Merge branch 'for-linus' of git://neil.brown.name/md
[deliverable/linux.git] / drivers / acpi / acpica / nssearch.c
CommitLineData
1da177e4
LT
1/*******************************************************************************
2 *
3 * Module Name: nssearch - Namespace search
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
e4c1ebfc
BM
48#ifdef ACPI_ASL_COMPILER
49#include "amlcode.h"
50#endif
51
1da177e4 52#define _COMPONENT ACPI_NAMESPACE
4be44fcd 53ACPI_MODULE_NAME("nssearch")
1da177e4 54
44f6c012 55/* Local prototypes */
44f6c012 56static acpi_status
4be44fcd
LB
57acpi_ns_search_parent_tree(u32 target_name,
58 struct acpi_namespace_node *node,
59 acpi_object_type type,
60 struct acpi_namespace_node **return_node);
1da177e4
LT
61
62/*******************************************************************************
63 *
4119532c 64 * FUNCTION: acpi_ns_search_one_scope
1da177e4 65 *
44f6c012 66 * PARAMETERS: target_name - Ascii ACPI name to search for
4119532c 67 * parent_node - Starting node where search will begin
44f6c012
RM
68 * Type - Object type to match
69 * return_node - Where the matched Named obj is returned
1da177e4
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70 *
71 * RETURN: Status
72 *
4119532c 73 * DESCRIPTION: Search a single level of the namespace. Performs a
1da177e4
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74 * simple search of the specified level, and does not add
75 * entries or search parents.
76 *
77 *
78 * Named object lists are built (and subsequently dumped) in the
79 * order in which the names are encountered during the namespace load;
80 *
81 * All namespace searching is linear in this implementation, but
82 * could be easily modified to support any improved search
4119532c 83 * algorithm. However, the linear search was chosen for simplicity
1da177e4
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84 * and because the trees are small and the other interpreter
85 * execution overhead is relatively high.
86 *
4119532c
BM
87 * Note: CPU execution analysis has shown that the AML interpreter spends
88 * a very small percentage of its time searching the namespace. Therefore,
89 * the linear search seems to be sufficient, as there would seem to be
90 * little value in improving the search.
91 *
1da177e4
LT
92 ******************************************************************************/
93
94acpi_status
4119532c
BM
95acpi_ns_search_one_scope(u32 target_name,
96 struct acpi_namespace_node *parent_node,
97 acpi_object_type type,
98 struct acpi_namespace_node **return_node)
1da177e4 99{
4119532c 100 struct acpi_namespace_node *node;
1da177e4 101
4119532c 102 ACPI_FUNCTION_TRACE(ns_search_one_scope);
1da177e4
LT
103
104#ifdef ACPI_DEBUG_OUTPUT
105 if (ACPI_LV_NAMES & acpi_dbg_level) {
4be44fcd 106 char *scope_name;
1da177e4 107
4119532c 108 scope_name = acpi_ns_get_external_pathname(parent_node);
1da177e4 109 if (scope_name) {
4be44fcd
LB
110 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
111 "Searching %s (%p) For [%4.4s] (%s)\n",
4119532c
BM
112 scope_name, parent_node,
113 ACPI_CAST_PTR(char, &target_name),
4be44fcd 114 acpi_ut_get_type_name(type)));
1da177e4 115
8313524a 116 ACPI_FREE(scope_name);
1da177e4
LT
117 }
118 }
119#endif
120
121 /*
122 * Search for name at this namespace level, which is to say that we
123 * must search for the name among the children of this object
124 */
4119532c
BM
125 node = parent_node->child;
126 while (node) {
52fc0b02 127
1da177e4
LT
128 /* Check for match against the name */
