xref: /titanic_50/usr/src/uts/intel/io/acpica/parser/psargs.c (revision 7b1f4223d0637b428ed4e46b5bc295f7a949e670)
1 /******************************************************************************
2  *
3  * Module Name: psargs - Parse AML opcode arguments
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2011, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #define __PSARGS_C__
45 
46 #include "acpi.h"
47 #include "accommon.h"
48 #include "acparser.h"
49 #include "amlcode.h"
50 #include "acnamesp.h"
51 #include "acdispat.h"
52 
53 #define _COMPONENT          ACPI_PARSER
54         ACPI_MODULE_NAME    ("psargs")
55 
56 /* Local prototypes */
57 
58 static UINT32
59 AcpiPsGetNextPackageLength (
60     ACPI_PARSE_STATE        *ParserState);
61 
62 static ACPI_PARSE_OBJECT *
63 AcpiPsGetNextField (
64     ACPI_PARSE_STATE        *ParserState);
65 
66 
67 /*******************************************************************************
68  *
69  * FUNCTION:    AcpiPsGetNextPackageLength
70  *
71  * PARAMETERS:  ParserState         - Current parser state object
72  *
73  * RETURN:      Decoded package length. On completion, the AML pointer points
74  *              past the length byte or bytes.
75  *
76  * DESCRIPTION: Decode and return a package length field.
77  *              Note: Largest package length is 28 bits, from ACPI specification
78  *
79  ******************************************************************************/
80 
81 static UINT32
82 AcpiPsGetNextPackageLength (
83     ACPI_PARSE_STATE        *ParserState)
84 {
85     UINT8                   *Aml = ParserState->Aml;
86     UINT32                  PackageLength = 0;
87     UINT32                  ByteCount;
88     UINT8                   ByteZeroMask = 0x3F; /* Default [0:5] */
89 
90 
91     ACPI_FUNCTION_TRACE (PsGetNextPackageLength);
92 
93 
94     /*
95      * Byte 0 bits [6:7] contain the number of additional bytes
96      * used to encode the package length, either 0,1,2, or 3
97      */
98     ByteCount = (Aml[0] >> 6);
99     ParserState->Aml += ((ACPI_SIZE) ByteCount + 1);
100 
101     /* Get bytes 3, 2, 1 as needed */
102 
103     while (ByteCount)
104     {
105         /*
106          * Final bit positions for the package length bytes:
107          *      Byte3->[20:27]
108          *      Byte2->[12:19]
109          *      Byte1->[04:11]
110          *      Byte0->[00:03]
111          */
112         PackageLength |= (Aml[ByteCount] << ((ByteCount << 3) - 4));
113 
114         ByteZeroMask = 0x0F; /* Use bits [0:3] of byte 0 */
115         ByteCount--;
116     }
117 
118     /* Byte 0 is a special case, either bits [0:3] or [0:5] are used */
119 
120     PackageLength |= (Aml[0] & ByteZeroMask);
121     return_UINT32 (PackageLength);
122 }
123 
124 
125 /*******************************************************************************
126  *
127  * FUNCTION:    AcpiPsGetNextPackageEnd
128  *
129  * PARAMETERS:  ParserState         - Current parser state object
130  *
131  * RETURN:      Pointer to end-of-package +1
132  *
133  * DESCRIPTION: Get next package length and return a pointer past the end of
134  *              the package.  Consumes the package length field
135  *
136  ******************************************************************************/
137 
138 UINT8 *
139 AcpiPsGetNextPackageEnd (
140     ACPI_PARSE_STATE        *ParserState)
141 {
142     UINT8                   *Start = ParserState->Aml;
143     UINT32                  PackageLength;
144 
145 
146     ACPI_FUNCTION_TRACE (PsGetNextPackageEnd);
147 
148 
149     /* Function below updates ParserState->Aml */
150 
151     PackageLength = AcpiPsGetNextPackageLength (ParserState);
152 
153     return_PTR (Start + PackageLength); /* end of package */
154 }
155 
156 
157 /*******************************************************************************
158  *
159  * FUNCTION:    AcpiPsGetNextNamestring
160  *
161  * PARAMETERS:  ParserState         - Current parser state object
162  *
163  * RETURN:      Pointer to the start of the name string (pointer points into
164  *              the AML.
