Revert "ARM: tegra: tegratab: dummy change"
[linux-2.6.git] / drivers / acpi / acpica / nswalk.c
1 /******************************************************************************
2  *
3  * Module Name: nswalk - Functions for walking the ACPI namespace
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 #define _COMPONENT          ACPI_NAMESPACE
49 ACPI_MODULE_NAME("nswalk")
50
51 /*******************************************************************************
52  *
53  * FUNCTION:    acpi_ns_get_next_node
54  *
55  * PARAMETERS:  parent_node         - Parent node whose children we are
56  *                                    getting
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  ******************************************************************************/
68 struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node
69                                                   *parent_node,
70                                                   struct acpi_namespace_node
71                                                   *child_node)
72 {
73         ACPI_FUNCTION_ENTRY();
74
75         if (!child_node) {
76
77                 /* It's really the parent's _scope_ that we want */
78
79                 return parent_node->child;
80         }
81
82         /* Otherwise just return the next peer */
83
84         return child_node->peer;
85 }
86
87 /*******************************************************************************
88  *
89  * FUNCTION:    acpi_ns_get_next_node_typed
90  *
91  * PARAMETERS:  Type                - Type of node to be searched for
92  *              parent_node         - Parent node whose children we are
93  *                                    getting
94  *              child_node          - Previous child that was found.
95  *                                    The NEXT child will be returned
96  *
97  * RETURN:      struct acpi_namespace_node - Pointer to the NEXT child or NULL if
98  *                                    none is found.
99  *
100  * DESCRIPTION: Return the next peer node within the namespace.  If Handle
101  *              is valid, Scope is ignored.  Otherwise, the first node
102  *              within Scope is returned.
103  *
104  ******************************************************************************/
105
106 struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type,
107                                                         struct
108                                                         acpi_namespace_node
109                                                         *parent_node,
110                                                         struct
111                                                         acpi_namespace_node
112                                                         *child_node)
113 {
114         struct acpi_namespace_node *next_node = NULL;
115
116         ACPI_FUNCTION_ENTRY();
117
118         next_node = acpi_ns_get_next_node(parent_node, child_node);
119
120
121         /* If any type is OK, we are done */
122
123         if (type == ACPI_TYPE_ANY) {
124
125                 /* next_node is NULL if we are at the end-of-list */
126
127                 return (next_node);
128         }
129
130         /* Must search for the node -- but within this scope only */
131
132         while (next_node) {
133
134                 /* If type matches, we are done */
135
136                 if (next_node->type == type) {
137                         return (next_node);
138                 }
139
140                 /* Otherwise, move on to the next peer node */
141
142                 next_node = next_node->peer;
143         }
144
145         /* Not found */
146
147         return (NULL);
148 }
149
150 /*******************************************************************************
151  *
152  * FUNCTION:    acpi_ns_walk_namespace
153  *
154  * PARAMETERS:  Type                - acpi_object_type to search for
155  *              start_node          - Handle in namespace where search begins
156  *              max_depth           - Depth to which search is to reach
157  *              Flags               - Whether to unlock the NS before invoking
158  *                                    the callback routine
159  *              pre_order_visit     - Called during tree pre-order visit
160  *                                    when an object of "Type" is found
161  *              post_order_visit    - Called during tree post-order visit
162  *                                    when an object of "Type" is found
163  *              Context             - Passed to user function(s) above
164  *              return_value        - from the user_function if terminated
165  *                                    early. Otherwise, returns NULL.
166  * RETURNS:     Status
167  *
168  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
169  *              starting (and ending) at the node specified by start_handle.
170  *              The callback function is called whenever a node that matches
171  *              the type parameter is found. If the callback function returns
172  *              a non-zero value, the search is terminated immediately and
173  *              this value is returned to the caller.
174  *
175  *              The point of this procedure is to provide a generic namespace
176  *              walk routine that can be called from multiple places to
177  *              provide multiple services; the callback function(s) can be
178  *              tailored to each task, whether it is a print function,
179  *              a compare function, etc.
