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 1.26 1997/08/25 22:15:11 bde 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 48 #include <vm/vm.h> 49 #include <vm/vm_prot.h> 50 #include <vm/vm_object.h> 51 #include <vm/vm_page.h> 52 #include <vm/vm_pager.h> 53 54 static void dev_pager_init __P((void)); 55 static vm_object_t dev_pager_alloc __P((void *, vm_size_t, vm_prot_t, 56 vm_ooffset_t)); 57 static void dev_pager_dealloc __P((vm_object_t)); 58 static int dev_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 59 static int dev_pager_putpages __P((vm_object_t, vm_page_t *, int, 60 boolean_t, int *)); 61 static boolean_t dev_pager_haspage __P((vm_object_t, vm_pindex_t, int *, 62 int *)); 63 64 /* list of device pager objects */ 65 static struct pagerlst dev_pager_object_list; 66 67 /* list of available vm_page_t's */ 68 static TAILQ_HEAD(, vm_page) dev_pager_fakelist; 69 70 static vm_page_t dev_pager_getfake __P((vm_offset_t)); 71 static void dev_pager_putfake __P((vm_page_t)); 72 73 static int dev_pager_alloc_lock, dev_pager_alloc_lock_want; 74 75 struct pagerops devicepagerops = { 76 dev_pager_init, 77 dev_pager_alloc, 78 dev_pager_dealloc, 79 dev_pager_getpages, 80 dev_pager_putpages, 81 dev_pager_haspage, 82 NULL 83 }; 84 85 static void 86 dev_pager_init() 87 { 88 TAILQ_INIT(&dev_pager_object_list); 89 TAILQ_INIT(&dev_pager_fakelist); 90 } 91 92 static vm_object_t 93 dev_pager_alloc(void *handle, vm_size_t size, vm_prot_t prot, vm_ooffset_t foff) 94 { 95 dev_t dev; 96 d_mmap_t *mapfunc; 97 vm_object_t object; 98 unsigned int npages, off; 99 100 /* 101 * Make sure this device can be mapped. 102 */ 103 dev = (dev_t) (u_long) handle; 104 mapfunc = cdevsw[major(dev)]->d_mmap; 105 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 106 printf("obsolete map function %p\n", (void *)mapfunc); 107 return (NULL); 108 } 109 110 /* 111 * Offset should be page aligned. 112 */ 113 if (foff & PAGE_MASK) 114 return (NULL); 115 116 /* 117 * Check that the specified range of the device allows the desired 118 * protection. 119 * 120 * XXX assumes VM_PROT_* == PROT_* 121 */ 122 npages = size; 123 for (off = foff; npages--; off += PAGE_SIZE) 124 if ((*mapfunc) (dev, off, (int) prot) == -1) 125 return (NULL); 126 127 /* 128 * Lock to prevent object creation race contion. 129 */ 130 while (dev_pager_alloc_lock) { 131 dev_pager_alloc_lock_want++; 132 tsleep(&dev_pager_alloc_lock, PVM, "dvpall", 0); 133 dev_pager_alloc_lock_want--; 134 } 135 dev_pager_alloc_lock = 1; 136 137 /* 138 * Look up pager, creating as necessary. 139 */ 140 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 141 if (object == NULL) { 142 /* 143 * Allocate object and associate it with the pager. 144 */ 145 object = vm_object_allocate(OBJT_DEVICE, 146 OFF_TO_IDX(foff) + size); 147 object->handle = handle; 148 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 149 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 150 } else { 151 /* 152 * Gain a reference to the object. 153 */ 154 vm_object_reference(object); 155 if (OFF_TO_IDX(foff) + size > object->size) 156 object->size = OFF_TO_IDX(foff) + size; 157 } 158 159 dev_pager_alloc_lock = 0; 160 if (dev_pager_alloc_lock_want) 161 wakeup(&dev_pager_alloc_lock); 162 163 return (object); 164 } 165 166 static void 167 dev_pager_dealloc(object) 168 vm_object_t object; 169 { 170 vm_page_t m; 171 172 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 173 /* 174 * Free up our fake pages. 175 */ 176 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 177 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 178 dev_pager_putfake(m); 179 } 180 } 181 182 static int 183 dev_pager_getpages(object, m, count, reqpage) 184 vm_object_t object; 185 vm_page_t *m; 186 int count; 187 int reqpage; 188 { 189 vm_offset_t offset; 190 vm_offset_t paddr; 191 vm_page_t page; 192 dev_t dev; 193 int i, s; 194 d_mmap_t *mapfunc; 195 int prot; 196 197 dev = (dev_t) (u_long) object->handle; 198 offset = m[reqpage]->pindex + OFF_TO_IDX(object->paging_offset); 199 prot = PROT_READ; /* XXX should pass in? */ 200 mapfunc = cdevsw[major(dev)]->d_mmap; 201 202 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 203 panic("dev_pager_getpage: no map function"); 204 205 paddr = pmap_phys_address((*mapfunc) ((dev_t) dev, (int) offset << PAGE_SHIFT, prot)); 206 #ifdef DIAGNOSTIC 207 if (paddr == -1) 208 panic("dev_pager_getpage: map function returns error"); 209 #endif 210 /* 211 * Replace the passed in reqpage page with our own fake page and free up the 212 * all of the original pages. 213 */ 214 page = dev_pager_getfake(paddr); 215 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 216 for (i = 0; i < count; i++) { 217 PAGE_WAKEUP(m[i]); 218 vm_page_free(m[i]); 219 } 220 s = splhigh(); 221 vm_page_insert(page, object, offset); 222 splx(s); 223 224 return (VM_PAGER_OK); 225 } 226 227 static int 228 dev_pager_putpages(object, m, count, sync, rtvals) 229 vm_object_t object; 230 vm_page_t *m; 231 int count; 232 boolean_t sync; 233 int *rtvals; 234 { 235 panic("dev_pager_putpage called"); 236 } 237 238 static boolean_t 239 dev_pager_haspage(object, pindex, before, after) 240 vm_object_t object; 241 vm_pindex_t pindex; 242 int *before; 243 int *after; 244 { 245 if (before != NULL) 246 *before = 0; 247 if (after != NULL) 248 *after = 0; 249 return (TRUE); 250 } 251 252 static vm_page_t 253 dev_pager_getfake(paddr) 254 vm_offset_t paddr; 255 { 256 vm_page_t m; 257 int i; 258 259 if (TAILQ_FIRST(&dev_pager_fakelist) == NULL) { 260 m = (vm_page_t) malloc(PAGE_SIZE * 2, M_VMPGDATA, M_WAITOK); 261 for (i = (PAGE_SIZE * 2) / sizeof(*m); i > 0; i--) { 262 TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq); 263 m++; 264 } 265 } 266 m = TAILQ_FIRST(&dev_pager_fakelist); 267 TAILQ_REMOVE(&dev_pager_fakelist, m, pageq); 268 269 m->flags = PG_BUSY | PG_FICTITIOUS; 270 m->valid = VM_PAGE_BITS_ALL; 271 m->dirty = 0; 272 m->busy = 0; 273 m->queue = PQ_NONE; 274 275 m->wire_count = 1; 276 m->hold_count = 0; 277 m->phys_addr = paddr; 278 279 return (m); 280 } 281 282 static void 283 dev_pager_putfake(m) 284 vm_page_t m; 285 { 286 if (!(m->flags & PG_FICTITIOUS)) 287 panic("dev_pager_putfake: bad page"); 288 TAILQ_INSERT_TAIL(&dev_pager_fakelist, m, pageq); 289 } 290