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 static __inline int 97 dev_mmap(struct cdevsw *csw, struct cdev *dev, vm_offset_t offset, 98 vm_paddr_t *paddr, int nprot, vm_memattr_t *memattr) 99 { 100 101 if (csw->d_flags & D_MMAP2) 102 return (csw->d_mmap2(dev, offset, paddr, nprot, memattr)); 103 else 104 return (csw->d_mmap(dev, offset, paddr, nprot)); 105 } 106 107 /* 108 * MPSAFE 109 */ 110 static vm_object_t 111 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 112 vm_ooffset_t foff, struct ucred *cred) 113 { 114 struct cdev *dev; 115 vm_object_t object, object1; 116 vm_pindex_t pindex; 117 unsigned int npages; 118 vm_paddr_t paddr; 119 vm_offset_t off; 120 vm_memattr_t dummy; 121 struct cdevsw *csw; 122 123 /* 124 * Offset should be page aligned. 125 */ 126 if (foff & PAGE_MASK) 127 return (NULL); 128 129 size = round_page(size); 130 pindex = OFF_TO_IDX(foff + size); 131 132 /* 133 * Make sure this device can be mapped. 134 */ 135 dev = handle; 136 csw = dev_refthread(dev); 137 if (csw == NULL) 138 return (NULL); 139 140 /* 141 * Check that the specified range of the device allows the desired 142 * protection. 143 * 144 * XXX assumes VM_PROT_* == PROT_* 145 */ 146 npages = OFF_TO_IDX(size); 147 for (off = foff; npages--; off += PAGE_SIZE) 148 if (dev_mmap(csw, dev, off, &paddr, (int)prot, &dummy) != 0) { 149 dev_relthread(dev); 150 return (NULL); 151 } 152 153 mtx_lock(&dev_pager_mtx); 154 155 /* 156 * Look up pager, creating as necessary. 157 */ 158 object1 = NULL; 159 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 160 if (object == NULL) { 161 /* 162 * Allocate object and associate it with the pager. Initialize 163 * the object's pg_color based upon the physical address of the 164 * device's memory. 165 */ 166 mtx_unlock(&dev_pager_mtx); 167 object1 = vm_object_allocate(OBJT_DEVICE, pindex); 168 object1->flags |= OBJ_COLORED; 169 object1->pg_color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE); 170 mtx_lock(&dev_pager_mtx); 171 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 172 if (object != NULL) { 173 /* 174 * We raced with other thread while allocating object. 175 */ 176 if (pindex > object->size) 177 object->size = pindex; 178 } else { 179 object = object1; 180 object1 = NULL; 181 object->handle = handle; 182 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 183 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, 184 pager_object_list); 185 } 186 } else { 187 if (pindex > object->size) 188 object->size = pindex; 189 } 190 mtx_unlock(&dev_pager_mtx); 191 dev_relthread(dev); 192 vm_object_deallocate(object1); 193 return (object); 194 } 195 196 static void 197 dev_pager_dealloc(object) 198 vm_object_t object; 199 { 200 vm_page_t m; 201 202 VM_OBJECT_UNLOCK(object); 203 mtx_lock(&dev_pager_mtx); 204 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 205 mtx_unlock(&dev_pager_mtx); 206 VM_OBJECT_LOCK(object); 207 /* 208 * Free up our fake pages. 209 */ 210 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != