1 /******************************************************************************
2  *
3  * Module Name: nswalk - Functions for walking the ACPI namespace
4  *
5  *****************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2018, Intel Corp.
12  * All rights reserved.
13  *
14  * 2. License
15  *
16  * 2.1. This is your license from Intel Corp. under its intellectual property
17  * rights. You may have additional license terms from the party that provided
18  * you this software, covering your right to use that party's intellectual
19  * property rights.
20  *
21  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
22  * copy of the source code appearing in this file ("Covered Code") an
23  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
24  * base code distributed originally by Intel ("Original Intel Code") to copy,
25  * make derivatives, distribute, use and display any portion of the Covered
26  * Code in any form, with the right to sublicense such rights; and
27  *
28  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
29  * license (with the right to sublicense), under only those claims of Intel
30  * patents that are infringed by the Original Intel Code, to make, use, sell,
31  * offer to sell, and import the Covered Code and derivative works thereof
32  * solely to the minimum extent necessary to exercise the above copyright
33  * license, and in no event shall the patent license extend to any additions
34  * to or modifications of the Original Intel Code. No other license or right
35  * is granted directly or by implication, estoppel or otherwise;
36  *
37  * The above copyright and patent license is granted only if the following
38  * conditions are met:
39  *
40  * 3. Conditions
41  *
42  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
43  * Redistribution of source code of any substantial portion of the Covered
44  * Code or modification with rights to further distribute source must include
45  * the above Copyright Notice, the above License, this list of Conditions,
46  * and the following Disclaimer and Export Compliance provision. In addition,
47  * Licensee must cause all Covered Code to which Licensee contributes to
48  * contain a file documenting the changes Licensee made to create that Covered
49  * Code and the date of any change. Licensee must include in that file the
50  * documentation of any changes made by any predecessor Licensee. Licensee
51  * must include a prominent statement that the modification is derived,
52  * directly or indirectly, from Original Intel Code.
53  *
54  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
55  * Redistribution of source code of any substantial portion of the Covered
56  * Code or modification without rights to further distribute source must
57  * include the following Disclaimer and Export Compliance provision in the
58  * documentation and/or other materials provided with distribution. In
59  * addition, Licensee may not authorize further sublicense of source of any
60  * portion of the Covered Code, and must include terms to the effect that the
61  * license from Licensee to its licensee is limited to the intellectual
62  * property embodied in the software Licensee provides to its licensee, and
63  * not to intellectual property embodied in modifications its licensee may
64  * make.
65  *
66  * 3.3. Redistribution of Executable. Redistribution in executable form of any
67  * substantial portion of the Covered Code or modification must reproduce the
68  * above Copyright Notice, and the following Disclaimer and Export Compliance
69  * provision in the documentation and/or other materials provided with the
70  * distribution.
71  *
72  * 3.4. Intel retains all right, title, and interest in and to the Original
73  * Intel Code.
74  *
75  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
76  * Intel shall be used in advertising or otherwise to promote the sale, use or
77  * other dealings in products derived from or relating to the Covered Code
78  * without prior written authorization from Intel.
79  *
80  * 4. Disclaimer and Export Compliance
81  *
82  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
83  * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
84  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
85  * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
86  * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
87  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
88  * PARTICULAR PURPOSE.
89  *
90  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
91  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
92  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
93  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
94  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
95  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
96  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
97  * LIMITED REMEDY.
98  *
99  * 4.3. Licensee shall not export, either directly or indirectly, any of this
100  * software or system incorporating such software without first obtaining any
101  * required license or other approval from the U. S. Department of Commerce or
102  * any other agency or department of the United States Government. In the
103  * event Licensee exports any such software from the United States or
104  * re-exports any such software from a foreign destination, Licensee shall
105  * ensure that the distribution and export/re-export of the software is in
106  * compliance with all laws, regulations, orders, or other restrictions of the
107  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
108  * any of its subsidiaries will export/re-export any technical data, process,
109  * software, or service, directly or indirectly, to any country for which the
110  * United States government or any agency thereof requires an export license,
111  * other governmental approval, or letter of assurance, without first obtaining
112  * such license, approval or letter.
