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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)device_pager.c 8.1 (Berkeley) 6/11/93 39 * $Id: device_pager.c,v 1.22 1996/05/03 21:01:45 phk Exp $ 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/conf.h> 45 #include <sys/mman.h> 46 #include <sys/malloc.h> 47 #include <sys/proc.h> 48 #include <sys/queue.h> 49 50 #include <vm/vm.h> 51 #include <vm/vm_param.h> 52 #include <vm/vm_prot.h> 53 #include <vm/vm_kern.h> 54 #include <vm/vm_object.h> 55 #include <vm/vm_page.h> 56 #include <vm/vm_pager.h> 57 #include <vm/device_pager.h> 58 59 static void dev_pager_init __P((void)); 60 static vm_object_t dev_pager_alloc __P((void *, vm_size_t, vm_prot_t, 61 vm_ooffset_t)); 62 static void dev_pager_dealloc __P((vm_object_t)); 63 static int dev_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 64 static int dev_pager_putpages __P((vm_object_t, vm_page_t *, int, 65 boolean_t, int *)); 66 static boolean_t dev_pager_haspage __P((vm_object_t, vm_pindex_t, int *, 67 int *)); 68 69 /* list of device pager objects */ 70 static struct pagerlst dev_pager_object_list; 71 72 /* list of available vm_page_t's */ 73 static TAILQ_HEAD(, vm_page) dev_pager_fakelist; 74 75 static vm_page_t dev_pager_getfake __P((vm_offset_t)); 76 static void dev_pager_putfake __P((vm_page_t)); 77 78 static int dev_pager_alloc_lock, dev_pager_alloc_lock_want; 79 80 struct pagerops devicepagerops = { 81 dev_pager_init, 82 dev_pager_alloc, 83 dev_pager_dealloc, 84 dev_pager_getpages, 85 dev_pager_putpages, 86 dev_pager_haspage, 87 NULL 88 }; 89 90 static void 91 dev_pager_init() 92 { 93 TAILQ_INIT(&dev_pager_object_list); 94 TAILQ_INIT(&dev_pager_fakelist); 95 } 96 97 static vm_object_t 98 dev_pager_alloc(handle, size, prot, foff) 99 void *handle; 100 vm_size_t size; 101 vm_prot_t prot; 102 vm_ooffset_t foff; 103 { 104 dev_t dev; 105 d_mmap_t *mapfunc; 106 vm_object_t object; 107 unsigned int npages, off; 108 109 /* 110 * Make sure this device can be mapped. 111 */ 112 dev = (dev_t) (u_long) handle; 113 mapfunc = cdevsw[major(dev)]->d_mmap; 114 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 115 printf("obsolete map function %p\n", (void *)mapfunc); 116 return (NULL); 117 } 118 119 /* 120 * Offset should be page aligned. 121 */ 122 if (foff & PAGE_MASK) 123 return (NULL); 124 125 /* 126 * Check that the specified range of the device allows the desired 127 * protection. 128 * 129 * XXX assumes VM_PROT_* == PROT_* 130 */ 131 npages = size; 132 for (off = foff; npages--; off += PAGE_SIZE) 133 if ((*mapfunc) (dev, off, (int) prot) == -1) 134 return (NULL); 135 136 /* 137 * Lock to prevent object creation race contion. 138 */ 139 while (dev_pager_alloc_lock) { 140 dev_pager_alloc_lock_want++; 141 tsleep(&dev_pager_alloc_lock, PVM, "dvpall", 0); 142 dev_pager_alloc_lock_want--; 143 } 144 dev_pager_alloc_lock = 1; 145 146 /* 147 * Look up pager, creating as necessary. 148 */ 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. 153 */ 154 object = vm_object_allocate(OBJT_DEVICE, 155 OFF_TO_IDX(foff) + size); 156 object->handle = handle; 157 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 158 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 159 } else { 160 /* 161 * Gain a reference to the object. 