1 /******************************************************************************
3 * Module Name: nswalk - Functions for walking the ACPI namespace
5 *****************************************************************************/
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47 #include <contrib/dev/acpica/include/acpi.h>
48 #include <contrib/dev/acpica/include/accommon.h>
49 #include <contrib/dev/acpica/include/acnamesp.h>
52 #define _COMPONENT ACPI_NAMESPACE
53 ACPI_MODULE_NAME ("nswalk")
56 /*******************************************************************************
58 * FUNCTION: AcpiNsGetNextNode
60 * PARAMETERS: ParentNode - Parent node whose children we are
62 * ChildNode - Previous child that was found.
63 * The NEXT child will be returned
65 * RETURN: ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if
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.
72 ******************************************************************************/
76 ACPI_NAMESPACE_NODE *ParentNode,
77 ACPI_NAMESPACE_NODE *ChildNode)
79 ACPI_FUNCTION_ENTRY ();
84 /* It's really the parent's _scope_ that we want */
86 return (ParentNode->Child);
89 /* Otherwise just return the next peer */
91 return (ChildNode->Peer);
95 /*******************************************************************************
97 * FUNCTION: AcpiNsGetNextNodeTyped
99 * PARAMETERS: Type - Type of node to be searched for
100 * ParentNode - Parent node whose children we are
102 * ChildNode - Previous child that was found.
103 * The NEXT child will be returned
105 * RETURN: ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if
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.
112 ******************************************************************************/
114 ACPI_NAMESPACE_NODE *
115 AcpiNsGetNextNodeTyped (
116 ACPI_OBJECT_TYPE Type,
117 ACPI_NAMESPACE_NODE *ParentNode,
118 ACPI_NAMESPACE_NODE *ChildNode)
120 ACPI_NAMESPACE_NODE *NextNode = NULL;
123 ACPI_FUNCTION_ENTRY ();
126 NextNode = AcpiNsGetNextNode (ParentNode, ChildNode);
128 /* If any type is OK, we are done */
130 if (Type == ACPI_TYPE_ANY)
132 /* NextNode is NULL if we are at the end-of-list */
137 /* Must search for the node -- but within this scope only */
141 /* If type matches, we are done */
143 if (NextNode->Type == Type)
148 /* Otherwise, move on to the next peer node */
150 NextNode = NextNode->Peer;
159 /*******************************************************************************
161 * FUNCTION: AcpiNsWalkNamespace
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 * PreOrderVisit - Called during tree pre-order visit
169 * when an object of "Type" is found
170 * PostOrderVisit - Called during tree post-order visit
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.
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.
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.
190 ******************************************************************************/
193 AcpiNsWalkNamespace (
194 ACPI_OBJECT_TYPE Type,
195 ACPI_HANDLE StartNode,
198 ACPI_WALK_CALLBACK PreOrderVisit,
199 ACPI_WALK_CALLBACK PostOrderVisit,
204 ACPI_STATUS MutexStatus;
205 ACPI_NAMESPACE_NODE *ChildNode;
206 ACPI_NAMESPACE_NODE *ParentNode;
207 ACPI_OBJECT_TYPE ChildType;
209 BOOLEAN NodePreviouslyVisited = FALSE;
212 ACPI_FUNCTION_TRACE (NsWalkNamespace);
215 /* Special case for the namespace Root Node */
217 if (StartNode == ACPI_ROOT_OBJECT)
219 StartNode = AcpiGbl_RootNode;
222 /* Null child means "get first node" */
224 ParentNode = StartNode;
225 ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
226 ChildType = ACPI_TYPE_ANY;
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)
234 while (Level > 0 && ChildNode)
238 /* Found next child, get the type if we are not searching for ANY */
240 if (Type != ACPI_TYPE_ANY)
242 ChildType = ChildNode->Type;
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.
253 if ((ChildNode->Flags & ANOBJ_TEMPORARY) &&
254 !(Flags & ACPI_NS_WALK_TEMP_NODES))
256 Status = AE_CTRL_DEPTH;
259 /* Type must match requested type */
261 else if (ChildType == Type)
264 * Found a matching node, invoke the user callback function.
265 * Unlock the namespace if flag is set.
267 if (Flags & ACPI_NS_WALK_UNLOCK)
269 MutexStatus = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
270 if (ACPI_FAILURE (MutexStatus))
272 return_ACPI_STATUS (MutexStatus);
277 * Invoke the user function, either pre-order or post-order
280 if (!NodePreviouslyVisited)
284 Status = PreOrderVisit (ChildNode, Level,
285 Context, ReturnValue);
292 Status = PostOrderVisit (ChildNode, Level,
293 Context, ReturnValue);
297 if (Flags & ACPI_NS_WALK_UNLOCK)
299 MutexStatus = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
300 if (ACPI_FAILURE (MutexStatus))
302 return_ACPI_STATUS (MutexStatus);
311 /* Just keep going */
314 case AE_CTRL_TERMINATE:
316 /* Exit now, with OK status */
318 return_ACPI_STATUS (AE_OK);
322 /* All others are valid exceptions */
324 return_ACPI_STATUS (Status);
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.
334 if (!NodePreviouslyVisited &&
335 (Level < MaxDepth) &&
336 (Status != AE_CTRL_DEPTH))
338 if (ChildNode->Child)
340 /* There is at least one child of this node, visit it */
343 ParentNode = ChildNode;
344 ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
349 /* No more children, re-visit this node */
351 if (!NodePreviouslyVisited)
353 NodePreviouslyVisited = TRUE;
357 /* No more children, visit peers */
359 ChildNode = AcpiNsGetNextNode (ParentNode, ChildNode);
362 NodePreviouslyVisited = FALSE;
365 /* No peers, re-visit parent */
370 * No more children of this node (AcpiNsGetNextNode failed), go
371 * back upwards in the namespace tree to the node's parent.
374 ChildNode = ParentNode;
375 ParentNode = ParentNode->Parent;
377 NodePreviouslyVisited = TRUE;
381 /* Complete walk, not terminated by user function */
383 return_ACPI_STATUS (AE_OK);