1 /******************************************************************************
2 *
3 * Module Name: nswalk - Functions for walking the ACPI namespace
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2013, 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
45 #define __NSWALK_C__
46
47 #include "acpi.h"
48 #include "accommon.h"
49 #include "acnamesp.h"
50
51
52 #define _COMPONENT ACPI_NAMESPACE
53 ACPI_MODULE_NAME ("nswalk")
54
55
56 /*******************************************************************************
57 *
58 * FUNCTION: AcpiNsGetNextNode
59 *
60 * PARAMETERS: ParentNode - Parent node whose children we are
61 * getting
62 * ChildNode - Previous child that was found.
63 * The NEXT child will be returned
64 *
65 * RETURN: ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if
66 * none is found.
67 *
68 * DESCRIPTION: Return the next peer node within the namespace. If Handle
69 * is valid, Scope is ignored. Otherwise, the first node
70 * within Scope is returned.
71 *
72 ******************************************************************************/
73
74 ACPI_NAMESPACE_NODE *
75 AcpiNsGetNextNode (
76 ACPI_NAMESPACE_NODE *ParentNode,
77 ACPI_NAMESPACE_NODE *ChildNode)
78 {
79 ACPI_FUNCTION_ENTRY ();
80
81
82 if (!ChildNode)
83 {
84 /* It's really the parent's _scope_ that we want */
85
86 return (ParentNode->Child);
87 }
88
89 /* Otherwise just return the next peer */
90
91 return (ChildNode->Peer);
92 }
93
94
95 /*******************************************************************************
96 *
97 * FUNCTION: AcpiNsGetNextNodeTyped
98 *
99 * PARAMETERS: Type - Type of node to be searched for
100 * ParentNode - Parent node whose children we are
101 * getting
102 * ChildNode - Previous child that was found.
103 * The NEXT child will be returned
104 *
105 * RETURN: ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if
106 * none is found.
107 *
108 * DESCRIPTION: Return the next peer node within the namespace. If Handle
109 * is valid, Scope is ignored. Otherwise, the first node
110 * within Scope is returned.
111 *
112 ******************************************************************************/
113
114 ACPI_NAMESPACE_NODE *
115 AcpiNsGetNextNodeTyped (
116 ACPI_OBJECT_TYPE Type,
117 ACPI_NAMESPACE_NODE *ParentNode,
118 ACPI_NAMESPACE_NODE *ChildNode)
119 {
120 ACPI_NAMESPACE_NODE *NextNode = NULL;
121
122
123 ACPI_FUNCTION_ENTRY ();
124
125
126 NextNode = AcpiNsGetNextNode (ParentNode, ChildNode);
127
128 /* If any type is OK, we are done */
129
130 if (Type == ACPI_TYPE_ANY)
131 {
132 /* NextNode is NULL if we are at the end-of-list */
133
134 return (NextNode);
135 }
136
137 /* Must search for the node -- but within this scope only */
138
139 while (NextNode)
140 {
141 /* If type matches, we are done */
142
143 if (NextNode->Type == Type)
144 {
145 return (NextNode);
146 }
147
148 /* Otherwise, move on to the next peer node */
149
150 NextNode = NextNode->Peer;
151 }
152
153 /* Not found */
154
155 return (NULL);
156 }
157
158
159 /*******************************************************************************
160 *
161 * FUNCTION: AcpiNsWalkNamespace
162 *
163 * PARAMETERS: Type - ACPI_OBJECT_TYPE to search for
164 * StartNode - Handle in namespace where search begins
165 * MaxDepth - Depth to which search is to reach
166 * Flags - Whether to unlock the NS before invoking
167 * the callback routine
168 * DescendingCallback - Called during tree descent
169 * when an object of "Type" is found
170 * AscendingCallback - Called during tree ascent
171 * when an object of "Type" is found
172 * Context - Passed to user function(s) above
173 * ReturnValue - from the UserFunction if terminated
174 * early. Otherwise, returns NULL.
175 * RETURNS: Status
176 *
177 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
178 * starting (and ending) at the node specified by StartHandle.
179 * The callback function is called whenever a node that matches
180 * the type parameter is found. If the callback function returns
181 * a non-zero value, the search is terminated immediately and
182 * this value is returned to the caller.
183 *
184 * The point of this procedure is to provide a generic namespace
185 * walk routine that can be called from multiple places to
186 * provide multiple services; the callback function(s) can be
187 * tailored to each task, whether it is a print function,
188 * a compare function, etc.