162 */ 163 vm_object_reference(object); 164 if (OFF_TO_IDX(foff) + size > object->size) 165 object->size = OFF_TO_IDX(foff) + size; 166 } 167 168 dev_pager_alloc_lock = 0; 169 if (dev_pager_alloc_lock_want) 170 wakeup(&dev_pager_alloc_lock); 171 172 return (object); 173 } 174 175 static void 176 dev_pager_dealloc(object) 177 vm_object_t object; 178 { 179 vm_page_t m; 180 181 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 182 /* 183 * Free up our fake pages. 184 */ 185 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 186 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 187 dev_pager_putfake(m); 188 } 189 } 190 191 static int 192 dev_pager_getpages(object, m, count, reqpage) 193 vm_object_t object; 194 vm_page_t *m; 195 int count; 196 int reqpage; 197 { 198 vm_offset_t offset; 199 vm_offset_t paddr; 200 vm_page_t page; 201 dev_t dev; 202 int i, s; 203 d_mmap_t *mapfunc; 204 int prot; 205 206 dev = (dev_t) (u_long) object->handle; 207 offset = m[reqpage]->pindex + OFF_TO_IDX(object->paging_offset); 208 prot = PROT_READ; /* XXX should pass in? */ 209 mapfunc = cdevsw[major(dev)]->d_mmap; 210 211 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 212 panic("dev_pager_getpage: no map function"); 213 214 paddr = pmap_phys_address((*mapfunc) ((dev_t) dev, (int) offset << PAGE_SHIFT, prot)); 215 #ifdef DIAGNOSTIC 216 if (paddr == -1) 217 panic("dev_pager_getpage: map function returns error"); 218 #endif 219 /* 220 * Replace the passed in reqpage page with our own fake page and free up the 221 * all of the original pages. 222 */ 223 page = dev_pager_getfake(paddr); 224 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 225 for (i = 0; i < count; i++) { 226 PAGE_WAKEUP(m[i]); 227 vm_page_free(m[i]); 228 } 229 s = splhigh(); 230 vm_page_insert(page, object, offset); 231 splx(s); 232 233 return (VM_PAGER_OK); 234 } 235 236 static int 237 dev_pager_putpages(object, m, count, sync, rtvals) 238 vm_object_t object; 239 vm_page_t *m; 240 int count; 241 boolean_t sync; 242 int *rtvals; 243 { 244 panic("dev_pager_putpage called"); 245 } 246 247 static boolean_t 248 dev_pager_haspage(object, pindex, before, after) 249 vm_object_t object; 250 vm_pindex_t pindex; 251 int *before; 252 int *after; 253 { 254 if (before != NULL) 255 *before = 0; 256 if (after != NULL) 257 *after = 0; 258 return (TRUE); 259 } 260 261 static vm_page_t 262 dev_pager_getfake(paddr) 263 vm_offset_t paddr; 264 { 265 vm_page_t m; 266 int i; 267 268 if (TAILQ_FIRST(&dev_pager_fakelist) == NULL) { 269 m = (vm_page_t) malloc(PAGE_SIZE * 2, M_VMPGDATA, M_WAITOK); 270 for (i = (PAGE_SIZE * 2) / sizeof(*m); i > 0; i--) { 271 TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq); 272 m++; 273 } 274 } 275 m = TAILQ_FIRST(&dev_pager_fakelist); 276 TAILQ_REMOVE(&dev_pager_fakelist, m, pageq); 277 278 m->flags = PG_BUSY | PG_FICTITIOUS; 279 m->valid = VM_PAGE_BITS_ALL; 280 m->dirty = 0; 281 m->busy = 0; 282 m->queue = PQ_NONE; 283 284 m->wire_count = 1; 285 m->hold_count = 0; 286 m->phys_addr = paddr; 287 288 return (m); 289 } 290 291 static void 292 dev_pager_putfake(m) 293 vm_page_t m; 294 { 295 if (!(m->flags & PG_FICTITIOUS)) 296 panic("dev_pager_putfake: bad page"); 297 TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq); 298 } 299