1 /*- 2 * Copyright (c) 2000 Peter Wemm 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 #include <sys/cdefs.h> 27 __FBSDID("$FreeBSD$"); 28 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/conf.h> 32 #include <sys/kernel.h> 33 #include <sys/lock.h> 34 #include <sys/proc.h> 35 #include <sys/mutex.h> 36 #include <sys/mman.h> 37 #include <sys/sysctl.h> 38 39 #include <vm/vm.h> 40 #include <vm/vm_object.h> 41 #include <vm/vm_page.h> 42 #include <vm/vm_pager.h> 43 44 /* list of phys pager objects */ 45 static struct pagerlst phys_pager_object_list; 46 /* protect access to phys_pager_object_list */ 47 static struct mtx phys_pager_mtx; 48 49 static void 50 phys_pager_init(void) 51 { 52 53 TAILQ_INIT(&phys_pager_object_list); 54 mtx_init(&phys_pager_mtx, "phys_pager list", NULL, MTX_DEF); 55 } 56 57 /* 58 * MPSAFE 59 */ 60 static vm_object_t 61 phys_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot, 62 vm_ooffset_t foff, struct ucred *cred) 63 { 64 vm_object_t object, object1; 65 vm_pindex_t pindex; 66 67 /* 68 * Offset should be page aligned. 69 */ 70 if (foff & PAGE_MASK) 71 return (NULL); 72 73 pindex = OFF_TO_IDX(foff + PAGE_MASK + size); 74 75 if (handle != NULL) { 76 mtx_lock(&phys_pager_mtx); 77 /* 78 * Look up pager, creating as necessary. 79 */ 80 object1 = NULL; 81 object = vm_pager_object_lookup(&phys_pager_object_list, handle); 82 if (object == NULL) { 83 /* 84 * Allocate object and associate it with the pager. 85 */ 86 mtx_unlock(&phys_pager_mtx); 87 object1 = vm_object_allocate(OBJT_PHYS, pindex); 88 mtx_lock(&phys_pager_mtx); 89 object = vm_pager_object_lookup(&phys_pager_object_list, 90 handle); 91 if (object != NULL) { 92 /* 93 * We raced with other thread while 94 * allocating object. 95 */ 96 if (pindex > object->size) 97 object->size = pindex; 98 } else { 99 object = object1; 100 object1 = NULL; 101 object->handle = handle; 102 TAILQ_INSERT_TAIL(&phys_pager_object_list, object, 103 pager_object_list); 104 } 105 } else { 106 if (pindex > object->size) 107 object->size = pindex; 108 } 109 mtx_unlock(&phys_pager_mtx); 110 vm_object_deallocate(object1); 111 } else { 112 object = vm_object_allocate(OBJT_PHYS, pindex); 113 } 114 115 return (object); 116 } 117 118 /* 119 * MPSAFE 120 */ 121 static void 122 phys_pager_dealloc(vm_object_t object) 123 { 124 125 if (object->handle != NULL) { 126 VM_OBJECT_UNLOCK(object); 127 mtx_lock(&phys_pager_mtx); 128 TAILQ_REMOVE(&phys_pager_object_list, object, pager_object_list); 129 mtx_unlock(&phys_pager_mtx); 130 VM_OBJECT_LOCK(object); 131 } 132 } 133 134 /* 135 * Fill as many pages as vm_fault has allocated for us. 136 */ 137 static int 138 phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int reqpage) 139 { 140 int i; 141 142 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 143 for (i = 0; i < count; i++) { 144 if (m[i]->valid == 0) { 145 if ((m[i]->flags & PG_ZERO) == 0) 146 pmap_zero_page(m[i]); 147 m[i]->valid = VM_PAGE_BITS_ALL; 148 } 149 KASSERT(m[i]->valid == VM_PAGE_BITS_ALL, 150 ("phys_pager_getpages: partially valid page %p", m[i])); 151 KASSERT(m[i]->dirty == 0, 152 ("phys_pager_getpages: dirty page %p", m[i])); 153 /* The requested page must remain busy, the others not. */ 154 if (i == reqpage) 155 vm_page_flash(m[i]); 156 else 157 vm_page_wakeup(m[i]); 158 } 159 return (VM_PAGER_OK); 160 } 161 162 static void 163 phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync, 164 int *rtvals) 165 { 166 167 panic("phys_pager_putpage called"); 168 } 169 170 /* 171 * Implement a pretty aggressive clustered getpages strategy. Hint that 172 * everything in an entire 4MB window should be prefaulted at once. 173 * 174 * XXX 4MB (1024 slots per page table page) is convenient for x86, 175 * but may not be for other arches. 176 */ 177 #ifndef PHYSCLUSTER 178 #define PHYSCLUSTER 1024 179 #endif 180 static boolean_t 181 phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, 182 int *after) 183 { 184 vm_pindex_t base, end; 185 186 base = pindex & (~(PHYSCLUSTER - 1)); 187 end = base + (PHYSCLUSTER - 1); 188 if (before != NULL) 189 *before = pindex - base; 190 if (after != NULL) 191 *after = end - pindex; 192 return (TRUE); 193 } 194 195 struct pagerops physpagerops = { 196 .pgo_init = phys_pager_init, 197 .pgo_alloc = phys_pager_alloc, 198 .pgo_dealloc = phys_pager_dealloc, 199 .pgo_getpages = phys_pager_getpages, 200 .pgo_putpages = phys_pager_putpages, 201 .pgo_haspage = phys_pager_haspage, 202 }; 203