uvm_fault_i.h revision 1.21
1 /* $NetBSD: uvm_fault_i.h,v 1.21 2006/02/16 20:17:20 perry Exp $ */ 2 3 /* 4 * 5 * Copyright (c) 1997 Charles D. Cranor and Washington University. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by Charles D. Cranor and 19 * Washington University. 20 * 4. The name of the author may not be used to endorse or promote products 21 * derived from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 * 34 * from: Id: uvm_fault_i.h,v 1.1.6.1 1997/12/08 16:07:12 chuck Exp 35 */ 36 37 #ifndef _UVM_UVM_FAULT_I_H_ 38 #define _UVM_UVM_FAULT_I_H_ 39 40 /* 41 * uvm_fault_i.h: fault inline functions 42 */ 43 44 /* 45 * uvmfault_unlockmaps: unlock the maps 46 */ 47 48 static __inline void 49 uvmfault_unlockmaps(struct uvm_faultinfo *ufi, boolean_t write_locked) 50 { 51 /* 52 * ufi can be NULL when this isn't really a fault, 53 * but merely paging in anon data. 54 */ 55 56 if (ufi == NULL) { 57 return; 58 } 59 60 if (write_locked) { 61 vm_map_unlock(ufi->map); 62 } else { 63 vm_map_unlock_read(ufi->map); 64 } 65 } 66 67 /* 68 * uvmfault_unlockall: unlock everything passed in. 69 * 70 * => maps must be read-locked (not write-locked). 71 */ 72 73 static __inline void 74 uvmfault_unlockall(struct uvm_faultinfo *ufi, struct vm_amap *amap, 75 struct uvm_object *uobj, struct vm_anon *anon) 76 { 77 78 if (anon) 79 simple_unlock(&anon->an_lock); 80 if (uobj) 81 simple_unlock(&uobj->vmobjlock); 82 if (amap) 83 amap_unlock(amap); 84 uvmfault_unlockmaps(ufi, FALSE); 85 } 86 87 /* 88 * uvmfault_lookup: lookup a virtual address in a map 89 * 90 * => caller must provide a uvm_faultinfo structure with the IN 91 * params properly filled in 92 * => we will lookup the map entry (handling submaps) as we go 93 * => if the lookup is a success we will return with the maps locked 94 * => if "write_lock" is TRUE, we write_lock the map, otherwise we only 95 * get a read lock. 96 * => note that submaps can only appear in the kernel and they are 97 * required to use the same virtual addresses as the map they 98 * are referenced by (thus address translation between the main 99 * map and the submap is unnecessary). 100 */ 101 102 static __inline boolean_t 103 uvmfault_lookup(struct uvm_faultinfo *ufi, boolean_t write_lock) 104 { 105 struct vm_map *tmpmap; 106 107 /* 108 * init ufi values for lookup. 109 */ 110 111 ufi->map = ufi->orig_map; 112 ufi->size = ufi->orig_size; 113 114 /* 115 * keep going down levels until we are done. note that there can 116 * only be two levels so we won't loop very long. 117 */ 118 119 /*CONSTCOND*/ 120 while (1) { 121 /* 122 * Make sure this is not an "interrupt safe" map. 123 * Such maps are never supposed to be involved in 124 * a fault. 125 */ 126 if (ufi->map->flags & VM_MAP_INTRSAFE) 127 return (FALSE); 128 129 /* 130 * lock map 131 */ 132 if (write_lock) { 133 vm_map_lock(ufi->map); 134 } else { 135 vm_map_lock_read(ufi->map); 136 } 137 138 /* 139 * lookup 140 */ 141 if (!uvm_map_lookup_entry(ufi->map, ufi->orig_rvaddr, 142 &ufi->entry)) { 143 uvmfault_unlockmaps(ufi, write_lock); 144 return(FALSE); 145 } 146 147 /* 148 * reduce size if necessary 149 */ 150 if (ufi->entry->end - ufi->orig_rvaddr < ufi->size) 151 ufi->size = ufi->entry->end - ufi->orig_rvaddr; 152 153 /* 154 * submap? replace map with the submap and lookup again. 155 * note: VAs in submaps must match VAs in main map. 156 */ 157 if (UVM_ET_ISSUBMAP(ufi->entry)) { 158 tmpmap = ufi->entry->object.sub_map; 159 if (write_lock) { 160 vm_map_unlock(ufi->map); 161 } else { 162 vm_map_unlock_read(ufi->map); 163 } 164 ufi->map = tmpmap; 165 continue; 166 } 167 168 /* 169 * got it! 170 */ 171 172 ufi->mapv = ufi->map->timestamp; 173 return(TRUE); 174 175 } /* while loop */ 176 177 /*NOTREACHED*/ 178 } 179 180 /* 181 * uvmfault_relock: attempt to relock the same version of the map 182 * 183 * => fault data structures should be unlocked before calling. 184 * => if a success (TRUE) maps will be locked after call. 185 */ 186 187 static __inline boolean_t 188 uvmfault_relock(struct uvm_faultinfo *ufi) 189 { 190 /* 191 * ufi can be NULL when this isn't really a fault, 192 * but merely paging in anon data. 193 */ 194 195 if (ufi == NULL) { 196 return TRUE; 197 } 198 199 uvmexp.fltrelck++; 200 201 /* 202 * relock map. fail if version mismatch (in which case nothing 203 * gets locked). 204 */ 205 206 vm_map_lock_read(ufi->map); 207 if (ufi->mapv != ufi->map->timestamp) { 208 vm_map_unlock_read(ufi->map); 209 return(FALSE); 210 } 211 212 uvmexp.fltrelckok++; 213 return(TRUE); 214 } 215 216 #endif /* _UVM_UVM_FAULT_I_H_ */ 217
Indexes created Thu Sep 25 06:09:39 GMT 2025