Revert "ARM: tegra: tegratab: dummy change"
[linux-2.6.git] / drivers / acpi / acpica / nssearch.c
1 /*******************************************************************************
2  *
3  * Module Name: nssearch - Namespace search
4  *
5  ******************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2012, Intel Corp.
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 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acnamesp.h"
47
48 #ifdef ACPI_ASL_COMPILER
49 #include "amlcode.h"
50 #endif
51
52 #define _COMPONENT          ACPI_NAMESPACE
53 ACPI_MODULE_NAME("nssearch")
54
55 /* Local prototypes */
56 static acpi_status
57 acpi_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);
61
62 /*******************************************************************************
63  *
64  * FUNCTION:    acpi_ns_search_one_scope
65  *
66  * PARAMETERS:  target_name     - Ascii ACPI name to search for
67  *              parent_node     - Starting node where search will begin
68  *              Type            - Object type to match
69  *              return_node     - Where the matched Named obj is returned
70  *
71  * RETURN:      Status
72  *
73  * DESCRIPTION: Search a single level of the namespace. Performs a
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
83  *      algorithm. However, the linear search was chosen for simplicity
84  *      and because the trees are small and the other interpreter
85  *      execution overhead is relatively high.
86  *
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  *
92  ******************************************************************************/
93
94 acpi_status
95 acpi_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)
99 {
100         struct acpi_namespace_node *node;
101
102         ACPI_FUNCTION_TRACE(ns_search_one_scope);
103
104 #ifdef ACPI_DEBUG_OUTPUT
105         if (ACPI_LV_NAMES & acpi_dbg_level) {
106                 char *scope_name;
107
108                 scope_name = acpi_ns_get_external_pathname(parent_node);
109                 if (scope_name) {
110                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
111                                           "Searching %s (%p) For [%4.4s] (%s)\n",
112                                           scope_name, parent_node,
113                                           ACPI_CAST_PTR(char, &target_name),
114                                           acpi_ut_get_type_name(type)));
115
116                         ACPI_FREE(scope_name);
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          */
125         node = parent_node->child;
126         while (node) {
127
128                 /* Check for match against the name */
129
130                 if (node->name.integer == target_name) {
131
132                         /* Resolve a control method alias if any */
133
134                         if (acpi_ns_get_type(node) ==
135                             ACPI_TYPE_LOCAL_METHOD_ALIAS) {
136                                 node =
137                                     ACPI_CAST_PTR(struct acpi_namespace_node,
138                                                   node->object);
139                         }
140
141                         /* Found matching entry */
142
143                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
144                                           "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",
145                                           ACPI_CAST_PTR(char, &target_name),
146                                           acpi_ut_get_type_name(node->type),
147                                           node,
148                                           acpi_ut_get_node_name(parent_node),
149                                           parent_node));
150
151                         *return_node = node;
152                         return_ACPI_STATUS(AE_OK);
153                 }
154
155                 /* Didn't match name, move on to the next peer object */
156
157                 node = node->peer;
158         }
159
160         /* Searched entire namespace level, not found */
161
162         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
163                           "Name [%4.4s] (%s) not found in search in scope [%4.4s] "
164                           "%p first child %p\n",
165                           ACPI_CAST_PTR(char, &target_name),
166                           acpi_ut_get_type_name(type),
167                           acpi_ut_get_node_name(parent_node), parent_node,
168                           parent_node->child));
169
170         return_ACPI_STATUS(AE_NOT_FOUND);
171 }
172
173 /*******************************************************************************
174  *
175  * FUNCTION:    acpi_ns_search_parent_tree
176  *
177  * PARAMETERS:  target_name     - Ascii ACPI name to search for
178  *              Node            - Starting node where search will begin
179  *              Type            - Object type to match
180  *              return_node     - Where the matched Node is returned
181  *
182  * RETURN:      Status
183  *
184  * DESCRIPTION: Called when a name has not been found in the current namespace
185  *              level. Before adding it or giving up, ACPI scope rules require
186  *              searching enclosing scopes in cases identified by acpi_ns_local().