113  *
114  *****************************************************************************
115  *
116  * Alternatively, you may choose to be licensed under the terms of the
117  * following license:
118  *
119  * Redistribution and use in source and binary forms, with or without
120  * modification, are permitted provided that the following conditions
121  * are met:
122  * 1. Redistributions of source code must retain the above copyright
123  *    notice, this list of conditions, and the following disclaimer,
124  *    without modification.
125  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
126  *    substantially similar to the "NO WARRANTY" disclaimer below
127  *    ("Disclaimer") and any redistribution must be conditioned upon
128  *    including a substantially similar Disclaimer requirement for further
129  *    binary redistribution.
130  * 3. Neither the names of the above-listed copyright holders nor the names
131  *    of any contributors may be used to endorse or promote products derived
132  *    from this software without specific prior written permission.
133  *
134  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
135  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
136  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
137  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
138  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
139  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
140  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
141  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
142  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
143  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
144  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
145  *
146  * Alternatively, you may choose to be licensed under the terms of the
147  * GNU General Public License ("GPL") version 2 as published by the Free
148  * Software Foundation.
149  *
150  *****************************************************************************/
151 
152 #include "acpi.h"
153 #include "accommon.h"
154 #include "acnamesp.h"
155 
156 
157 #define _COMPONENT          ACPI_NAMESPACE
158         ACPI_MODULE_NAME    ("nswalk")
159 
160 
161 /*******************************************************************************
162  *
163  * FUNCTION:    AcpiNsGetNextNode
164  *
165  * PARAMETERS:  ParentNode          - Parent node whose children we are
166  *                                    getting
167  *              ChildNode           - Previous child that was found.
168  *                                    The NEXT child will be returned
169  *
170  * RETURN:      ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if
171  *                                    none is found.
172  *
173  * DESCRIPTION: Return the next peer node within the namespace. If Handle
174  *              is valid, Scope is ignored. Otherwise, the first node
175  *              within Scope is returned.
176  *
177  ******************************************************************************/
178 
179 ACPI_NAMESPACE_NODE *
AcpiNsGetNextNode(ACPI_NAMESPACE_NODE * ParentNode,ACPI_NAMESPACE_NODE * ChildNode)180 AcpiNsGetNextNode (
181     ACPI_NAMESPACE_NODE     *ParentNode,
182     ACPI_NAMESPACE_NODE     *ChildNode)
183 {
184     ACPI_FUNCTION_ENTRY ();
185 
186 
187     if (!ChildNode)
188     {
189         /* It's really the parent's _scope_ that we want */
190 
191         return (ParentNode->Child);
192     }
193 
194     /* Otherwise just return the next peer */
195 
196     return (ChildNode->Peer);
197 }
198 
199 
200 /*******************************************************************************
201  *
202  * FUNCTION:    AcpiNsGetNextNodeTyped
203  *
204  * PARAMETERS:  Type                - Type of node to be searched for
205  *              ParentNode          - Parent node whose children we are
206  *                                    getting
207  *              ChildNode           - Previous child that was found.
208  *                                    The NEXT child will be returned
209  *
210  * RETURN:      ACPI_NAMESPACE_NODE - Pointer to the NEXT child or NULL if
211  *                                    none is found.
212  *
213  * DESCRIPTION: Return the next peer node within the namespace. If Handle
214  *              is valid, Scope is ignored. Otherwise, the first node
215  *              within Scope is returned.
