xref: /freebsd/sys/contrib/dev/acpica/components/namespace/nsutils.c (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
1 /******************************************************************************
2  *
3  * Module Name: nsutils - Utilities for accessing ACPI namespace, accessing
4  *                        parents and siblings and Scope manipulation
5  *
6  *****************************************************************************/
7 
8 /*
9  * Copyright (C) 2000 - 2016, Intel Corp.
10  * All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions, and the following disclaimer,
17  *    without modification.
18  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19  *    substantially similar to the "NO WARRANTY" disclaimer below
20  *    ("Disclaimer") and any redistribution must be conditioned upon
21  *    including a substantially similar Disclaimer requirement for further
22  *    binary redistribution.
23  * 3. Neither the names of the above-listed copyright holders nor the names
24  *    of any contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * Alternatively, this software may be distributed under the terms of the
28  * GNU General Public License ("GPL") version 2 as published by the Free
29  * Software Foundation.
30  *
31  * NO WARRANTY
32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42  * POSSIBILITY OF SUCH DAMAGES.
43  */
44 
45 #include <contrib/dev/acpica/include/acpi.h>
46 #include <contrib/dev/acpica/include/accommon.h>
47 #include <contrib/dev/acpica/include/acnamesp.h>
48 #include <contrib/dev/acpica/include/amlcode.h>
49 
50 #define _COMPONENT          ACPI_NAMESPACE
51         ACPI_MODULE_NAME    ("nsutils")
52 
53 /* Local prototypes */
54 
55 #ifdef ACPI_OBSOLETE_FUNCTIONS
56 ACPI_NAME
57 AcpiNsFindParentName (
58     ACPI_NAMESPACE_NODE     *NodeToSearch);
59 #endif
60 
61 
62 /*******************************************************************************
63  *
64  * FUNCTION:    AcpiNsPrintNodePathname
65  *
66  * PARAMETERS:  Node            - Object
67  *              Message         - Prefix message
68  *
69  * DESCRIPTION: Print an object's full namespace pathname
70  *              Manages allocation/freeing of a pathname buffer
71  *
72  ******************************************************************************/
73 
74 void
75 AcpiNsPrintNodePathname (
76     ACPI_NAMESPACE_NODE     *Node,
77     const char              *Message)
78 {
79     ACPI_BUFFER             Buffer;
80     ACPI_STATUS             Status;
81 
82 
83     if (!Node)
84     {
85         AcpiOsPrintf ("[NULL NAME]");
86         return;
87     }
88 
89     /* Convert handle to full pathname and print it (with supplied message) */
90 
91     Buffer.Length = ACPI_ALLOCATE_LOCAL_BUFFER;
92 
93     Status = AcpiNsHandleToPathname (Node, &Buffer, TRUE);
94     if (ACPI_SUCCESS (Status))
95     {
96         if (Message)
97         {
98             AcpiOsPrintf ("%s ", Message);
99         }
100 
101         AcpiOsPrintf ("[%s] (Node %p)", (char *) Buffer.Pointer, Node);
102         ACPI_FREE (Buffer.Pointer);
103     }
104 }
105 
106 
107 /*******************************************************************************
108  *
109  * FUNCTION:    AcpiNsGetType
110  *
111  * PARAMETERS:  Node        - Parent Node to be examined
112  *
113  * RETURN:      Type field from Node whose handle is passed
114  *
115  * DESCRIPTION: Return the type of a Namespace node
116  *
117  ******************************************************************************/
118 
119 ACPI_OBJECT_TYPE
120 AcpiNsGetType (
121     ACPI_NAMESPACE_NODE     *Node)
122 {
123     ACPI_FUNCTION_TRACE (NsGetType);
124 
125 
126     if (!Node)
127     {
128         ACPI_WARNING ((AE_INFO, "Null Node parameter"));
129         return_UINT8 (ACPI_TYPE_ANY);
130     }
131 
132     return_UINT8 (Node->Type);
133 }
134 
135 
136 /*******************************************************************************
137  *
138  * FUNCTION:    AcpiNsLocal
139  *
140  * PARAMETERS:  Type        - A namespace object type
141  *
142  * RETURN:      LOCAL if names must be found locally in objects of the
143  *              passed type, 0 if enclosing scopes should be searched
144  *
145  * DESCRIPTION: Returns scope rule for the given object type.
