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_paddr_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_paddr_t paddr; 111 vm_offset_t off; 112 113 /* 114 * Offset should be page aligned. 115 */ 116 if (foff & PAGE_MASK) 117 return (NULL); 118 119 size = round_page(size); 120 121 /* 122 * Make sure this device can be mapped. 123 */ 124 dev = handle; 125 mtx_lock(&Giant); 126 mapfunc = devsw(dev)->d_mmap; 127 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 128 printf("obsolete map function %p\n", (void *)mapfunc); 129 mtx_unlock(&Giant); 130 return (NULL); 131 } 132 133 /* 134 * Check that the specified range of the device allows the desired 135 * protection. 136 * 137 * XXX assumes VM_PROT_* == PROT_* 138 */ 139 npages = OFF_TO_IDX(size); 140 for (off = foff; npages--; off += PAGE_SIZE) 141 if ((*mapfunc)(dev, off, &paddr, (int)prot) != 0) { 142 mtx_unlock(&Giant); 143 return (NULL); 144 } 145 146 /* 147 * Lock to prevent object creation race condition. 148 */ 149 sx_xlock(&dev_pager_sx); 150 151 /* 152 * Look up pager, creating as necessary. 153 */ 154 object = vm_pager_object_lookup(&dev_pager_object_list, handle); 155 if (object == NULL) { 156 /* 157 * Allocate object and associate it with the pager. 158 */ 159 object = vm_object_allocate(OBJT_DEVICE, 160 OFF_TO_IDX(foff + size)); 161 object->handle = handle; 162 TAILQ_INIT(&object->un_pager.devp.devp_pglist); 163 mtx_lock(&dev_pager_mtx); 164 TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); 165 mtx_unlock(&dev_pager_mtx); 166 } else { 167 /* 168 * Gain a reference to the object. 169 */ 170 vm_object_reference(object); 171 if (OFF_TO_IDX(foff + size) > object->size) 172 object->size = OFF_TO_IDX(foff + size); 173 } 174 175 sx_xunlock(&dev_pager_sx); 176 mtx_unlock(&Giant); 177 return (object); 178 } 179 180 static void 181 dev_pager_dealloc(object) 182 vm_object_t object; 183 { 184 vm_page_t m; 185 186 mtx_lock(&dev_pager_mtx); 187 TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); 188 mtx_unlock(&dev_pager_mtx); 189 /* 190 * Free up our fake pages. 191 */ 192 while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { 193 TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); 194 dev_pager_putfake(m); 195 } 196 } 197 198 static int 199 dev_pager_getpages(object, m, count, reqpage) 200 vm_object_t object; 201 vm_page_t *m; 202 int count; 203 int reqpage; 204 { 205 vm_pindex_t offset; 206 vm_paddr_t paddr; 207 vm_page_t page; 208 dev_t dev; 209 int i, ret; 210 d_mmap_t *mapfunc; 211 int prot; 212 213 mtx_assert(&Giant, MA_OWNED); 214 dev = object->handle; 215 offset = m[reqpage]->pindex; 216 prot = PROT_READ; /* XXX should pass in? */ 217 mapfunc = devsw(dev)->d_mmap; 218 219 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) 220 panic("dev_pager_getpage: no map function"); 221 222 ret = (*mapfunc)(dev, (vm_offset_t)offset << PAGE_SHIFT, &paddr, prot); 223 KASSERT(ret == 0, ("dev_pager_getpage: map function returns error")); 224 /* 225 * Replace the passed in reqpage page with our own fake page and 226 * free up the all of the original pages. 227 */ 228 page = dev_pager_getfake(paddr); 229 TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); 230 vm_page_lock_queues(); 231 for (i = 0; i < count; i++) 232 vm_page_free(m[i]); 233 vm_page_unlock_queues(); 234 vm_page_insert(page, object, offset); 235 236 return (VM_PAGER_OK); 237 } 238 239 static void 240 dev_pager_putpages(object, m, count, sync, rtvals) 241 vm_object_t object; 242 vm_page_t *m; 243 int count; 244 boolean_t sync; 245 int *rtvals; 246 { 247 panic("dev_pager_putpage called"); 248 } 249 250 static boolean_t 251 dev_pager_haspage(object, pindex, before, after) 252 vm_object_t object; 253 vm_pindex_t pindex; 254 int *before; 255 int *after; 256 { 257 if (before != NULL) 258 *before = 0; 259 if (after != NULL) 260 *after = 0; 261 return (TRUE); 262 } 263 264 static vm_page_t 265 dev_pager_getfake(paddr) 266 vm_paddr_t paddr; 267 { 268 vm_page_t m; 269 270 m = uma_zalloc(fakepg_zone, M_WAITOK); 271 272 m->flags = PG_BUSY | PG_FICTITIOUS; 273 m->valid = VM_PAGE_BITS_ALL; 274 m->dirty = 0; 275 m->busy = 0; 276 m->queue = PQ_NONE; 277 m->object = NULL; 278 279 m->wire_count = 1; 280 m->hold_count = 0; 281 m->phys_addr = paddr; 282 283 return (m); 284 } 285 286 static void 287 dev_pager_putfake(m) 288 vm_page_t m; 289 { 290 if (!(m->flags & PG_FICTITIOUS)) 291 panic("dev_pager_putfake: bad page"); 292 uma_zfree(fakepg_zone, m); 293 } 294