129
4119532c 130 if (node->name.integer == target_name) {
52fc0b02 131
1da177e4
LT
132 /* Resolve a control method alias if any */
133
4119532c 134 if (acpi_ns_get_type(node) ==
4be44fcd 135 ACPI_TYPE_LOCAL_METHOD_ALIAS) {
4119532c 136 node =
4be44fcd 137 ACPI_CAST_PTR(struct acpi_namespace_node,
4119532c 138 node->object);
1da177e4
LT
139 }
140
793c2388
BM
141 /* Found matching entry */
142
4be44fcd
LB
143 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
144 "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",
defba1d8 145 ACPI_CAST_PTR(char, &target_name),
4119532c
BM
146 acpi_ut_get_type_name(node->type),
147 node,
148 acpi_ut_get_node_name(parent_node),
149 parent_node));
1da177e4 150
4119532c 151 *return_node = node;
4be44fcd 152 return_ACPI_STATUS(AE_OK);
1da177e4
LT
153 }
154
155 /*
156 * The last entry in the list points back to the parent,
157 * so a flag is used to indicate the end-of-list
158 */
4119532c 159 if (node->flags & ANOBJ_END_OF_PEER_LIST) {
52fc0b02 160
1da177e4
LT
161 /* Searched entire list, we are done */
162
163 break;
164 }
165
166 /* Didn't match name, move on to the next peer object */
167
4119532c 168 node = node->peer;
1da177e4
LT
169 }
170
171 /* Searched entire namespace level, not found */
172
4be44fcd 173 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
d4913dc6
BM
174 "Name [%4.4s] (%s) not found in search in scope [%4.4s] "
175 "%p first child %p\n",
defba1d8
BM
176 ACPI_CAST_PTR(char, &target_name),
177 acpi_ut_get_type_name(type),
4119532c
BM
178 acpi_ut_get_node_name(parent_node), parent_node,
179 parent_node->child));
1da177e4 180
4be44fcd 181 return_ACPI_STATUS(AE_NOT_FOUND);
1da177e4
LT
182}
183
1da177e4
LT
184/*******************************************************************************
185 *
186 * FUNCTION: acpi_ns_search_parent_tree
187 *
44f6c012
RM
188 * PARAMETERS: target_name - Ascii ACPI name to search for
189 * Node - Starting node where search will begin
190 * Type - Object type to match
191 * return_node - Where the matched Node is returned
1da177e4
LT
192 *
193 * RETURN: Status
194 *
195 * DESCRIPTION: Called when a name has not been found in the current namespace
4119532c 196 * level. Before adding it or giving up, ACPI scope rules require
1da177e4
LT
197 * searching enclosing scopes in cases identified by acpi_ns_local().
198 *
199 * "A name is located by finding the matching name in the current
200 * name space, and then in the parent name space. If the parent
201 * name space does not contain the name, the search continues
202 * recursively until either the name is found or the name space
4119532c 203 * does not have a parent (the root of the name space). This
1da177e4
LT
204 * indicates that the name is not found" (From ACPI Specification,
205 * section 5.3)
206 *
207 ******************************************************************************/
208
209static acpi_status
4be44fcd
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210acpi_ns_search_parent_tree(u32 target_name,
211 struct acpi_namespace_node *node,
212 acpi_object_type type,
213 struct acpi_namespace_node **return_node)
1da177e4 214{
4be44fcd
LB
215 acpi_status status;
216 struct acpi_namespace_node *parent_node;
1da177e4 217
b229cf92 218 ACPI_FUNCTION_TRACE(ns_search_parent_tree);
1da177e4 219
4be44fcd 220 parent_node = acpi_ns_get_parent_node(node);
1da177e4
LT
221
222 /*
223 * If there is no parent (i.e., we are at the root) or type is "local",
224 * we won't be searching the parent tree.