146  *
147  ******************************************************************************/
148 
149 UINT32
150 AcpiNsLocal (
151     ACPI_OBJECT_TYPE        Type)
152 {
153     ACPI_FUNCTION_TRACE (NsLocal);
154 
155 
156     if (!AcpiUtValidObjectType (Type))
157     {
158         /* Type code out of range  */
159 
160         ACPI_WARNING ((AE_INFO, "Invalid Object Type 0x%X", Type));
161         return_UINT32 (ACPI_NS_NORMAL);
162     }
163 
164     return_UINT32 (AcpiGbl_NsProperties[Type] & ACPI_NS_LOCAL);
165 }
166 
167 
168 /*******************************************************************************
169  *
170  * FUNCTION:    AcpiNsGetInternalNameLength
171  *
172  * PARAMETERS:  Info            - Info struct initialized with the
173  *                                external name pointer.
174  *
175  * RETURN:      None
176  *
177  * DESCRIPTION: Calculate the length of the internal (AML) namestring
178  *              corresponding to the external (ASL) namestring.
179  *
180  ******************************************************************************/
181 
182 void
183 AcpiNsGetInternalNameLength (
184     ACPI_NAMESTRING_INFO    *Info)
185 {
186     const char              *NextExternalChar;
187     UINT32                  i;
188 
189 
190     ACPI_FUNCTION_ENTRY ();
191 
192 
193     NextExternalChar = Info->ExternalName;
194     Info->NumCarats = 0;
195     Info->NumSegments = 0;
196     Info->FullyQualified = FALSE;
197 
198     /*
199      * For the internal name, the required length is 4 bytes per segment,
200      * plus 1 each for RootPrefix, MultiNamePrefixOp, segment count,
201      * trailing null (which is not really needed, but no there's harm in
202      * putting it there)
203      *
204      * strlen() + 1 covers the first NameSeg, which has no path separator
205      */
206     if (ACPI_IS_ROOT_PREFIX (*NextExternalChar))
207     {
208         Info->FullyQualified = TRUE;
209         NextExternalChar++;
210 
211         /* Skip redundant RootPrefix, like \\_SB.PCI0.SBRG.EC0 */
212 
213         while (ACPI_IS_ROOT_PREFIX (*NextExternalChar))
214         {
215             NextExternalChar++;
216         }
217     }
218     else
219     {
220         /* Handle Carat prefixes */
221 
222         while (ACPI_IS_PARENT_PREFIX (*NextExternalChar))
223         {
224             Info->NumCarats++;
225             NextExternalChar++;
226         }
227     }
228 
229     /*
230      * Determine the number of ACPI name "segments" by counting the number of
231      * path separators within the string. Start with one segment since the
232      * segment count is [(# separators) + 1], and zero separators is ok.
233      */
234     if (*NextExternalChar)
235     {
236         Info->NumSegments = 1;
237         for (i = 0; NextExternalChar[i]; i++)
238         {
239             if (ACPI_IS_PATH_SEPARATOR (NextExternalChar[i]))
240             {
241                 Info->NumSegments++;
242             }
243         }
244     }
245 
246     Info->Length = (ACPI_NAME_SIZE * Info->NumSegments) +
247         4 + Info->NumCarats;
248 
249     Info->NextExternalChar = NextExternalChar;
250 }
251 
252 
253 /*******************************************************************************
254  *
255  * FUNCTION:    AcpiNsBuildInternalName
256  *
257  * PARAMETERS:  Info            - Info struct fully initialized
258  *
259  * RETURN:      Status
260  *
261  * DESCRIPTION: Construct the internal (AML) namestring
262  *              corresponding to the external (ASL) namestring.
