xref: /titanic_51/usr/src/uts/intel/io/acpica/namespace/nsxfname.c (revision 58dbc5075c2263a035b497f4bb080ab9bfb6aab4)
1 /******************************************************************************
2  *
3  * Module Name: nsxfname - Public interfaces to the ACPI subsystem
4  *                         ACPI Namespace oriented interfaces
5  *
6  *****************************************************************************/
7 
8 /******************************************************************************
9  *
10  * 1. Copyright Notice
11  *
12  * Some or all of this work - Copyright (c) 1999 - 2009, Intel Corp.
13  * All rights reserved.
14  *
15  * 2. License
16  *
17  * 2.1. This is your license from Intel Corp. under its intellectual property
18  * rights.  You may have additional license terms from the party that provided
19  * you this software, covering your right to use that party's intellectual
20  * property rights.
21  *
22  * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
23  * copy of the source code appearing in this file ("Covered Code") an
24  * irrevocable, perpetual, worldwide license under Intel's copyrights in the
25  * base code distributed originally by Intel ("Original Intel Code") to copy,
26  * make derivatives, distribute, use and display any portion of the Covered
27  * Code in any form, with the right to sublicense such rights; and
28  *
29  * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
30  * license (with the right to sublicense), under only those claims of Intel
31  * patents that are infringed by the Original Intel Code, to make, use, sell,
32  * offer to sell, and import the Covered Code and derivative works thereof
33  * solely to the minimum extent necessary to exercise the above copyright
34  * license, and in no event shall the patent license extend to any additions
35  * to or modifications of the Original Intel Code.  No other license or right
36  * is granted directly or by implication, estoppel or otherwise;
37  *
38  * The above copyright and patent license is granted only if the following
39  * conditions are met:
40  *
41  * 3. Conditions
42  *
43  * 3.1. Redistribution of Source with Rights to Further Distribute Source.
44  * Redistribution of source code of any substantial portion of the Covered
45  * Code or modification with rights to further distribute source must include
46  * the above Copyright Notice, the above License, this list of Conditions,
47  * and the following Disclaimer and Export Compliance provision.  In addition,
48  * Licensee must cause all Covered Code to which Licensee contributes to
49  * contain a file documenting the changes Licensee made to create that Covered
50  * Code and the date of any change.  Licensee must include in that file the
51  * documentation of any changes made by any predecessor Licensee.  Licensee
52  * must include a prominent statement that the modification is derived,
53  * directly or indirectly, from Original Intel Code.
54  *
55  * 3.2. Redistribution of Source with no Rights to Further Distribute Source.
56  * Redistribution of source code of any substantial portion of the Covered
57  * Code or modification without rights to further distribute source must
58  * include the following Disclaimer and Export Compliance provision in the
59  * documentation and/or other materials provided with distribution.  In
60  * addition, Licensee may not authorize further sublicense of source of any
61  * portion of the Covered Code, and must include terms to the effect that the
62  * license from Licensee to its licensee is limited to the intellectual
63  * property embodied in the software Licensee provides to its licensee, and
64  * not to intellectual property embodied in modifications its licensee may
65  * make.
66  *
67  * 3.3. Redistribution of Executable. Redistribution in executable form of any
68  * substantial portion of the Covered Code or modification must reproduce the
69  * above Copyright Notice, and the following Disclaimer and Export Compliance
70  * provision in the documentation and/or other materials provided with the
71  * distribution.
72  *
73  * 3.4. Intel retains all right, title, and interest in and to the Original
74  * Intel Code.
75  *
76  * 3.5. Neither the name Intel nor any other trademark owned or controlled by
77  * Intel shall be used in advertising or otherwise to promote the sale, use or
78  * other dealings in products derived from or relating to the Covered Code
79  * without prior written authorization from Intel.
