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/uma.h> 56 57 static void dev_pager_init(void); 58 static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t, 59 vm_ooffset_t); 60 static void dev_pager_dealloc(vm_object_t); 61 static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int); 62 static void dev_pager_putpages(vm_object_t, vm_page_t *, int, 63 boolean_t, int *); 64 static boolean_t dev_pager_haspage(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 uma_zone_t fakepg_zone; 76 77 static vm_page_t dev_pager_getfake(vm_offset_t); 78 static void dev_pager_putfake(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", NULL, MTX_DEF); 96 fakepg_zone = uma_zcreate("DP fakepg", sizeof(struct vm_page), 97 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 98 } 99 100 /* 101 * MPSAFE 102 */ 103 static vm_object_t 104 dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff) 105 { 106 dev_t dev; 107 d_mmap_t *mapfunc; 108 vm_object_t object; 109 unsigned int npages; 110 vm_offset_t off; 111 112 /* 113 * Offset should be page aligned. 114 */ 115 if (foff & PAGE_MASK) 116 return (NULL); 117 118 size = round_page(size); 119 120 /* 121 * Make sure this device can be mapped. 122 */ 123 dev = handle; 124 mtx_lock(&Giant); 125 mapfunc = devsw(dev)->d_mmap; 126 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 127 printf("obsolete map function %p\n", (void *)mapfunc); 128 mtx_unlock(&Giant); 129 return (NULL); 130 } 131 132 /* 133 * Check that the specified range of the device allows the desired 134 * protection. 135 * 136 * XXX assumes VM_PROT_* == PROT_* 137 */ 138 npages = OFF_TO_IDX(size); 139 for (off = foff; npages--; off += PAGE_SIZE) 140 if ((*mapfunc)(dev, off, (int) prot) == -1) { 141 mtx_unlock(&Giant); 142 return (NULL); 143 } 144 145 /* 146 * Lock to prevent object creation race condition. 147 */ 148 sx_xlock(&dev_pager_sx); 149 150 /* 151 * Look up pager, creating as necessary. 152 */ 153 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 154 if (object == NULL) { 155 /* 156 * Allocate object and associate it with the pager. 157 */ 158 object = vm_object_allocate(OBJT_DEVICE, 159 OFF_TO_IDX(foff + size)); 160 object->handle = handle; 161 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 162 mtx_lock(&dev_pager_mtx); 163 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 164 mtx_unlock(&dev_pager_mtx); 165 } else { 166 /* 167 * Gain a reference to the object. 168 */ 169 vm_object_reference(object); 170 if (OFF_TO_IDX(foff + size) > object->size) 171 object->size = OFF_TO_IDX(foff + size); 172 } 173 174 sx_xunlock(&dev_pager_sx); 175 mtx_unlock(&Giant); 176 return (object); 177 } 178 179 static void 180 dev_pager_dealloc(object) 181 vm_object_t object; 182 { 183 vm_page_t m; 184 185 mtx_lock(&dev_pager_mtx); 186 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 187 mtx_unlock(&dev_pager_mtx); 188 /* 189 * Free up our fake pages. 190 */ 191 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 192 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 193 dev_pager_putfake(m); 194 } 195 } 196 197 static int 198 dev_pager_getpages(object, m, count, reqpage) 199 vm_object_t object; 200 vm_page_t *m; 201 int count; 202 int reqpage; 203 { 204 vm_pindex_t offset; 205 vm_offset_t paddr; 206 vm_page_t page; 207 dev_t dev; 208 int i; 209 d_mmap_t *mapfunc; 210 int prot; 211 212 mtx_assert(&Giant, MA_OWNED); 213 dev = object->handle; 214 offset = m[reqpage]->pindex; 215 prot = PROT_READ; /* XXX should pass in? */ 216 mapfunc = devsw(dev)->d_mmap; 217 218 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 219 panic("dev_pager_getpage: no map function"); 220 221 paddr = pmap_phys_address((*mapfunc) (dev, (vm_offset_t) offset << PAGE_SHIFT, prot)); 222 KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); 223 /* 224 * Replace the passed in reqpage page with our own fake page and free up the 225 * all of the original pages. 226 */ 227 page = dev_pager_getfake(paddr); 228 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 229 for (i = 0; i < count; i++) { 230 vm_page_free(m[i]); 231 } 232 vm_page_insert(page, object, offset); 233 234 return (VM_PAGER_OK); 235 } 236 237 static void 238 dev_pager_putpages(object, m, count, sync, rtvals) 239 vm_object_t object; 240 vm_page_t *m; 241 int count; 242 boolean_t sync; 243 int *rtvals; 244 { 245 panic("dev_pager_putpage called"); 246 } 247 248 static boolean_t 249 dev_pager_haspage(object, pindex, before, after) 250 vm_object_t object; 251 vm_pindex_t pindex; 252 int *before; 253 int *after; 254 { 255 if (before != NULL) 256 *before = 0; 257 if (after != NULL) 258 *after = 0; 259 return (TRUE); 260 } 261 262 static vm_page_t 263 dev_pager_getfake(paddr) 264 vm_offset_t paddr; 265 { 266 vm_page_t m; 267 268 m = uma_zalloc(fakepg_zone, M_WAITOK); 269 270 m->flags = PG_BUSY | PG_FICTITIOUS; 271 m->valid = VM_PAGE_BITS_ALL; 272 m->dirty = 0; 273 m->busy = 0; 274 m->queue = PQ_NONE; 275 m->object = NULL; 276 277 m->wire_count = 1; 278 m->hold_count = 0; 279 m->phys_addr = paddr; 280 281 return (m); 282 } 283 284 static void 285 dev_pager_putfake(m) 286 vm_page_t m; 287 { 288 if (!(m->flags & PG_FICTITIOUS)) 289 panic("dev_pager_putfake: bad page"); 290 uma_zfree(fakepg_zone, m); 291 } 292