263  *
264  ******************************************************************************/
265 
266 ACPI_STATUS
267 AcpiNsBuildInternalName (
268     ACPI_NAMESTRING_INFO    *Info)
269 {
270     UINT32                  NumSegments = Info->NumSegments;
271     char                    *InternalName = Info->InternalName;
272     const char              *ExternalName = Info->NextExternalChar;
273     char                    *Result = NULL;
274     UINT32                  i;
275 
276 
277     ACPI_FUNCTION_TRACE (NsBuildInternalName);
278 
279 
280     /* Setup the correct prefixes, counts, and pointers */
281 
282     if (Info->FullyQualified)
283     {
284         InternalName[0] = AML_ROOT_PREFIX;
285 
286         if (NumSegments <= 1)
287         {
288             Result = &InternalName[1];
289         }
290         else if (NumSegments == 2)
291         {
292             InternalName[1] = AML_DUAL_NAME_PREFIX;
293             Result = &InternalName[2];
294         }
295         else
296         {
297             InternalName[1] = AML_MULTI_NAME_PREFIX_OP;
298             InternalName[2] = (char) NumSegments;
299             Result = &InternalName[3];
300         }
301     }
302     else
303     {
304         /*
305          * Not fully qualified.
306          * Handle Carats first, then append the name segments
307          */
308         i = 0;
309         if (Info->NumCarats)
310         {
311             for (i = 0; i < Info->NumCarats; i++)
312             {
313                 InternalName[i] = AML_PARENT_PREFIX;
314             }
315         }
316 
317         if (NumSegments <= 1)
318         {
319             Result = &InternalName[i];
320         }
321         else if (NumSegments == 2)
322         {
323             InternalName[i] = AML_DUAL_NAME_PREFIX;
324             Result = &InternalName[(ACPI_SIZE) i+1];
325         }
326         else
327         {
328             InternalName[i] = AML_MULTI_NAME_PREFIX_OP;
329             InternalName[(ACPI_SIZE) i+1] = (char) NumSegments;
330             Result = &InternalName[(ACPI_SIZE) i+2];
331         }
332     }
333 
334     /* Build the name (minus path separators) */
335 
336     for (; NumSegments; NumSegments--)
337     {
338         for (i = 0; i < ACPI_NAME_SIZE; i++)
339         {
340             if (ACPI_IS_PATH_SEPARATOR (*ExternalName) ||
341                (*ExternalName == 0))
342             {
343                 /* Pad the segment with underscore(s) if segment is short */
344 
345                 Result[i] = '_';
346             }
347             else
348             {
349                 /* Convert the character to uppercase and save it */
350 
351                 Result[i] = (char) toupper ((int) *ExternalName);
352                 ExternalName++;
353             }
354         }
355 
356         /* Now we must have a path separator, or the pathname is bad */
357 
358         if (!ACPI_IS_PATH_SEPARATOR (*ExternalName) &&
359             (*ExternalName != 0))
360         {
361             return_ACPI_STATUS (AE_BAD_PATHNAME);
362         }
363 
364         /* Move on the next segment */
365 
366         ExternalName++;
367         Result += ACPI_NAME_SIZE;
368     }
369 
370     /* Terminate the string */
371 
372     *Result = 0;
373 
374     if (Info->FullyQualified)
375     {
376         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Returning [%p] (abs) \"\\%s\"\n",
377             InternalName, InternalName));
378     }
379     else
380     {
381         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Returning [%p] (rel) \"%s\"\n",
382             InternalName, InternalName));
383     }
384 
385     return_ACPI_STATUS (AE_OK);
386 }
387 
388 
389 /*******************************************************************************
390  *
391  * FUNCTION:    AcpiNsInternalizeName
392  *
393  * PARAMETERS:  *ExternalName           - External representation of name
394  *              **Converted Name        - Where to return the resulting