80  *
81  * 4. Disclaimer and Export Compliance
82  *
83  * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
84  * HERE.  ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
85  * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT,  ASSISTANCE,
86  * INSTALLATION, TRAINING OR OTHER SERVICES.  INTEL WILL NOT PROVIDE ANY
87  * UPDATES, ENHANCEMENTS OR EXTENSIONS.  INTEL SPECIFICALLY DISCLAIMS ANY
88  * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
89  * PARTICULAR PURPOSE.
90  *
91  * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
92  * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
93  * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
94  * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
95  * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
96  * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.  THESE LIMITATIONS
97  * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
98  * LIMITED REMEDY.
99  *
100  * 4.3. Licensee shall not export, either directly or indirectly, any of this
101  * software or system incorporating such software without first obtaining any
102  * required license or other approval from the U. S. Department of Commerce or
103  * any other agency or department of the United States Government.  In the
104  * event Licensee exports any such software from the United States or
105  * re-exports any such software from a foreign destination, Licensee shall
106  * ensure that the distribution and export/re-export of the software is in
107  * compliance with all laws, regulations, orders, or other restrictions of the
108  * U.S. Export Administration Regulations. Licensee agrees that neither it nor
109  * any of its subsidiaries will export/re-export any technical data, process,
110  * software, or service, directly or indirectly, to any country for which the
111  * United States government or any agency thereof requires an export license,
112  * other governmental approval, or letter of assurance, without first obtaining
113  * such license, approval or letter.
114  *
115  *****************************************************************************/
116 
117 #define __NSXFNAME_C__
118 
119 #include "acpi.h"
120 #include "accommon.h"
121 #include "acnamesp.h"
122 #include "acparser.h"
123 #include "amlcode.h"
124 
125 
126 #define _COMPONENT          ACPI_NAMESPACE
127         ACPI_MODULE_NAME    ("nsxfname")
128 
129 /* Local prototypes */
130 
131 static char *
132 AcpiNsCopyDeviceId (
133     ACPI_DEVICE_ID          *Dest,
134     ACPI_DEVICE_ID          *Source,
135     char                    *StringArea);
136 
137 
138 /******************************************************************************
139  *
140  * FUNCTION:    AcpiGetHandle
141  *
142  * PARAMETERS:  Parent          - Object to search under (search scope).
143  *              Pathname        - Pointer to an asciiz string containing the
144  *                                name
145  *              RetHandle       - Where the return handle is returned
146  *
147  * RETURN:      Status
148  *
149  * DESCRIPTION: This routine will search for a caller specified name in the
150  *              name space.  The caller can restrict the search region by
151  *              specifying a non NULL parent.  The parent value is itself a
152  *              namespace handle.
153  *
154  ******************************************************************************/
155 
156 ACPI_STATUS
157 AcpiGetHandle (
158     ACPI_HANDLE             Parent,
159     ACPI_STRING             Pathname,
160     ACPI_HANDLE             *RetHandle)
161 {
162     ACPI_STATUS             Status;
163     ACPI_NAMESPACE_NODE     *Node = NULL;
164     ACPI_NAMESPACE_NODE     *PrefixNode = NULL;
165 
166 
167     ACPI_FUNCTION_ENTRY ();
168 
169 
170     /* Parameter Validation */
171 
172     if (!RetHandle || !Pathname)
173     {
174         return (AE_BAD_PARAMETER);
175     }
176 
177     /* Convert a parent handle to a prefix node */
178 
179     if (Parent)
180     {
181         PrefixNode = AcpiNsMapHandleToNode (Parent);
182         if (!PrefixNode)
183         {
184             return (AE_BAD_PARAMETER);
185         }
186     }
187 
188     /*
