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 * $FreeBSD: src/sys/vm/device_pager.c,v 1.46.2.1 2000/08/02 21:54:37 peter Exp $ 40 * $DragonFly: src/sys/vm/device_pager.c,v 1.6 2003/11/03 17:11:23 dillon Exp $ 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/conf.h> 46 #include <sys/mman.h> 47 #include <sys/device.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/vm_zone.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); 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 68 static vm_zone_t fakepg_zone; 69 static struct vm_zone fakepg_zone_store; 70 71 static vm_page_t dev_pager_getfake (vm_paddr_t); 72 static void dev_pager_putfake (vm_page_t); 73 74 static int dev_pager_alloc_lock, dev_pager_alloc_lock_want; 75 76 struct pagerops devicepagerops = { 77 dev_pager_init, 78 dev_pager_alloc, 79 dev_pager_dealloc, 80 dev_pager_getpages, 81 dev_pager_putpages, 82 dev_pager_haspage, 83 NULL 84 }; 85 86 static void 87 dev_pager_init() 88 { 89 TAILQ_INIT(&dev_pager_object_list); 90 fakepg_zone = &fakepg_zone_store; 91 zinitna(fakepg_zone, NULL, "DP fakepg", sizeof(struct vm_page), 0, 0, 2); 92 } 93 94 static vm_object_t 95 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff) 96 { 97 dev_t dev; 98 vm_object_t object; 99 unsigned int npages; 100 vm_offset_t off; 101 102 /* 103 * Make sure this device can be mapped. 104 */ 105 dev = handle; 106 107 /* 108 * Offset should be page aligned. 109 */ 110 if (foff & PAGE_MASK) 111 return (NULL); 112 113 size = round_page(size); 114 115 /* 116 * Check that the specified range of the device allows the desired 117 * protection. 118 * 119 * XXX assumes VM_PROT_* == PROT_* 120 */ 121 npages = OFF_TO_IDX(size); 122 for (off = foff; npages--; off += PAGE_SIZE) { 123 if (dev_dmmap(dev, off, (int)prot) == -1) 124 return (NULL); 125 } 126 127 /* 128 * Lock to prevent object creation race condition. 129 */ 130 while (dev_pager_alloc_lock) { 131 dev_pager_alloc_lock_want++; 132 tsleep(&dev_pager_alloc_lock, 0, "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_paddr_t paddr; 191 vm_page_t page; 192 dev_t dev; 193 int i, s; 194 int prot; 195 196 dev = object->handle; 197 offset = m[reqpage]->pindex; 198 prot = PROT_READ; /* XXX should pass in? */ 199 200 paddr = pmap_phys_address(dev_dmmap(dev, (vm_offset_t) offset << PAGE_SHIFT, prot)); 201 KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); 202 /* 203 * Replace the passed in reqpage page with our own fake page and free up the 204 * all of the original pages. 205 */ 206 page = dev_pager_getfake(paddr); 207 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 208 for (i = 0; i < count; i++) { 209 vm_page_free(m[i]); 210 } 211 s = splhigh(); 212 vm_page_insert(page, object, offset); 213 splx(s); 214 215 return (VM_PAGER_OK); 216 } 217 218 static void 219 dev_pager_putpages(object, m, count, sync, rtvals) 220 vm_object_t object; 221 vm_page_t *m; 222 int count; 223 boolean_t sync; 224 int *rtvals; 225 { 226 panic("dev_pager_putpage called"); 227 } 228 229 static boolean_t 230 dev_pager_haspage(object, pindex, before, after) 231 vm_object_t object; 232 vm_pindex_t pindex; 233 int *before; 234 int *after; 235 { 236 if (before != NULL) 237 *before = 0; 238 if (after != NULL) 239 *after = 0; 240 return (TRUE); 241 } 242 243 static vm_page_t 244 dev_pager_getfake(paddr) 245 vm_paddr_t paddr; 246 { 247 vm_page_t m; 248 249 m = zalloc(fakepg_zone); 250 251 m->flags = PG_BUSY | PG_FICTITIOUS; 252 m->valid = VM_PAGE_BITS_ALL; 253 m->dirty = 0; 254 m->busy = 0; 255 m->queue = PQ_NONE; 256 m->object = NULL; 257 258 m->wire_count = 1; 259 m->hold_count = 0; 260 m->phys_addr = paddr; 261 262 return (m); 263 } 264 265 static void 266 dev_pager_putfake(m) 267 vm_page_t m; 268 { 269 if (!(m->flags & PG_FICTITIOUS)) 270 panic("dev_pager_putfake: bad page"); 271 zfree(fakepg_zone, m); 272 } 273