| 1 | /* $NetBSD: uvm_fault_i.h,v 1.28 2012/02/19 00:05:56 rmind Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1997 Charles D. Cranor and Washington University. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 17 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 18 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 19 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 20 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 21 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 22 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 23 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 24 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 25 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | * |
| 27 | * from: Id: uvm_fault_i.h,v 1.1.6.1 1997/12/08 16:07:12 chuck Exp |
| 28 | */ |
| 29 | |
| 30 | #ifndef _UVM_UVM_FAULT_I_H_ |
| 31 | #define _UVM_UVM_FAULT_I_H_ |
| 32 | |
| 33 | /* |
| 34 | * uvm_fault_i.h: fault inline functions |
| 35 | */ |
| 36 | |
| 37 | /* |
| 38 | * uvmfault_unlockmaps: unlock the maps |
| 39 | */ |
| 40 | |
| 41 | static inline void |
| 42 | uvmfault_unlockmaps(struct uvm_faultinfo *ufi, bool write_locked) |
| 43 | { |
| 44 | /* |
| 45 | * ufi can be NULL when this isn't really a fault, |
| 46 | * but merely paging in anon data. |
| 47 | */ |
| 48 | |
| 49 | if (ufi == NULL) { |
| 50 | return; |
| 51 | } |
| 52 | |
| 53 | if (write_locked) { |
| 54 | vm_map_unlock(ufi->map); |
| 55 | } else { |
| 56 | vm_map_unlock_read(ufi->map); |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | /* |
| 61 | * uvmfault_unlockall: unlock everything passed in. |
| 62 | * |
| 63 | * => maps must be read-locked (not write-locked). |
| 64 | */ |
| 65 | |
| 66 | static inline void |
| 67 | uvmfault_unlockall(struct uvm_faultinfo *ufi, struct vm_amap *amap, |
| 68 | struct uvm_object *uobj) |
| 69 | { |
| 70 | |
| 71 | if (uobj) |
| 72 | mutex_exit(uobj->vmobjlock); |
| 73 | if (amap) |
| 74 | amap_unlock(amap); |
| 75 | uvmfault_unlockmaps(ufi, false); |
| 76 | } |
| 77 | |
| 78 | /* |
| 79 | * uvmfault_lookup: lookup a virtual address in a map |
| 80 | * |
| 81 | * => caller must provide a uvm_faultinfo structure with the IN |
| 82 | * params properly filled in |
| 83 | * => we will lookup the map entry (handling submaps) as we go |
| 84 | * => if the lookup is a success we will return with the maps locked |
| 85 | * => if "write_lock" is true, we write_lock the map, otherwise we only |
| 86 | * get a read lock. |
| 87 | * => note that submaps can only appear in the kernel and they are |
| 88 | * required to use the same virtual addresses as the map they |
| 89 | * are referenced by (thus address translation between the main |
| 90 | * map and the submap is unnecessary). |
| 91 | */ |
| 92 | |
| 93 | static inline bool |
| 94 | uvmfault_lookup(struct uvm_faultinfo *ufi, bool write_lock) |
| 95 | { |
| 96 | struct vm_map *tmpmap; |
| 97 | |
| 98 | /* |
| 99 | * init ufi values for lookup. |
| 100 | */ |
| 101 | |
| 102 | ufi->map = ufi->orig_map; |
| 103 | ufi->size = ufi->orig_size; |
| 104 | |
| 105 | /* |
| 106 | * keep going down levels until we are done. note that there can |
| 107 | * only be two levels so we won't loop very long. |
| 108 | */ |
| 109 | |
| 110 | for (;;) { |
| 111 | /* |
| 112 | * lock map |
| 113 | */ |
| 114 | if (write_lock) { |
| 115 | vm_map_lock(ufi->map); |
| 116 | } else { |
| 117 | vm_map_lock_read(ufi->map); |
| 118 | } |
| 119 | |
| 120 | /* |
| 121 | * lookup |
| 122 | */ |
| 123 | if (!uvm_map_lookup_entry(ufi->map, ufi->orig_rvaddr, |
| 124 | &ufi->entry)) { |
| 125 | uvmfault_unlockmaps(ufi, write_lock); |
| 126 | return(false); |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * reduce size if necessary |
| 131 | */ |
| 132 | if (ufi->entry->end - ufi->orig_rvaddr < ufi->size) |
| 133 | ufi->size = ufi->entry->end - ufi->orig_rvaddr; |
| 134 | |
| 135 | /* |
| 136 | * submap? replace map with the submap and lookup again. |
| 137 | * note: VAs in submaps must match VAs in main map. |
| 138 | */ |
| 139 | if (UVM_ET_ISSUBMAP(ufi->entry)) { |
| 140 | tmpmap = ufi->entry->object.sub_map; |
| 141 | if (write_lock) { |
| 142 | vm_map_unlock(ufi->map); |
| 143 | } else { |
| 144 | vm_map_unlock_read(ufi->map); |
| 145 | } |
| 146 | ufi->map = tmpmap; |
| 147 | continue; |
| 148 | } |
| 149 | |
| 150 | /* |
| 151 | * got it! |
| 152 | */ |
| 153 | |
| 154 | ufi->mapv = ufi->map->timestamp; |
| 155 | return(true); |
| 156 | |
| 157 | } /* while loop */ |
| 158 | |
| 159 | /*NOTREACHED*/ |
| 160 | } |
| 161 | |
| 162 | /* |
| 163 | * uvmfault_relock: attempt to relock the same version of the map |
| 164 | * |
| 165 | * => fault data structures should be unlocked before calling. |
| 166 | * => if a success (true) maps will be locked after call. |
| 167 | */ |
| 168 | |
| 169 | static inline bool |
| 170 | uvmfault_relock(struct uvm_faultinfo *ufi) |
| 171 | { |
| 172 | /* |
| 173 | * ufi can be NULL when this isn't really a fault, |
| 174 | * but merely paging in anon data. |
| 175 | */ |
| 176 | |
| 177 | if (ufi == NULL) { |
| 178 | return true; |
| 179 | } |
| 180 | |
| 181 | uvmexp.fltrelck++; |
| 182 | |
| 183 | /* |
| 184 | * relock map. fail if version mismatch (in which case nothing |
| 185 | * gets locked). |
| 186 | */ |
| 187 | |
| 188 | vm_map_lock_read(ufi->map); |
| 189 | if (ufi->mapv != ufi->map->timestamp) { |
| 190 | vm_map_unlock_read(ufi->map); |
| 191 | return(false); |
| 192 | } |
| 193 | |
| 194 | uvmexp.fltrelckok++; |
| 195 | return(true); |
| 196 | } |
| 197 | |
| 198 | #endif /* _UVM_UVM_FAULT_I_H_ */ |
| 199 | |