189      * Valid cases are:
190      * 1) Fully qualified pathname
191      * 2) Parent + Relative pathname
192      *
193      * Error for <null Parent + relative path>
194      */
195     if (AcpiNsValidRootPrefix (Pathname[0]))
196     {
197         /* Pathname is fully qualified (starts with '\') */
198 
199         /* Special case for root-only, since we can't search for it */
200 
201         if (!ACPI_STRCMP (Pathname, ACPI_NS_ROOT_PATH))
202         {
203             *RetHandle = AcpiNsConvertEntryToHandle (AcpiGbl_RootNode);
204             return (AE_OK);
205         }
206     }
207     else if (!PrefixNode)
208     {
209         /* Relative path with null prefix is disallowed */
210 
211         return (AE_BAD_PARAMETER);
212     }
213 
214     /* Find the Node and convert to a handle */
215 
216     Status = AcpiNsGetNode (PrefixNode, Pathname, ACPI_NS_NO_UPSEARCH, &Node);
217     if (ACPI_SUCCESS (Status))
218     {
219         *RetHandle = AcpiNsConvertEntryToHandle (Node);
220     }
221 
222     return (Status);
223 }
224 
225 ACPI_EXPORT_SYMBOL (AcpiGetHandle)
226 
227 
228 /******************************************************************************
229  *
230  * FUNCTION:    AcpiGetName
231  *
232  * PARAMETERS:  Handle          - Handle to be converted to a pathname
233  *              NameType        - Full pathname or single segment
234  *              Buffer          - Buffer for returned path
235  *
236  * RETURN:      Pointer to a string containing the fully qualified Name.
237  *
238  * DESCRIPTION: This routine returns the fully qualified name associated with
239  *              the Handle parameter.  This and the AcpiPathnameToHandle are
240  *              complementary functions.
241  *
242  ******************************************************************************/
243 
244 ACPI_STATUS
245 AcpiGetName (
246     ACPI_HANDLE             Handle,
247     UINT32                  NameType,
248     ACPI_BUFFER             *Buffer)
249 {
250     ACPI_STATUS             Status;
251     ACPI_NAMESPACE_NODE     *Node;
252 
253 
254     /* Parameter validation */
255 
256     if (NameType > ACPI_NAME_TYPE_MAX)
257     {
258         return (AE_BAD_PARAMETER);
259     }
260 
261     Status = AcpiUtValidateBuffer (Buffer);
262     if (ACPI_FAILURE (Status))
263     {
264         return (Status);
265     }
266 
267     if (NameType == ACPI_FULL_PATHNAME)
268     {
269         /* Get the full pathname (From the namespace root) */
270 
271         Status = AcpiNsHandleToPathname (Handle, Buffer);
272         return (Status);
273     }
274 
275     /*
276      * Wants the single segment ACPI name.
277      * Validate handle and convert to a namespace Node
278      */
279     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
280     if (ACPI_FAILURE (Status))
281     {
282         return (Status);
283     }
284 
285     Node = AcpiNsMapHandleToNode (Handle);
286     if (!Node)
287     {
288         Status = AE_BAD_PARAMETER;
289         goto UnlockAndExit;
290     }
291 
292     /* Validate/Allocate/Clear caller buffer */
293 
294     Status = AcpiUtInitializeBuffer (Buffer, ACPI_PATH_SEGMENT_LENGTH);
295     if (ACPI_FAILURE (Status))
296     {
297         goto UnlockAndExit;
298     }
299 
300     /* Just copy the ACPI name from the Node and zero terminate it */
301 
302     ACPI_STRNCPY (Buffer->Pointer, AcpiUtGetNodeName (Node),
303                 ACPI_NAME_SIZE);
304     ((char *) Buffer->Pointer) [ACPI_NAME_SIZE] = 0;
305     Status = AE_OK;
306 
307 
308 UnlockAndExit:
309 
310     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
311     return (Status);
312 }
313 
314 ACPI_EXPORT_SYMBOL (AcpiGetName)
315 
316 
317 /******************************************************************************
318  *
319  * FUNCTION:    AcpiNsCopyDeviceId
320  *
321  * PARAMETERS:  Dest                - Pointer to the destination DEVICE_ID
322  *              Source              - Pointer to the source DEVICE_ID
323  *              StringArea          - Pointer to where to copy the dest string
324  *
325  * RETURN:      Pointer to the next string area
326  *
327  * DESCRIPTION: Copy a single DEVICE_ID, including the string data.