189 *
190 ******************************************************************************/
191
192 ACPI_STATUS
193 AcpiNsWalkNamespace (
194 ACPI_OBJECT_TYPE Type,
195 ACPI_HANDLE StartNode,
196 UINT32 MaxDepth,
197 UINT32 Flags,
198 ACPI_WALK_CALLBACK DescendingCallback,
199 ACPI_WALK_CALLBACK AscendingCallback,
200 void *Context,
201 void **ReturnValue)
202 {
203 ACPI_STATUS Status;
204 ACPI_STATUS MutexStatus;
205 ACPI_NAMESPACE_NODE *ChildNode;
206 ACPI_NAMESPACE_NODE *ParentNode;
207 ACPI_OBJECT_TYPE ChildType;
208 UINT32 Level;
209 BOOLEAN NodePreviouslyVisited = FALSE;
210
211
212 ACPI_FUNCTION_TRACE (NsWalkNamespace);
213
214
215 /* Special case for the namespace Root Node */
216
217 if (StartNode == ACPI_ROOT_OBJECT)
218 {
219 StartNode = AcpiGbl_RootNode;
220 }
221
222 /* Null child means "get first node" */
223
224 ParentNode = StartNode;
225 ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
226 ChildType = ACPI_TYPE_ANY;
227 Level = 1;
228
229 /*
230 * Traverse the tree of nodes until we bubble back up to where we
231 * started. When Level is zero, the loop is done because we have
232 * bubbled up to (and passed) the original parent handle (StartEntry)
233 */
234 while (Level > 0 && ChildNode)
235 {
236 Status = AE_OK;
237
238 /* Found next child, get the type if we are not searching for ANY */
239
240 if (Type != ACPI_TYPE_ANY)
241 {
242 ChildType = ChildNode->Type;
243 }
244
245 /*
246 * Ignore all temporary namespace nodes (created during control
247 * method execution) unless told otherwise. These temporary nodes
248 * can cause a race condition because they can be deleted during
249 * the execution of the user function (if the namespace is
250 * unlocked before invocation of the user function.) Only the
251 * debugger namespace dump will examine the temporary nodes.
252 */
253 if ((ChildNode->Flags & ANOBJ_TEMPORARY) &&
254 !(Flags & ACPI_NS_WALK_TEMP_NODES))
255 {
256 Status = AE_CTRL_DEPTH;
257 }
258
259 /* Type must match requested type */
260
261 else if (ChildType == Type)
262 {
263 /*
264 * Found a matching node, invoke the user callback function.
265 * Unlock the namespace if flag is set.
266 */
267 if (Flags & ACPI_NS_WALK_UNLOCK)
268 {
269 MutexStatus = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
270 if (ACPI_FAILURE (MutexStatus))
271 {
272 return_ACPI_STATUS (MutexStatus);
273 }
274 }
275
276 /*
277 * Invoke the user function, either descending, ascending,
278 * or both.
279 */
280 if (!NodePreviouslyVisited)
281 {
282 if (DescendingCallback)
283 {
284 Status = DescendingCallback (ChildNode, Level,
285 Context, ReturnValue);
286 }
287 }
288 else
289 {
290 if (AscendingCallback)
291 {
292 Status = AscendingCallback (ChildNode, Level,
293 Context, ReturnValue);
294 }
295 }
296
297 if (Flags & ACPI_NS_WALK_UNLOCK)
298 {
299 MutexStatus = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
300 if (ACPI_FAILURE (MutexStatus))
301 {
302 return_ACPI_STATUS (MutexStatus);
303 }
304 }
305
306 switch (Status)
307 {
308 case AE_OK:
309 case AE_CTRL_DEPTH:
310
311 /* Just keep going */
312 break;
313
314 case AE_CTRL_TERMINATE:
315
316 /* Exit now, with OK status */
317
318 return_ACPI_STATUS (AE_OK);
319
320 default:
321
322 /* All others are valid exceptions */
323
324 return_ACPI_STATUS (Status);
325 }
326 }
327
328 /*
329 * Depth first search: Attempt to go down another level in the
330 * namespace if we are allowed to. Don't go any further if we have
331 * reached the caller specified maximum depth or if the user
332 * function has specified that the maximum depth has been reached.
333 */
334 if (!NodePreviouslyVisited &&
335 (Level < MaxDepth) &&
336 (Status != AE_CTRL_DEPTH))
337 {
338 if (ChildNode->Child)
339 {
340 /* There is at least one child of this node, visit it */
341
342 Level++;
343 ParentNode = ChildNode;
344 ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
345 continue;
346 }
347 }
348
349 /* No more children, re-visit this node */
350
351 if (!NodePreviouslyVisited)
352 {
353 NodePreviouslyVisited = TRUE;
354 continue;
355 }
356
357 /* No more children, visit peers */
358
359 ChildNode = AcpiNsGetNextNode (ParentNode, ChildNode);
360 if (ChildNode)
361 {
362 NodePreviouslyVisited = FALSE;
363 }
364
365 /* No peers, re-visit parent */
366
367 else
368 {
369 /*
370 * No more children of this node (AcpiNsGetNextNode failed), go
371 * back upwards in the namespace tree to the node's parent.
372 */
373 Level--;
374 ChildNode = ParentNode;
375 ParentNode = ParentNode->Parent;
376
377 NodePreviouslyVisited = TRUE;
378 }
379 }
380
381 /* Complete walk, not terminated by user function */
382
383 return_ACPI_STATUS (AE_OK);
384 }