_mtx); 181 dev_relthread(dev, ref); 182 vm_object_deallocate(object1); 183 return (object); 184 } 185 186 static void 187 dev_pager_dealloc(object) 188 vm_object_t object; 189 { 190 vm_page_t m; 191 192 VM_OBJECT_UNLOCK(object); 193 mtx_lock(&dev_pager_mtx); 194 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 195 mtx_unlock(&dev_pager_mtx); 196 VM_OBJECT_LOCK(object); 197 /* 198 * Free up our fake pages. 199 */ 200 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != NULL) { 201 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 202 dev_pager_putfake(m); 203 } 204 } 205 206 static int 207 dev_pager_getpages(object, m, count, reqpage) 208 vm_object_t object; 209 vm_page_t *m; 210 int count; 211 int reqpage; 212 { 213 vm_pindex_t offset; 214 vm_paddr_t paddr; 215 vm_page_t m_paddr, page; 216 vm_memattr_t memattr; 217 struct cdev *dev; 218 int i, ref, ret; 219 struct cdevsw *csw; 220 struct thread *td; 221 struct file *fpop; 222 223 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 224 dev = object->handle; 225 page = m[reqpage]; 226 offset = page->pindex; 227 memattr = object->memattr; 228 VM_OBJECT_UNLOCK(object); 229 csw = dev_refthread(dev, &ref); 230 if (csw == NULL) 231 panic("dev_pager_getpage: no cdevsw"); 232 td = curthread; 233 fpop = td->td_fpop; 234 td->td_fpop = NULL; 235 ret = csw->d_mmap(dev, (vm_ooffset_t)offset << PAGE_SHIFT, &paddr, 236 PROT_READ, &memattr); 237 KASSERT(ret == 0, ("dev_pager_getpage: map function returns error")); 238 td->td_fpop = fpop; 239 dev_relthread(dev, ref); 240 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 241 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 242 pmap_page_get_memattr(m_paddr) != memattr) { 243 memattr = pmap_page_get_memattr(m_paddr); 244 printf( 245 "WARNING: A device driver has set \"memattr\" inconsistently.\n"); 246 } 247 if ((page->flags & PG_FICTITIOUS) != 0) { 248 /* 249 * If the passed in reqpage page is a fake page, update it with 250 * the new physical address. 251 */ 252 VM_OBJECT_LOCK(object); 253 dev_pager_updatefake(page, paddr, memattr); 254 if (count > 1) { 255 256 for (i = 0; i < count; i++) { 257 if (i != reqpage) { 258 vm_page_lock(m[i]); 259 vm_page_free(m[i]); 260 vm_page_unlock(m[i]); 261 } 262 } 263 } 264 } else { 265 /* 266 * Replace the passed in reqpage page with our own fake page and 267 * free up the all of the original pages. 268 */ 269 page = dev_pager_getfake(paddr, memattr); 270 VM_OBJECT_LOCK(object); 271 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 272 for (i = 0; i < count; i++) { 273 vm_page_lock(m[i]); 274 vm_page_free(m[i]); 275 vm_page_unlock(m[i]); 276 } 277 vm_page_insert(page, object, offset); 278 m[reqpage] = page; 279 } 280 page->valid = VM_PAGE_BITS_ALL; 281 return (VM_PAGER_OK); 282 } 283 284 static void 285 dev_pager_putpages(object, m, count, sync, rtvals) 286 vm_object_t object; 287 vm_page_t *m; 288 int count; 289 boolean_t sync; 290 int *rtvals; 291 { 292 panic("dev_pager_putpage called"); 293 } 294 295 static boolean_t 296 dev_pager_haspage(object, pindex, before, after) 297 vm_object_t object; 298 vm_pindex_t pindex; 299 int *before; 300 int *after; 301 { 302 if (before != NULL) 303 *before = 0; 304 if (after != NULL) 305 *after = 0; 306 return (TRUE); 307 } 308 309 /* 310 * Create a fictitious page with the specified physical address and memory 311 * attribute. The memory attribute is the only the machine-dependent aspect 312 * of a fictitious page that must be initialized. 313 */ 314 static vm_page_t 315 dev_pager_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 316 { 317 vm_page_t m; 318 319 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 320 m->phys_addr = paddr; 321 /* Fictitious pages don't use "segind". */ 322 m->flags = PG_FICTITIOUS; 323 /* Fictitious pages don't use "order" or "pool". */ 324 m->oflags = VPO_BUSY; 325 m->wire_count = 1; 326 pmap_page_set_memattr(m, memattr); 327 return (m); 328 } 329 330 /* 331 * Release a fictitious page. 332 */ 333 static void 334 dev_pager_putfake(vm_page_t m) 335 { 336 337 if (!(m->flags & PG_FICTITIOUS)) 338 panic("dev_pager_putfake: bad page"); 339 uma_zfree(fakepg_zone, m); 340 } 341 342 /* 343 * Update the given fictitious page to the specified physical address and 344 * memory attribute. 345 */ 346 static void 347 dev_pager_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 348 { 349 350 if (!(m->flags & PG_FICTITIOUS)) 351 panic("dev_pager_updatefake: bad page"); 352 m->phys_addr = paddr; 353 pmap_page_set_memattr(m, memattr); 354 } 355