xref: /freebsd/sys/contrib/dev/acpica/components/namespace/nsnames.c (revision 722b16673c40aedf280895f2f2f676bb494518d7)
1 /*******************************************************************************
2  *
3  * Module Name: nsnames - Name manipulation and search
4  *
5  ******************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2023, 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 
157 
158 #define _COMPONENT          ACPI_NAMESPACE
159         ACPI_MODULE_NAME    ("nsnames")
160 
161 
162 /*******************************************************************************
163  *
164  * FUNCTION:    AcpiNsGetExternalPathname
165  *
166  * PARAMETERS:  Node            - Namespace node whose pathname is needed
167  *
168  * RETURN:      Pointer to storage containing the fully qualified name of
169  *              the node, In external format (name segments separated by path
170  *              separators.)
171  *
172  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
173  *              for error and debug statements.
174  *
175  ******************************************************************************/
176 
177 char *
AcpiNsGetExternalPathname(ACPI_NAMESPACE_NODE * Node)178 AcpiNsGetExternalPathname (
179     ACPI_NAMESPACE_NODE     *Node)
180 {
181     char                    *NameBuffer;
182 
183 
184     ACPI_FUNCTION_TRACE_PTR (NsGetExternalPathname, Node);
185 
186 
187     NameBuffer = AcpiNsGetNormalizedPathname (Node, FALSE);
188     return_PTR (NameBuffer);
189 }
190 
191 
192 /*******************************************************************************
193  *
194  * FUNCTION:    AcpiNsGetPathnameLength
195  *
196  * PARAMETERS:  Node        - Namespace node
197  *
198  * RETURN:      Length of path, including prefix
199  *
200  * DESCRIPTION: Get the length of the pathname string for this node
201  *
202  ******************************************************************************/
203 
204 ACPI_SIZE
AcpiNsGetPathnameLength(ACPI_NAMESPACE_NODE * Node)205 AcpiNsGetPathnameLength (
206     ACPI_NAMESPACE_NODE     *Node)
207 {
208     ACPI_SIZE               Size;
209 
210 
211     /* Validate the Node */
212 
213     if (ACPI_GET_DESCRIPTOR_TYPE (Node) != ACPI_DESC_TYPE_NAMED)
214     {
215         ACPI_ERROR ((AE_INFO,
216             "Invalid/cached reference target node: %p, descriptor type %d",
217             Node, ACPI_GET_DESCRIPTOR_TYPE (Node)));
218         return (0);
219     }
220 
221     Size = AcpiNsBuildNormalizedPath (Node, NULL, 0, FALSE);
222     return (Size);
223 }
224 
225 
226 /*******************************************************************************
227  *
228  * FUNCTION:    AcpiNsHandleToName
229  *
230  * PARAMETERS:  TargetHandle            - Handle of named object whose name is
231  *                                        to be found
232  *              Buffer                  - Where the name is returned
233  *
234  * RETURN:      Status, Buffer is filled with name if status is AE_OK
235  *
236  * DESCRIPTION: Build and return a full namespace name
237  *
238  ******************************************************************************/
239 
240 ACPI_STATUS
AcpiNsHandleToName(ACPI_HANDLE TargetHandle,ACPI_BUFFER * Buffer)241 AcpiNsHandleToName (
242     ACPI_HANDLE             TargetHandle,
243     ACPI_BUFFER             *Buffer)
244 {
245     ACPI_STATUS             Status;
246     ACPI_NAMESPACE_NODE     *Node;
247     const char              *NodeName;
248 
249 
250     ACPI_FUNCTION_TRACE_PTR (NsHandleToName, TargetHandle);
251 
252 
253     Node = AcpiNsValidateHandle (TargetHandle);
254     if (!Node)
255     {
256         return_ACPI_STATUS (AE_BAD_PARAMETER);
257     }
258 
259     /* Validate/Allocate/Clear caller buffer */
260 
261     Status = AcpiUtInitializeBuffer (Buffer, ACPI_PATH_SEGMENT_LENGTH);
262     if (ACPI_FAILURE (Status))
263     {
264         return_ACPI_STATUS (Status);
265     }
266 
267     /* Just copy the ACPI name from the Node and zero terminate it */
268 
269     NodeName = AcpiUtGetNodeName (Node);
270     ACPI_COPY_NAMESEG (Buffer->Pointer, NodeName);
271     ((char *) Buffer->Pointer) [ACPI_NAMESEG_SIZE] = 0;
272 
273     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "%4.4s\n", (char *) Buffer->Pointer));
274     return_ACPI_STATUS (AE_OK);
275 }
276 
277 
278 /*******************************************************************************
279  *
