| 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: src/sys/vm/device_pager.c,v 1.46.2.1 2000/08/02 21:54:37 peter Exp $ |
| 40 | * $DragonFly: src/sys/vm/device_pager.c,v 1.11 2006/09/10 01:26:41 dillon Exp $ |
| 41 | */ |
| 42 | |
| 43 | #include <sys/param.h> |
| 44 | #include <sys/systm.h> |
| 45 | #include <sys/conf.h> |
| 46 | #include <sys/mman.h> |
| 47 | #include <sys/device.h> |
| 48 | #include <sys/thread2.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 (void); |
| 57 | static vm_object_t dev_pager_alloc (void *, off_t, vm_prot_t, off_t); |
| 58 | static void dev_pager_dealloc (vm_object_t); |
| 59 | static int dev_pager_getpages (vm_object_t, vm_page_t *, int, int); |
| 60 | static void dev_pager_putpages (vm_object_t, vm_page_t *, int, |
| 61 | boolean_t, int *); |
| 62 | static boolean_t dev_pager_haspage (vm_object_t, vm_pindex_t, int *, |
| 63 | int *); |
| 64 | |
| 65 | /* list of device pager objects */ |
| 66 | static struct pagerlst dev_pager_object_list; |
| 67 | |
| 68 | static vm_zone_t fakepg_zone; |
| 69 | static struct vm_zone fakepg_zone_store; |
| 70 | |
| 71 | static vm_page_t dev_pager_getfake (vm_paddr_t); |
| 72 | static void dev_pager_putfake (vm_page_t); |
| 73 | |
| 74 | static int dev_pager_alloc_lock, dev_pager_alloc_lock_want; |
| 75 | |
| 76 | struct pagerops devicepagerops = { |
| 77 | dev_pager_init, |
| 78 | dev_pager_alloc, |
| 79 | dev_pager_dealloc, |
| 80 | dev_pager_getpages, |
| 81 | dev_pager_putpages, |
| 82 | dev_pager_haspage, |
| 83 | NULL |
| 84 | }; |
| 85 | |
| 86 | static void |
| 87 | dev_pager_init(void) |
| 88 | { |
| 89 | TAILQ_INIT(&dev_pager_object_list); |
| 90 | fakepg_zone = &fakepg_zone_store; |
| 91 | zinitna(fakepg_zone, NULL, "DP fakepg", sizeof(struct vm_page), 0, 0, 2); |
| 92 | } |
| 93 | |
| 94 | static vm_object_t |
| 95 | dev_pager_alloc(void *handle, off_t size, vm_prot_t prot, off_t foff) |
| 96 | { |
| 97 | cdev_t dev; |
| 98 | vm_object_t object; |
| 99 | unsigned int npages; |
| 100 | vm_offset_t off; |
| 101 | |
| 102 | /* |
| 103 | * Make sure this device can be mapped. |
| 104 | */ |
| 105 | dev = handle; |
| 106 | |
| 107 | /* |
| 108 | * Offset should be page aligned. |
| 109 | */ |
| 110 | if (foff & PAGE_MASK) |
| 111 | return (NULL); |
| 112 | |
| 113 | size = round_page(size); |
| 114 | |
| 115 | /* |
| 116 | * Check that the specified range of the device allows the desired |
| 117 | * protection. |
| 118 | * |
| 119 | * XXX assumes VM_PROT_* == PROT_* |
| 120 | */ |
| 121 | npages = OFF_TO_IDX(size); |
| 122 | for (off = foff; npages--; off += PAGE_SIZE) { |
| 123 | if (dev_dmmap(dev, off, (int)prot) == -1) |
| 124 | return (NULL); |
| 125 | } |
| 126 | |
| 127 | /* |
| 128 | * Lock to prevent object creation race condition. |
| 129 | */ |
| 130 | while (dev_pager_alloc_lock) { |
| 131 | dev_pager_alloc_lock_want++; |
| 132 | tsleep(&dev_pager_alloc_lock, 0, "dvpall", 0); |
| 133 | dev_pager_alloc_lock_want--; |
| 134 | } |
| 135 | dev_pager_alloc_lock = 1; |
| 136 | |
| 137 | /* |
| 138 | * Look up pager, creating as necessary. |
| 139 | */ |
| 140 | object = vm_pager_object_lookup(&dev_pager_object_list, handle); |
| 141 | if (object == NULL) { |
| 142 | /* |
| 143 | * Allocate object and associate it with the pager. |
| 144 | */ |
| 145 | object = vm_object_allocate(OBJT_DEVICE, |
| 146 | OFF_TO_IDX(foff + size)); |
| 147 | object->handle = handle; |
| 148 | TAILQ_INIT(&object->un_pager.devp.devp_pglist); |
| 149 | TAILQ_INSERT_TAIL(&dev_pager_object_list, object, pager_object_list); |