165  *
166  * DESCRIPTION: Get next raw namestring within the AML stream.  Handles all name
167  *              prefix characters.  Set parser state to point past the string.
168  *              (Name is consumed from the AML.)
169  *
170  ******************************************************************************/
171 
172 char *
173 AcpiPsGetNextNamestring (
174     ACPI_PARSE_STATE        *ParserState)
175 {
176     UINT8                   *Start = ParserState->Aml;
177     UINT8                   *End = ParserState->Aml;
178 
179 
180     ACPI_FUNCTION_TRACE (PsGetNextNamestring);
181 
182 
183     /* Point past any namestring prefix characters (backslash or carat) */
184 
185     while (AcpiPsIsPrefixChar (*End))
186     {
187         End++;
188     }
189 
190     /* Decode the path prefix character */
191 
192     switch (*End)
193     {
194     case 0:
195 
196         /* NullName */
197 
198         if (End == Start)
199         {
200             Start = NULL;
201         }
202         End++;
203         break;
204 
205     case AML_DUAL_NAME_PREFIX:
206 
207         /* Two name segments */
208 
209         End += 1 + (2 * ACPI_NAME_SIZE);
210         break;
211 
212     case AML_MULTI_NAME_PREFIX_OP:
213 
214         /* Multiple name segments, 4 chars each, count in next byte */
215 
216         End += 2 + (*(End + 1) * ACPI_NAME_SIZE);
217         break;
218 
219     default:
220 
221         /* Single name segment */
222 
223         End += ACPI_NAME_SIZE;
224         break;
225     }
226 
227     ParserState->Aml = End;
228     return_PTR ((char *) Start);
229 }
230 
231 
232 /*******************************************************************************
233  *
234  * FUNCTION:    AcpiPsGetNextNamepath
235  *
236  * PARAMETERS:  ParserState         - Current parser state object
237  *              Arg                 - Where the namepath will be stored
238  *              ArgCount            - If the namepath points to a control method
239  *                                    the method's argument is returned here.
240  *              PossibleMethodCall  - Whether the namepath can possibly be the
241  *                                    start of a method call
242  *
243  * RETURN:      Status
244  *
245  * DESCRIPTION: Get next name (if method call, return # of required args).
246  *              Names are looked up in the internal namespace to determine
247  *              if the name represents a control method.  If a method
248  *              is found, the number of arguments to the method is returned.
249  *              This information is critical for parsing to continue correctly.
250  *
251  ******************************************************************************/
252 
253 ACPI_STATUS
254 AcpiPsGetNextNamepath (
255     ACPI_WALK_STATE         *WalkState,
256     ACPI_PARSE_STATE        *ParserState,
257     ACPI_PARSE_OBJECT       *Arg,
258     BOOLEAN                 PossibleMethodCall)
259 {
260     ACPI_STATUS             Status;
261     char                    *Path;
262     ACPI_PARSE_OBJECT       *NameOp;
263     ACPI_OPERAND_OBJECT     *MethodDesc;
264     ACPI_NAMESPACE_NODE     *Node;
265     UINT8                   *Start = ParserState->Aml;
266 
267 
268     ACPI_FUNCTION_TRACE (PsGetNextNamepath);
269 
270 
271     Path = AcpiPsGetNextNamestring (ParserState);
272     AcpiPsInitOp (Arg, AML_INT_NAMEPATH_OP);
273 
274     /* Null path case is allowed, just exit */
275 
276     if (!Path)
277     {
278         Arg->Common.Value.Name = Path;
279         return_ACPI_STATUS (AE_OK);
280     }
281 
282     /*
283      * Lookup the name in the internal namespace, starting with the current
284      * scope. We don't want to add anything new to the namespace here,
285      * however, so we use MODE_EXECUTE.
