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1 | /****************************************************************************** |
2 | * | |
3 | * Module Name: nswalk - Functions for walking the ACPI namespace | |
4 | * | |
5 | *****************************************************************************/ | |
6 | ||
7 | /* | |
8 | * Copyright (C) 2000 - 2005, R. Byron Moore | |
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 | ||
44 | ||
45 | #include <acpi/acpi.h> | |
46 | #include <acpi/acnamesp.h> | |
47 | ||
48 | ||
49 | #define _COMPONENT ACPI_NAMESPACE | |
50 | ACPI_MODULE_NAME ("nswalk") | |
51 | ||
52 | ||
53 | /******************************************************************************* | |
54 | * | |
55 | * FUNCTION: acpi_ns_get_next_node | |
56 | * | |
57 | * PARAMETERS: Type - Type of node to be searched for | |
58 | * parent_node - Parent node whose children we are | |
44f6c012 | 59 | * getting |
1da177e4 LT |
60 | * child_node - Previous child that was found. |
61 | * The NEXT child will be returned | |
62 | * | |
63 | * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if | |
64 | * none is found. | |
65 | * | |
66 | * DESCRIPTION: Return the next peer node within the namespace. If Handle | |
67 | * is valid, Scope is ignored. Otherwise, the first node | |
68 | * within Scope is returned. | |
69 | * | |
70 | ******************************************************************************/ | |
71 | ||
72 | struct acpi_namespace_node * | |
73 | acpi_ns_get_next_node ( | |
74 | acpi_object_type type, | |
75 | struct acpi_namespace_node *parent_node, | |
76 | struct acpi_namespace_node *child_node) | |
77 | { | |
78 | struct acpi_namespace_node *next_node = NULL; | |
79 | ||
80 | ||
81 | ACPI_FUNCTION_ENTRY (); | |
82 | ||
83 | ||
84 | if (!child_node) { | |
85 | /* It's really the parent's _scope_ that we want */ | |
86 | ||
87 | if (parent_node->child) { | |
88 | next_node = parent_node->child; | |
89 | } | |
90 | } | |
91 | ||
92 | else { | |
93 | /* Start search at the NEXT node */ | |
94 | ||
95 | next_node = acpi_ns_get_next_valid_node (child_node); | |
96 | } | |
97 | ||
98 | /* If any type is OK, we are done */ | |
99 | ||
100 | if (type == ACPI_TYPE_ANY) { | |
101 | /* next_node is NULL if we are at the end-of-list */ | |
102 | ||
103 | return (next_node); | |
104 | } | |
105 | ||
106 | /* Must search for the node -- but within this scope only */ | |
107 | ||
108 | while (next_node) { | |
109 | /* If type matches, we are done */ | |
110 | ||
111 | if (next_node->type == type) { | |
112 | return (next_node); | |
113 | } | |
114 | ||
115 | /* Otherwise, move on to the next node */ | |
116 | ||
117 | next_node = acpi_ns_get_next_valid_node (next_node); | |
118 | } | |
119 | ||
120 | /* Not found */ | |
121 | ||
122 | return (NULL); | |
123 | } | |
124 | ||
125 | ||
126 | /******************************************************************************* | |
127 | * | |
128 | * FUNCTION: acpi_ns_walk_namespace | |
129 | * | |
130 | * PARAMETERS: Type - acpi_object_type to search for | |
131 | * start_node - Handle in namespace where search begins | |
132 | * max_depth - Depth to which search is to reach | |
133 | * unlock_before_callback- Whether to unlock the NS before invoking | |
134 | * the callback routine | |
135 | * user_function - Called when an object of "Type" is found | |
136 | * Context - Passed to user function | |
137 | * return_value - from the user_function if terminated early. | |
138 | * Otherwise, returns NULL. | |
139 | * RETURNS: Status | |
140 | * | |
141 | * DESCRIPTION: Performs a modified depth-first walk of the namespace tree, | |
142 | * starting (and ending) at the node specified by start_handle. | |
143 | * The user_function is called whenever a node that matches | |
144 | * the type parameter is found. If the user function returns | |
145 | * a non-zero value, the search is terminated immediately and this | |
146 | * value is returned to the caller. | |
147 | * | |
148 | * The point of this procedure is to provide a generic namespace | |
149 | * walk routine that can be called from multiple places to | |
150 | * provide multiple services; the User Function can be tailored | |
