1 /* 2 * Copyright (c) 1991 Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * %sccs.include.redist.c% 9 * 10 * @(#)vm_pager.c 7.3 (Berkeley) 04/21/91 11 * 12 * 13 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 14 * All rights reserved. 15 * 16 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 17 * 18 * Permission to use, copy, modify and distribute this software and 19 * its documentation is hereby granted, provided that both the copyright 20 * notice and this permission notice appear in all copies of the 21 * software, derivative works or modified versions, and any portions 22 * thereof, and that both notices appear in supporting documentation. 23 * 24 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 25 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 26 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 27 * 28 * Carnegie Mellon requests users of this software to return to 29 * 30 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 31 * School of Computer Science 32 * Carnegie Mellon University 33 * Pittsburgh PA 15213-3890 34 * 35 * any improvements or extensions that they make and grant Carnegie the 36 * rights to redistribute these changes. 37 */ 38 39 /* 40 * Paging space routine stubs. Emulates a matchmaker-like interface 41 * for builtin pagers. 42 */ 43 44 #include "param.h" 45 #include "malloc.h" 46 47 #include "vm.h" 48 #include "vm_page.h" 49 #include "vm_kern.h" 50 51 #ifdef hp300 52 #include "../hp300/hp300/pte.h" /* XXX XXX XXX */ 53 #endif 54 55 #include "swappager.h" 56 57 #if NSWAPPAGER > 0 58 extern struct pagerops swappagerops; 59 #else 60 #define swappagerops NULL 61 #endif 62 #include "vnodepager.h" 63 #if NVNODEPAGER > 0 64 extern struct pagerops vnodepagerops; 65 #else 66 #define vnodepagerops NULL 67 #endif 68 #include "devpager.h" 69 #if NDEVPAGER > 0 70 extern struct pagerops devicepagerops; 71 #else 72 #define devicepagerops NULL 73 #endif 74 75 struct pagerops *pagertab[] = { 76 &swappagerops, /* PG_SWAP */ 77 &vnodepagerops, /* PG_VNODE */ 78 &devicepagerops, /* PG_DEV */ 79 }; 80 int npagers = sizeof (pagertab) / sizeof (pagertab[0]); 81 82 struct pagerops *dfltpagerops = NULL; /* default pager */ 83 84 /* 85 * Kernel address space for mapping pages. 86 * Used by pagers where KVAs are needed for IO. 87 */ 88 #define PAGER_MAP_SIZE (256 * PAGE_SIZE) 89 vm_map_t pager_map; 90 91 void 92 vm_pager_init() 93 { 94 vm_offset_t whocares1, whocares2; 95 struct pagerops **pgops; 96 97 /* 98 * Allocate a kernel submap for tracking get/put page mappings 99 */ 100 pager_map = kmem_suballoc(kernel_map, &whocares1, &whocares2, 101 PAGER_MAP_SIZE, FALSE); 102 /* 103 * Initialize known pagers 104 */ 105 for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++) 106 (*(*pgops)->pgo_init)(); 107 if (dfltpagerops == NULL) 108 panic("no default pager"); 109 } 110 111 /* 112 * Allocate an instance of a pager of the given type. 113 */ 114 vm_pager_t 115 vm_pager_allocate(type, handle, size, prot) 116 int type; 117 caddr_t handle; 118 vm_size_t size; 119 vm_prot_t prot; 120 { 121 vm_pager_t pager; 122 struct pagerops *ops; 123 124 ops = (type == PG_DFLT) ? dfltpagerops : pagertab[type]; 125 return((*ops->pgo_alloc)(handle, size, prot)); 126 } 127 128 void 129 vm_pager_deallocate(pager) 130 vm_pager_t pager; 131 { 132 if (pager == NULL) 133 panic("vm_pager_deallocate: null pager"); 134 135 VM_PAGER_DEALLOC(pager); 136 } 137 138 vm_pager_get(pager, m, sync) 139 vm_pager_t pager; 140 vm_page_t m; 141 boolean_t sync; 142 { 143 extern boolean_t vm_page_zero_fill(); 144 145 if (pager == NULL) 146 return(vm_page_zero_fill(m) ? VM_PAGER_OK : VM_PAGER_FAIL); 147 return(VM_PAGER_GET(pager, m, sync)); 148 } 149 150 vm_pager_put(pager, m, sync) 151 vm_pager_t pager; 152 vm_page_t m; 153 boolean_t sync; 154 { 155 if (pager == NULL) 156 panic("vm_pager_put: null pager"); 157 return(VM_PAGER_PUT(pager, m, sync)); 158 } 159 160 boolean_t 161 vm_pager_has_page(pager, offset) 162 vm_pager_t pager; 163 vm_offset_t offset; 164 { 165 if (pager == NULL) 166 panic("vm_pager_has_page"); 167 return(VM_PAGER_HASPAGE(pager, offset)); 168 } 169 170 /* 171 * Called by pageout daemon before going back to sleep. 172 * Gives pagers a chance to clean up any completed async pageing operations. 173 */ 174 void 175 vm_pager_sync() 176 { 177 struct pagerops **pgops; 178 179 for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++) 180 (*(*pgops)->pgo_putpage)(NULL, NULL, FALSE); 181 } 182 183 vm_offset_t 184 vm_pager_map_page(m) 185 vm_page_t m; 186 { 187 vm_offset_t kva; 188 189 kva = kmem_alloc_wait(pager_map, PAGE_SIZE); 190 #ifdef hp300 191 /* 192 * XXX: cannot use pmap_enter as the mapping would be 193 * removed by a pmap_remove_all(). 194 */ 195 *(int *)kvtopte(kva) = VM_PAGE_TO_PHYS(m) | PG_CI | PG_V; 196 TBIS(kva); 197 #else 198 pmap_enter(vm_map_pmap(pager_map), kva, VM_PAGE_TO_PHYS(m), 199 VM_PROT_DEFAULT, TRUE); 200 #endif 201 return(kva); 202 } 203 204 void 205 vm_pager_unmap_page(kva) 206 vm_offset_t kva; 207 { 208 #ifdef hp300 209 *(int *)kvtopte(kva) = PG_NV; 210 TBIS(kva); 211 #endif 212 kmem_free_wakeup(pager_map, kva, PAGE_SIZE); 213 } 214 215 vm_pager_t 216 vm_pager_lookup(list, handle) 217 register queue_head_t *list; 218 caddr_t handle; 219 { 220 register vm_pager_t pager; 221 222 pager = (vm_pager_t) queue_first(list); 223 while (!queue_end(list, (queue_entry_t)pager)) { 224 if (pager->pg_handle == handle) 225 return(pager); 226 pager = (vm_pager_t) queue_next(&pager->pg_list); 227 } 228 return(NULL); 229 } 230 231 /* 232 * This routine gains a reference to the object. 233 * Explicit deallocation is necessary. 234 */ 235 pager_cache(object, should_cache) 236 vm_object_t object; 237 boolean_t should_cache; 238 { 239 if (object == NULL) 240 return(KERN_INVALID_ARGUMENT); 241 242 vm_object_cache_lock(); 243 vm_object_lock(object); 244 object->can_persist = should_cache; 245 vm_object_unlock(object); 246 vm_object_cache_unlock(); 247 248 vm_object_deallocate(object); 249 250 return(KERN_SUCCESS); 251 } 252