| 150 | } else { |
| 151 | /* |
| 152 | * Gain a reference to the object. |
| 153 | */ |
| 154 | vm_object_reference(object); |
| 155 | if (OFF_TO_IDX(foff + size) > object->size) |
| 156 | object->size = OFF_TO_IDX(foff + size); |
| 157 | } |
| 158 | |
| 159 | dev_pager_alloc_lock = 0; |
| 160 | if (dev_pager_alloc_lock_want) |
| 161 | wakeup(&dev_pager_alloc_lock); |
| 162 | |
| 163 | return (object); |
| 164 | } |
| 165 | |
| 166 | static void |
| 167 | dev_pager_dealloc(vm_object_t object) |
| 168 | { |
| 169 | vm_page_t m; |
| 170 | |
| 171 | TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list); |
| 172 | /* |
| 173 | * Free up our fake pages. |
| 174 | */ |
| 175 | while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist)) != 0) { |
| 176 | TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq); |
| 177 | dev_pager_putfake(m); |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | static int |
| 182 | dev_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage) |
| 183 | { |
| 184 | vm_offset_t offset; |
| 185 | vm_paddr_t paddr; |
| 186 | vm_page_t page; |
| 187 | cdev_t dev; |
| 188 | int prot; |
| 189 | int i; |
| 190 | |
| 191 | dev = object->handle; |
| 192 | offset = m[reqpage]->pindex; |
| 193 | prot = PROT_READ; /* XXX should pass in? */ |
| 194 | |
| 195 | paddr = pmap_phys_address(dev_dmmap(dev, (vm_offset_t) offset << PAGE_SHIFT, prot)); |
| 196 | KASSERT(paddr != -1,("dev_pager_getpage: map function returns error")); |
| 197 | |
| 198 | if (m[reqpage]->flags & PG_FICTITIOUS) { |
| 199 | /* |
| 200 | * If the passed in reqpage page is a fake page, update it |
| 201 | * with the new physical address. |
| 202 | */ |
| 203 | m[reqpage]->phys_addr = paddr; |
| 204 | } else { |
| 205 | /* |
| 206 | * Replace the passed in reqpage page with our own fake page |
| 207 | * and free up all the original pages. |
| 208 | */ |
| 209 | page = dev_pager_getfake(paddr); |
| 210 | TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq); |
| 211 | crit_enter(); |
| 212 | vm_page_free(m[reqpage]); |
| 213 | vm_page_insert(page, object, offset); |
| 214 | crit_exit(); |
| 215 | } |
| 216 | for (i = 0; i < count; i++) { |
| 217 | if (i != reqpage) |
| 218 | vm_page_free(m[i]); |
| 219 | } |
| 220 | return (VM_PAGER_OK); |
| 221 | } |
| 222 | |
| 223 | static void |
| 224 | dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync, |
| 225 | int *rtvals) |
| 226 | { |
| 227 | panic("dev_pager_putpage called"); |
| 228 | } |
| 229 | |
| 230 | static boolean_t |
| 231 | dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, |
| 232 | int *after) |
| 233 | { |
| 234 | if (before != NULL) |
| 235 | *before = 0; |
| 236 | if (after != NULL) |
| 237 | *after = 0; |
| 238 | return (TRUE); |
| 239 | } |
| 240 | |
| 241 | static vm_page_t |
| 242 | dev_pager_getfake(vm_paddr_t paddr) |
| 243 | { |
| 244 | vm_page_t m; |
| 245 | |
| 246 | m = zalloc(fakepg_zone); |
| 247 | |
| 248 | m->flags = PG_BUSY | PG_FICTITIOUS; |
| 249 | m->valid = VM_PAGE_BITS_ALL; |
| 250 | m->dirty = 0; |
| 251 | m->busy = 0; |
| 252 | m->queue = PQ_NONE; |
| 253 | m->object = NULL; |
| 254 | |
| 255 | m->wire_count = 1; |
| 256 | m->hold_count = 0; |
| 257 | m->phys_addr = paddr; |
| 258 | |
| 259 | return (m); |
| 260 | } |
| 261 | |
| 262 | static void |
| 263 | dev_pager_putfake(vm_page_t m) |
| 264 | { |
| 265 | if (!(m->flags & PG_FICTITIOUS)) |
| 266 | panic("dev_pager_putfake: bad page"); |
| 267 | KKASSERT(m->object == NULL); |
| 268 | zfree(fakepg_zone, m); |
| 269 | } |
| 270 | |