xref: /freebsd/sys/contrib/dev/acpica/components/namespace/nsaccess.c (revision dd21556857e8d40f66bf5ad54754d9d52669ebf7)
1 /*******************************************************************************
2  *
3  * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
4  *
5  ******************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2024, 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 <contrib/dev/acpica/include/acpi.h>
153 #include <contrib/dev/acpica/include/accommon.h>
154 #include <contrib/dev/acpica/include/amlcode.h>
155 #include <contrib/dev/acpica/include/acnamesp.h>
156 #include <contrib/dev/acpica/include/acdispat.h>
157 
158 #ifdef ACPI_ASL_COMPILER
159     #include <contrib/dev/acpica/include/acdisasm.h>
160 #endif
161 
162 #define _COMPONENT          ACPI_NAMESPACE
163         ACPI_MODULE_NAME    ("nsaccess")
164 
165 
166 /*******************************************************************************
167  *
168  * FUNCTION:    AcpiNsRootInitialize
169  *
170  * PARAMETERS:  None
171  *
172  * RETURN:      Status
173  *
174  * DESCRIPTION: Allocate and initialize the default root named objects
175  *
176  * MUTEX:       Locks namespace for entire execution
177  *
178  ******************************************************************************/
179 
180 ACPI_STATUS
181 AcpiNsRootInitialize (
182     void)
183 {
184     ACPI_STATUS                 Status;
185     const ACPI_PREDEFINED_NAMES *InitVal = NULL;
186     ACPI_NAMESPACE_NODE         *NewNode;
187     ACPI_NAMESPACE_NODE         *PrevNode = NULL;
188     ACPI_OPERAND_OBJECT         *ObjDesc;
189     ACPI_STRING                 Val = NULL;
190 
191 
192     ACPI_FUNCTION_TRACE (NsRootInitialize);
193 
194 
195     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
196     if (ACPI_FAILURE (Status))
197     {
198         return_ACPI_STATUS (Status);
199     }
200 
201     /*
202      * The global root ptr is initially NULL, so a non-NULL value indicates
203      * that AcpiNsRootInitialize() has already been called; just return.
204      */
205     if (AcpiGbl_RootNode)
206     {
207         Status = AE_OK;
208         goto UnlockAndExit;
209     }
210 
211     /*
212      * Tell the rest of the subsystem that the root is initialized
213      * (This is OK because the namespace is locked)
214      */
215     AcpiGbl_RootNode = &AcpiGbl_RootNodeStruct;
216 
217     /* Enter the predefined names in the name table */
218 
219     ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
220         "Entering predefined entries into namespace\n"));
221 
222     /*
223      * Create the initial (default) namespace.
224      * This namespace looks like something similar to this:
225      *
226      *   ACPI Namespace (from Namespace Root):
227      *    0  _GPE Scope        00203160 00
228      *    0  _PR_ Scope        002031D0 00
229      *    0  _SB_ Device       00203240 00 Notify Object: 0020ADD8
230      *    0  _SI_ Scope        002032B0 00
231      *    0  _TZ_ Device       00203320 00
232      *    0  _REV Integer      00203390 00 = 0000000000000002
233      *    0  _OS_ String       00203488 00 Len 14 "Microsoft Windows NT"
234      *    0  _GL_ Mutex        00203580 00 Object 002035F0
235      *    0  _OSI Method       00203678 00 Args 1 Len 0000 Aml 00000000
236      */
237     for (InitVal = AcpiGbl_PreDefinedNames; InitVal->Name; InitVal++)
238     {
239         Status = AE_OK;
240 
241         /* _OSI is optional for now, will be permanent later */
242 
243         if (!strcmp (InitVal->Name, "_OSI") && !AcpiGbl_CreateOsiMethod)
244         {
245             continue;
246         }
247 
248         /*
249          * Create, init, and link the new predefined name
250          * Note: No need to use AcpiNsLookup here because all the
251          * predefined names are at the root level. It is much easier to
252          * just create and link the new node(s) here.
