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_offset_t off; 109 struct cdevsw *csw; 110 111 /* 112 * Offset should be page aligned. 113 */ 114 if (foff & PAGE_MASK) 115 return (NULL); 116 117 size = round_page(size); 118 pindex = OFF_TO_IDX(foff + size); 119 120 /* 121 * Make sure this device can be mapped. 122 */ 123 dev = handle; 124 csw = dev_refthread(dev); 125 if (csw == NULL) 126 return (NULL); 127 128 /* 129 * Check that the specified range of the device allows the desired 130 * protection. 131 * 132 * XXX assumes VM_PROT_* == PROT_* 133 */ 134 npages = OFF_TO_IDX(size); 135 for (off = foff; npages--; off += PAGE_SIZE) 136 if ((*csw->d_mmap)(dev, off, &paddr, (int)prot) != 0) { 137 dev_relthread(dev); 138 return (NULL); 139 } 140 141 mtx_lock(&dev_pager_mtx); 142 143 /* 144 * Look up pager, creating as necessary. 145 */ 146 object1 = NULL; 147 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 148 if (object == NULL) { 149 /* 150 * Allocate object and associate it with the pager. Initialize 151 * the object's pg_color based upon the physical address of the 152 * device's memory. 153 */ 154 mtx_unlock(&dev_pager_mtx); 155 object1 = vm_object_allocate(OBJT_DEVICE, pindex); 156 object1->flags |= OBJ_COLORED; 157 object1->pg_color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 158 mtx_lock(&dev_pager_mtx); 159 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 160 if (object != NULL) { 161 /* 162 * We raced with other thread while allocating object. 163 */ 164 if (pindex > object->size) 165 object->size = pindex; 166 } else { 167 object = object1; 168 object1 = NULL; 169 object->handle = handle; 170 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 171 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 172 pager_object_list); 173 } 174 } else { 175 if (pindex > object->size) 176 object->size = pindex; 177 } 178 mtx_unlock(&dev_pager_mtx); 179 dev_relthread(dev); 180 vm_object_deallocate(object1); 181 return (object); 182 } 183 184 static void 185 dev_pager_dealloc(object) 186 vm_object_t object; 187 { 188 vm_page_t m; 189 190 VM_OBJECT_UNLOCK(object); 191 mtx_lock(&dev_pager_mtx); 192 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 193 mtx_unlock(&dev_pager_mtx); 194 VM_OBJECT_LOCK(object); 195 /* 196 * Free up our fake pages. 197 */ 198 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != NULL) { 199 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 200 dev_pager_putfake(m); 201 } 202 } 203 204 static int 205 dev_pager_getpages(object, m, count, reqpage) 206 vm_object_t object; 207 vm_page_t *m; 208 int count; 209 int reqpage; 210 { 211 vm_pindex_t offset; 212 vm_paddr_t paddr; 213 vm_page_t m_paddr, page; 214 vm_memattr_t memattr; 215 struct cdev *dev; 216 int i, ret; 217 int prot; 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 prot = PROT_READ; /* XXX should pass in? */ 232 233 td = curthread; 234 fpop = td->td_fpop; 235 td->td_fpop = NULL; 236 ret = (*csw->d_mmap)(dev, (vm_offset_t)offset << PAGE_SHIFT, &paddr, prot); 237 KASSERT(ret == 0, ("dev_pager_getpage: map function returns error")); 238 td->td_fpop = fpop; 239 dev_relthread(dev); 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 vm_page_lock_queues(); 256 for (i = 0; i < count; i++) { 257 if (i != reqpage) 258 vm_page_free(m[i]); 259 } 260 vm_page_unlock_queues(); 261 } 262 } else { 263 /* 264 * Replace the passed in reqpage page with our own fake page and 265 * free up the all of the original pages. 266 */ 267 page = dev_pager_getfake(paddr, memattr); 268 VM_OBJECT_LOCK(object); 269 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 270 vm_page_lock_queues(); 271 for (i = 0; i < count; i++) 272 vm_page_free(m[i]); 273 vm_page_unlock_queues(); 274 vm_page_insert(page, object, offset); 275 m[reqpage] = page; 276 } 277 page->valid = VM_PAGE_BITS_ALL; 278 return (VM_PAGER_OK); 279 } 280 281 static void 282 dev_pager_putpages(object, m, count, sync, rtvals) 283 vm_object_t object; 284 vm_page_t *m; 285 int count; 286 boolean_t sync; 287 int *rtvals; 288 { 289 panic("dev_pager_putpage called"); 290 } 291 292 static boolean_t 293 dev_pager_haspage(object, pindex, before, after) 294 vm_object_t object; 295 vm_pindex_t pindex; 296 int *before; 297 int *after; 298 { 299 if (before != NULL) 300 *before = 0; 301 if (after != NULL) 302 *after = 0; 303 return (TRUE); 304 } 305 306 /* 307 * Create a fictitious page with the specified physical address and memory 308 * attribute. 309 */ 310 static vm_page_t 311 dev_pager_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 312 { 313 vm_page_t m; 314 315 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 316 m->phys_addr = paddr; 317 /* Fictitious pages don't use "segind". */ 318 m->flags = PG_FICTITIOUS; 319 /* Fictitious pages don't use "order" or "pool". */ 320 pmap_page_init(m); 321 m->oflags = VPO_BUSY; 322 m->wire_count = 1; 323 if (memattr != VM_MEMATTR_DEFAULT) 324 pmap_page_set_memattr(m, memattr); 325 return (m); 326 } 327 328 /* 329 * Release a fictitious page. 330 */ 331 static void 332 dev_pager_putfake(vm_page_t m) 333 { 334 335 if (!(m->flags & PG_FICTITIOUS)) 336 panic("dev_pager_putfake: bad page"); 337 /* Restore the default memory attribute to "phys_addr". */ 338 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 339 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 340 uma_zfree(fakepg_zone, m); 341 } 342 343 /* 344 * Update the given fictitious page to the specified physical address and 345 * memory attribute. 346 */ 347 static void 348 dev_pager_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 349 { 350 351 if (!(m->flags & PG_FICTITIOUS)) 352 panic("dev_pager_updatefake: bad page"); 353 /* Restore the default memory attribute before changing "phys_addr". */ 354 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT) 355 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT); 356 m->phys_addr = paddr; 357 if (memattr != VM_MEMATTR_DEFAULT) 358 pmap_page_set_memattr(m, memattr); 359 } 360