395  *                                        internal represention of the name
396  *
397  * RETURN:      Status
398  *
399  * DESCRIPTION: Convert an external representation (e.g. "\_PR_.CPU0")
400  *              to internal form (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
401  *
402  *******************************************************************************/
403 
404 ACPI_STATUS
405 AcpiNsInternalizeName (
406     const char              *ExternalName,
407     char                    **ConvertedName)
408 {
409     char                    *InternalName;
410     ACPI_NAMESTRING_INFO    Info;
411     ACPI_STATUS             Status;
412 
413 
414     ACPI_FUNCTION_TRACE (NsInternalizeName);
415 
416 
417     if ((!ExternalName)      ||
418         (*ExternalName == 0) ||
419         (!ConvertedName))
420     {
421         return_ACPI_STATUS (AE_BAD_PARAMETER);
422     }
423 
424     /* Get the length of the new internal name */
425 
426     Info.ExternalName = ExternalName;
427     AcpiNsGetInternalNameLength (&Info);
428 
429     /* We need a segment to store the internal  name */
430 
431     InternalName = ACPI_ALLOCATE_ZEROED (Info.Length);
432     if (!InternalName)
433     {
434         return_ACPI_STATUS (AE_NO_MEMORY);
435     }
436 
437     /* Build the name */
438 
439     Info.InternalName = InternalName;
440     Status = AcpiNsBuildInternalName (&Info);
441     if (ACPI_FAILURE (Status))
442     {
443         ACPI_FREE (InternalName);
444         return_ACPI_STATUS (Status);
445     }
446 
447     *ConvertedName = InternalName;
448     return_ACPI_STATUS (AE_OK);
449 }
450 
451 
452 /*******************************************************************************
453  *
454  * FUNCTION:    AcpiNsExternalizeName
455  *
456  * PARAMETERS:  InternalNameLength  - Lenth of the internal name below
457  *              InternalName        - Internal representation of name
458  *              ConvertedNameLength - Where the length is returned
459  *              ConvertedName       - Where the resulting external name
460  *                                    is returned
461  *
462  * RETURN:      Status
463  *
464  * DESCRIPTION: Convert internal name (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
465  *              to its external (printable) form (e.g. "\_PR_.CPU0")
466  *
467  ******************************************************************************/
468 
469 ACPI_STATUS
470 AcpiNsExternalizeName (
471     UINT32                  InternalNameLength,
472     const char              *InternalName,
473     UINT32                  *ConvertedNameLength,
474     char                    **ConvertedName)
475 {
476     UINT32                  NamesIndex = 0;
477     UINT32                  NumSegments = 0;
478     UINT32                  RequiredLength;
479     UINT32                  PrefixLength = 0;
480     UINT32                  i = 0;
481     UINT32                  j = 0;
482 
483 
484     ACPI_FUNCTION_TRACE (NsExternalizeName);
485 
486 
487     if (!InternalNameLength     ||
488         !InternalName           ||
489         !ConvertedName)
490     {
491         return_ACPI_STATUS (AE_BAD_PARAMETER);
492     }
493 
494     /* Check for a prefix (one '\' | one or more '^') */
495 
496     switch (InternalName[0])
497     {
498     case AML_ROOT_PREFIX:
499 
500         PrefixLength = 1;
501         break;
502 
503     case AML_PARENT_PREFIX:
504 
505         for (i = 0; i < InternalNameLength; i++)
506         {
507             if (ACPI_IS_PARENT_PREFIX (InternalName[i]))
508             {
509                 PrefixLength = i + 1;
510             }
511             else
512             {
513                 break;
514             }
515         }
516 
517         if (i == InternalNameLength)
518         {
519             PrefixLength = i;
520         }
521 
522         break;
523 
524     default:
525 
526         break;
527     }
528 
529     /*
530      * Check for object names. Note that there could be 0-255 of these
531      * 4-byte elements.