253          */
254         NewNode = AcpiNsCreateNode (*ACPI_CAST_PTR (UINT32, InitVal->Name));
255         if (!NewNode)
256         {
257             Status = AE_NO_MEMORY;
258             goto UnlockAndExit;
259         }
260 
261         NewNode->DescriptorType = ACPI_DESC_TYPE_NAMED;
262         NewNode->Type = InitVal->Type;
263 
264         if (!PrevNode)
265         {
266             AcpiGbl_RootNodeStruct.Child = NewNode;
267         }
268         else
269         {
270             PrevNode->Peer = NewNode;
271         }
272 
273         NewNode->Parent = &AcpiGbl_RootNodeStruct;
274         PrevNode = NewNode;
275 
276         /*
277          * Name entered successfully. If entry in PreDefinedNames[] specifies
278          * an initial value, create the initial value.
279          */
280         if (InitVal->Val)
281         {
282             Status = AcpiOsPredefinedOverride (InitVal, &Val);
283             if (ACPI_FAILURE (Status))
284             {
285                 ACPI_ERROR ((AE_INFO,
286                     "Could not override predefined %s",
287                     InitVal->Name));
288             }
289 
290             if (!Val)
291             {
292                 Val = InitVal->Val;
293             }
294 
295             /*
296              * Entry requests an initial value, allocate a
297              * descriptor for it.
298              */
299             ObjDesc = AcpiUtCreateInternalObject (InitVal->Type);
300             if (!ObjDesc)
301             {
302                 Status = AE_NO_MEMORY;
303                 goto UnlockAndExit;
304             }
305 
306             /*
307              * Convert value string from table entry to
308              * internal representation. Only types actually
309              * used for initial values are implemented here.
310              */
311             switch (InitVal->Type)
312             {
313             case ACPI_TYPE_METHOD:
314 
315                 ObjDesc->Method.ParamCount = (UINT8) ACPI_TO_INTEGER (Val);
316                 ObjDesc->Common.Flags |= AOPOBJ_DATA_VALID;
317 
318 #if defined (ACPI_ASL_COMPILER)
319 
320                 /* Save the parameter count for the iASL compiler */
321 
322                 NewNode->Value = ObjDesc->Method.ParamCount;
323 #else
324                 /* Mark this as a very SPECIAL method (_OSI) */
325 
326                 ObjDesc->Method.InfoFlags = ACPI_METHOD_INTERNAL_ONLY;
327                 ObjDesc->Method.Dispatch.Implementation = AcpiUtOsiImplementation;
328 #endif
329                 break;
330 
331             case ACPI_TYPE_INTEGER:
332 
333                 ObjDesc->Integer.Value = ACPI_TO_INTEGER (Val);
334                 break;
335 
336             case ACPI_TYPE_STRING:
337 
338                 /* Build an object around the static string */
339 
340                 ObjDesc->String.Length = (UINT32) strlen (Val);
341                 ObjDesc->String.Pointer = Val;
342                 ObjDesc->Common.Flags |= AOPOBJ_STATIC_POINTER;
343                 break;
344 
345             case ACPI_TYPE_MUTEX:
346 
347                 ObjDesc->Mutex.Node = NewNode;
348                 ObjDesc->Mutex.SyncLevel = (UINT8) (ACPI_TO_INTEGER (Val) - 1);
349 
350                 /* Create a mutex */
351 
352                 Status = AcpiOsCreateMutex (&ObjDesc->Mutex.OsMutex);
353                 if (ACPI_FAILURE (Status))
354                 {
355                     AcpiUtRemoveReference (ObjDesc);
356                     goto UnlockAndExit;
357                 }
358 
359                 /* Special case for ACPI Global Lock */
360 
361                 if (strcmp (InitVal->Name, "_GL_") == 0)
362                 {
363                     AcpiGbl_GlobalLockMutex = ObjDesc;
364 
365                     /* Create additional counting semaphore for global lock */
366 
367                     Status = AcpiOsCreateSemaphore (
368                         1, 0, &AcpiGbl_GlobalLockSemaphore);
369                     if (ACPI_FAILURE (Status))
370                     {
371                         AcpiUtRemoveReference (ObjDesc);
