1 /*******************************************************************************
2 *
3 * Module Name: nssearch - Namespace search
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 ("nssearch")
51
52
53 /*******************************************************************************
54 *
55 * FUNCTION: acpi_ns_search_node
56 *
57 * PARAMETERS: *target_name - Ascii ACPI name to search for
58 * *Node - Starting node where search will begin
59 * Type - Object type to match
60 * **return_node - Where the matched Named obj is returned
61 *
62 * RETURN: Status
63 *
64 * DESCRIPTION: Search a single level of the namespace. Performs a
65 * simple search of the specified level, and does not add
66 * entries or search parents.
67 *
68 *
69 * Named object lists are built (and subsequently dumped) in the
70 * order in which the names are encountered during the namespace load;
71 *
72 * All namespace searching is linear in this implementation, but
73 * could be easily modified to support any improved search
74 * algorithm. However, the linear search was chosen for simplicity
75 * and because the trees are small and the other interpreter
76 * execution overhead is relatively high.
77 *
78 ******************************************************************************/
79
80 acpi_status
81 acpi_ns_search_node (
82 u32 target_name,
83 struct acpi_namespace_node *node,
84 acpi_object_type type,
85 struct acpi_namespace_node **return_node)
86 {
87 struct acpi_namespace_node *next_node;
88
89
90 ACPI_FUNCTION_TRACE ("ns_search_node");
91
92
93 #ifdef ACPI_DEBUG_OUTPUT
94 if (ACPI_LV_NAMES & acpi_dbg_level) {
95 char *scope_name;
96
97 scope_name = acpi_ns_get_external_pathname (node);
98 if (scope_name) {
99 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
100 "Searching %s (%p) For [%4.4s] (%s)\n",
101 scope_name, node, (char *) &target_name,
102 acpi_ut_get_type_name (type)));
103
104 ACPI_MEM_FREE (scope_name);
105 }
106 }
107 #endif
108
109 /*
110 * Search for name at this namespace level, which is to say that we
111 * must search for the name among the children of this object
112 */
113 next_node = node->child;
114 while (next_node) {
115 /* Check for match against the name */
116
117 if (next_node->name.integer == target_name) {
118 /* Resolve a control method alias if any */
119
120 if (acpi_ns_get_type (next_node) == ACPI_TYPE_LOCAL_METHOD_ALIAS) {
121 next_node = ACPI_CAST_PTR (struct acpi_namespace_node, next_node->object);
122 }
123
124 /*
125 * Found matching entry.
126 */
127 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
128 "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",
129 (char *) &target_name, acpi_ut_get_type_name (next_node->type),
130 next_node, acpi_ut_get_node_name (node), node));
131
132 *return_node = next_node;
133 return_ACPI_STATUS (AE_OK);
134 }
135
136 /*
137 * The last entry in the list points back to the parent,
138 * so a flag is used to indicate the end-of-list
139 */
140 if (next_node->flags & ANOBJ_END_OF_PEER_LIST) {
141 /* Searched entire list, we are done */
142
143 break;
144 }
145
146 /* Didn't match name, move on to the next peer object */
147
148 next_node = next_node->peer;
149 }
150
151 /* Searched entire namespace level, not found */
152
153 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
154 "Name [%4.4s] (%s) not found in search in scope [%4.4s] %p first child %p\n",
155 (char *) &target_name, acpi_ut_get_type_name (type),
156 acpi_ut_get_node_name (node), node, node->child));
157
158 return_ACPI_STATUS (AE_NOT_FOUND);
159 }
160
161
162 /*******************************************************************************
163 *
164 * FUNCTION: acpi_ns_search_parent_tree
165 *
166 * PARAMETERS: *target_name - Ascii ACPI name to search for
167 * *Node - Starting node where search will begin
168 * Type - Object type to match
169 * **return_node - Where the matched Node is returned
170 *
171 * RETURN: Status
172 *
173 * DESCRIPTION: Called when a name has not been found in the current namespace
174 * level. Before adding it or giving up, ACPI scope rules require
175 * searching enclosing scopes in cases identified by acpi_ns_local().
176 *
177 * "A name is located by finding the matching name in the current
178 * name space, and then in the parent name space. If the parent
179 * name space does not contain the name, the search continues
180 * recursively until either the name is found or the name space
181 * does not have a parent (the root of the name space). This
182 * indicates that the name is not found" (From ACPI Specification,
183 * section 5.3)
184 *
185 ******************************************************************************/
186
187 static acpi_status
188 acpi_ns_search_parent_tree (
189 u32 target_name,
190 struct acpi_namespace_node *node,
191 acpi_object_type type,
192 struct acpi_namespace_node **return_node)
193 {
194 acpi_status status;
195 struct acpi_namespace_node *parent_node;
196
197
198 ACPI_FUNCTION_TRACE ("ns_search_parent_tree");
199
200
201 parent_node = acpi_ns_get_parent_node (node);
202
203 /*
204 * If there is no parent (i.e., we are at the root) or type is "local",
205 * we won't be searching the parent tree.
