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); 74 static void dev_pager_putfake(vm_page_t); 75 static void dev_pager_updatefake(vm_page_t, vm_paddr_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 page; 214 struct cdev *dev; 215 int i, ret; 216 int prot; 217 struct cdevsw *csw; 218 struct thread *td; 219 struct file *fpop; 220 221 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 222 dev = object->handle; 223 page = m[reqpage]; 224 offset = page->pindex; 225 VM_OBJECT_UNLOCK(object); 226 csw = dev_refthread(dev); 227 if (csw == NULL) 228 panic("dev_pager_getpage: no cdevsw"); 229 prot = PROT_READ; /* XXX should pass in? */ 230 231 td = curthread; 232 fpop = td->td_fpop; 233 td->td_fpop = NULL; 234 ret = (*csw->d_mmap)(dev, (vm_offset_t)offset << PAGE_SHIFT, &paddr, prot); 235 KASSERT(ret == 0, ("dev_pager_getpage: map function returns error")); 236 td->td_fpop = fpop; 237 dev_relthread(dev); 238 239 if ((page->flags & PG_FICTITIOUS) != 0) { 240 /* 241 * If the passed in reqpage page is a fake page, update it with 242 * the new physical address. 243 */ 244 VM_OBJECT_LOCK(object); 245 dev_pager_updatefake(page, paddr); 246 if (count > 1) { 247 vm_page_lock_queues(); 248 for (i = 0; i < count; i++) { 249 if (i != reqpage) 250 vm_page_free(m[i]); 251 } 252 vm_page_unlock_queues(); 253 } 254 } else { 255 /* 256 * Replace the passed in reqpage page with our own fake page and 257 * free up the all of the original pages. 258 */ 259 page = dev_pager_getfake(paddr); 260 VM_OBJECT_LOCK(object); 261 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 262 vm_page_lock_queues(); 263 for (i = 0; i < count; i++) 264 vm_page_free(m[i]); 265 vm_page_unlock_queues(); 266 vm_page_insert(page, object, offset); 267 m[reqpage] = page; 268 } 269 page->valid = VM_PAGE_BITS_ALL; 270 return (VM_PAGER_OK); 271 } 272 273 static void 274 dev_pager_putpages(object, m, count, sync, rtvals) 275 vm_object_t object; 276 vm_page_t *m; 277 int count; 278 boolean_t sync; 279 int *rtvals; 280 { 281 panic("dev_pager_putpage called"); 282 } 283 284 static boolean_t 285 dev_pager_haspage(object, pindex, before, after) 286 vm_object_t object; 287 vm_pindex_t pindex; 288 int *before; 289 int *after; 290 { 291 if (before != NULL) 292 *before = 0; 293 if (after != NULL) 294 *after = 0; 295 return (TRUE); 296 } 297 298 /* 299 * Instantiate a fictitious page. Unlike physical memory pages, only 300 * the machine-independent fields must be initialized. 301 */ 302 static vm_page_t 303 dev_pager_getfake(paddr) 304 vm_paddr_t paddr; 305 { 306 vm_page_t m; 307 308 m = uma_zalloc(fakepg_zone, M_WAITOK); 309 310 m->flags = PG_FICTITIOUS; 311 m->oflags = VPO_BUSY; 312 /* Fictitious pages don't use "act_count". */ 313 m->dirty = 0; 314 m->busy = 0; 315 m->queue = PQ_NONE; 316 m->object = NULL; 317 318 m->wire_count = 1; 319 m->hold_count = 0; 320 m->phys_addr = paddr; 321 322 return (m); 323 } 324 325 static void 326 dev_pager_putfake(m) 327 vm_page_t m; 328 { 329 if (!(m->flags & PG_FICTITIOUS)) 330 panic("dev_pager_putfake: bad page"); 331 uma_zfree(fakepg_zone, m); 332 } 333 334 static void 335 dev_pager_updatefake(m, paddr) 336 vm_page_t m; 337 vm_paddr_t paddr; 338 { 339 if (!(m->flags & PG_FICTITIOUS)) 340 panic("dev_pager_updatefake: bad page"); 341 m->phys_addr = paddr; 342 } 343