372                         goto UnlockAndExit;
373                     }
374                 }
375                 break;
376 
377             default:
378 
379                 ACPI_ERROR ((AE_INFO, "Unsupported initial type value 0x%X",
380                     InitVal->Type));
381                 AcpiUtRemoveReference (ObjDesc);
382                 ObjDesc = NULL;
383                 continue;
384             }
385 
386             /* Store pointer to value descriptor in the Node */
387 
388             Status = AcpiNsAttachObject (NewNode, ObjDesc,
389                 ObjDesc->Common.Type);
390 
391             /* Remove local reference to the object */
392 
393             AcpiUtRemoveReference (ObjDesc);
394         }
395     }
396 
397 UnlockAndExit:
398     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
399 
400     /* Save a handle to "_GPE", it is always present */
401 
402     if (ACPI_SUCCESS (Status))
403     {
404         Status = AcpiNsGetNode (NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
405             &AcpiGbl_FadtGpeDevice);
406     }
407 
408     return_ACPI_STATUS (Status);
409 }
410 
411 
412 /*******************************************************************************
413  *
414  * FUNCTION:    AcpiNsLookup
415  *
416  * PARAMETERS:  ScopeInfo       - Current scope info block
417  *              Pathname        - Search pathname, in internal format
418  *                                (as represented in the AML stream)
419  *              Type            - Type associated with name
420  *              InterpreterMode - IMODE_LOAD_PASS2 => add name if not found
421  *              Flags           - Flags describing the search restrictions
422  *              WalkState       - Current state of the walk
423  *              ReturnNode      - Where the Node is placed (if found
424  *                                or created successfully)
425  *
426  * RETURN:      Status
427  *
428  * DESCRIPTION: Find or enter the passed name in the name space.
429  *              Log an error if name not found in Exec mode.
430  *
431  * MUTEX:       Assumes namespace is locked.
432  *
433  ******************************************************************************/
434 
435 ACPI_STATUS
436 AcpiNsLookup (
437     ACPI_GENERIC_STATE      *ScopeInfo,
438     char                    *Pathname,
439     ACPI_OBJECT_TYPE        Type,
440     ACPI_INTERPRETER_MODE   InterpreterMode,
441     UINT32                  Flags,
442     ACPI_WALK_STATE         *WalkState,
443     ACPI_NAMESPACE_NODE     **ReturnNode)
444 {
445     ACPI_STATUS             Status;
446     char                    *Path = Pathname;
447     char                    *ExternalPath;
448     ACPI_NAMESPACE_NODE     *PrefixNode;
449     ACPI_NAMESPACE_NODE     *CurrentNode = NULL;
450     ACPI_NAMESPACE_NODE     *ThisNode = NULL;
451     UINT32                  NumSegments;
452 #ifdef ACPI_DEBUG_OUTPUT
453     UINT32                  NumCarats;
454 #endif
455     ACPI_NAME               SimpleName;
456     ACPI_OBJECT_TYPE        TypeToCheckFor;
457     ACPI_OBJECT_TYPE        ThisSearchType;
458     UINT32                  SearchParentFlag = ACPI_NS_SEARCH_PARENT;
459     UINT32                  LocalFlags;
460     ACPI_INTERPRETER_MODE   LocalInterpreterMode;
461 
462 
463     ACPI_FUNCTION_TRACE (NsLookup);
464 
465 
466     if (!ReturnNode)
467     {
468         return_ACPI_STATUS (AE_BAD_PARAMETER);
469     }
470 
471     LocalFlags = Flags &
472         ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_OVERRIDE_IF_FOUND |
473           ACPI_NS_SEARCH_PARENT);
474     *ReturnNode = ACPI_ENTRY_NOT_FOUND;
475     AcpiGbl_NsLookupCount++;
476 
477     if (!AcpiGbl_RootNode)
478     {
479         return_ACPI_STATUS (AE_NO_NAMESPACE);
480     }
481 
482     /* Get the prefix scope. A null scope means use the root scope */
483 
484     if ((!ScopeInfo) ||
485         (!ScopeInfo->Scope.Node))
486     {
487         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
488             "Null scope prefix, using root node (%p)\n",