180  *
181  ******************************************************************************/
182
183 acpi_status
184 acpi_ns_walk_namespace(acpi_object_type type,
185                        acpi_handle start_node,
186                        u32 max_depth,
187                        u32 flags,
188                        acpi_walk_callback pre_order_visit,
189                        acpi_walk_callback post_order_visit,
190                        void *context, void **return_value)
191 {
192         acpi_status status;
193         acpi_status mutex_status;
194         struct acpi_namespace_node *child_node;
195         struct acpi_namespace_node *parent_node;
196         acpi_object_type child_type;
197         u32 level;
198         u8 node_previously_visited = FALSE;
199
200         ACPI_FUNCTION_TRACE(ns_walk_namespace);
201
202         /* Special case for the namespace Root Node */
203
204         if (start_node == ACPI_ROOT_OBJECT) {
205                 start_node = acpi_gbl_root_node;
206         }
207
208         /* Null child means "get first node" */
209
210         parent_node = start_node;
211         child_node = acpi_ns_get_next_node(parent_node, NULL);
212         child_type = ACPI_TYPE_ANY;
213         level = 1;
214
215         /*
216          * Traverse the tree of nodes until we bubble back up to where we
217          * started. When Level is zero, the loop is done because we have
218          * bubbled up to (and passed) the original parent handle (start_entry)
219          */
220         while (level > 0 && child_node) {
221                 status = AE_OK;
222
223                 /* Found next child, get the type if we are not searching for ANY */
224
225                 if (type != ACPI_TYPE_ANY) {
226                         child_type = child_node->type;
227                 }
228
229                 /*
230                  * Ignore all temporary namespace nodes (created during control
231                  * method execution) unless told otherwise. These temporary nodes
232                  * can cause a race condition because they can be deleted during
233                  * the execution of the user function (if the namespace is
234                  * unlocked before invocation of the user function.) Only the
235                  * debugger namespace dump will examine the temporary nodes.
236                  */
237                 if ((child_node->flags & ANOBJ_TEMPORARY) &&
238                     !(flags & ACPI_NS_WALK_TEMP_NODES)) {
239                         status = AE_CTRL_DEPTH;
240                 }
241
242                 /* Type must match requested type */
243
244                 else if (child_type == type) {
245                         /*
246                          * Found a matching node, invoke the user callback function.
247                          * Unlock the namespace if flag is set.
248                          */
249                         if (flags & ACPI_NS_WALK_UNLOCK) {
250                                 mutex_status =
251                                     acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
252                                 if (ACPI_FAILURE(mutex_status)) {
253                                         return_ACPI_STATUS(mutex_status);
254                                 }
255                         }
256
257                         /*
258                          * Invoke the user function, either pre-order or post-order
259                          * or both.
260                          */
261                         if (!node_previously_visited) {
262                                 if (pre_order_visit) {
263                                         status =
264                                             pre_order_visit(child_node, level,
265                                                             context,
266                                                             return_value);
267                                 }
268                         } else {
269                                 if (post_order_visit) {
270                                         status =
271                                             post_order_visit(child_node, level,
272                                                              context,
273                                                              return_value);
274                                 }
275                         }
276
277                         if (flags & ACPI_NS_WALK_UNLOCK) {
278                                 mutex_status =
279                                     acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
280                                 if (ACPI_FAILURE(mutex_status)) {
281                                         return_ACPI_STATUS(mutex_status);
282                                 }
283                         }
284
285                         switch (status) {
286                         case AE_OK:
287                         case AE_CTRL_DEPTH:
288
289                                 /* Just keep going */
290                                 break;
291
292                         case AE_CTRL_TERMINATE:
293
294                                 /* Exit now, with OK status */
295
296                                 return_ACPI_STATUS(AE_OK);
297
298                         default:
299
300                                 /* All others are valid exceptions */
301
302                                 return_ACPI_STATUS(status);
303                         }
304                 }
305
306                 /*
307                  * Depth first search: Attempt to go down another level in the
308                  * namespace if we are allowed to.  Don't go any further if we have
309                  * reached the caller specified maximum depth or if the user
310                  * function has specified that the maximum depth has been reached.
311                  */
312                 if (!node_previously_visited &&
313                     (level < max_depth) && (status != AE_CTRL_DEPTH)) {
314                         if (child_node->child) {
315
316                                 /* There is at least one child of this node, visit it */
317
318                                 level++;
319                                 parent_node = child_node;
320                                 child_node =
321                                     acpi_ns_get_next_node(parent_node, NULL);
322                                 continue;
323                         }
324                 }
325
326                 /* No more children, re-visit this node */
327
328                 if (!node_previously_visited) {
329                         node_previously_visited = TRUE;
330                         continue;
331                 }
332
333                 /* No more children, visit peers */
334
335                 child_node = acpi_ns_get_next_node(parent_node, child_node);
336                 if (child_node) {
337                         node_previously_visited = FALSE;
338                 }
339
340                 /* No peers, re-visit parent */
341
342                 else {
343                         /*
344                          * No more children of this node (acpi_ns_get_next_node failed), go
345                          * back upwards in the namespace tree to the node's parent.
346                          */
347                         level--;
348                         child_node = parent_node;
349                         parent_node = parent_node->parent;
350
351                         node_previously_visited = TRUE;
352                 }
353         }
354
355         /* Complete walk, not terminated by user function */
356
357         return_ACPI_STATUS(AE_OK);
358 }