286      * Allow searching of the parent tree, but don't open a new scope -
287      * we just want to lookup the object (must be mode EXECUTE to perform
288      * the upsearch)
289      */
290     Status = AcpiNsLookup (WalkState->ScopeInfo, Path,
291                 ACPI_TYPE_ANY, ACPI_IMODE_EXECUTE,
292                 ACPI_NS_SEARCH_PARENT | ACPI_NS_DONT_OPEN_SCOPE, NULL, &Node);
293 
294     /*
295      * If this name is a control method invocation, we must
296      * setup the method call
297      */
298     if (ACPI_SUCCESS (Status) &&
299         PossibleMethodCall &&
300         (Node->Type == ACPI_TYPE_METHOD))
301     {
302         if (WalkState->Opcode == AML_UNLOAD_OP)
303         {
304             /*
305              * AcpiPsGetNextNamestring has increased the AML pointer,
306              * so we need to restore the saved AML pointer for method call.
307              */
308             WalkState->ParserState.Aml = Start;
309             WalkState->ArgCount = 1;
310             AcpiPsInitOp (Arg, AML_INT_METHODCALL_OP);
311             return_ACPI_STATUS (AE_OK);
312         }
313 
314         /* This name is actually a control method invocation */
315 
316         MethodDesc = AcpiNsGetAttachedObject (Node);
317         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
318             "Control Method - %p Desc %p Path=%p\n", Node, MethodDesc, Path));
319 
320         NameOp = AcpiPsAllocOp (AML_INT_NAMEPATH_OP);
321         if (!NameOp)
322         {
323             return_ACPI_STATUS (AE_NO_MEMORY);
324         }
325 
326         /* Change Arg into a METHOD CALL and attach name to it */
327 
328         AcpiPsInitOp (Arg, AML_INT_METHODCALL_OP);
329         NameOp->Common.Value.Name = Path;
330 
331         /* Point METHODCALL/NAME to the METHOD Node */
332 
333         NameOp->Common.Node = Node;
334         AcpiPsAppendArg (Arg, NameOp);
335 
336         if (!MethodDesc)
337         {
338             ACPI_ERROR ((AE_INFO,
339                 "Control Method %p has no attached object",
340                 Node));
341             return_ACPI_STATUS (AE_AML_INTERNAL);
342         }
343 
344         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
345             "Control Method - %p Args %X\n",
346             Node, MethodDesc->Method.ParamCount));
347 
348         /* Get the number of arguments to expect */
349 
350         WalkState->ArgCount = MethodDesc->Method.ParamCount;
351         return_ACPI_STATUS (AE_OK);
352     }
353 
354     /*
355      * Special handling if the name was not found during the lookup -
356      * some NotFound cases are allowed
357      */
358     if (Status == AE_NOT_FOUND)
359     {
360         /* 1) NotFound is ok during load pass 1/2 (allow forward references) */
361 
362         if ((WalkState->ParseFlags & ACPI_PARSE_MODE_MASK) !=
363                 ACPI_PARSE_EXECUTE)
364         {
365             Status = AE_OK;
366         }
367 
368         /* 2) NotFound during a CondRefOf(x) is ok by definition */
369 
370         else if (WalkState->Op->Common.AmlOpcode == AML_COND_REF_OF_OP)
371         {
372             Status = AE_OK;
373         }
374 
375         /*
376          * 3) NotFound while building a Package is ok at this point, we
377          * may flag as an error later if slack mode is not enabled.
