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1da177e4 LT |
1 | /****************************************************************************** |
2 | * | |
3 | * Module Name: nswalk - Functions for walking the ACPI namespace | |
4 | * | |
5 | *****************************************************************************/ | |
6 | ||
7 | /* | |
75a44ce0 | 8 | * Copyright (C) 2000 - 2008, Intel Corp. |
1da177e4 LT |
9 | * All rights reserved. |
10 | * | |
11 | * Redistribution and use in source and binary forms, with or without | |
12 | * modification, are permitted provided that the following conditions | |
13 | * are met: | |
14 | * 1. Redistributions of source code must retain the above copyright | |
15 | * notice, this list of conditions, and the following disclaimer, | |
16 | * without modification. | |
17 | * 2. Redistributions in binary form must reproduce at minimum a disclaimer | |
18 | * substantially similar to the "NO WARRANTY" disclaimer below | |
19 | * ("Disclaimer") and any redistribution must be conditioned upon | |
20 | * including a substantially similar Disclaimer requirement for further | |
21 | * binary redistribution. | |
22 | * 3. Neither the names of the above-listed copyright holders nor the names | |
23 | * of any contributors may be used to endorse or promote products derived | |
24 | * from this software without specific prior written permission. | |
25 | * | |
26 | * Alternatively, this software may be distributed under the terms of the | |
27 | * GNU General Public License ("GPL") version 2 as published by the Free | |
28 | * Software Foundation. | |
29 | * | |
30 | * NO WARRANTY | |
31 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
32 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
33 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR | |
34 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
35 | * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
36 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
37 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
38 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
39 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING | |
40 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
41 | * POSSIBILITY OF SUCH DAMAGES. | |
42 | */ | |
43 | ||
1da177e4 | 44 | #include <acpi/acpi.h> |
e2f7a777 LB |
45 | #include "accommon.h" |
46 | #include "acnamesp.h" | |
1da177e4 | 47 | |
1da177e4 | 48 | #define _COMPONENT ACPI_NAMESPACE |
4be44fcd | 49 | ACPI_MODULE_NAME("nswalk") |
1da177e4 LT |
50 | |
51 | /******************************************************************************* | |
52 | * | |
53 | * FUNCTION: acpi_ns_get_next_node | |
54 | * | |
8c725bf9 | 55 | * PARAMETERS: parent_node - Parent node whose children we are |
44f6c012 | 56 | * getting |
1da177e4 LT |
57 | * child_node - Previous child that was found. |
58 | * The NEXT child will be returned | |
59 | * | |
60 | * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if | |
61 | * none is found. | |
62 | * | |
63 | * DESCRIPTION: Return the next peer node within the namespace. If Handle | |
64 | * is valid, Scope is ignored. Otherwise, the first node | |
65 | * within Scope is returned. | |
66 | * | |
67 | ******************************************************************************/ | |
8c725bf9 BM |
68 | struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node |
69 | *parent_node, | |
70 | struct acpi_namespace_node | |
4be44fcd | 71 | *child_node) |
1da177e4 | 72 | { |
4be44fcd | 73 | ACPI_FUNCTION_ENTRY(); |
1da177e4 LT |
74 | |
75 | if (!child_node) { | |
52fc0b02 | 76 | |
1da177e4 LT |
77 | /* It's really the parent's _scope_ that we want */ |
78 | ||
8c725bf9 | 79 | return parent_node->child; |
1da177e4 LT |
80 | } |
81 | ||
8c725bf9 BM |
82 | /* |
83 | * Get the next node. | |
84 | * | |
85 | * If we are at the end of this peer list, return NULL | |
86 | */ | |
87 | if (child_node->flags & ANOBJ_END_OF_PEER_LIST) { | |
88 | return NULL; | |
1da177e4 LT |
89 | } |
90 | ||
8c725bf9 BM |
91 | /* Otherwise just return the next peer */ |
92 | ||
93 | return child_node->peer; | |
94 | } | |
95 | ||
96 | /******************************************************************************* | |
97 | * | |
98 | * FUNCTION: acpi_ns_get_next_node_typed | |
99 | * | |