216  *
217  ******************************************************************************/
218 
219 ACPI_NAMESPACE_NODE *
AcpiNsGetNextNodeTyped(ACPI_OBJECT_TYPE Type,ACPI_NAMESPACE_NODE * ParentNode,ACPI_NAMESPACE_NODE * ChildNode)220 AcpiNsGetNextNodeTyped (
221     ACPI_OBJECT_TYPE        Type,
222     ACPI_NAMESPACE_NODE     *ParentNode,
223     ACPI_NAMESPACE_NODE     *ChildNode)
224 {
225     ACPI_NAMESPACE_NODE     *NextNode = NULL;
226 
227 
228     ACPI_FUNCTION_ENTRY ();
229 
230 
231     NextNode = AcpiNsGetNextNode (ParentNode, ChildNode);
232 
233     /* If any type is OK, we are done */
234 
235     if (Type == ACPI_TYPE_ANY)
236     {
237         /* NextNode is NULL if we are at the end-of-list */
238 
239         return (NextNode);
240     }
241 
242     /* Must search for the node -- but within this scope only */
243 
244     while (NextNode)
245     {
246         /* If type matches, we are done */
247 
248         if (NextNode->Type == Type)
249         {
250             return (NextNode);
251         }
252 
253         /* Otherwise, move on to the next peer node */
254 
255         NextNode = NextNode->Peer;
256     }
257 
258     /* Not found */
259 
260     return (NULL);
261 }
262 
263 
264 /*******************************************************************************
265  *
266  * FUNCTION:    AcpiNsWalkNamespace
267  *
268  * PARAMETERS:  Type                - ACPI_OBJECT_TYPE to search for
269  *              StartNode           - Handle in namespace where search begins
270  *              MaxDepth            - Depth to which search is to reach
271  *              Flags               - Whether to unlock the NS before invoking
272  *                                    the callback routine
273  *              DescendingCallback  - Called during tree descent
274  *                                    when an object of "Type" is found
275  *              AscendingCallback   - Called during tree ascent
276  *                                    when an object of "Type" is found
277  *              Context             - Passed to user function(s) above
278  *              ReturnValue         - from the UserFunction if terminated
279  *                                    early. Otherwise, returns NULL.
280  * RETURNS:     Status
281  *
282  * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
283  *              starting (and ending) at the node specified by StartHandle.
284  *              The callback function is called whenever a node that matches
285  *              the type parameter is found. If the callback function returns
286  *              a non-zero value, the search is terminated immediately and
287  *              this value is returned to the caller.
288  *
289  *              The point of this procedure is to provide a generic namespace
290  *              walk routine that can be called from multiple places to
291  *              provide multiple services; the callback function(s) can be
292  *              tailored to each task, whether it is a print function,
293  *              a compare function, etc.
294  *
295  ******************************************************************************/
296 
297 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)298 AcpiNsWalkNamespace (
299     ACPI_OBJECT_TYPE        Type,
300     ACPI_HANDLE             StartNode,
301     UINT32                  MaxDepth,
302     UINT32                  Flags,
303     ACPI_WALK_CALLBACK      DescendingCallback,
304     ACPI_WALK_CALLBACK      AscendingCallback,
305     void                    *Context,
306     void                    **ReturnValue)
307 {
308     ACPI_STATUS             Status;
309     ACPI_STATUS             MutexStatus;
310     ACPI_NAMESPACE_NODE     *ChildNode;
311     ACPI_NAMESPACE_NODE     *ParentNode;
312     ACPI_OBJECT_TYPE        ChildType;
313     UINT32                  Level;
314     BOOLEAN                 NodePreviouslyVisited = FALSE;
315 
316 
317     ACPI_FUNCTION_TRACE (NsWalkNamespace);
318 
319 
320     /* Special case for the namespace Root Node */
321 
322     if (StartNode == ACPI_ROOT_OBJECT)
323     {
324         StartNode = AcpiGbl_RootNode;
325     }
326 
327     /* Null child means "get first node" */
328 
329     ParentNode = StartNode;
330     ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
331     ChildType = ACPI_TYPE_ANY;
332     Level = 1;
333 
334     /*
335      * Traverse the tree of nodes until we bubble back up to where we
336      * started. When Level is zero, the loop is done because we have
337      * bubbled up to (and passed) the original parent handle (StartEntry)
338      */
339     while (Level > 0 && ChildNode)
340     {
341         Status = AE_OK;
342 
343         /* Found next child, get the type if we are not searching for ANY */
344 
345         if (Type != ACPI_TYPE_ANY)
346         {
347             ChildType = ChildNode->Type;
348         }
349 
350         /*
351          * Ignore all temporary namespace nodes (created during control
352          * method execution) unless told otherwise. These temporary nodes
353          * can cause a race condition because they can be deleted during
354          * the execution of the user function (if the namespace is
355          * unlocked before invocation of the user function.) Only the
356          * debugger namespace dump will examine the temporary nodes.