378          * (Some ASL code depends on allowing this behavior)
379          */
380         else if ((Arg->Common.Parent) &&
381             ((Arg->Common.Parent->Common.AmlOpcode == AML_PACKAGE_OP) ||
382              (Arg->Common.Parent->Common.AmlOpcode == AML_VAR_PACKAGE_OP)))
383         {
384             Status = AE_OK;
385         }
386     }
387 
388     /* Final exception check (may have been changed from code above) */
389 
390     if (ACPI_FAILURE (Status))
391     {
392         ACPI_ERROR_NAMESPACE (Path, Status);
393 
394         if ((WalkState->ParseFlags & ACPI_PARSE_MODE_MASK) ==
395                 ACPI_PARSE_EXECUTE)
396         {
397             /* Report a control method execution error */
398 
399             Status = AcpiDsMethodError (Status, WalkState);
400         }
401     }
402 
403     /* Save the namepath */
404 
405     Arg->Common.Value.Name = Path;
406     return_ACPI_STATUS (Status);
407 }
408 
409 
410 /*******************************************************************************
411  *
412  * FUNCTION:    AcpiPsGetNextSimpleArg
413  *
414  * PARAMETERS:  ParserState         - Current parser state object
415  *              ArgType             - The argument type (AML_*_ARG)
416  *              Arg                 - Where the argument is returned
417  *
418  * RETURN:      None
419  *
420  * DESCRIPTION: Get the next simple argument (constant, string, or namestring)
421  *
422  ******************************************************************************/
423 
424 void
425 AcpiPsGetNextSimpleArg (
426     ACPI_PARSE_STATE        *ParserState,
427     UINT32                  ArgType,
428     ACPI_PARSE_OBJECT       *Arg)
429 {
430     UINT32                  Length;
431     UINT16                  Opcode;
432     UINT8                   *Aml = ParserState->Aml;
433 
434 
435     ACPI_FUNCTION_TRACE_U32 (PsGetNextSimpleArg, ArgType);
436 
437 
438     switch (ArgType)
439     {
440     case ARGP_BYTEDATA:
441 
442         /* Get 1 byte from the AML stream */
443 
444         Opcode = AML_BYTE_OP;
445         Arg->Common.Value.Integer = (UINT64) *Aml;
446         Length = 1;
447         break;
448 
449 
450     case ARGP_WORDDATA:
451 
452         /* Get 2 bytes from the AML stream */
453 
454         Opcode = AML_WORD_OP;
455         ACPI_MOVE_16_TO_64 (&Arg->Common.Value.Integer, Aml);
456         Length = 2;
457         break;
458 
459 
460     case ARGP_DWORDDATA:
461 
462         /* Get 4 bytes from the AML stream */
463 
464         Opcode = AML_DWORD_OP;
465         ACPI_MOVE_32_TO_64 (&Arg->Common.Value.Integer, Aml);
466         Length = 4;
467         break;
468 
469 
470     case ARGP_QWORDDATA:
471 
472         /* Get 8 bytes from the AML stream */
473 
474         Opcode = AML_QWORD_OP;
475         ACPI_MOVE_64_TO_64 (&Arg->Common.Value.Integer, Aml);
476         Length = 8;
477         break;
478 
479 
480     case ARGP_CHARLIST:
481 
482         /* Get a pointer to the string, point past the string */
483 
484         Opcode = AML_STRING_OP;
485         Arg->Common.Value.String = ACPI_CAST_PTR (char, Aml);
486 
487         /* Find the null terminator */
488 
489         Length = 0;
490         while (Aml[Length])
491         {
492             Length++;
493         }
494         Length++;
495         break;
496 
497 
498     case ARGP_NAME:
499     case ARGP_NAMESTRING:
500 
501         AcpiPsInitOp (Arg, AML_INT_NAMEPATH_OP);
502         Arg->Common.Value.Name = AcpiPsGetNextNamestring (ParserState);
503         return_VOID;
504 
505 
506     default:
507 
508         ACPI_ERROR ((AE_INFO, "Invalid ArgType 0x%X", ArgType));
509         return_VOID;
510     }
511 
512     AcpiPsInitOp (Arg, Opcode);
513     ParserState->Aml += Length;
514     return_VOID;
515 }
516 
517 
518 /*******************************************************************************
519  *
520  * FUNCTION:    AcpiPsGetNextField
521  *
522  * PARAMETERS:  ParserState         - Current parser state object
523  *
524  * RETURN:      A newly allocated FIELD op
525  *
526  * DESCRIPTION: Get next field (NamedField, ReservedField, or AccessField)
527  *