187  *
188  *              "A name is located by finding the matching name in the current
189  *              name space, and then in the parent name space. If the parent
190  *              name space does not contain the name, the search continues
191  *              recursively until either the name is found or the name space
192  *              does not have a parent (the root of the name space). This
193  *              indicates that the name is not found" (From ACPI Specification,
194  *              section 5.3)
195  *
196  ******************************************************************************/
197
198 static acpi_status
199 acpi_ns_search_parent_tree(u32 target_name,
200                            struct acpi_namespace_node *node,
201                            acpi_object_type type,
202                            struct acpi_namespace_node **return_node)
203 {
204         acpi_status status;
205         struct acpi_namespace_node *parent_node;
206
207         ACPI_FUNCTION_TRACE(ns_search_parent_tree);
208
209         parent_node = node->parent;
210
211         /*
212          * If there is no parent (i.e., we are at the root) or type is "local",
213          * we won't be searching the parent tree.
214          */
215         if (!parent_node) {
216                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "[%4.4s] has no parent\n",
217                                   ACPI_CAST_PTR(char, &target_name)));
218                 return_ACPI_STATUS(AE_NOT_FOUND);
219         }
220
221         if (acpi_ns_local(type)) {
222                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
223                                   "[%4.4s] type [%s] must be local to this scope (no parent search)\n",
224                                   ACPI_CAST_PTR(char, &target_name),
225                                   acpi_ut_get_type_name(type)));
226                 return_ACPI_STATUS(AE_NOT_FOUND);
227         }
228
229         /* Search the parent tree */
230
231         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
232                           "Searching parent [%4.4s] for [%4.4s]\n",
233                           acpi_ut_get_node_name(parent_node),
234                           ACPI_CAST_PTR(char, &target_name)));
235
236         /* Search parents until target is found or we have backed up to the root */
237
238         while (parent_node) {
239                 /*
240                  * Search parent scope. Use TYPE_ANY because we don't care about the
241                  * object type at this point, we only care about the existence of
242                  * the actual name we are searching for. Typechecking comes later.
243                  */
244                 status =
245                     acpi_ns_search_one_scope(target_name, parent_node,
246                                              ACPI_TYPE_ANY, return_node);
247                 if (ACPI_SUCCESS(status)) {
248                         return_ACPI_STATUS(status);
249                 }
250
251                 /* Not found here, go up another level (until we reach the root) */
252
253                 parent_node = parent_node->parent;
254         }
255
256         /* Not found in parent tree */
257
258         return_ACPI_STATUS(AE_NOT_FOUND);
259 }
260
261 /*******************************************************************************
262  *
263  * FUNCTION:    acpi_ns_search_and_enter
264  *
265  * PARAMETERS:  target_name         - Ascii ACPI name to search for (4 chars)
266  *              walk_state          - Current state of the walk
267  *              Node                - Starting node where search will begin
268  *              interpreter_mode    - Add names only in ACPI_MODE_LOAD_PASS_x.
269  *                                    Otherwise,search only.
270  *              Type                - Object type to match
271  *              Flags               - Flags describing the search restrictions
272  *              return_node         - Where the Node is returned
273  *
274  * RETURN:      Status
275  *
276  * DESCRIPTION: Search for a name segment in a single namespace level,
277  *              optionally adding it if it is not found. If the passed
278  *              Type is not Any and the type previously stored in the
279  *              entry was Any (i.e. unknown), update the stored type.
280  *
281  *              In ACPI_IMODE_EXECUTE, search only.
282  *              In other modes, search and add if not found.
283  *
284  ******************************************************************************/
285
286 acpi_status
287 acpi_ns_search_and_enter(u32 target_name,
288                          struct acpi_walk_state *walk_state,
289                          struct acpi_namespace_node *node,
290                          acpi_interpreter_mode interpreter_mode,
291                          acpi_object_type type,
292                          u32 flags, struct acpi_namespace_node **return_node)
293 {
294         acpi_status status;
295         struct acpi_namespace_node *new_node;
296
297         ACPI_FUNCTION_TRACE(ns_search_and_enter);
298
299         /* Parameter validation */
300
301         if (!node || !target_name || !return_node) {
302                 ACPI_ERROR((AE_INFO,
303                             "Null parameter: Node %p Name 0x%X ReturnNode %p",
304                             node, target_name, return_node));
305                 return_ACPI_STATUS(AE_BAD_PARAMETER);
306         }
307
308         /*
309          * Name must consist of valid ACPI characters. We will repair the name if
310          * necessary because we don't want to abort because of this, but we want
311          * all namespace names to be printable. A warning message is appropriate.