489             AcpiGbl_RootNode));
490 
491         PrefixNode = AcpiGbl_RootNode;
492     }
493     else
494     {
495         PrefixNode = ScopeInfo->Scope.Node;
496         if (ACPI_GET_DESCRIPTOR_TYPE (PrefixNode) != ACPI_DESC_TYPE_NAMED)
497         {
498             ACPI_ERROR ((AE_INFO, "%p is not a namespace node [%s]",
499                 PrefixNode, AcpiUtGetDescriptorName (PrefixNode)));
500             return_ACPI_STATUS (AE_AML_INTERNAL);
501         }
502 
503         if (!(Flags & ACPI_NS_PREFIX_IS_SCOPE))
504         {
505             /*
506              * This node might not be a actual "scope" node (such as a
507              * Device/Method, etc.)  It could be a Package or other object
508              * node. Backup up the tree to find the containing scope node.
509              */
510             while (!AcpiNsOpensScope (PrefixNode->Type) &&
511                     PrefixNode->Type != ACPI_TYPE_ANY)
512             {
513                 PrefixNode = PrefixNode->Parent;
514             }
515         }
516     }
517 
518     /* Save type. TBD: may be no longer necessary */
519 
520     TypeToCheckFor = Type;
521 
522     /*
523      * Begin examination of the actual pathname
524      */
525     if (!Pathname)
526     {
527         /* A Null NamePath is allowed and refers to the root */
528 
529         NumSegments = 0;
530         ThisNode = AcpiGbl_RootNode;
531         Path = "";
532 
533         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
534             "Null Pathname (Zero segments), Flags=%X\n", Flags));
535     }
536     else
537     {
538         /*
539          * Name pointer is valid (and must be in internal name format)
540          *
541          * Check for scope prefixes:
542          *
543          * As represented in the AML stream, a namepath consists of an
544          * optional scope prefix followed by a name segment part.
545          *
546          * If present, the scope prefix is either a Root Prefix (in
547          * which case the name is fully qualified), or one or more
548          * Parent Prefixes (in which case the name's scope is relative
549          * to the current scope).
550          */
551         if (*Path == (UINT8) AML_ROOT_PREFIX)
552         {
553             /* Pathname is fully qualified, start from the root */
554 
555             ThisNode = AcpiGbl_RootNode;
556             SearchParentFlag = ACPI_NS_NO_UPSEARCH;
557 
558             /* Point to name segment part */
559 
560             Path++;
561 
562             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
563                 "Path is absolute from root [%p]\n", ThisNode));
564         }
565         else
566         {
567             /* Pathname is relative to current scope, start there */
568 
569             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
570                 "Searching relative to prefix scope [%4.4s] (%p)\n",
571                 AcpiUtGetNodeName (PrefixNode), PrefixNode));
572 
573             /*
574              * Handle multiple Parent Prefixes (carat) by just getting
575              * the parent node for each prefix instance.
576              */
577             ThisNode = PrefixNode;
578 #ifdef ACPI_DEBUG_OUTPUT
579             NumCarats = 0;
580 #endif
581             while (*Path == (UINT8) AML_PARENT_PREFIX)
582             {
583                 /* Name is fully qualified, no search rules apply */
584 
585                 SearchParentFlag = ACPI_NS_NO_UPSEARCH;
586 
587                 /*
588                  * Point past this prefix to the name segment
589                  * part or the next Parent Prefix
590                  */
591                 Path++;
592 
593                 /* Backup to the parent node */
594 
595 #ifdef ACPI_DEBUG_OUTPUT
596                 NumCarats++;
597 #endif
598                 ThisNode = ThisNode->Parent;
599                 if (!ThisNode)
600                 {
601                     /*
602                      * Current scope has no parent scope. Externalize
603                      * the internal path for error message.