528  ******************************************************************************/
529 
530 static ACPI_PARSE_OBJECT *
531 AcpiPsGetNextField (
532     ACPI_PARSE_STATE        *ParserState)
533 {
534     UINT32                  AmlOffset = (UINT32)
535                                 ACPI_PTR_DIFF (ParserState->Aml,
536                                                ParserState->AmlStart);
537     ACPI_PARSE_OBJECT       *Field;
538     UINT16                  Opcode;
539     UINT32                  Name;
540 
541 
542     ACPI_FUNCTION_TRACE (PsGetNextField);
543 
544 
545     /* Determine field type */
546 
547     switch (ACPI_GET8 (ParserState->Aml))
548     {
549     default:
550 
551         Opcode = AML_INT_NAMEDFIELD_OP;
552         break;
553 
554     case 0x00:
555 
556         Opcode = AML_INT_RESERVEDFIELD_OP;
557         ParserState->Aml++;
558         break;
559 
560     case 0x01:
561 
562         Opcode = AML_INT_ACCESSFIELD_OP;
563         ParserState->Aml++;
564         break;
565     }
566 
567     /* Allocate a new field op */
568 
569     Field = AcpiPsAllocOp (Opcode);
570     if (!Field)
571     {
572         return_PTR (NULL);
573     }
574 
575     Field->Common.AmlOffset = AmlOffset;
576 
577     /* Decode the field type */
578 
579     switch (Opcode)
580     {
581     case AML_INT_NAMEDFIELD_OP:
582 
583         /* Get the 4-character name */
584 
585         ACPI_MOVE_32_TO_32 (&Name, ParserState->Aml);
586         AcpiPsSetName (Field, Name);
587         ParserState->Aml += ACPI_NAME_SIZE;
588 
589         /* Get the length which is encoded as a package length */
590 
591         Field->Common.Value.Size = AcpiPsGetNextPackageLength (ParserState);
592         break;
593 
594 
595     case AML_INT_RESERVEDFIELD_OP:
596 
597         /* Get the length which is encoded as a package length */
598 
599         Field->Common.Value.Size = AcpiPsGetNextPackageLength (ParserState);
600         break;
601 
602 
603     case AML_INT_ACCESSFIELD_OP:
604 
605         /*
606          * Get AccessType and AccessAttrib and merge into the field Op
607          * AccessType is first operand, AccessAttribute is second
608          */
609         Field->Common.Value.Integer = (((UINT32) ACPI_GET8 (ParserState->Aml) << 8));
610         ParserState->Aml++;
611         Field->Common.Value.Integer |= ACPI_GET8 (ParserState->Aml);
612         ParserState->Aml++;
613         break;
614 
615     default:
616 
617         /* Opcode was set in previous switch */
618         break;
619     }
620 
621     return_PTR (Field);
622 }
623 
624 
625 /*******************************************************************************
626  *
627  * FUNCTION:    AcpiPsGetNextArg
628  *
629  * PARAMETERS:  WalkState           - Current state
630  *              ParserState         - Current parser state object
631  *              ArgType             - The argument type (AML_*_ARG)
632  *              ReturnArg           - Where the next arg is returned
633  *
634  * RETURN:      Status, and an op object containing the next argument.
635  *
636  * DESCRIPTION: Get next argument (including complex list arguments that require
637  *              pushing the parser stack)
638  *
639  ******************************************************************************/
640 
641 ACPI_STATUS
642 AcpiPsGetNextArg (
643     ACPI_WALK_STATE         *WalkState,
644     ACPI_PARSE_STATE        *ParserState,
645     UINT32                  ArgType,
646     ACPI_PARSE_OBJECT       **ReturnArg)
647 {
648     ACPI_PARSE_OBJECT       *Arg = NULL;
649     ACPI_PARSE_OBJECT       *Prev = NULL;
650     ACPI_PARSE_OBJECT       *Field;
651     UINT32                  Subop;
652     ACPI_STATUS             Status = AE_OK;
653 
654 
655     ACPI_FUNCTION_TRACE_PTR (PsGetNextArg, ParserState);
656 
657 
658     switch (ArgType)
659     {
660     case ARGP_BYTEDATA:
661     case ARGP_WORDDATA:
662     case ARGP_DWORDDATA:
663     case ARGP_CHARLIST:
664     case ARGP_NAME:
665     case ARGP_NAMESTRING:
666 
667         /* Constants, strings, and namestrings are all the same size */
668 
669         Arg = AcpiPsAllocOp (AML_BYTE_OP);
670         if (!Arg)
671         {