328  *
329  ******************************************************************************/
330 
331 static char *
332 AcpiNsCopyDeviceId (
333     ACPI_DEVICE_ID          *Dest,
334     ACPI_DEVICE_ID          *Source,
335     char                    *StringArea)
336 {
337     /* Create the destination DEVICE_ID */
338 
339     Dest->String = StringArea;
340     Dest->Length = Source->Length;
341 
342     /* Copy actual string and return a pointer to the next string area */
343 
344     ACPI_MEMCPY (StringArea, Source->String, Source->Length);
345     return (StringArea + Source->Length);
346 }
347 
348 
349 /******************************************************************************
350  *
351  * FUNCTION:    AcpiGetObjectInfo
352  *
353  * PARAMETERS:  Handle              - Object Handle
354  *              ReturnBuffer        - Where the info is returned
355  *
356  * RETURN:      Status
357  *
358  * DESCRIPTION: Returns information about an object as gleaned from the
359  *              namespace node and possibly by running several standard
360  *              control methods (Such as in the case of a device.)
361  *
362  * For Device and Processor objects, run the Device _HID, _UID, _CID, _STA,
363  * _ADR, _SxW, and _SxD methods.
364  *
365  * Note: Allocates the return buffer, must be freed by the caller.
366  *
367  ******************************************************************************/
368 
369 ACPI_STATUS
370 AcpiGetObjectInfo (
371     ACPI_HANDLE             Handle,
372     ACPI_DEVICE_INFO        **ReturnBuffer)
373 {
374     ACPI_NAMESPACE_NODE     *Node;
375     ACPI_DEVICE_INFO        *Info;
376     ACPI_DEVICE_ID_LIST     *CidList = NULL;
377     ACPI_DEVICE_ID          *Hid = NULL;
378     ACPI_DEVICE_ID          *Uid = NULL;
379     char                    *NextIdString;
380     ACPI_OBJECT_TYPE        Type;
381     ACPI_NAME               Name;
382     UINT8                   ParamCount= 0;
383     UINT8                   Valid = 0;
384     UINT32                  InfoSize;
385     UINT32                  i;
386     ACPI_STATUS             Status;
387 
388 
389     /* Parameter validation */
390 
391     if (!Handle || !ReturnBuffer)
392     {
393         return (AE_BAD_PARAMETER);
394     }
395 
396     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
397     if (ACPI_FAILURE (Status))
398     {
399         goto Cleanup;
400     }
401 
402     Node = AcpiNsMapHandleToNode (Handle);
403     if (!Node)
404     {
405         (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
406         return (AE_BAD_PARAMETER);
407     }
408 
409     /* Get the namespace node data while the namespace is locked */
410 
411     InfoSize = sizeof (ACPI_DEVICE_INFO);
412     Type = Node->Type;
413     Name = Node->Name.Integer;
414 
415     if (Node->Type == ACPI_TYPE_METHOD)
416     {
417         ParamCount = Node->Object->Method.ParamCount;
418     }
419 
420     Status = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
421     if (ACPI_FAILURE (Status))
422     {
423         return (Status);
424     }
425 
426     if ((Type == ACPI_TYPE_DEVICE) ||
427         (Type == ACPI_TYPE_PROCESSOR))
428     {
429         /*
430          * Get extra info for ACPI Device/Processor objects only:
431          * Run the Device _HID, _UID, and _CID methods.
432          *
433          * Note: none of these methods are required, so they may or may
434          * not be present for this device. The Info->Valid bitfield is used
435          * to indicate which methods were found and run successfully.