NULL) { 211 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 212 dev_pager_putfake(m); 213 } 214 } 215 216 static int 217 dev_pager_getpages(object, m, count, reqpage) 218 vm_object_t object; 219 vm_page_t *m; 220 int count; 221 int reqpage; 222 { 223 vm_pindex_t offset; 224 vm_paddr_t paddr; 225 vm_page_t m_paddr, page; 226 vm_memattr_t memattr; 227 struct cdev *dev; 228 int i, ret; 229 struct cdevsw *csw; 230 struct thread *td; 231 struct file *fpop; 232 233 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 234 dev = object->handle; 235 page = m[reqpage]; 236 offset = page->pindex; 237 memattr = object->memattr; 238 VM_OBJECT_UNLOCK(object); 239 csw = dev_refthread(dev); 240 if (csw == NULL) 241 panic("dev_pager_getpage: no cdevsw"); 242 td = curthread; 243 fpop = td->td_fpop; 244 td->td_fpop = NULL; 245 ret = dev_mmap(csw, dev, (vm_offset_t)offset << PAGE_SHIFT, &paddr, 246 PROT_READ, &memattr); 247 KASSERT(ret == 0, ("dev_pager_getpage: map function returns error")); 248 td->td_fpop = fpop; 249 dev_relthread(dev); 250 /* If "paddr" is a real page, perform a sanity check on "memattr". */ 251 if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && 252 pmap_page_get_memattr(m_paddr) != memattr) { 253 memattr = pmap_page_get_memattr(m_paddr); 254 printf( 255 "WARNING: A device driver has set \"memattr\" inconsistently.\n"); 256 } 257 if ((page->flags & PG_FICTITIOUS) != 0) { 258 /* 259 * If the passed in reqpage page is a fake page, update it with 260 * the new physical address. 261 */ 262 VM_OBJECT_LOCK(object); 263 dev_pager_updatefake(page, paddr, memattr); 264 if (count > 1) { 265 vm_page_lock_queues(); 266 for (i = 0; i < count; i++) { 267 if (i != reqpage) 268 vm_page_free(m[i]); 269 } 270 vm_page_unlock_queues(); 271 } 272 } else { 273 /* 274 * Replace the passed in reqpage page with our own fake page and 275 * free up the all of the original pages. 276 */ 277 page = dev_pager_getfake(paddr, memattr); 278 VM_OBJECT_LOCK(object); 279 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 280 vm_page_lock_queues(); 281 for (i = 0; i < count; i++) 282 vm_page_free(m[i]); 283 vm_page_unlock_queues(); 284 vm_page_insert(page, object, offset); 285 m[reqpage] = page; 286 } 287 page->valid = VM_PAGE_BITS_ALL; 288 return (VM_PAGER_OK); 289 } 290 291 static void 292 dev_pager_putpages(object, m, count, sync, rtvals) 293 vm_object_t object; 294 vm_page_t *m; 295 int count; 296 boolean_t sync; 297 int *rtvals; 298 { 299 panic("dev_pager_putpage called"); 300 } 301 302 static boolean_t 303 dev_pager_haspage(object, pindex, before, after) 304 vm_object_t object; 305 vm_pindex_t pindex; 306 int *before; 307 int *after; 308 { 309 if (before != NULL) 310 *before = 0; 311 if (after != NULL) 312 *after = 0; 313 return (TRUE); 314 } 315 316 /* 317 * Create a fictitious page with the specified physical address and memory 318 * attribute. The memory attribute is the only the machine-dependent aspect 319 * of a fictitious page that must be initialized. 320 */ 321 static vm_page_t 322 dev_pager_getfake(vm_paddr_t paddr, vm_memattr_t memattr) 323 { 324 vm_page_t m; 325 326 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO); 327 m->phys_addr = paddr; 328 /* Fictitious pages don't use "segind". */ 329 m->flags = PG_FICTITIOUS; 330 /* Fictitious pages don't use "order" or "pool". */ 331 m->oflags = VPO_BUSY; 332 m->wire_count = 1; 333 pmap_page_set_memattr(m, memattr); 334 return (m); 335 } 336 337 /* 338 * Release a fictitious page. 339 */ 340 static void 341 dev_pager_putfake(vm_page_t m) 342 { 343 344 if (!(m->flags & PG_FICTITIOUS)) 345 panic("dev_pager_putfake: bad page"); 346 uma_zfree(fakepg_zone, m); 347 } 348 349 /* 350 * Update the given fictitious page to the specified physical address and 351 * memory attribute. 352 */ 353 static void 354 dev_pager_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr) 355 { 356 357 if (!(m->flags & PG_FICTITIOUS)) 358 panic("dev_pager_updatefake: bad page"); 359 m->phys_addr = paddr; 360 pmap_page_set_memattr(m, memattr); 361 } 362