672             return_ACPI_STATUS (AE_NO_MEMORY);
673         }
674         AcpiPsGetNextSimpleArg (ParserState, ArgType, Arg);
675         break;
676 
677 
678     case ARGP_PKGLENGTH:
679 
680         /* Package length, nothing returned */
681 
682         ParserState->PkgEnd = AcpiPsGetNextPackageEnd (ParserState);
683         break;
684 
685 
686     case ARGP_FIELDLIST:
687 
688         if (ParserState->Aml < ParserState->PkgEnd)
689         {
690             /* Non-empty list */
691 
692             while (ParserState->Aml < ParserState->PkgEnd)
693             {
694                 Field = AcpiPsGetNextField (ParserState);
695                 if (!Field)
696                 {
697                     return_ACPI_STATUS (AE_NO_MEMORY);
698                 }
699 
700                 if (Prev)
701                 {
702                     Prev->Common.Next = Field;
703                 }
704                 else
705                 {
706                     Arg = Field;
707                 }
708                 Prev = Field;
709             }
710 
711             /* Skip to End of byte data */
712 
713             ParserState->Aml = ParserState->PkgEnd;
714         }
715         break;
716 
717 
718     case ARGP_BYTELIST:
719 
720         if (ParserState->Aml < ParserState->PkgEnd)
721         {
722             /* Non-empty list */
723 
724             Arg = AcpiPsAllocOp (AML_INT_BYTELIST_OP);
725             if (!Arg)
726             {
727                 return_ACPI_STATUS (AE_NO_MEMORY);
728             }
729 
730             /* Fill in bytelist data */
731 
732             Arg->Common.Value.Size = (UINT32)
733                 ACPI_PTR_DIFF (ParserState->PkgEnd, ParserState->Aml);
734             Arg->Named.Data = ParserState->Aml;
735 
736             /* Skip to End of byte data */
737 
738             ParserState->Aml = ParserState->PkgEnd;
739         }
740         break;
741 
742 
743     case ARGP_TARGET:
744     case ARGP_SUPERNAME:
745     case ARGP_SIMPLENAME:
746 
747         Subop = AcpiPsPeekOpcode (ParserState);
748         if (Subop == 0                  ||
749             AcpiPsIsLeadingChar (Subop) ||
750             AcpiPsIsPrefixChar (Subop))
751         {
752             /* NullName or NameString */
753 
754             Arg = AcpiPsAllocOp (AML_INT_NAMEPATH_OP);
755             if (!Arg)
756             {
757                 return_ACPI_STATUS (AE_NO_MEMORY);
758             }
759 
760             /* To support SuperName arg of Unload */
761 
762             if (WalkState->Opcode == AML_UNLOAD_OP)
763             {
764                 Status = AcpiPsGetNextNamepath (WalkState, ParserState, Arg, 1);
765 
766                 /*
767                  * If the SuperName arg of Unload is a method call,
768                  * we have restored the AML pointer, just free this Arg
769                  */
770                 if (Arg->Common.AmlOpcode == AML_INT_METHODCALL_OP)
771                 {
772                     AcpiPsFreeOp (Arg);
773                     Arg = NULL;
774                 }
775             }
776             else
777             {
778                 Status = AcpiPsGetNextNamepath (WalkState, ParserState, Arg, 0);
779             }
780         }
781         else
782         {
783             /* Single complex argument, nothing returned */
784 
785             WalkState->ArgCount = 1;
786         }
787         break;
788 
789 
790     case ARGP_DATAOBJ:
791     case ARGP_TERMARG:
792 
793         /* Single complex argument, nothing returned */
794 
795         WalkState->ArgCount = 1;
796         break;
797 
798 
799     case ARGP_DATAOBJLIST:
800     case ARGP_TERMLIST:
801     case ARGP_OBJLIST:
802 
803         if (ParserState->Aml < ParserState->PkgEnd)
804         {
805             /* Non-empty list of variable arguments, nothing returned */
806 
807             WalkState->ArgCount = ACPI_VAR_ARGS;
808         }
809         break;
810 
811 
812     default:
813 
814         ACPI_ERROR ((AE_INFO, "Invalid ArgType: 0x%X", ArgType));
815         Status = AE_AML_OPERAND_TYPE;
816         break;
817     }
818 
819     *ReturnArg = Arg;
820     return_ACPI_STATUS (Status);
821 }
822