436          */
437 
438         /* Execute the Device._HID method */
439 
440         Status = AcpiUtExecute_HID (Node, &Hid);
441         if (ACPI_SUCCESS (Status))
442         {
443             InfoSize += Hid->Length;
444             Valid |= ACPI_VALID_HID;
445         }
446 
447         /* Execute the Device._UID method */
448 
449         Status = AcpiUtExecute_UID (Node, &Uid);
450         if (ACPI_SUCCESS (Status))
451         {
452             InfoSize += Uid->Length;
453             Valid |= ACPI_VALID_UID;
454         }
455 
456         /* Execute the Device._CID method */
457 
458         Status = AcpiUtExecute_CID (Node, &CidList);
459         if (ACPI_SUCCESS (Status))
460         {
461             /* Add size of CID strings and CID pointer array */
462 
463             InfoSize += (CidList->ListSize - sizeof (ACPI_DEVICE_ID_LIST));
464             Valid |= ACPI_VALID_CID;
465         }
466     }
467 
468     /*
469      * Now that we have the variable-length data, we can allocate the
470      * return buffer
471      */
472     Info = ACPI_ALLOCATE_ZEROED (InfoSize);
473     if (!Info)
474     {
475         Status = AE_NO_MEMORY;
476         goto Cleanup;
477     }
478 
479     /* Get the fixed-length data */
480 
481     if ((Type == ACPI_TYPE_DEVICE) ||
482         (Type == ACPI_TYPE_PROCESSOR))
483     {
484         /*
485          * Get extra info for ACPI Device/Processor objects only:
486          * Run the _STA, _ADR and, SxW, and _SxD methods.
487          *
488          * Note: none of these methods are required, so they may or may
489          * not be present for this device. The Info->Valid bitfield is used
490          * to indicate which methods were found and run successfully.
491          */
492 
493         /* Execute the Device._STA method */
494 
495         Status = AcpiUtExecute_STA (Node, &Info->CurrentStatus);
496         if (ACPI_SUCCESS (Status))
497         {
498             Valid |= ACPI_VALID_STA;
499         }
500 
501         /* Execute the Device._ADR method */
502 
503         Status = AcpiUtEvaluateNumericObject (METHOD_NAME__ADR, Node,
504                     &Info->Address);
505         if (ACPI_SUCCESS (Status))
506         {
507             Valid |= ACPI_VALID_ADR;
508         }
509 
510         /* Execute the Device._SxW methods */
511 
512         Status = AcpiUtExecutePowerMethods (Node,
513                     AcpiGbl_LowestDstateNames, ACPI_NUM_SxW_METHODS,
514                     Info->LowestDstates);
515         if (ACPI_SUCCESS (Status))
516         {
517             Valid |= ACPI_VALID_SXWS;
518         }
519 
520         /* Execute the Device._SxD methods */
521 
522         Status = AcpiUtExecutePowerMethods (Node,
523                     AcpiGbl_HighestDstateNames, ACPI_NUM_SxD_METHODS,
524                     Info->HighestDstates);
525         if (ACPI_SUCCESS (Status))
526         {
527             Valid |= ACPI_VALID_SXDS;
528         }
529     }
530 
531     /*
532      * Create a pointer to the string area of the return buffer.
533      * Point to the end of the base ACPI_DEVICE_INFO structure.
534      */
535     NextIdString = ACPI_CAST_PTR (char, Info->CompatibleIdList.Ids);
536     if (CidList)
537     {
538         /* Point past the CID DEVICE_ID array */
539 
540         NextIdString += ((ACPI_SIZE) CidList->Count * sizeof (ACPI_DEVICE_ID));
541     }
542 
543     /*
544      * Copy the HID, UID, and CIDs to the return buffer. The variable-length
545      * strings are copied to the reserved area at the end of the buffer.
546      *
547      * For HID and CID, check if the ID is a PCI Root Bridge.
