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 * $FreeBSD$ 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/conf.h> 45 #include <sys/lock.h> 46 #include <sys/mutex.h> 47 #include <sys/mman.h> 48 #include <sys/sx.h> 49 50 #include <vm/vm.h> 51 #include <vm/vm_object.h> 52 #include <vm/vm_page.h> 53 #include <vm/vm_pager.h> 54 #include <vm/vm_zone.h> 55 56 static void dev_pager_init __P((void)); 57 static vm_object_t dev_pager_alloc __P((void *, vm_ooffset_t, vm_prot_t, 58 vm_ooffset_t)); 59 static void dev_pager_dealloc __P((vm_object_t)); 60 static int dev_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 61 static void dev_pager_putpages __P((vm_object_t, vm_page_t *, int, 62 boolean_t, int *)); 63 static boolean_t dev_pager_haspage __P((vm_object_t, vm_pindex_t, int *, 64 int *)); 65 66 /* list of device pager objects */ 67 static struct pagerlst dev_pager_object_list; 68 /* protect against object creation */ 69 static struct sx dev_pager_sx; 70 /* protect list manipulation */ 71 static struct mtx dev_pager_mtx; 72 73 74 static vm_zone_t fakepg_zone; 75 static struct vm_zone fakepg_zone_store; 76 77 static vm_page_t dev_pager_getfake __P((vm_offset_t)); 78 static void dev_pager_putfake __P((vm_page_t)); 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 sx_init(&dev_pager_sx, "dev_pager create"); 95 mtx_init(&dev_pager_mtx, "dev_pager list", MTX_DEF); 96 fakepg_zone = &fakepg_zone_store; 97 zinitna(fakepg_zone, NULL, "DP fakepg", sizeof(struct vm_page), 0, 0, 2); 98 } 99 100 static vm_object_t 101 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff) 102 { 103 dev_t dev; 104 d_mmap_t *mapfunc; 105 vm_object_t object; 106 unsigned int npages; 107 vm_offset_t off; 108 109 /* 110 * Make sure this device can be mapped. 111 */ 112 dev = handle; 113 mapfunc = devsw(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 size = round_page(size); 126 127 /* 128 * Check that the specified range of the device allows the desired 129 * protection. 130 * 131 * XXX assumes VM_PROT_* == PROT_* 132 */ 133 npages = OFF_TO_IDX(size); 134 for (off = foff; npages--; off += PAGE_SIZE) 135 if ((*mapfunc) (dev, off, (int) prot) == -1) 136 return (NULL); 137 138 /* 139 * Lock to prevent object creation race condition. 140 */ 141 sx_xlock(&dev_pager_sx); 142 143 /* 144 * Look up pager, creating as necessary. 145 */ 146 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 147 if (object == NULL) { 148 /* 149 * Allocate object and associate it with the pager. 150 */ 151 object = vm_object_allocate(OBJT_DEVICE, 152 OFF_TO_IDX(foff + size)); 153 object->handle = handle; 154 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 155 mtx_lock(&dev_pager_mtx); 156 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 157 mtx_unlock(&dev_pager_mtx); 158 } else { 159 /* 160 * Gain a reference to the object. 161 */ 162 vm_object_reference(object); 163 if (OFF_TO_IDX(foff + size) > object->size) 164 object->size = OFF_TO_IDX(foff + size); 165 } 166 167 sx_xunlock(&dev_pager_sx); 168 169 return (object); 170 } 171 172 static void 173 dev_pager_dealloc(object) 174 vm_object_t object; 175 { 176 vm_page_t m; 177 178 mtx_lock(&dev_pager_mtx); 179 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 180 mtx_unlock(&dev_pager_mtx); 181 /* 182 * Free up our fake pages. 183 */ 184 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 185 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 186 dev_pager_putfake(m); 187 } 188 } 189 190 static int 191 dev_pager_getpages(object, m, count, reqpage) 192 vm_object_t object; 193 vm_page_t *m; 194 int count; 195 int reqpage; 196 { 197 vm_offset_t offset; 198 vm_offset_t paddr; 199 vm_page_t page; 200 dev_t dev; 201 int i, s; 202 d_mmap_t *mapfunc; 203 int prot; 204 205 dev = object->handle; 206 offset = m[reqpage]->pindex; 207 prot = PROT_READ; /* XXX should pass in? */ 208 mapfunc = devsw(dev)->d_mmap; 209 210 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 211 panic("dev_pager_getpage: no map function"); 212 213 paddr = pmap_phys_address((*mapfunc) (dev, (vm_offset_t) offset << PAGE_SHIFT, prot)); 214 KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); 215 /* 216 * Replace the passed in reqpage page with our own fake page and free up the 217 * all of the original pages. 218 */ 219 page = dev_pager_getfake(paddr); 220 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 221 for (i = 0; i < count; i++) { 222 vm_page_free(m[i]); 223 } 224 s = splhigh(); 225 vm_page_insert(page, object, offset); 226 splx(s); 227 228 return (VM_PAGER_OK); 229 } 230 231 static void 232 dev_pager_putpages(object, m, count, sync, rtvals) 233 vm_object_t object; 234 vm_page_t *m; 235 int count; 236 boolean_t sync; 237 int *rtvals; 238 { 239 panic("dev_pager_putpage called"); 240 } 241 242 static boolean_t 243 dev_pager_haspage(object, pindex, before, after) 244 vm_object_t object; 245 vm_pindex_t pindex; 246 int *before; 247 int *after; 248 { 249 if (before != NULL) 250 *before = 0; 251 if (after != NULL) 252 *after = 0; 253 return (TRUE); 254 } 255 256 static vm_page_t 257 dev_pager_getfake(paddr) 258 vm_offset_t paddr; 259 { 260 vm_page_t m; 261 262 m = zalloc(fakepg_zone); 263 264 m->flags = PG_BUSY | PG_FICTITIOUS; 265 m->valid = VM_PAGE_BITS_ALL; 266 m->dirty = 0; 267 m->busy = 0; 268 m->queue = PQ_NONE; 269 m->object = NULL; 270 271 m->wire_count = 1; 272 m->hold_count = 0; 273 m->phys_addr = paddr; 274 275 return (m); 276 } 277 278 static void 279 dev_pager_putfake(m) 280 vm_page_t m; 281 { 282 if (!(m->flags & PG_FICTITIOUS)) 283 panic("dev_pager_putfake: bad page"); 284 zfree(fakepg_zone, m); 285 } 286