100 | * PARAMETERS: Type - Type of node to be searched for | |
101 | * parent_node - Parent node whose children we are | |
102 | * getting | |
103 | * child_node - Previous child that was found. | |
104 | * The NEXT child will be returned | |
105 | * | |
106 | * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if | |
107 | * none is found. | |
108 | * | |
109 | * DESCRIPTION: Return the next peer node within the namespace. If Handle | |
110 | * is valid, Scope is ignored. Otherwise, the first node | |
111 | * within Scope is returned. | |
112 | * | |
113 | ******************************************************************************/ | |
114 | ||
115 | struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type, | |
116 | struct | |
117 | acpi_namespace_node | |
118 | *parent_node, | |
119 | struct | |
120 | acpi_namespace_node | |
121 | *child_node) | |
122 | { | |
123 | struct acpi_namespace_node *next_node = NULL; | |
124 | ||
125 | ACPI_FUNCTION_ENTRY(); | |
126 | ||
127 | next_node = acpi_ns_get_next_node(parent_node, child_node); | |
128 | ||
129 | ||
1da177e4 LT |
130 | /* If any type is OK, we are done */ |
131 | ||
132 | if (type == ACPI_TYPE_ANY) { | |
52fc0b02 | 133 | |
1da177e4 LT |
134 | /* next_node is NULL if we are at the end-of-list */ |
135 | ||
136 | return (next_node); | |
137 | } | |
138 | ||
139 | /* Must search for the node -- but within this scope only */ | |
140 | ||
141 | while (next_node) { | |
52fc0b02 | 142 | |
1da177e4 LT |
143 | /* If type matches, we are done */ |
144 | ||
145 | if (next_node->type == type) { | |
146 | return (next_node); | |
147 | } | |
148 | ||
149 | /* Otherwise, move on to the next node */ | |
150 | ||
4be44fcd | 151 | next_node = acpi_ns_get_next_valid_node(next_node); |
1da177e4 LT |
152 | } |
153 | ||
154 | /* Not found */ | |
155 | ||
156 | return (NULL); | |
157 | } | |
158 | ||
1da177e4 LT |
159 | /******************************************************************************* |
160 | * | |
161 | * FUNCTION: acpi_ns_walk_namespace | |
162 | * | |
163 | * PARAMETERS: Type - acpi_object_type to search for | |
164 | * start_node - Handle in namespace where search begins | |
165 | * max_depth - Depth to which search is to reach | |
d1fdda83 | 166 | * Flags - Whether to unlock the NS before invoking |
1da177e4 LT |
167 | * the callback routine |
168 | * user_function - Called when an object of "Type" is found | |
169 | * Context - Passed to user function | |
170 | * return_value - from the user_function if terminated early. | |
171 | * Otherwise, returns NULL. | |
172 | * RETURNS: Status | |
173 | * | |
174 | * DESCRIPTION: Performs a modified depth-first walk of the namespace tree, | |
175 | * starting (and ending) at the node specified by start_handle. | |
176 | * The user_function is called whenever a node that matches | |
177 | * the type parameter is found. If the user function returns | |
d4913dc6 BM |
178 | * a non-zero value, the search is terminated immediately and |
179 | * this value is returned to the caller. | |
1da177e4 LT |
180 | * |
181 | * The point of this procedure is to provide a generic namespace | |
182 | * walk routine that can be called from multiple places to | |
183 | * provide multiple services; the User Function can be tailored | |
184 | * to each task, whether it is a print function, a compare | |
185 | * function, etc. | |
186 | * | |
187 | ******************************************************************************/ | |
188 | ||
189 | acpi_status | |
4be44fcd LB |
190 | acpi_ns_walk_namespace(acpi_object_type type, |
191 | acpi_handle start_node, | |
192 | u32 max_depth, | |
d1fdda83 | 193 | u32 flags, |
4be44fcd LB |
194 | acpi_walk_callback user_function, |
195 | void *context, void **return_value) | |
1da177e4 | 196 | { |
4be44fcd LB |
197 | acpi_status status; |
198 | acpi_status mutex_status; | |
199 | struct acpi_namespace_node *child_node; | |
200 | struct acpi_namespace_node *parent_node; | |
201 | acpi_object_type child_type; | |
202 | u32 level; | |
1da177e4 | 203 | |
b229cf92 | 204 | ACPI_FUNCTION_TRACE(ns_walk_namespace); |
1da177e4 LT |
205 | |
206 | /* Special case for the namespace Root Node */ | |
207 | ||
208 | if (start_node == ACPI_ROOT_OBJECT) { | |
209 | start_node = acpi_gbl_root_node; | |
210 | } | |
211 | ||
212 | /* Null child means "get first node" */ | |