532      */
533     if (PrefixLength < InternalNameLength)
534     {
535         switch (InternalName[PrefixLength])
536         {
537         case AML_MULTI_NAME_PREFIX_OP:
538 
539             /* <count> 4-byte names */
540 
541             NamesIndex = PrefixLength + 2;
542             NumSegments = (UINT8)
543                 InternalName[(ACPI_SIZE) PrefixLength + 1];
544             break;
545 
546         case AML_DUAL_NAME_PREFIX:
547 
548             /* Two 4-byte names */
549 
550             NamesIndex = PrefixLength + 1;
551             NumSegments = 2;
552             break;
553 
554         case 0:
555 
556             /* NullName */
557 
558             NamesIndex = 0;
559             NumSegments = 0;
560             break;
561 
562         default:
563 
564             /* one 4-byte name */
565 
566             NamesIndex = PrefixLength;
567             NumSegments = 1;
568             break;
569         }
570     }
571 
572     /*
573      * Calculate the length of ConvertedName, which equals the length
574      * of the prefix, length of all object names, length of any required
575      * punctuation ('.') between object names, plus the NULL terminator.
576      */
577     RequiredLength = PrefixLength + (4 * NumSegments) +
578         ((NumSegments > 0) ? (NumSegments - 1) : 0) + 1;
579 
580     /*
581      * Check to see if we're still in bounds. If not, there's a problem
582      * with InternalName (invalid format).
583      */
584     if (RequiredLength > InternalNameLength)
585     {
586         ACPI_ERROR ((AE_INFO, "Invalid internal name"));
587         return_ACPI_STATUS (AE_BAD_PATHNAME);
588     }
589 
590     /* Build the ConvertedName */
591 
592     *ConvertedName = ACPI_ALLOCATE_ZEROED (RequiredLength);
593     if (!(*ConvertedName))
594     {
595         return_ACPI_STATUS (AE_NO_MEMORY);
596     }
597 
598     j = 0;
599 
600     for (i = 0; i < PrefixLength; i++)
601     {
602         (*ConvertedName)[j++] = InternalName[i];
603     }
604 
605     if (NumSegments > 0)
606     {
607         for (i = 0; i < NumSegments; i++)
608         {
609             if (i > 0)
610             {
611                 (*ConvertedName)[j++] = '.';
612             }
613 
614             /* Copy and validate the 4-char name segment */
615 
616             ACPI_MOVE_NAME (&(*ConvertedName)[j],
617                 &InternalName[NamesIndex]);
618             AcpiUtRepairName (&(*ConvertedName)[j]);
619 
620             j += ACPI_NAME_SIZE;
621             NamesIndex += ACPI_NAME_SIZE;
622         }
623     }
624 
625     if (ConvertedNameLength)
626     {
627         *ConvertedNameLength = (UINT32) RequiredLength;
628     }
629 
630     return_ACPI_STATUS (AE_OK);
631 }
632 
633 
634 /*******************************************************************************
635  *
636  * FUNCTION:    AcpiNsValidateHandle
637  *
638  * PARAMETERS:  Handle          - Handle to be validated and typecast to a
639  *                                namespace node.
640  *
641  * RETURN:      A pointer to a namespace node
642  *
643  * DESCRIPTION: Convert a namespace handle to a namespace node. Handles special
644  *              cases for the root node.
645  *
646  * NOTE: Real integer handles would allow for more verification
647  *       and keep all pointers within this subsystem - however this introduces
648  *       more overhead and has not been necessary to this point. Drivers
649  *       holding handles are typically notified before a node becomes invalid
650  *       due to a table unload.