280  * FUNCTION:    AcpiNsHandleToPathname
281  *
282  * PARAMETERS:  TargetHandle            - Handle of named object whose name is
283  *                                        to be found
284  *              Buffer                  - Where the pathname is returned
285  *              NoTrailing              - Remove trailing '_' for each name
286  *                                        segment
287  *
288  * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
289  *
290  * DESCRIPTION: Build and return a full namespace pathname
291  *
292  ******************************************************************************/
293 
294 ACPI_STATUS
AcpiNsHandleToPathname(ACPI_HANDLE TargetHandle,ACPI_BUFFER * Buffer,BOOLEAN NoTrailing)295 AcpiNsHandleToPathname (
296     ACPI_HANDLE             TargetHandle,
297     ACPI_BUFFER             *Buffer,
298     BOOLEAN                 NoTrailing)
299 {
300     ACPI_STATUS             Status;
301     ACPI_NAMESPACE_NODE     *Node;
302     ACPI_SIZE               RequiredSize;
303 
304 
305     ACPI_FUNCTION_TRACE_PTR (NsHandleToPathname, TargetHandle);
306 
307 
308     Node = AcpiNsValidateHandle (TargetHandle);
309     if (!Node)
310     {
311         return_ACPI_STATUS (AE_BAD_PARAMETER);
312     }
313 
314     /* Determine size required for the caller buffer */
315 
316     RequiredSize = AcpiNsBuildNormalizedPath (Node, NULL, 0, NoTrailing);
317     if (!RequiredSize)
318     {
319         return_ACPI_STATUS (AE_BAD_PARAMETER);
320     }
321 
322     /* Validate/Allocate/Clear caller buffer */
323 
324     Status = AcpiUtInitializeBuffer (Buffer, RequiredSize);
325     if (ACPI_FAILURE (Status))
326     {
327         return_ACPI_STATUS (Status);
328     }
329 
330     /* Build the path in the caller buffer */
331 
332     (void) AcpiNsBuildNormalizedPath (Node, Buffer->Pointer,
333         (UINT32) RequiredSize, NoTrailing);
334 
335     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "%s [%X]\n",
336         (char *) Buffer->Pointer, (UINT32) RequiredSize));
337     return_ACPI_STATUS (AE_OK);
338 }
339 
340 
341 /*******************************************************************************
342  *
343  * FUNCTION:    AcpiNsBuildNormalizedPath
344  *
345  * PARAMETERS:  Node        - Namespace node
346  *              FullPath    - Where the path name is returned
347  *              PathSize    - Size of returned path name buffer
348  *              NoTrailing  - Remove trailing '_' from each name segment
349  *
350  * RETURN:      Return 1 if the AML path is empty, otherwise returning (length
351  *              of pathname + 1) which means the 'FullPath' contains a trailing
352  *              null.
353  *
354  * DESCRIPTION: Build and return a full namespace pathname.
355  *              Note that if the size of 'FullPath' isn't large enough to
356  *              contain the namespace node's path name, the actual required
357  *              buffer length is returned, and it should be greater than
358  *              'PathSize'. So callers are able to check the returning value
359  *              to determine the buffer size of 'FullPath'.
360  *
361  ******************************************************************************/
362 
363 UINT32
AcpiNsBuildNormalizedPath(ACPI_NAMESPACE_NODE * Node,char * FullPath,UINT32 PathSize,BOOLEAN NoTrailing)364 AcpiNsBuildNormalizedPath (
365     ACPI_NAMESPACE_NODE     *Node,
366     char                    *FullPath,
367     UINT32                  PathSize,
368     BOOLEAN                 NoTrailing)
369 {
370     UINT32                  Length = 0, i;
371     char                    Name[ACPI_NAMESEG_SIZE];
372     BOOLEAN                 DoNoTrailing;
373     char                    c, *Left, *Right;
374     ACPI_NAMESPACE_NODE     *NextNode;
375 
376 
377     ACPI_FUNCTION_TRACE_PTR (NsBuildNormalizedPath, Node);
378 
379 
380 #define ACPI_PATH_PUT8(Path, Size, Byte, Length)    \
381     do {                                            \
382         if ((Length) < (Size))                      \
383         {                                           \
384             (Path)[(Length)] = (Byte);              \
385         }                                           \
386         (Length)++;                                 \
387     } while (0)
388 
389     /*
390      * Make sure the PathSize is correct, so that we don't need to
391      * validate both FullPath and PathSize.