213 | ||
214 | parent_node = start_node; | |
4be44fcd LB |
215 | child_node = NULL; |
216 | child_type = ACPI_TYPE_ANY; | |
217 | level = 1; | |
1da177e4 LT |
218 | |
219 | /* | |
220 | * Traverse the tree of nodes until we bubble back up to where we | |
221 | * started. When Level is zero, the loop is done because we have | |
222 | * bubbled up to (and passed) the original parent handle (start_entry) | |
223 | */ | |
224 | while (level > 0) { | |
52fc0b02 | 225 | |
1da177e4 LT |
226 | /* Get the next node in this scope. Null if not found */ |
227 | ||
228 | status = AE_OK; | |
8c725bf9 | 229 | child_node = acpi_ns_get_next_node(parent_node, child_node); |
1da177e4 | 230 | if (child_node) { |
3effba32 | 231 | |
c1014629 | 232 | /* Found next child, get the type if we are not searching for ANY */ |
3effba32 | 233 | |
1da177e4 LT |
234 | if (type != ACPI_TYPE_ANY) { |
235 | child_type = child_node->type; | |
236 | } | |
237 | ||
3effba32 | 238 | /* |
c1014629 BM |
239 | * Ignore all temporary namespace nodes (created during control |
240 | * method execution) unless told otherwise. These temporary nodes | |
d4913dc6 BM |
241 | * can cause a race condition because they can be deleted during |
242 | * the execution of the user function (if the namespace is | |
243 | * unlocked before invocation of the user function.) Only the | |
244 | * debugger namespace dump will examine the temporary nodes. | |
3effba32 | 245 | */ |
c1014629 BM |
246 | if ((child_node->flags & ANOBJ_TEMPORARY) && |
247 | !(flags & ACPI_NS_WALK_TEMP_NODES)) { | |
248 | status = AE_CTRL_DEPTH; | |
249 | } | |
250 | ||
251 | /* Type must match requested type */ | |
252 | ||
253 | else if (child_type == type) { | |
1da177e4 | 254 | /* |
3effba32 BM |
255 | * Found a matching node, invoke the user callback function. |
256 | * Unlock the namespace if flag is set. | |
1da177e4 | 257 | */ |
d1fdda83 | 258 | if (flags & ACPI_NS_WALK_UNLOCK) { |
4be44fcd LB |
259 | mutex_status = |
260 | acpi_ut_release_mutex | |
261 | (ACPI_MTX_NAMESPACE); | |
262 | if (ACPI_FAILURE(mutex_status)) { | |
263 | return_ACPI_STATUS | |
264 | (mutex_status); | |
1da177e4 LT |
265 | } |
266 | } | |
267 | ||
3effba32 BM |
268 | status = |
269 | user_function(child_node, level, context, | |
270 | return_value); | |
1da177e4 | 271 | |
d1fdda83 | 272 | if (flags & ACPI_NS_WALK_UNLOCK) { |
4be44fcd LB |
273 | mutex_status = |
274 | acpi_ut_acquire_mutex | |
275 | (ACPI_MTX_NAMESPACE); | |
276 | if (ACPI_FAILURE(mutex_status)) { | |
277 | return_ACPI_STATUS | |
278 | (mutex_status); | |
1da177e4 LT |
279 | } |
280 | } | |
281 | ||
282 | switch (status) { | |
283 | case AE_OK: | |
284 | case AE_CTRL_DEPTH: | |
285 | ||
286 | /* Just keep going */ | |
287 | break; | |
288 | ||
289 | case AE_CTRL_TERMINATE: | |
290 | ||
291 | /* Exit now, with OK status */ | |
292 | ||
4be44fcd | 293 | return_ACPI_STATUS(AE_OK); |
1da177e4 LT |
294 | |
295 | default: | |
296 | ||
297 | /* All others are valid exceptions */ | |
298 | ||
4be44fcd | 299 | return_ACPI_STATUS(status); |
1da177e4 LT |
300 | } |
301 | } | |
302 | ||
303 | /* | |
3effba32 BM |
304 | * Depth first search: Attempt to go down another level in the |
305 | * namespace if we are allowed to. Don't go any further if we have | |
306 | * reached the caller specified maximum depth or if the user | |
307 | * function has specified that the maximum depth has been reached. | |
1da177e4 LT |
308 | */ |
309 | if ((level < max_depth) && (status != AE_CTRL_DEPTH)) { | |
8c725bf9 | 310 | if (child_node->child) { |
3effba32 BM |
311 | |
312 | /* There is at least one child of this node, visit it */ | |
313 | ||
1da177e4 LT |
314 | level++; |
315 | parent_node = child_node; | |
316 | child_node = NULL; | |
317 | } | |
318 | } | |
4be44fcd | 319 | } else { |
1da177e4 | 320 | /* |
3effba32 BM |
321 | * No more children of this node (acpi_ns_get_next_node failed), go |
322 | * back upwards in the namespace tree to the node's parent. | |
1da177e4 LT |
323 | */ |
324 | level--; | |
325 | child_node = parent_node; | |
4be44fcd | 326 | parent_node = acpi_ns_get_parent_node(parent_node); |
1da177e4 LT |
327 | } |
328 | } | |
329 | ||
330 | /* Complete walk, not terminated by user function */ | |
331 | ||
4be44fcd | 332 | return_ACPI_STATUS(AE_OK); |
1da177e4 | 333 | } |