151 | * to each task, whether it is a print function, a compare | |
152 | * function, etc. | |
153 | * | |
154 | ******************************************************************************/ | |
155 | ||
156 | acpi_status | |
157 | acpi_ns_walk_namespace ( | |
158 | acpi_object_type type, | |
159 | acpi_handle start_node, | |
160 | u32 max_depth, | |
161 | u8 unlock_before_callback, | |
162 | acpi_walk_callback user_function, | |
163 | void *context, | |
164 | void **return_value) | |
165 | { | |
166 | acpi_status status; | |
167 | acpi_status mutex_status; | |
168 | struct acpi_namespace_node *child_node; | |
169 | struct acpi_namespace_node *parent_node; | |
170 | acpi_object_type child_type; | |
171 | u32 level; | |
172 | ||
173 | ||
174 | ACPI_FUNCTION_TRACE ("ns_walk_namespace"); | |
175 | ||
176 | ||
177 | /* Special case for the namespace Root Node */ | |
178 | ||
179 | if (start_node == ACPI_ROOT_OBJECT) { | |
180 | start_node = acpi_gbl_root_node; | |
181 | } | |
182 | ||
183 | /* Null child means "get first node" */ | |
184 | ||
185 | parent_node = start_node; | |
186 | child_node = NULL; | |
187 | child_type = ACPI_TYPE_ANY; | |
188 | level = 1; | |
189 | ||
190 | /* | |
191 | * Traverse the tree of nodes until we bubble back up to where we | |
192 | * started. When Level is zero, the loop is done because we have | |
193 | * bubbled up to (and passed) the original parent handle (start_entry) | |
194 | */ | |
195 | while (level > 0) { | |
196 | /* Get the next node in this scope. Null if not found */ | |
197 | ||
198 | status = AE_OK; | |
199 | child_node = acpi_ns_get_next_node (ACPI_TYPE_ANY, parent_node, child_node); | |
200 | if (child_node) { | |
201 | /* | |
202 | * Found node, Get the type if we are not | |
203 | * searching for ANY | |
204 | */ | |
205 | if (type != ACPI_TYPE_ANY) { | |
206 | child_type = child_node->type; | |
207 | } | |
208 | ||
209 | if (child_type == type) { | |
210 | /* | |
211 | * Found a matching node, invoke the user | |
212 | * callback function | |
213 | */ | |
214 | if (unlock_before_callback) { | |
215 | mutex_status = acpi_ut_release_mutex (ACPI_MTX_NAMESPACE); | |
216 | if (ACPI_FAILURE (mutex_status)) { | |
217 | return_ACPI_STATUS (mutex_status); | |
218 | } | |
219 | } | |
220 | ||
221 | status = user_function (child_node, level, | |
222 | context, return_value); | |
223 | ||
224 | if (unlock_before_callback) { | |
225 | mutex_status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE); | |
226 | if (ACPI_FAILURE (mutex_status)) { | |
227 | return_ACPI_STATUS (mutex_status); | |
228 | } | |
229 | } | |
230 | ||
231 | switch (status) { | |
232 | case AE_OK: | |
233 | case AE_CTRL_DEPTH: | |
234 | ||
235 | /* Just keep going */ | |
236 | break; | |
237 | ||
238 | case AE_CTRL_TERMINATE: | |
239 | ||
240 | /* Exit now, with OK status */ | |
241 | ||
242 | return_ACPI_STATUS (AE_OK); | |
243 | ||
244 | default: | |
245 | ||
246 | /* All others are valid exceptions */ | |
247 | ||
248 | return_ACPI_STATUS (status); | |
249 | } | |
250 | } | |
251 | ||
252 | /* | |
253 | * Depth first search: | |
254 | * Attempt to go down another level in the namespace | |
255 | * if we are allowed to. Don't go any further if we | |
256 | * have reached the caller specified maximum depth | |
257 | * or if the user function has specified that the | |
258 | * maximum depth has been reached. | |
259 | */ | |
260 | if ((level < max_depth) && (status != AE_CTRL_DEPTH)) { | |
261 | if (acpi_ns_get_next_node (ACPI_TYPE_ANY, child_node, NULL)) { | |
262 | /* | |
263 | * There is at least one child of this | |
264 | * node, visit the onde | |
265 | */ | |
266 | level++; | |
267 | parent_node = child_node; | |
268 | child_node = NULL; | |
269 | } | |
270 | } | |
271 | } | |
272 | else { | |
273 | /* | |
274 | * No more children of this node (acpi_ns_get_next_node | |
275 | * failed), go back upwards in the namespace tree to | |
276 | * the node's parent. | |
277 | */ | |
278 | level--; | |
279 | child_node = parent_node; | |
280 | parent_node = acpi_ns_get_parent_node (parent_node); | |
281 | } | |
282 | } | |
283 | ||
284 | /* Complete walk, not terminated by user function */ | |
285 | ||
286 | return_ACPI_STATUS (AE_OK); | |
287 | } | |
288 | ||
289 |