392      */
393     if (!FullPath)
394     {
395         PathSize = 0;
396     }
397 
398     if (!Node)
399     {
400         goto BuildTrailingNull;
401     }
402 
403     NextNode = Node;
404     while (NextNode && NextNode != AcpiGbl_RootNode)
405     {
406         if (NextNode != Node)
407         {
408             ACPI_PATH_PUT8(FullPath, PathSize, AML_DUAL_NAME_PREFIX, Length);
409         }
410 
411         ACPI_MOVE_32_TO_32 (Name, &NextNode->Name);
412         DoNoTrailing = NoTrailing;
413         for (i = 0; i < 4; i++)
414         {
415             c = Name[4-i-1];
416             if (DoNoTrailing && c != '_')
417             {
418                 DoNoTrailing = FALSE;
419             }
420             if (!DoNoTrailing)
421             {
422                 ACPI_PATH_PUT8(FullPath, PathSize, c, Length);
423             }
424         }
425 
426         NextNode = NextNode->Parent;
427     }
428 
429     ACPI_PATH_PUT8(FullPath, PathSize, AML_ROOT_PREFIX, Length);
430 
431     /* Reverse the path string */
432 
433     if (Length <= PathSize)
434     {
435         Left = FullPath;
436         Right = FullPath+Length - 1;
437 
438         while (Left < Right)
439         {
440             c = *Left;
441             *Left++ = *Right;
442             *Right-- = c;
443         }
444     }
445 
446     /* Append the trailing null */
447 
448 BuildTrailingNull:
449     ACPI_PATH_PUT8 (FullPath, PathSize, '\0', Length);
450 
451 #undef ACPI_PATH_PUT8
452 
453     return_UINT32 (Length);
454 }
455 
456 
457 /*******************************************************************************
458  *
459  * FUNCTION:    AcpiNsGetNormalizedPathname
460  *
461  * PARAMETERS:  Node            - Namespace node whose pathname is needed
462  *              NoTrailing      - Remove trailing '_' from each name segment
463  *
464  * RETURN:      Pointer to storage containing the fully qualified name of
465  *              the node, In external format (name segments separated by path
466  *              separators.)
467  *
468  * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
469  *              for error and debug statements. All trailing '_' will be
470  *              removed from the full pathname if 'NoTrailing' is specified..
471  *
472  ******************************************************************************/
473 
474 char *
AcpiNsGetNormalizedPathname(ACPI_NAMESPACE_NODE * Node,BOOLEAN NoTrailing)475 AcpiNsGetNormalizedPathname (
476     ACPI_NAMESPACE_NODE     *Node,
477     BOOLEAN                 NoTrailing)
478 {
479     char                    *NameBuffer;
480     ACPI_SIZE               Size;
481 
482 
483     ACPI_FUNCTION_TRACE_PTR (NsGetNormalizedPathname, Node);
484 
485 
486     /* Calculate required buffer size based on depth below root */
487 
488     Size = AcpiNsBuildNormalizedPath (Node, NULL, 0, NoTrailing);
489     if (!Size)
490     {
491         return_PTR (NULL);
492     }
493 
494     /* Allocate a buffer to be returned to caller */
495 
496     NameBuffer = ACPI_ALLOCATE_ZEROED (Size);
497     if (!NameBuffer)
498     {
499         ACPI_ERROR ((AE_INFO,
500             "Could not allocate %u bytes", (UINT32) Size));
501         return_PTR (NULL);
502     }
503 
504     /* Build the path in the allocated buffer */
505 
506     (void) AcpiNsBuildNormalizedPath (Node, NameBuffer, (UINT32) Size, NoTrailing);
507 
508     ACPI_DEBUG_PRINT_RAW ((ACPI_DB_NAMES, "%s: Path \"%s\"\n",
509         ACPI_GET_FUNCTION_NAME, NameBuffer));
510 
511     return_PTR (NameBuffer);
512 }
513 
514 
515 /*******************************************************************************
516  *
517  * FUNCTION:    AcpiNsBuildPrefixedPathname
518  *
519  * PARAMETERS:  PrefixScope         - Scope/Path that prefixes the internal path
520  *              InternalPath        - Name or path of the namespace node
521  *
522  * RETURN:      None
523  *
524  * DESCRIPTION: Construct a fully qualified pathname from a concatenation of:
525  *              1) Path associated with the PrefixScope namespace node
526  *              2) External path representation of the Internal path
527  *
528  ******************************************************************************/
529 
530 char *
