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
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39 * $FreeBSD: head/sys/vm/device_pager.c 79224 2001-07-04 16:20:28Z dillon $
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39 * $FreeBSD: head/sys/vm/device_pager.c 92654 2002-03-19 09:11:49Z jeff $ |
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 57static void dev_pager_init __P((void)); 58static vm_object_t dev_pager_alloc __P((void *, vm_ooffset_t, vm_prot_t, 59 vm_ooffset_t)); 60static void dev_pager_dealloc __P((vm_object_t)); 61static int dev_pager_getpages __P((vm_object_t, vm_page_t *, int, int)); 62static void dev_pager_putpages __P((vm_object_t, vm_page_t *, int, 63 boolean_t, int *)); 64static boolean_t dev_pager_haspage __P((vm_object_t, vm_pindex_t, int *, 65 int *)); 66 67/* list of device pager objects */ 68static struct pagerlst dev_pager_object_list; 69/* protect against object creation */ 70static struct sx dev_pager_sx; 71/* protect list manipulation */ 72static struct mtx dev_pager_mtx; 73 74 75static vm_zone_t fakepg_zone;
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76#if 0 |
77static struct vm_zone fakepg_zone_store;
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78#endif |
79 80static vm_page_t dev_pager_getfake __P((vm_offset_t)); 81static void dev_pager_putfake __P((vm_page_t)); 82 83struct pagerops devicepagerops = { 84 dev_pager_init, 85 dev_pager_alloc, 86 dev_pager_dealloc, 87 dev_pager_getpages, 88 dev_pager_putpages, 89 dev_pager_haspage, 90 NULL 91}; 92 93static void 94dev_pager_init() 95{ 96 TAILQ_INIT(&dev_pager_object_list); 97 sx_init(&dev_pager_sx, "dev_pager create"); 98 mtx_init(&dev_pager_mtx, "dev_pager list", MTX_DEF);
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99#if 0 |
100 fakepg_zone = &fakepg_zone_store; 101 zinitna(fakepg_zone, NULL, "DP fakepg", sizeof(struct vm_page), 0, 0, 2);
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102#endif 103 fakepg_zone = zinit("DP fakepg", sizeof(struct vm_page), 0, 0, 0); |
104} 105 106static vm_object_t 107dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff) 108{ 109 dev_t dev; 110 d_mmap_t *mapfunc; 111 vm_object_t object; 112 unsigned int npages; 113 vm_offset_t off; 114 115 mtx_assert(&Giant, MA_OWNED); 116 /* 117 * Make sure this device can be mapped. 118 */ 119 dev = handle; 120 mapfunc = devsw(dev)->d_mmap; 121 if (mapfunc == NULL || mapfunc == (d_mmap_t *)nullop) { 122 printf("obsolete map function %p\n", (void *)mapfunc); 123 return (NULL); 124 } 125 126 /* 127 * Offset should be page aligned. 128 */ 129 if (foff & PAGE_MASK) 130 return (NULL); 131 132 size = round_page(size); 133 134 /* 135 * Check that the specified range of the device allows the desired 136 * protection. 137 * 138 * XXX assumes VM_PROT_* == PROT_* 139 */ 140 npages = OFF_TO_IDX(size); 141 for (off = foff; npages--; off += PAGE_SIZE) 142 if ((*mapfunc) (dev, off, (int) prot) == -1) 143 return (NULL); 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); 175 176 return (object); 177} 178 179static void 180dev_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 197static int 198dev_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_offset_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 237static void 238dev_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 248static boolean_t 249dev_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 262static vm_page_t 263dev_pager_getfake(paddr) 264 vm_offset_t paddr; 265{ 266 vm_page_t m; 267 268 m = zalloc(fakepg_zone); 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 284static void 285dev_pager_putfake(m) 286 vm_page_t m; 287{ 288 if (!(m->flags & PG_FICTITIOUS)) 289 panic("dev_pager_putfake: bad page"); 290 zfree(fakepg_zone, m); 291}
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