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/proc.h> 47 #include <sys/mutex.h> 48 #include <sys/mman.h> 49 #include <sys/sx.h> 50 51 #include <vm/vm.h> 52 #include <vm/vm_object.h> 53 #include <vm/vm_page.h> 54 #include <vm/vm_pager.h> 55 #include <vm/vm_zone.h> 56 57 static void dev_pager_init __P((void)); 58 static vm_object_t dev_pager_alloc __P((void *, vm_ooffset_t, vm_prot_t, 59 vm_ooffset_t)); 60 static void dev_pager_dealloc __P((vm_object_t)); 61 static int dev_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 62 static void dev_pager_putpages __P((vm_object_t, vm_page_t *, int, 63 boolean_t, int *)); 64 static boolean_t dev_pager_haspage __P((vm_object_t, vm_pindex_t, int *, 65 int *)); 66 67 /* list of device pager objects */ 68 static struct pagerlst dev_pager_object_list; 69 /* protect against object creation */ 70 static struct sx dev_pager_sx; 71 /* protect list manipulation */ 72 static struct mtx dev_pager_mtx; 73 74 75 static vm_zone_t fakepg_zone; 76 static struct vm_zone fakepg_zone_store; 77 78 static vm_page_t dev_pager_getfake __P((vm_offset_t)); 79 static void dev_pager_putfake __P((vm_page_t)); 80 81 struct pagerops devicepagerops = { 82 dev_pager_init, 83 dev_pager_alloc, 84 dev_pager_dealloc, 85 dev_pager_getpages, 86 dev_pager_putpages, 87 dev_pager_haspage, 88 NULL 89 }; 90 91 static void 92 dev_pager_init() 93 { 94 TAILQ_INIT(&dev_pager_object_list); 95 sx_init(&dev_pager_sx, "dev_pager create"); 96 mtx_init(&dev_pager_mtx, "dev_pager list", MTX_DEF); 97 fakepg_zone = &fakepg_zone_store; 98 zinitna(fakepg_zone, NULL, "DP fakepg", sizeof(struct vm_page), 0, 0, 2); 99 } 100 101 static vm_object_t 102 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff) 103 { 104 dev_t dev; 105 d_mmap_t *mapfunc; 106 vm_object_t object; 107 unsigned int npages; 108 vm_offset_t off; 109 110 mtx_assert(&Giant, MA_OWNED); 111 /* 112 * Make sure this device can be mapped. 113 */ 114 dev = handle; 115 mapfunc = devsw(dev)->d_mmap; 116 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 117 printf("obsolete map function %p\n", (void *)mapfunc); 118 return (NULL); 119 } 120 121 /* 122 * Offset should be page aligned. 123 */ 124 if (foff & PAGE_MASK) 125 return (NULL); 126 127 size = round_page(size); 128 129 /* 130 * Check that the specified range of the device allows the desired 131 * protection. 132 * 133 * XXX assumes VM_PROT_* == PROT_* 134 */ 135 npages = OFF_TO_IDX(size); 136 for (off = foff; npages--; off += PAGE_SIZE) 137 if ((*mapfunc) (dev, off, (int) prot) == -1) 138 return (NULL); 139 140 /* 141 * Lock to prevent object creation race condition. 142 */ 143 sx_xlock(&dev_pager_sx); 144 145 /* 146 * Look up pager, creating as necessary. 147 */ 148 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 149 if (object == NULL) { 150 /* 151 * Allocate object and associate it with the pager. 152 */ 153 object = vm_object_allocate(OBJT_DEVICE, 154 OFF_TO_IDX(foff + size)); 155 object->handle = handle; 156 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 157 mtx_lock(&dev_pager_mtx); 158 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 159 mtx_unlock(&dev_pager_mtx); 160 } else { 161 /* 162 * Gain a reference to the object. 163 */ 164 vm_object_reference(object); 165 if (OFF_TO_IDX(foff + size) > object->size) 166 object->size = OFF_TO_IDX(foff + size); 167 } 168 169 sx_xunlock(&dev_pager_sx); 170 171 return (object); 172 } 173 174 static void 175 dev_pager_dealloc(object) 176 vm_object_t object; 177 { 178 vm_page_t m; 179 180 mtx_lock(&dev_pager_mtx); 181 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 182 mtx_unlock(&dev_pager_mtx); 183 /* 184 * Free up our fake pages. 185 */ 186 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 187 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 188 dev_pager_putfake(m); 189 } 190 } 191 192 static int 193 dev_pager_getpages(object, m, count, reqpage) 194 vm_object_t object; 195 vm_page_t *m; 196 int count; 197 int reqpage; 198 { 199 vm_offset_t offset; 200 vm_offset_t paddr; 201 vm_page_t page; 202 dev_t dev; 203 int i; 204 d_mmap_t *mapfunc; 205 int prot; 206 207 mtx_assert(&Giant, MA_OWNED); 208 dev = object->handle; 209 offset = m[reqpage]->pindex; 210 prot = PROT_READ; /* XXX should pass in? */ 211 mapfunc = devsw(dev)->d_mmap; 212 213 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 214 panic("dev_pager_getpage: no map function"); 215 216 paddr = pmap_phys_address((*mapfunc) (dev, (vm_offset_t) offset << PAGE_SHIFT, prot)); 217 KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); 218 /* 219 * Replace the passed in reqpage page with our own fake page and free up the 220 * all of the original pages. 221 */ 222 page = dev_pager_getfake(paddr); 223 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 224 for (i = 0; i < count; i++) { 225 vm_page_free(m[i]); 226 } 227 vm_page_insert(page, object, offset); 228 229 return (VM_PAGER_OK); 230 } 231 232 static void 233 dev_pager_putpages(object, m, count, sync, rtvals) 234 vm_object_t object; 235 vm_page_t *m; 236 int count; 237 boolean_t sync; 238 int *rtvals; 239 { 240 panic("dev_pager_putpage called"); 241 } 242 243 static boolean_t 244 dev_pager_haspage(object, pindex, before, after) 245 vm_object_t object; 246 vm_pindex_t pindex; 247 int *before; 248 int *after; 249 { 250 if (before != NULL) 251 *before = 0; 252 if (after != NULL) 253 *after = 0; 254 return (TRUE); 255 } 256 257 static vm_page_t 258 dev_pager_getfake(paddr) 259 vm_offset_t paddr; 260 { 261 vm_page_t m; 262 263 m = zalloc(fakepg_zone); 264 265 m->flags = PG_BUSY | PG_FICTITIOUS; 266 m->valid = VM_PAGE_BITS_ALL; 267 m->dirty = 0; 268 m->busy = 0; 269 m->queue = PQ_NONE; 270 m->object = NULL; 271 272 m->wire_count = 1; 273 m->hold_count = 0; 274 m->phys_addr = paddr; 275 276 return (m); 277 } 278 279 static void 280 dev_pager_putfake(m) 281 vm_page_t m; 282 { 283 if (!(m->flags & PG_FICTITIOUS)) 284 panic("dev_pager_putfake: bad page"); 285 zfree(fakepg_zone, m); 286 } 287