xref: /netbsd-src/sys/uvm/uvm_fault_i.h (revision 4472dbe5e3bd91ef2540bada7a7ca7384627ff9b)
1 /*	$NetBSD: uvm_fault_i.h,v 1.10 2000/01/11 06:57:50 chs 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(ufi, write_locked)
50 	struct uvm_faultinfo *ufi;
51 	boolean_t write_locked;
52 {
53 	/*
54 	 * ufi can be NULL when this isn't really a fault,
55 	 * but merely paging in anon data.
56 	 */
57 
58 	if (ufi == NULL) {
59 		return;
60 	}
61 
62 	if (write_locked) {
63 		vm_map_unlock(ufi->map);
64 	} else {
65 		vm_map_unlock_read(ufi->map);
66 	}
67 }
68 
69 /*
70  * uvmfault_unlockall: unlock everything passed in.
71  *
72  * => maps must be read-locked (not write-locked).
73  */
74 
75 static __inline void
76 uvmfault_unlockall(ufi, amap, uobj, anon)
77 	struct uvm_faultinfo *ufi;
78 	struct vm_amap *amap;
79 	struct uvm_object *uobj;
80 	struct vm_anon *anon;
81 {
82 
83 	if (anon)
84 		simple_unlock(&anon->an_lock);
85 	if (uobj)
86 		simple_unlock(&uobj->vmobjlock);
87 	if (amap)
88 		amap_unlock(amap);
89 	uvmfault_unlockmaps(ufi, FALSE);
90 }
91 
92 /*
93  * uvmfault_check_intrsafe: check for a virtual address managed by
94  * an interrupt-safe map.
95  *
96  * => caller must provide a uvm_faultinfo structure with the IN
97  *	params properly filled in
98  * => if we find an intersafe VA, we fill in ufi->map, and return TRUE
99  */
100 
101 static __inline boolean_t
102 uvmfault_check_intrsafe(ufi)
103 	struct uvm_faultinfo *ufi;
104 {
105 	struct vm_map_intrsafe *vmi;
106 	int s;
107 
108 	s = vmi_list_lock();
109 	for (vmi = LIST_FIRST(&vmi_list); vmi != NULL;
110 	     vmi = LIST_NEXT(vmi, vmi_list)) {
111 		if (ufi->orig_rvaddr >= vm_map_min(&vmi->vmi_map) &&
112 		    ufi->orig_rvaddr < vm_map_max(&vmi->vmi_map))
113 			break;
114 	}
115 	vmi_list_unlock(s);
116 
117 	if (vmi != NULL) {
118 		ufi->map = &vmi->vmi_map;
119 		return (TRUE);
120 	}
121 
122 	return (FALSE);
123 }
124 
125 /*
126  * uvmfault_lookup: lookup a virtual address in a map
127  *
128  * => caller must provide a uvm_faultinfo structure with the IN
129  *	params properly filled in
130  * => we will lookup the map entry (handling submaps) as we go
131  * => if the lookup is a success we will return with the maps locked
132  * => if "write_lock" is TRUE, we write_lock the map, otherwise we only
133  *	get a read lock.
134  * => note that submaps can only appear in the kernel and they are
135  *	required to use the same virtual addresses as the map they
136  *	are referenced by (thus address translation between the main
137  *	map and the submap is unnecessary).
138  */
139 
140 static __inline boolean_t
141 uvmfault_lookup(ufi, write_lock)
142 	struct uvm_faultinfo *ufi;
143 	boolean_t write_lock;
144 {
145 	vm_map_t tmpmap;
146 
147 	/*
148 	 * init ufi values for lookup.
149 	 */
150 
151 	ufi->map = ufi->orig_map;
152 	ufi->size = ufi->orig_size;
153 
154 	/*
155 	 * keep going down levels until we are done.   note that there can
156 	 * only be two levels so we won't loop very long.
157 	 */
158 
159 	while (1) {
160 
161 		/*
162 		 * lock map
163 		 */
164 		if (write_lock) {
165 			vm_map_lock(ufi->map);
166 		} else {
167 			vm_map_lock_read(ufi->map);
168 		}
169 
170 		/*
171 		 * lookup
172 		 */
173 		if (!uvm_map_lookup_entry(ufi->map, ufi->orig_rvaddr,
174 								&ufi->entry)) {
175 			uvmfault_unlockmaps(ufi, write_lock);
176 			return(FALSE);
177 		}
178 
179 		/*
180 		 * reduce size if necessary
181 		 */
182 		if (ufi->entry->end - ufi->orig_rvaddr < ufi->size)
183 			ufi->size = ufi->entry->end - ufi->orig_rvaddr;
184 
185 		/*
186 		 * submap?    replace map with the submap and lookup again.
187 		 * note: VAs in submaps must match VAs in main map.
188 		 */
189 		if (UVM_ET_ISSUBMAP(ufi->entry)) {
190 			tmpmap = ufi->entry->object.sub_map;
191 			if (write_lock) {
192 				vm_map_unlock(ufi->map);
193 			} else {
194 				vm_map_unlock_read(ufi->map);
195 			}
196 			ufi->map = tmpmap;
197 			continue;
198 		}
199 
200 		/*
201 		 * got it!
202 		 */
203 
204 		ufi->mapv = ufi->map->timestamp;
205 		return(TRUE);
206 
207 	}	/* while loop */
208 
209 	/*NOTREACHED*/
210 }
211 
212 /*
213  * uvmfault_relock: attempt to relock the same version of the map
214  *
215  * => fault data structures should be unlocked before calling.
216  * => if a success (TRUE) maps will be locked after call.
217  */
218 
219 static __inline boolean_t
220 uvmfault_relock(ufi)
221 	struct uvm_faultinfo *ufi;
222 {
223 	/*
224 	 * ufi can be NULL when this isn't really a fault,
225 	 * but merely paging in anon data.
226 	 */
227 
228 	if (ufi == NULL) {
229 		return TRUE;
230 	}
231 
232 	uvmexp.fltrelck++;
233 
234 	/*
235 	 * relock map.   fail if version mismatch (in which case nothing
236 	 * gets locked).
237 	 */
238 
239 	vm_map_lock_read(ufi->map);
240 	if (ufi->mapv != ufi->map->timestamp) {
241 		vm_map_unlock_read(ufi->map);
242 		return(FALSE);
243 	}
244 
245 	uvmexp.fltrelckok++;
246 	return(TRUE);		/* got it! */
247 }
248 
249 #endif /* _UVM_UVM_FAULT_I_H_ */
250