225 */
226 if (!parent_node) {
4be44fcd 227 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "[%4.4s] has no parent\n",
defba1d8 228 ACPI_CAST_PTR(char, &target_name)));
4be44fcd 229 return_ACPI_STATUS(AE_NOT_FOUND);
1da177e4
LT
230 }
231
4be44fcd
LB
232 if (acpi_ns_local(type)) {
233 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
234 "[%4.4s] type [%s] must be local to this scope (no parent search)\n",
defba1d8 235 ACPI_CAST_PTR(char, &target_name),
4be44fcd
LB
236 acpi_ut_get_type_name(type)));
237 return_ACPI_STATUS(AE_NOT_FOUND);
1da177e4
LT
238 }
239
240 /* Search the parent tree */
241
4be44fcd
LB
242 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
243 "Searching parent [%4.4s] for [%4.4s]\n",
244 acpi_ut_get_node_name(parent_node),
defba1d8 245 ACPI_CAST_PTR(char, &target_name)));
1da177e4 246
d4913dc6
BM
247 /* Search parents until target is found or we have backed up to the root */
248
1da177e4
LT
249 while (parent_node) {
250 /*
4119532c 251 * Search parent scope. Use TYPE_ANY because we don't care about the
1da177e4 252 * object type at this point, we only care about the existence of
4119532c 253 * the actual name we are searching for. Typechecking comes later.
1da177e4 254 */
4119532c
BM
255 status =
256 acpi_ns_search_one_scope(target_name, parent_node,
4be44fcd
LB
257 ACPI_TYPE_ANY, return_node);
258 if (ACPI_SUCCESS(status)) {
259 return_ACPI_STATUS(status);
1da177e4
LT
260 }
261
793c2388
BM
262 /* Not found here, go up another level (until we reach the root) */
263
4be44fcd 264 parent_node = acpi_ns_get_parent_node(parent_node);
1da177e4
LT
265 }
266
267 /* Not found in parent tree */
268
4be44fcd 269 return_ACPI_STATUS(AE_NOT_FOUND);
1da177e4
LT
270}
271
1da177e4
LT
272/*******************************************************************************
273 *
274 * FUNCTION: acpi_ns_search_and_enter
275 *
276 * PARAMETERS: target_name - Ascii ACPI name to search for (4 chars)
277 * walk_state - Current state of the walk
44f6c012 278 * Node - Starting node where search will begin
1da177e4
LT
279 * interpreter_mode - Add names only in ACPI_MODE_LOAD_PASS_x.
280 * Otherwise,search only.
281 * Type - Object type to match
282 * Flags - Flags describing the search restrictions
44f6c012 283 * return_node - Where the Node is returned
1da177e4
LT
284 *
285 * RETURN: Status
286 *
287 * DESCRIPTION: Search for a name segment in a single namespace level,
4119532c 288 * optionally adding it if it is not found. If the passed
1da177e4
LT
289 * Type is not Any and the type previously stored in the
290 * entry was Any (i.e. unknown), update the stored type.
291 *
292 * In ACPI_IMODE_EXECUTE, search only.
293 * In other modes, search and add if not found.
294 *
295 ******************************************************************************/
296
297acpi_status
4be44fcd
LB
298acpi_ns_search_and_enter(u32 target_name,
299 struct acpi_walk_state *walk_state,
300 struct acpi_namespace_node *node,
301 acpi_interpreter_mode interpreter_mode,
302 acpi_object_type type,
303 u32 flags, struct acpi_namespace_node **return_node)
1da177e4 304{
4be44fcd
LB
305 acpi_status status;
306 struct acpi_namespace_node *new_node;
1da177e4 307
b229cf92 308 ACPI_FUNCTION_TRACE(ns_search_and_enter);
1da177e4
LT
309
310 /* Parameter validation */
311
312 if (!node || !target_name || !return_node) {
b8e4d893 313 ACPI_ERROR((AE_INFO,
958dd242 314 "Null parameter: Node %p Name %X ReturnNode %p",
b8e4d893 315 node, target_name, return_node));
4be44fcd 316 return_ACPI_STATUS(AE_BAD_PARAMETER);
1da177e4
LT
317 }
318
793c2388
BM
319 /*
320 * Name must consist of valid ACPI characters. We will repair the name if
321 * necessary because we don't want to abort because of this, but we want
322 * all namespace names to be printable. A warning message is appropriate.
323 *
324 * This issue came up because there are in fact machines that exhibit
325 * this problem, and we want to be able to enable ACPI support for them,
326 * even though there are a few bad names.
