1 /******************************************************************************
2 *
3 * Module Name: nswalk - Functions for walking the ACPI namespace
4 *
5 *****************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2022, 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 MERCHANTABILITY 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.h"
45 #include "accommon.h"
46 #include "acnamesp.h"
47
48
49 #define _COMPONENT ACPI_NAMESPACE
50 ACPI_MODULE_NAME ("nswalk")
51
52
53 /*******************************************************************************
54 *
55 * FUNCTION: AcpiNsGetNextNode
56 *
57 * PARAMETERS: ParentNode - Parent node whose children we are
58 * getting
59 * ChildNode - Previous child that was found.
60 * The NEXT child will be returned
61 *
62 * RETURN: ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if
63 * none is found.
64 *
65 * DESCRIPTION: Return the next peer node within the namespace. If Handle
66 * is valid, Scope is ignored. Otherwise, the first node
67 * within Scope is returned.
68 *
69 ******************************************************************************/
70
71 ACPI_NAMESPACE_NODE *
AcpiNsGetNextNode(ACPI_NAMESPACE_NODE * ParentNode,ACPI_NAMESPACE_NODE * ChildNode)72 AcpiNsGetNextNode (
73 ACPI_NAMESPACE_NODE *ParentNode,
74 ACPI_NAMESPACE_NODE *ChildNode)
75 {
76 ACPI_FUNCTION_ENTRY ();
77
78
79 if (!ChildNode)
80 {
81 /* It's really the parent's _scope_ that we want */
82
83 return (ParentNode->Child);
84 }
85
86 /* Otherwise just return the next peer */
87
88 return (ChildNode->Peer);
89 }
90
91
92 /*******************************************************************************
93 *
94 * FUNCTION: AcpiNsGetNextNodeTyped
95 *
96 * PARAMETERS: Type - Type of node to be searched for
97 * ParentNode - Parent node whose children we are
98 * getting
99 * ChildNode - Previous child that was found.
100 * The NEXT child will be returned
101 *
102 * RETURN: ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if
103 * none is found.
104 *
105 * DESCRIPTION: Return the next peer node within the namespace. If Handle
106 * is valid, Scope is ignored. Otherwise, the first node
107 * within Scope is returned.
108 *
109 ******************************************************************************/
110
111 ACPI_NAMESPACE_NODE *
AcpiNsGetNextNodeTyped(ACPI_OBJECT_TYPE Type,ACPI_NAMESPACE_NODE * ParentNode,ACPI_NAMESPACE_NODE * ChildNode)112 AcpiNsGetNextNodeTyped (
113 ACPI_OBJECT_TYPE Type,
114 ACPI_NAMESPACE_NODE *ParentNode,
115 ACPI_NAMESPACE_NODE *ChildNode)
116 {
117 ACPI_NAMESPACE_NODE *NextNode = NULL;
118
119
120 ACPI_FUNCTION_ENTRY ();
121
122
123 NextNode = AcpiNsGetNextNode (ParentNode, ChildNode);
124
125 /* If any type is OK, we are done */
126
127 if (Type == ACPI_TYPE_ANY)
128 {
129 /* NextNode is NULL if we are at the end-of-list */
130
131 return (NextNode);
132 }
133
134 /* Must search for the node -- but within this scope only */
135
136 while (NextNode)
137 {
138 /* If type matches, we are done */
139
140 if (NextNode->Type == Type)
141 {
142 return (NextNode);
143 }
144
145 /* Otherwise, move on to the next peer node */
146
147 NextNode = NextNode->Peer;
148 }
149
150 /* Not found */
151
152 return (NULL);
153 }
154
155
156 /*******************************************************************************
157 *
158 * FUNCTION: AcpiNsWalkNamespace
159 *
160 * PARAMETERS: Type - ACPI_OBJECT_TYPE to search for
161 * StartNode - Handle in namespace where search begins
162 * MaxDepth - Depth to which search is to reach
163 * Flags - Whether to unlock the NS before invoking
164 * the callback routine
165 * DescendingCallback - Called during tree descent
166 * when an object of "Type" is found
167 * AscendingCallback - Called during tree ascent
168 * when an object of "Type" is found
169 * Context - Passed to user function(s) above
170 * ReturnValue - from the UserFunction if terminated
171 * early. Otherwise, returns NULL.
172 * RETURNS: Status
173 *
174 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
175 * starting (and ending) at the node specified by StartHandle.
176 * The callback function is called whenever a node that matches
177 * the type parameter is found. If the callback function returns
178 * a non-zero value, the search is terminated immediately and
179 * this value is returned to the caller.
180 *
181 * The point of this procedure is to provide a generic namespace
182 * walk routine that can be called from multiple places to
183 * provide multiple services; the callback function(s) can be
184 * tailored to each task, whether it is a print function,
185 * a compare function, etc.