548      */
549     if (Hid)
550     {
551         NextIdString = AcpiNsCopyDeviceId (&Info->HardwareId,
552             Hid, NextIdString);
553 
554         if (AcpiUtIsPciRootBridge (Hid->String))
555         {
556             Info->Flags |= ACPI_PCI_ROOT_BRIDGE;
557         }
558     }
559 
560     if (Uid)
561     {
562         NextIdString = AcpiNsCopyDeviceId (&Info->UniqueId,
563             Uid, NextIdString);
564     }
565 
566     if (CidList)
567     {
568         Info->CompatibleIdList.Count = CidList->Count;
569         Info->CompatibleIdList.ListSize = CidList->ListSize;
570 
571         /* Copy each CID */
572 
573         for (i = 0; i < CidList->Count; i++)
574         {
575             NextIdString = AcpiNsCopyDeviceId (&Info->CompatibleIdList.Ids[i],
576                 &CidList->Ids[i], NextIdString);
577 
578             if (AcpiUtIsPciRootBridge (CidList->Ids[i].String))
579             {
580                 Info->Flags |= ACPI_PCI_ROOT_BRIDGE;
581             }
582         }
583     }
584 
585     /* Copy the fixed-length data */
586 
587     Info->InfoSize = InfoSize;
588     Info->Type = Type;
589     Info->Name = Name;
590     Info->ParamCount = ParamCount;
591     Info->Valid = Valid;
592 
593     *ReturnBuffer = Info;
594     Status = AE_OK;
595 
596 
597 Cleanup:
598     if (Hid)
599     {
600         ACPI_FREE (Hid);
601     }
602     if (Uid)
603     {
604         ACPI_FREE (Uid);
605     }
606     if (CidList)
607     {
608         ACPI_FREE (CidList);
609     }
610     return (Status);
611 }
612 
613 ACPI_EXPORT_SYMBOL (AcpiGetObjectInfo)
614 
615 
616 /******************************************************************************
617  *
618  * FUNCTION:    AcpiInstallMethod
619  *
620  * PARAMETERS:  Buffer         - An ACPI table containing one control method
621  *
622  * RETURN:      Status
623  *
624  * DESCRIPTION: Install a control method into the namespace. If the method
625  *              name already exists in the namespace, it is overwritten. The
626  *              input buffer must contain a valid DSDT or SSDT containing a
627  *              single control method.
628  *
629  ******************************************************************************/
630 
631 ACPI_STATUS
632 AcpiInstallMethod (
633     UINT8                   *Buffer)
634 {
635     ACPI_TABLE_HEADER       *Table = ACPI_CAST_PTR (ACPI_TABLE_HEADER, Buffer);
636     UINT8                   *AmlBuffer;
637     UINT8                   *AmlStart;
638     char                    *Path;
639     ACPI_NAMESPACE_NODE     *Node;
640     ACPI_OPERAND_OBJECT     *MethodObj;
641     ACPI_PARSE_STATE        ParserState;
642     UINT32                  AmlLength;
643     UINT16                  Opcode;
644     UINT8                   MethodFlags;
645     ACPI_STATUS             Status;
646 
647 
648     /* Parameter validation */
649 
650     if (!Buffer)
651     {
652         return (AE_BAD_PARAMETER);
653     }
654 
655     /* Table must be a DSDT or SSDT */
656 
657     if (!ACPI_COMPARE_NAME (Table->Signature, ACPI_SIG_DSDT) &&
658         !ACPI_COMPARE_NAME (Table->Signature, ACPI_SIG_SSDT))
659     {
660         return (AE_BAD_HEADER);
661     }
662 
663     /* First AML opcode in the table must be a control method */
664 
665     ParserState.Aml = Buffer + sizeof (ACPI_TABLE_HEADER);
666     Opcode = AcpiPsPeekOpcode (&ParserState);
667     if (Opcode != AML_METHOD_OP)
668     {
669         return (AE_BAD_PARAMETER);
670     }
671 
672     /* Extract method information from the raw AML */
673 
674     ParserState.Aml += AcpiPsGetOpcodeSize (Opcode);
675     ParserState.PkgEnd = AcpiPsGetNextPackageEnd (&ParserState);
676     Path = AcpiPsGetNextNamestring (&ParserState);
677     MethodFlags = *ParserState.Aml++;
678     AmlStart = ParserState.Aml;
679     AmlLength = ACPI_PTR_DIFF (ParserState.PkgEnd, AmlStart);
680 
681     /*
682      * Allocate resources up-front. We don't want to have to delete a new
683      * node from the namespace if we cannot allocate memory.