651  *
652  ******************************************************************************/
653 
654 ACPI_NAMESPACE_NODE *
655 AcpiNsValidateHandle (
656     ACPI_HANDLE             Handle)
657 {
658 
659     ACPI_FUNCTION_ENTRY ();
660 
661 
662     /* Parameter validation */
663 
664     if ((!Handle) || (Handle == ACPI_ROOT_OBJECT))
665     {
666         return (AcpiGbl_RootNode);
667     }
668 
669     /* We can at least attempt to verify the handle */
670 
671     if (ACPI_GET_DESCRIPTOR_TYPE (Handle) != ACPI_DESC_TYPE_NAMED)
672     {
673         return (NULL);
674     }
675 
676     return (ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, Handle));
677 }
678 
679 
680 /*******************************************************************************
681  *
682  * FUNCTION:    AcpiNsTerminate
683  *
684  * PARAMETERS:  none
685  *
686  * RETURN:      none
687  *
688  * DESCRIPTION: free memory allocated for namespace and ACPI table storage.
689  *
690  ******************************************************************************/
691 
692 void
693 AcpiNsTerminate (
694     void)
695 {
696     ACPI_STATUS             Status;
697 
698 
699     ACPI_FUNCTION_TRACE (NsTerminate);
700 
701 
702 #ifdef ACPI_EXEC_APP
703     {
704         ACPI_OPERAND_OBJECT     *Prev;
705         ACPI_OPERAND_OBJECT     *Next;
706 
707         /* Delete any module-level code blocks */
708 
709         Next = AcpiGbl_ModuleCodeList;
710         while (Next)
711         {
712             Prev = Next;
713             Next = Next->Method.Mutex;
714             Prev->Method.Mutex = NULL; /* Clear the Mutex (cheated) field */
715             AcpiUtRemoveReference (Prev);
716         }
717     }
718 #endif
719 
720     /*
721      * Free the entire namespace -- all nodes and all objects
722      * attached to the nodes
723      */
724     AcpiNsDeleteNamespaceSubtree (AcpiGbl_RootNode);
725 
726     /* Delete any objects attached to the root node */
727 
728     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
729     if (ACPI_FAILURE (Status))
730     {
731         return_VOID;
732     }
733 
734     AcpiNsDeleteNode (AcpiGbl_RootNode);
735     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
736 
737     ACPI_DEBUG_PRINT ((ACPI_DB_INFO, "Namespace freed\n"));
738     return_VOID;
739 }
740 
741 
742 /*******************************************************************************
743  *
744  * FUNCTION:    AcpiNsOpensScope
745  *
746  * PARAMETERS:  Type        - A valid namespace type
747  *
748  * RETURN:      NEWSCOPE if the passed type "opens a name scope" according
749  *              to the ACPI specification, else 0
750  *
751  ******************************************************************************/
752 
753 UINT32
754 AcpiNsOpensScope (
755     ACPI_OBJECT_TYPE        Type)
756 {
757     ACPI_FUNCTION_ENTRY ();
758 
759 
760     if (Type > ACPI_TYPE_LOCAL_MAX)
761     {
762         /* type code out of range  */
763 
764         ACPI_WARNING ((AE_INFO, "Invalid Object Type 0x%X", Type));
765         return (ACPI_NS_NORMAL);
766     }
767 
768     return (((UINT32) AcpiGbl_NsProperties[Type]) & ACPI_NS_NEWSCOPE);
769 }
770 
771 
772 /*******************************************************************************
773  *
774  * FUNCTION:    AcpiNsGetNodeUnlocked
775  *
776  * PARAMETERS:  *Pathname   - Name to be found, in external (ASL) format. The
777  *                            \ (backslash) and ^ (carat) prefixes, and the
778  *                            . (period) to separate segments are supported.
779  *              PrefixNode   - Root of subtree to be searched, or NS_ALL for the
780  *                            root of the name space. If Name is fully
781  *                            qualified (first INT8 is '\'), the passed value
782  *                            of Scope will not be accessed.
783  *              Flags       - Used to indicate whether to perform upsearch or
784  *                            not.
785  *              ReturnNode  - Where the Node is returned
786  *
787  * DESCRIPTION: Look up a name relative to a given scope and return the
788  *              corresponding Node. NOTE: Scope can be null.