312          *
313          * This issue came up because there are in fact machines that exhibit
314          * this problem, and we want to be able to enable ACPI support for them,
315          * even though there are a few bad names.
316          */
317         if (!acpi_ut_valid_acpi_name(target_name)) {
318                 target_name =
319                     acpi_ut_repair_name(ACPI_CAST_PTR(char, &target_name));
320
321                 /* Report warning only if in strict mode or debug mode */
322
323                 if (!acpi_gbl_enable_interpreter_slack) {
324                         ACPI_WARNING((AE_INFO,
325                                       "Found bad character(s) in name, repaired: [%4.4s]\n",
326                                       ACPI_CAST_PTR(char, &target_name)));
327                 } else {
328                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
329                                           "Found bad character(s) in name, repaired: [%4.4s]\n",
330                                           ACPI_CAST_PTR(char, &target_name)));
331                 }
332         }
333
334         /* Try to find the name in the namespace level specified by the caller */
335
336         *return_node = ACPI_ENTRY_NOT_FOUND;
337         status = acpi_ns_search_one_scope(target_name, node, type, return_node);
338         if (status != AE_NOT_FOUND) {
339                 /*
340                  * If we found it AND the request specifies that a find is an error,
341                  * return the error
342                  */
343                 if ((status == AE_OK) && (flags & ACPI_NS_ERROR_IF_FOUND)) {
344                         status = AE_ALREADY_EXISTS;
345                 }
346
347                 /* Either found it or there was an error: finished either way */
348
349                 return_ACPI_STATUS(status);
350         }
351
352         /*
353          * The name was not found. If we are NOT performing the first pass
354          * (name entry) of loading the namespace, search the parent tree (all the
355          * way to the root if necessary.) We don't want to perform the parent
356          * search when the namespace is actually being loaded. We want to perform
357          * the search when namespace references are being resolved (load pass 2)
358          * and during the execution phase.
359          */
360         if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) &&
361             (flags & ACPI_NS_SEARCH_PARENT)) {
362                 /*
363                  * Not found at this level - search parent tree according to the
364                  * ACPI specification
365                  */
366                 status =
367                     acpi_ns_search_parent_tree(target_name, node, type,
368                                                return_node);
369                 if (ACPI_SUCCESS(status)) {
370                         return_ACPI_STATUS(status);
371                 }
372         }
373
374         /* In execute mode, just search, never add names. Exit now */
375
376         if (interpreter_mode == ACPI_IMODE_EXECUTE) {
377                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
378                                   "%4.4s Not found in %p [Not adding]\n",
379                                   ACPI_CAST_PTR(char, &target_name), node));
380
381                 return_ACPI_STATUS(AE_NOT_FOUND);
382         }
383
384         /* Create the new named object */
385
386         new_node = acpi_ns_create_node(target_name);
387         if (!new_node) {
388                 return_ACPI_STATUS(AE_NO_MEMORY);
389         }
390 #ifdef ACPI_ASL_COMPILER
391
392         /* Node is an object defined by an External() statement */
393
394         if (flags & ACPI_NS_EXTERNAL) {
395                 new_node->flags |= ANOBJ_IS_EXTERNAL;
396         }
397 #endif
398
399         if (flags & ACPI_NS_TEMPORARY) {
400                 new_node->flags |= ANOBJ_TEMPORARY;
401         }
402
403         /* Install the new object into the parent's list of children */
404
405         acpi_ns_install_node(walk_state, node, new_node, type);
406         *return_node = new_node;
407         return_ACPI_STATUS(AE_OK);
408 }