684      */
685     AmlBuffer = ACPI_ALLOCATE (AmlLength);
686     if (!AmlBuffer)
687     {
688         return (AE_NO_MEMORY);
689     }
690 
691     MethodObj = AcpiUtCreateInternalObject (ACPI_TYPE_METHOD);
692     if (!MethodObj)
693     {
694         ACPI_FREE (AmlBuffer);
695         return (AE_NO_MEMORY);
696     }
697 
698     /* Lock namespace for AcpiNsLookup, we may be creating a new node */
699 
700     Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
701     if (ACPI_FAILURE (Status))
702     {
703         goto ErrorExit;
704     }
705 
706     /* The lookup either returns an existing node or creates a new one */
707 
708     Status = AcpiNsLookup (NULL, Path, ACPI_TYPE_METHOD, ACPI_IMODE_LOAD_PASS1,
709                 ACPI_NS_DONT_OPEN_SCOPE | ACPI_NS_ERROR_IF_FOUND, NULL, &Node);
710 
711     (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
712 
713     if (ACPI_FAILURE (Status)) /* NsLookup */
714     {
715         if (Status != AE_ALREADY_EXISTS)
716         {
717             goto ErrorExit;
718         }
719 
720         /* Node existed previously, make sure it is a method node */
721 
722         if (Node->Type != ACPI_TYPE_METHOD)
723         {
724             Status = AE_TYPE;
725             goto ErrorExit;
726         }
727     }
728 
729     /* Copy the method AML to the local buffer */
730 
731     ACPI_MEMCPY (AmlBuffer, AmlStart, AmlLength);
732 
733     /* Initialize the method object with the new method's information */
734 
735     MethodObj->Method.AmlStart = AmlBuffer;
736     MethodObj->Method.AmlLength = AmlLength;
737 
738     MethodObj->Method.ParamCount = (UINT8)
739         (MethodFlags & AML_METHOD_ARG_COUNT);
740 
741     MethodObj->Method.MethodFlags = (UINT8)
742         (MethodFlags & ~AML_METHOD_ARG_COUNT);
743 
744     if (MethodFlags & AML_METHOD_SERIALIZED)
745     {
746         MethodObj->Method.SyncLevel = (UINT8)
747             ((MethodFlags & AML_METHOD_SYNC_LEVEL) >> 4);
748     }
749 
750     /*
751      * Now that it is complete, we can attach the new method object to
752      * the method Node (detaches/deletes any existing object)
753      */
754     Status = AcpiNsAttachObject (Node, MethodObj,
755                 ACPI_TYPE_METHOD);
756 
757     /*
758      * Flag indicates AML buffer is dynamic, must be deleted later.
759      * Must be set only after attach above.
760      */
761     Node->Flags |= ANOBJ_ALLOCATED_BUFFER;
762 
763     /* Remove local reference to the method object */
764 
765     AcpiUtRemoveReference (MethodObj);
766     return (Status);
767 
768 
769 ErrorExit:
770 
771     ACPI_FREE (AmlBuffer);
772     ACPI_FREE (MethodObj);
773     return (Status);
774 }
775 
776 ACPI_EXPORT_SYMBOL (AcpiInstallMethod)
777