186 *
187 ******************************************************************************/
188
189 ACPI_STATUS
AcpiNsWalkNamespace(ACPI_OBJECT_TYPE Type,ACPI_HANDLE StartNode,UINT32 MaxDepth,UINT32 Flags,ACPI_WALK_CALLBACK DescendingCallback,ACPI_WALK_CALLBACK AscendingCallback,void * Context,void ** ReturnValue)190 AcpiNsWalkNamespace (
191 ACPI_OBJECT_TYPE Type,
192 ACPI_HANDLE StartNode,
193 UINT32 MaxDepth,
194 UINT32 Flags,
195 ACPI_WALK_CALLBACK DescendingCallback,
196 ACPI_WALK_CALLBACK AscendingCallback,
197 void *Context,
198 void **ReturnValue)
199 {
200 ACPI_STATUS Status;
201 ACPI_STATUS MutexStatus;
202 ACPI_NAMESPACE_NODE *ChildNode;
203 ACPI_NAMESPACE_NODE *ParentNode;
204 ACPI_OBJECT_TYPE ChildType;
205 UINT32 Level;
206 BOOLEAN NodePreviouslyVisited = FALSE;
207
208
209 ACPI_FUNCTION_TRACE (NsWalkNamespace);
210
211
212 /* Special case for the namespace Root Node */
213
214 if (StartNode == ACPI_ROOT_OBJECT)
215 {
216 StartNode = AcpiGbl_RootNode;
217 if (!StartNode)
218 {
219 return_ACPI_STATUS (AE_NO_NAMESPACE);
220 }
221 }
222
223 /* Null child means "get first node" */
224
225 ParentNode = StartNode;
226 ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
227 ChildType = ACPI_TYPE_ANY;
228 Level = 1;
229
230 /*
231 * Traverse the tree of nodes until we bubble back up to where we
232 * started. When Level is zero, the loop is done because we have
233 * bubbled up to (and passed) the original parent handle (StartEntry)
234 */
235 while (Level > 0 && ChildNode)
236 {
237 Status = AE_OK;
238
239 /* Found next child, get the type if we are not searching for ANY */
240
241 if (Type != ACPI_TYPE_ANY)
242 {
243 ChildType = ChildNode->Type;
244 }
245
246 /*
247 * Ignore all temporary namespace nodes (created during control
248 * method execution) unless told otherwise. These temporary nodes
249 * can cause a race condition because they can be deleted during
250 * the execution of the user function (if the namespace is
251 * unlocked before invocation of the user function.) Only the
252 * debugger namespace dump will examine the temporary nodes.
253 */
254 if ((ChildNode->Flags & ANOBJ_TEMPORARY) &&
255 !(Flags & ACPI_NS_WALK_TEMP_NODES))
256 {
257 Status = AE_CTRL_DEPTH;
258 }
259
260 /* Type must match requested type */
261
262 else if (ChildType == Type)
263 {
264 /*
265 * Found a matching node, invoke the user callback function.
266 * Unlock the namespace if flag is set.
267 */
268 if (Flags & ACPI_NS_WALK_UNLOCK)
269 {
270 MutexStatus = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
271 if (ACPI_FAILURE (MutexStatus))
272 {
273 return_ACPI_STATUS (MutexStatus);
274 }
275 }
276
277 /*
278 * Invoke the user function, either descending, ascending,
279 * or both.
280 */
281 if (!NodePreviouslyVisited)
282 {
283 if (DescendingCallback)
284 {
285 Status = DescendingCallback (ChildNode, Level,
286 Context, ReturnValue);
287 }
288 }
289 else
290 {
291 if (AscendingCallback)
292 {
293 Status = AscendingCallback (ChildNode, Level,
294 Context, ReturnValue);
295 }
296 }
297
298 if (Flags & ACPI_NS_WALK_UNLOCK)
299 {
300 MutexStatus = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
301 if (ACPI_FAILURE (MutexStatus))
302 {
303 return_ACPI_STATUS (MutexStatus);
304 }
305 }
306
307 switch (Status)
308 {
309 case AE_OK:
310 case AE_CTRL_DEPTH:
311
312 /* Just keep going */
313 break;
314
315 case AE_CTRL_TERMINATE:
316
317 /* Exit now, with OK status */
318
319 return_ACPI_STATUS (AE_OK);
320
321 default:
322
323 /* All others are valid exceptions */
324
325 return_ACPI_STATUS (Status);
326 }
327 }
328
329 /*
330 * Depth first search: Attempt to go down another level in the
331 * namespace if we are allowed to. Don't go any further if we have
332 * reached the caller specified maximum depth or if the user
333 * function has specified that the maximum depth has been reached.
334 */
335 if (!NodePreviouslyVisited &&
336 (Level < MaxDepth) &&
337 (Status != AE_CTRL_DEPTH))
338 {
339 if (ChildNode->Child)
340 {
341 /* There is at least one child of this node, visit it */
342
343 Level++;
344 ParentNode = ChildNode;
345 ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
346 continue;
347 }
348 }
349
350 /* No more children, re-visit this node */
351
352 if (!NodePreviouslyVisited)
353 {
354 NodePreviouslyVisited = TRUE;
355 continue;
356 }
357
358 /* No more children, visit peers */
359
360 ChildNode = AcpiNsGetNextNode (ParentNode, ChildNode);
361 if (ChildNode)
362 {
363 NodePreviouslyVisited = FALSE;
364 }
365
366 /* No peers, re-visit parent */
367
368 else
369 {
370 /*
371 * No more children of this node (AcpiNsGetNextNode failed), go
372 * back upwards in the namespace tree to the node's parent.
373 */
374 Level--;
375 ChildNode = ParentNode;
376 ParentNode = ParentNode->Parent;
377
378 NodePreviouslyVisited = TRUE;
379 }
380 }
381
382 /* Complete walk, not terminated by user function */
383
384 return_ACPI_STATUS (AE_OK);
385 }
386