206 */
207 if (!parent_node) {
208 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "[%4.4s] has no parent\n",
209 (char *) &target_name));
210 return_ACPI_STATUS (AE_NOT_FOUND);
211 }
212
213 if (acpi_ns_local (type)) {
214 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
215 "[%4.4s] type [%s] must be local to this scope (no parent search)\n",
216 (char *) &target_name, acpi_ut_get_type_name (type)));
217 return_ACPI_STATUS (AE_NOT_FOUND);
218 }
219
220 /* Search the parent tree */
221
222 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
223 "Searching parent [%4.4s] for [%4.4s]\n",
224 acpi_ut_get_node_name (parent_node), (char *) &target_name));
225
226 /*
227 * Search parents until target is found or we have backed up to the root
228 */
229 while (parent_node) {
230 /*
231 * Search parent scope. Use TYPE_ANY because we don't care about the
232 * object type at this point, we only care about the existence of
233 * the actual name we are searching for. Typechecking comes later.
234 */
235 status = acpi_ns_search_node (target_name, parent_node,
236 ACPI_TYPE_ANY, return_node);
237 if (ACPI_SUCCESS (status)) {
238 return_ACPI_STATUS (status);
239 }
240
241 /*
242 * Not found here, go up another level
243 * (until we reach the root)
244 */
245 parent_node = acpi_ns_get_parent_node (parent_node);
246 }
247
248 /* Not found in parent tree */
249
250 return_ACPI_STATUS (AE_NOT_FOUND);
251 }
252
253
254 /*******************************************************************************
255 *
256 * FUNCTION: acpi_ns_search_and_enter
257 *
258 * PARAMETERS: target_name - Ascii ACPI name to search for (4 chars)
259 * walk_state - Current state of the walk
260 * *Node - Starting node where search will begin
261 * interpreter_mode - Add names only in ACPI_MODE_LOAD_PASS_x.
262 * Otherwise,search only.
263 * Type - Object type to match
264 * Flags - Flags describing the search restrictions
265 * **return_node - Where the Node is returned
266 *
267 * RETURN: Status
268 *
269 * DESCRIPTION: Search for a name segment in a single namespace level,
270 * optionally adding it if it is not found. If the passed
271 * Type is not Any and the type previously stored in the
272 * entry was Any (i.e. unknown), update the stored type.
273 *
274 * In ACPI_IMODE_EXECUTE, search only.
275 * In other modes, search and add if not found.
276 *
277 ******************************************************************************/
278
279 acpi_status
280 acpi_ns_search_and_enter (
281 u32 target_name,
282 struct acpi_walk_state *walk_state,
283 struct acpi_namespace_node *node,
284 acpi_interpreter_mode interpreter_mode,
285 acpi_object_type type,
286 u32 flags,
287 struct acpi_namespace_node **return_node)
288 {
289 acpi_status status;
290 struct acpi_namespace_node *new_node;
291
292
293 ACPI_FUNCTION_TRACE ("ns_search_and_enter");
294
295
296 /* Parameter validation */
297
298 if (!node || !target_name || !return_node) {
299 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
300 "Null param: Node %p Name %X return_node %p\n",
301 node, target_name, return_node));
302
303 ACPI_REPORT_ERROR (("ns_search_and_enter: Null parameter\n"));
304 return_ACPI_STATUS (AE_BAD_PARAMETER);
305 }
306
307 /* Name must consist of printable characters */
308
309 if (!acpi_ut_valid_acpi_name (target_name)) {
310 ACPI_REPORT_ERROR (("ns_search_and_enter: Bad character in ACPI Name: %X\n",
311 target_name));
312 return_ACPI_STATUS (AE_BAD_CHARACTER);
313 }
314
315 /* Try to find the name in the namespace level specified by the caller */
316
317 *return_node = ACPI_ENTRY_NOT_FOUND;
318 status = acpi_ns_search_node (target_name, node, type, return_node);
319 if (status != AE_NOT_FOUND) {
320 /*
321 * If we found it AND the request specifies that a find is an error,
322 * return the error
323 */
324 if ((status == AE_OK) &&
325 (flags & ACPI_NS_ERROR_IF_FOUND)) {
326 status = AE_ALREADY_EXISTS;
327 }
328
329 /*
330 * Either found it or there was an error
331 * -- finished either way
332 */
333 return_ACPI_STATUS (status);
334 }
335
336 /*
337 * The name was not found. If we are NOT performing the first pass
338 * (name entry) of loading the namespace, search the parent tree (all the
339 * way to the root if necessary.) We don't want to perform the parent
340 * search when the namespace is actually being loaded. We want to perform
341 * the search when namespace references are being resolved (load pass 2)
342 * and during the execution phase.
343 */
344 if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) &&
345 (flags & ACPI_NS_SEARCH_PARENT)) {
346 /*
347 * Not found at this level - search parent tree according to the
348 * ACPI specification
349 */
350 status = acpi_ns_search_parent_tree (target_name, node, type, return_node);
351 if (ACPI_SUCCESS (status)) {
352 return_ACPI_STATUS (status);
353 }
354 }
355
356 /*
357 * In execute mode, just search, never add names. Exit now.
358 */
359 if (interpreter_mode == ACPI_IMODE_EXECUTE) {
360 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
361 "%4.4s Not found in %p [Not adding]\n",
362 (char *) &target_name, node));
363
364 return_ACPI_STATUS (AE_NOT_FOUND);
365 }
366
367 /* Create the new named object */
368
369 new_node = acpi_ns_create_node (target_name);
370 if (!new_node) {
371 return_ACPI_STATUS (AE_NO_MEMORY);
372 }
373
374 /* Install the new object into the parent's list of children */
375
376 acpi_ns_install_node (walk_state, node, new_node, type);
377 *return_node = new_node;
378
379 return_ACPI_STATUS (AE_OK);
380 }
381
382
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