357          */
358         if ((ChildNode->Flags & ANOBJ_TEMPORARY) &&
359             !(Flags & ACPI_NS_WALK_TEMP_NODES))
360         {
361             Status = AE_CTRL_DEPTH;
362         }
363 
364         /* Type must match requested type */
365 
366         else if (ChildType == Type)
367         {
368             /*
369              * Found a matching node, invoke the user callback function.
370              * Unlock the namespace if flag is set.
371              */
372             if (Flags & ACPI_NS_WALK_UNLOCK)
373             {
374                 MutexStatus = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
375                 if (ACPI_FAILURE (MutexStatus))
376                 {
377                     return_ACPI_STATUS (MutexStatus);
378                 }
379             }
380 
381             /*
382              * Invoke the user function, either descending, ascending,
383              * or both.
384              */
385             if (!NodePreviouslyVisited)
386             {
387                 if (DescendingCallback)
388                 {
389                     Status = DescendingCallback (ChildNode, Level,
390                         Context, ReturnValue);
391                 }
392             }
393             else
394             {
395                 if (AscendingCallback)
396                 {
397                     Status = AscendingCallback (ChildNode, Level,
398                         Context, ReturnValue);
399                 }
400             }
401 
402             if (Flags & ACPI_NS_WALK_UNLOCK)
403             {
404                 MutexStatus = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
405                 if (ACPI_FAILURE (MutexStatus))
406                 {
407                     return_ACPI_STATUS (MutexStatus);
408                 }
409             }
410 
411             switch (Status)
412             {
413             case AE_OK:
414             case AE_CTRL_DEPTH:
415 
416                 /* Just keep going */
417                 break;
418 
419             case AE_CTRL_TERMINATE:
420 
421                 /* Exit now, with OK status */
422 
423                 return_ACPI_STATUS (AE_OK);
424 
425             default:
426 
427                 /* All others are valid exceptions */
428 
429                 return_ACPI_STATUS (Status);
430             }
431         }
432 
433         /*
434          * Depth first search: Attempt to go down another level in the
435          * namespace if we are allowed to. Don't go any further if we have
436          * reached the caller specified maximum depth or if the user
437          * function has specified that the maximum depth has been reached.
438          */
439         if (!NodePreviouslyVisited &&
440             (Level < MaxDepth) &&
441             (Status != AE_CTRL_DEPTH))
442         {
443             if (ChildNode->Child)
444             {
445                 /* There is at least one child of this node, visit it */
446 
447                 Level++;
448                 ParentNode = ChildNode;
449                 ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
450                 continue;
451             }
452         }
453 
454         /* No more children, re-visit this node */
455 
456         if (!NodePreviouslyVisited)
457         {
458             NodePreviouslyVisited = TRUE;
459             continue;
460         }
461 
462         /* No more children, visit peers */
463 
464         ChildNode = AcpiNsGetNextNode (ParentNode, ChildNode);
465         if (ChildNode)
466         {
467             NodePreviouslyVisited = FALSE;
468         }
469 
470         /* No peers, re-visit parent */
471 
472         else
473         {
474             /*
475              * No more children of this node (AcpiNsGetNextNode failed), go
476              * back upwards in the namespace tree to the node's parent.
477              */
478             Level--;
479             ChildNode = ParentNode;
480             ParentNode = ParentNode->Parent;
481 
482             NodePreviouslyVisited = TRUE;
483         }
484     }
485 
486     /* Complete walk, not terminated by user function */
487 
488     return_ACPI_STATUS (AE_OK);
489 }
490