AcpiNsBuildPrefixedPathname(ACPI_GENERIC_STATE * PrefixScope,const char * InternalPath)531 AcpiNsBuildPrefixedPathname (
532     ACPI_GENERIC_STATE      *PrefixScope,
533     const char              *InternalPath)
534 {
535     ACPI_STATUS             Status;
536     char                    *FullPath = NULL;
537     char                    *ExternalPath = NULL;
538     char                    *PrefixPath = NULL;
539     ACPI_SIZE               PrefixPathLength = 0;
540 
541 
542     /* If there is a prefix, get the pathname to it */
543 
544     if (PrefixScope && PrefixScope->Scope.Node)
545     {
546         PrefixPath = AcpiNsGetNormalizedPathname (PrefixScope->Scope.Node, TRUE);
547         if (PrefixPath)
548         {
549             PrefixPathLength = strlen (PrefixPath);
550         }
551     }
552 
553     Status = AcpiNsExternalizeName (ACPI_UINT32_MAX, InternalPath,
554         NULL, &ExternalPath);
555     if (ACPI_FAILURE (Status))
556     {
557         goto Cleanup;
558     }
559 
560     /* Merge the prefix path and the path. 2 is for one dot and trailing null */
561 
562     FullPath = ACPI_ALLOCATE_ZEROED (
563         PrefixPathLength + strlen (ExternalPath) + 2);
564     if (!FullPath)
565     {
566         goto Cleanup;
567     }
568 
569     /* Don't merge if the External path is already fully qualified */
570 
571     if (PrefixPath &&
572         (*ExternalPath != '\\') &&
573         (*ExternalPath != '^'))
574     {
575         strcat (FullPath, PrefixPath);
576         if (PrefixPath[1])
577         {
578             strcat (FullPath, ".");
579         }
580     }
581 
582     AcpiNsNormalizePathname (ExternalPath);
583     strcat (FullPath, ExternalPath);
584 
585 Cleanup:
586     if (PrefixPath)
587     {
588         ACPI_FREE (PrefixPath);
589     }
590     if (ExternalPath)
591     {
592         ACPI_FREE (ExternalPath);
593     }
594 
595     return (FullPath);
596 }
597 
598 
599 /*******************************************************************************
600  *
601  * FUNCTION:    AcpiNsNormalizePathname
602  *
603  * PARAMETERS:  OriginalPath        - Path to be normalized, in External format
604  *
605  * RETURN:      The original path is processed in-place
606  *
607  * DESCRIPTION: Remove trailing underscores from each element of a path.
608  *
609  *              For example:  \A___.B___.C___ becomes \A.B.C
610  *
611  ******************************************************************************/
612 
613 void
AcpiNsNormalizePathname(char * OriginalPath)614 AcpiNsNormalizePathname (
615     char                    *OriginalPath)
616 {
617     char                    *InputPath = OriginalPath;
618     char                    *NewPathBuffer;
619     char                    *NewPath;
620     UINT32                  i;
621 
622 
623     /* Allocate a temp buffer in which to construct the new path */
624 
625     NewPathBuffer = ACPI_ALLOCATE_ZEROED (strlen (InputPath) + 1);
626     NewPath = NewPathBuffer;
627     if (!NewPathBuffer)
628     {
629         return;
630     }
631 
632     /* Special characters may appear at the beginning of the path */
633 
634     if (*InputPath == '\\')
635     {
636         *NewPath = *InputPath;
637         NewPath++;
638         InputPath++;
639     }
640 
641     while (*InputPath == '^')
642     {
643         *NewPath = *InputPath;
644         NewPath++;
645         InputPath++;
646     }
647 
648     /* Remainder of the path */
649 
650     while (*InputPath)
651     {
652         /* Do one nameseg at a time */
653 
654         for (i = 0; (i < ACPI_NAMESEG_SIZE) && *InputPath; i++)
655         {
656             if ((i == 0) || (*InputPath != '_')) /* First char is allowed to be underscore */
657             {
658                 *NewPath = *InputPath;
659                 NewPath++;
660             }
661 
662             InputPath++;
663         }
664 
665         /* Dot means that there are more namesegs to come */
666 
667         if (*InputPath == '.')
668         {
669             *NewPath = *InputPath;
670             NewPath++;
671             InputPath++;
672         }
673     }
674 
675     *NewPath = 0;
676     strcpy (OriginalPath, NewPathBuffer);
677     ACPI_FREE (NewPathBuffer);
678 }
679