604                      */
605                     Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, Pathname,
606                         NULL, &ExternalPath);
607                     if (ACPI_SUCCESS (Status))
608                     {
609                         ACPI_ERROR ((AE_INFO,
610                             "%s: Path has too many parent prefixes (^)",
611                             ExternalPath));
612 
613                         ACPI_FREE (ExternalPath);
614                     }
615 
616                     return_ACPI_STATUS (AE_NOT_FOUND);
617                 }
618             }
619 
620 #ifdef ACPI_DEBUG_OUTPUT
621             if (SearchParentFlag == ACPI_NS_NO_UPSEARCH)
622             {
623                 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
624                     "Search scope is [%4.4s], path has %u carat(s)\n",
625                     AcpiUtGetNodeName (ThisNode), NumCarats));
626             }
627 #endif
628         }
629 
630         /*
631          * Determine the number of ACPI name segments in this pathname.
632          *
633          * The segment part consists of either:
634          *  - A Null name segment (0)
635          *  - A DualNamePrefix followed by two 4-byte name segments
636          *  - A MultiNamePrefix followed by a byte indicating the
637          *      number of segments and the segments themselves.
638          *  - A single 4-byte name segment
639          *
640          * Examine the name prefix opcode, if any, to determine the number of
641          * segments.
642          */
643         switch (*Path)
644         {
645         case 0:
646             /*
647              * Null name after a root or parent prefixes. We already
648              * have the correct target node and there are no name segments.
649              */
650             NumSegments  = 0;
651             Type = ThisNode->Type;
652 
653             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
654                 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
655                 Flags));
656             break;
657 
658         case AML_DUAL_NAME_PREFIX:
659 
660             /* More than one NameSeg, search rules do not apply */
661 
662             SearchParentFlag = ACPI_NS_NO_UPSEARCH;
663 
664             /* Two segments, point to first name segment */
665 
666             NumSegments = 2;
667             Path++;
668 
669             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
670                 "Dual Pathname (2 segments, Flags=%X)\n", Flags));
671             break;
672 
673         case AML_MULTI_NAME_PREFIX:
674 
675             /* More than one NameSeg, search rules do not apply */
676 
677             SearchParentFlag = ACPI_NS_NO_UPSEARCH;
678 
679             /* Extract segment count, point to first name segment */
680 
681             Path++;
682             NumSegments = (UINT32) (UINT8) *Path;
683             Path++;
684 
685             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
686                 "Multi Pathname (%u Segments, Flags=%X)\n",
687                 NumSegments, Flags));
688             break;
689 
690         default:
691             /*
692              * Not a Null name, no Dual or Multi prefix, hence there is
693              * only one name segment and Pathname is already pointing to it.
694              */
695             NumSegments = 1;
696 
697             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
698                 "Simple Pathname (1 segment, Flags=%X)\n", Flags));
699             break;
700         }
701 
702         ACPI_DEBUG_EXEC (AcpiNsPrintPathname (NumSegments, Path));
703     }
704 
705 
706     /*
707      * Search namespace for each segment of the name. Loop through and
708      * verify (or add to the namespace) each name segment.
709      *
710      * The object type is significant only at the last name
711      * segment. (We don't care about the types along the path, only
712      * the type of the final target object.)