789  *
790  * MUTEX:       Doesn't locks namespace
791  *
792  ******************************************************************************/
793 
794 ACPI_STATUS
795 AcpiNsGetNodeUnlocked (
796     ACPI_NAMESPACE_NODE     *PrefixNode,
797     const char              *Pathname,
798     UINT32                  Flags,
799     ACPI_NAMESPACE_NODE     **ReturnNode)
800 {
801     ACPI_GENERIC_STATE      ScopeInfo;
802     ACPI_STATUS             Status;
803     char                    *InternalPath;
804 
805 
806     ACPI_FUNCTION_TRACE_PTR (NsGetNodeUnlocked, ACPI_CAST_PTR (char, Pathname));
807 
808 
809     /* Simplest case is a null pathname */
810 
811     if (!Pathname)
812     {
813         *ReturnNode = PrefixNode;
814         if (!PrefixNode)
815         {
816             *ReturnNode = AcpiGbl_RootNode;
817         }
818 
819         return_ACPI_STATUS (AE_OK);
820     }
821 
822     /* Quick check for a reference to the root */
823 
824     if (ACPI_IS_ROOT_PREFIX (Pathname[0]) && (!Pathname[1]))
825     {
826         *ReturnNode = AcpiGbl_RootNode;
827         return_ACPI_STATUS (AE_OK);
828     }
829 
830     /* Convert path to internal representation */
831 
832     Status = AcpiNsInternalizeName (Pathname, &InternalPath);
833     if (ACPI_FAILURE (Status))
834     {
835         return_ACPI_STATUS (Status);
836     }
837 
838     /* Setup lookup scope (search starting point) */
839 
840     ScopeInfo.Scope.Node = PrefixNode;
841 
842     /* Lookup the name in the namespace */
843 
844     Status = AcpiNsLookup (&ScopeInfo, InternalPath, ACPI_TYPE_ANY,
845         ACPI_IMODE_EXECUTE, (Flags | ACPI_NS_DONT_OPEN_SCOPE),
846         NULL, ReturnNode);
847     if (ACPI_FAILURE (Status))
848     {
849         ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "%s, %s\n",
850             Pathname, AcpiFormatException (Status)));
851     }
852 
853     ACPI_FREE (InternalPath);
854     return_ACPI_STATUS (Status);
855 }
856 
857 
858 /*******************************************************************************
859  *
860  * FUNCTION:    AcpiNsGetNode
861  *
862  * PARAMETERS:  *Pathname   - Name to be found, in external (ASL) format. The
863  *                            \ (backslash) and ^ (carat) prefixes, and the
864  *                            . (period) to separate segments are supported.
865  *              PrefixNode   - Root of subtree to be searched, or NS_ALL for the
866  *                            root of the name space. If Name is fully
867  *                            qualified (first INT8 is '\'), the passed value
868  *                            of Scope will not be accessed.
869  *              Flags       - Used to indicate whether to perform upsearch or
870  *                            not.
871  *              ReturnNode  - Where the Node is returned
872  *
873  * DESCRIPTION: Look up a name relative to a given scope and return the
874  *              corresponding Node. NOTE: Scope can be null.
875  *
876  * MUTEX:       Locks namespace
877  *
878  ******************************************************************************/
879 
880 ACPI_STATUS
881 AcpiNsGetNode (
882     ACPI_NAMESPACE_NODE     *PrefixNode,
883     const char              *Pathname,
884     UINT32                  Flags,
885     ACPI_NAMESPACE_NODE     **ReturnNode)
886 {
887     ACPI_STATUS             Status;
888 
889 
890     ACPI_FUNCTION_TRACE_PTR (NsGetNode, ACPI_CAST_PTR (char, Pathname));
891 
892 
893     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
894     if (ACPI_FAILURE (Status))
895     {
896         return_ACPI_STATUS (Status);
897     }
898 
899     Status = AcpiNsGetNodeUnlocked (PrefixNode, Pathname,
900         Flags, ReturnNode);
901 
902     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
903     return_ACPI_STATUS (Status);
904 }
905