FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_fault_i.h
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_ */
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