713      */
714     ThisSearchType = ACPI_TYPE_ANY;
715     CurrentNode = ThisNode;
716 
717     while (NumSegments && CurrentNode)
718     {
719         NumSegments--;
720         if (!NumSegments)
721         {
722             /* This is the last segment, enable typechecking */
723 
724             ThisSearchType = Type;
725 
726             /*
727              * Only allow automatic parent search (search rules) if the caller
728              * requested it AND we have a single, non-fully-qualified NameSeg
729              */
730             if ((SearchParentFlag != ACPI_NS_NO_UPSEARCH) &&
731                 (Flags & ACPI_NS_SEARCH_PARENT))
732             {
733                 LocalFlags |= ACPI_NS_SEARCH_PARENT;
734             }
735 
736             /* Set error flag according to caller */
737 
738             if (Flags & ACPI_NS_ERROR_IF_FOUND)
739             {
740                 LocalFlags |= ACPI_NS_ERROR_IF_FOUND;
741             }
742 
743             /* Set override flag according to caller */
744 
745             if (Flags & ACPI_NS_OVERRIDE_IF_FOUND)
746             {
747                 LocalFlags |= ACPI_NS_OVERRIDE_IF_FOUND;
748             }
749         }
750 
751         /* Handle opcodes that create a new NameSeg via a full NamePath */
752 
753         LocalInterpreterMode = InterpreterMode;
754         if ((Flags & ACPI_NS_PREFIX_MUST_EXIST) && (NumSegments > 0))
755         {
756             /* Every element of the path must exist (except for the final NameSeg) */
757 
758             LocalInterpreterMode = ACPI_IMODE_EXECUTE;
759         }
760 
761         /* Extract one ACPI name from the front of the pathname */
762 
763         ACPI_MOVE_32_TO_32 (&SimpleName, Path);
764 
765         /* Try to find the single (4 character) ACPI name */
766 
767         Status = AcpiNsSearchAndEnter (SimpleName, WalkState, CurrentNode,
768             LocalInterpreterMode, ThisSearchType, LocalFlags, &ThisNode);
769         if (ACPI_FAILURE (Status))
770         {
771             if (Status == AE_NOT_FOUND)
772             {
773 #if !defined ACPI_ASL_COMPILER /* Note: iASL reports this error by itself, not needed here */
774                 if (Flags & ACPI_NS_PREFIX_MUST_EXIST)
775                 {
776                     AcpiOsPrintf (ACPI_MSG_BIOS_ERROR
777                         "Object does not exist: %4.4s\n", (char *) &SimpleName);
778                 }
779 #endif
780                 /* Name not found in ACPI namespace */
781 
782                 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
783                     "Name [%4.4s] not found in scope [%4.4s] %p\n",
784                     (char *) &SimpleName, (char *) &CurrentNode->Name,
785                     CurrentNode));
786             }
787 
788 #ifdef ACPI_EXEC_APP
789             if ((Status == AE_ALREADY_EXISTS) &&
790                 (ThisNode->Flags & ANOBJ_NODE_EARLY_INIT))
791             {
792                 ThisNode->Flags &= ~ANOBJ_NODE_EARLY_INIT;
793                 Status = AE_OK;
794             }
795 #endif
796 
797 #ifdef ACPI_ASL_COMPILER
798             /*
799              * If this ACPI name already exists within the namespace as an
800              * external declaration, then mark the external as a conflicting
801              * declaration and proceed to process the current node as if it did
802              * not exist in the namespace. If this node is not processed as
803              * normal, then it could cause improper namespace resolution
804              * by failing to open a new scope.
805              */
806             if (AcpiGbl_DisasmFlag &&
807                 (Status == AE_ALREADY_EXISTS) &&
808                 ((ThisNode->Flags & ANOBJ_IS_EXTERNAL) ||
809                     (WalkState && WalkState->Opcode == AML_EXTERNAL_OP)))
810             {
811                 ThisNode->Flags &= ~ANOBJ_IS_EXTERNAL;
812                 ThisNode->Type = (UINT8)ThisSearchType;
813                 if (WalkState->Opcode != AML_EXTERNAL_OP)
814                 {
815                     AcpiDmMarkExternalConflict (ThisNode);
816                 }
817                 break;
818             }
819 #endif
820 
821             *ReturnNode = ThisNode;
822             return_ACPI_STATUS (Status);
823         }
824 
825         /* More segments to follow? */
826 
827         if (NumSegments > 0)
828         {
829             /*
830              * If we have an alias to an object that opens a scope (such as a
831              * device or processor), we need to dereference the alias here so
832              * that we can access any children of the original node (via the
833              * remaining segments).