327 */
4be44fcd 328 if (!acpi_ut_valid_acpi_name(target_name)) {
3d81b236
BM
329 target_name =
330 acpi_ut_repair_name(ACPI_CAST_PTR(char, &target_name));
793c2388
BM
331
332 /* Report warning only if in strict mode or debug mode */
333
334 if (!acpi_gbl_enable_interpreter_slack) {
335 ACPI_WARNING((AE_INFO,
336 "Found bad character(s) in name, repaired: [%4.4s]\n",
337 ACPI_CAST_PTR(char, &target_name)));
338 } else {
23d3e055 339 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
793c2388
BM
340 "Found bad character(s) in name, repaired: [%4.4s]\n",
341 ACPI_CAST_PTR(char, &target_name)));
342 }
1da177e4
LT
343 }
344
345 /* Try to find the name in the namespace level specified by the caller */
346
347 *return_node = ACPI_ENTRY_NOT_FOUND;
4119532c 348 status = acpi_ns_search_one_scope(target_name, node, type, return_node);
1da177e4
LT
349 if (status != AE_NOT_FOUND) {
350 /*
351 * If we found it AND the request specifies that a find is an error,
352 * return the error
353 */
4be44fcd 354 if ((status == AE_OK) && (flags & ACPI_NS_ERROR_IF_FOUND)) {
1da177e4
LT
355 status = AE_ALREADY_EXISTS;
356 }
357
793c2388
BM
358 /* Either found it or there was an error: finished either way */
359
4be44fcd 360 return_ACPI_STATUS(status);
1da177e4
LT
361 }
362
363 /*
4119532c 364 * The name was not found. If we are NOT performing the first pass
1da177e4
LT
365 * (name entry) of loading the namespace, search the parent tree (all the
366 * way to the root if necessary.) We don't want to perform the parent
4119532c 367 * search when the namespace is actually being loaded. We want to perform
1da177e4
LT
368 * the search when namespace references are being resolved (load pass 2)
369 * and during the execution phase.
370 */
371 if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) &&
4be44fcd 372 (flags & ACPI_NS_SEARCH_PARENT)) {
1da177e4
LT
373 /*
374 * Not found at this level - search parent tree according to the
375 * ACPI specification
376 */
4be44fcd
LB
377 status =
378 acpi_ns_search_parent_tree(target_name, node, type,
379 return_node);
380 if (ACPI_SUCCESS(status)) {
381 return_ACPI_STATUS(status);
1da177e4
LT
382 }
383 }
384
793c2388
BM
385 /* In execute mode, just search, never add names. Exit now */
386
1da177e4 387 if (interpreter_mode == ACPI_IMODE_EXECUTE) {
4be44fcd
LB
388 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
389 "%4.4s Not found in %p [Not adding]\n",
defba1d8 390 ACPI_CAST_PTR(char, &target_name), node));
1da177e4 391
4be44fcd 392 return_ACPI_STATUS(AE_NOT_FOUND);
1da177e4
LT
393 }
394
395 /* Create the new named object */
396
4be44fcd 397 new_node = acpi_ns_create_node(target_name);
1da177e4 398 if (!new_node) {
4be44fcd 399 return_ACPI_STATUS(AE_NO_MEMORY);
1da177e4 400 }
958dd242 401#ifdef ACPI_ASL_COMPILER
d4913dc6
BM
402
403 /* Node is an object defined by an External() statement */
404
958dd242
BM
405 if (flags & ACPI_NS_EXTERNAL) {
406 new_node->flags |= ANOBJ_IS_EXTERNAL;
407 }
408#endif
1da177e4 409
d1fdda83
BM
410 if (flags & ACPI_NS_TEMPORARY) {
411 new_node->flags |= ANOBJ_TEMPORARY;
412 }
413
1da177e4
LT
414 /* Install the new object into the parent's list of children */
415
4be44fcd 416 acpi_ns_install_node(walk_state, node, new_node, type);
1da177e4 417 *return_node = new_node;
4be44fcd 418 return_ACPI_STATUS(AE_OK);
1da177e4 419}
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