834              */
835             if (ThisNode->Type == ACPI_TYPE_LOCAL_ALIAS)
836             {
837                 if (!ThisNode->Object)
838                 {
839                     return_ACPI_STATUS (AE_NOT_EXIST);
840                 }
841 
842                 if (AcpiNsOpensScope (((ACPI_NAMESPACE_NODE *)
843                         ThisNode->Object)->Type))
844                 {
845                     ThisNode = (ACPI_NAMESPACE_NODE *) ThisNode->Object;
846                 }
847             }
848         }
849 
850         /* Special handling for the last segment (NumSegments == 0) */
851 
852         else
853         {
854             /*
855              * Sanity typecheck of the target object:
856              *
857              * If 1) This is the last segment (NumSegments == 0)
858              *    2) And we are looking for a specific type
859              *       (Not checking for TYPE_ANY)
860              *    3) Which is not an alias
861              *    4) Which is not a local type (TYPE_SCOPE)
862              *    5) And the type of target object is known (not TYPE_ANY)
863              *    6) And target object does not match what we are looking for
864              *
865              * Then we have a type mismatch. Just warn and ignore it.
866              */
867             if ((TypeToCheckFor != ACPI_TYPE_ANY)                   &&
868                 (TypeToCheckFor != ACPI_TYPE_LOCAL_ALIAS)           &&
869                 (TypeToCheckFor != ACPI_TYPE_LOCAL_METHOD_ALIAS)    &&
870                 (TypeToCheckFor != ACPI_TYPE_LOCAL_SCOPE)           &&
871                 (ThisNode->Type != ACPI_TYPE_ANY)                   &&
872                 (ThisNode->Type != TypeToCheckFor))
873             {
874                 /* Complain about a type mismatch */
875 
876                 ACPI_WARNING ((AE_INFO,
877                     "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
878                     ACPI_CAST_PTR (char, &SimpleName),
879                     AcpiUtGetTypeName (ThisNode->Type),
880                     AcpiUtGetTypeName (TypeToCheckFor)));
881             }
882 
883             /*
884              * If this is the last name segment and we are not looking for a
885              * specific type, but the type of found object is known, use that
886              * type to (later) see if it opens a scope.
887              */
888             if (Type == ACPI_TYPE_ANY)
889             {
890                 Type = ThisNode->Type;
891             }
892         }
893 
894         /* Point to next name segment and make this node current */
895 
896         Path += ACPI_NAMESEG_SIZE;
897         CurrentNode = ThisNode;
898     }
899 
900     /* Always check if we need to open a new scope */
901 
902     if (!(Flags & ACPI_NS_DONT_OPEN_SCOPE) && (WalkState))
903     {
904         /*
905          * If entry is a type which opens a scope, push the new scope on the
906          * scope stack.
907          */
908         if (AcpiNsOpensScope (Type))
909         {
910             Status = AcpiDsScopeStackPush (ThisNode, Type, WalkState);
911             if (ACPI_FAILURE (Status))
912             {
913                 return_ACPI_STATUS (Status);
914             }
915         }
916     }
917 
918 #ifdef ACPI_EXEC_APP
919     if (Flags & ACPI_NS_EARLY_INIT)
920     {
921         ThisNode->Flags |= ANOBJ_NODE_EARLY_INIT;
922     }
923 #endif
924 
925     *ReturnNode = ThisNode;
926     return_ACPI_STATUS (AE_OK);
927 }
928