xref: /titanic_50/usr/src/uts/intel/io/acpica/parser/psobject.c (revision 385cc6b4ad1792caef3f84eb61eed3f27085801f)
1 /******************************************************************************
2  *
3  * Module Name: psobject - Support for parse objects
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2016, 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 #include "acpi.h"
45 #include "accommon.h"
46 #include "acparser.h"
47 #include "amlcode.h"
48 
49 #define _COMPONENT          ACPI_PARSER
50         ACPI_MODULE_NAME    ("psobject")
51 
52 
53 /* Local prototypes */
54 
55 static ACPI_STATUS
56 AcpiPsGetAmlOpcode (
57     ACPI_WALK_STATE         *WalkState);
58 
59 
60 /*******************************************************************************
61  *
62  * FUNCTION:    AcpiPsGetAmlOpcode
63  *
64  * PARAMETERS:  WalkState           - Current state
65  *
66  * RETURN:      Status
67  *
68  * DESCRIPTION: Extract the next AML opcode from the input stream.
69  *
70  ******************************************************************************/
71 
72 static ACPI_STATUS
AcpiPsGetAmlOpcode(ACPI_WALK_STATE * WalkState)73 AcpiPsGetAmlOpcode (
74     ACPI_WALK_STATE         *WalkState)
75 {
76     UINT32                  AmlOffset;
77 
78 
79     ACPI_FUNCTION_TRACE_PTR (PsGetAmlOpcode, WalkState);
80 
81 
82     WalkState->Aml = WalkState->ParserState.Aml;
83     WalkState->Opcode = AcpiPsPeekOpcode (&(WalkState->ParserState));
84 
85     /*
86      * First cut to determine what we have found:
87      * 1) A valid AML opcode
88      * 2) A name string
89      * 3) An unknown/invalid opcode
90      */
91     WalkState->OpInfo = AcpiPsGetOpcodeInfo (WalkState->Opcode);
92 
93     switch (WalkState->OpInfo->Class)
94     {
95     case AML_CLASS_ASCII:
96     case AML_CLASS_PREFIX:
97         /*
98          * Starts with a valid prefix or ASCII char, this is a name
99          * string. Convert the bare name string to a namepath.
100          */
101         WalkState->Opcode = AML_INT_NAMEPATH_OP;
102         WalkState->ArgTypes = ARGP_NAMESTRING;
103         break;
104 
105     case AML_CLASS_UNKNOWN:
106 
107         /* The opcode is unrecognized. Complain and skip unknown opcodes */
108 
109         if (WalkState->PassNumber == 2)
110         {
111             AmlOffset = (UINT32) ACPI_PTR_DIFF (WalkState->Aml,
112                 WalkState->ParserState.AmlStart);
113 
114             ACPI_ERROR ((AE_INFO,
115                 "Unknown opcode 0x%.2X at table offset 0x%.4X, ignoring",
116                 WalkState->Opcode,
117                 (UINT32) (AmlOffset + sizeof (ACPI_TABLE_HEADER))));
118 
119             ACPI_DUMP_BUFFER ((WalkState->ParserState.Aml - 16), 48);
120 
121 #ifdef ACPI_ASL_COMPILER
122             /*
123              * This is executed for the disassembler only. Output goes
124              * to the disassembled ASL output file.
125              */
126             AcpiOsPrintf (
127                 "/*\nError: Unknown opcode 0x%.2X at table offset 0x%.4X, context:\n",
128                 WalkState->Opcode,
129                 (UINT32) (AmlOffset + sizeof (ACPI_TABLE_HEADER)));
130 
131             /* Dump the context surrounding the invalid opcode */
132 
133             AcpiUtDumpBuffer (((UINT8 *) WalkState->ParserState.Aml - 16),
134                 48, DB_BYTE_DISPLAY,
135                 (AmlOffset + sizeof (ACPI_TABLE_HEADER) - 16));
136             AcpiOsPrintf (" */\n");
137 #endif
138         }
139 
140         /* Increment past one-byte or two-byte opcode */
141 
142         WalkState->ParserState.Aml++;
143         if (WalkState->Opcode > 0xFF) /* Can only happen if first byte is 0x5B */
144         {
145             WalkState->ParserState.Aml++;
146         }
147 
148         return_ACPI_STATUS (AE_CTRL_PARSE_CONTINUE);
149 
150     default:
151 
152         /* Found opcode info, this is a normal opcode */
153 
154         WalkState->ParserState.Aml +=
155             AcpiPsGetOpcodeSize (WalkState->Opcode);
156         WalkState->ArgTypes = WalkState->OpInfo->ParseArgs;
157         break;
158     }
159 
160     return_ACPI_STATUS (AE_OK);
161 }
162 
163 
164 /*******************************************************************************
165  *
166  * FUNCTION:    AcpiPsBuildNamedOp
167  *
168  * PARAMETERS:  WalkState           - Current state
169  *              AmlOpStart          - Begin of named Op in AML
170  *              UnnamedOp           - Early Op (not a named Op)
171  *              Op                  - Returned Op
172  *
173  * RETURN:      Status
174  *
175  * DESCRIPTION: Parse a named Op
176  *
177  ******************************************************************************/
178 
179 ACPI_STATUS
AcpiPsBuildNamedOp(ACPI_WALK_STATE * WalkState,UINT8 * AmlOpStart,ACPI_PARSE_OBJECT * UnnamedOp,ACPI_PARSE_OBJECT ** Op)180 AcpiPsBuildNamedOp (
181     ACPI_WALK_STATE         *WalkState,
182     UINT8                   *AmlOpStart,
183     ACPI_PARSE_OBJECT       *UnnamedOp,
184     ACPI_PARSE_OBJECT       **Op)
185 {
186     ACPI_STATUS             Status = AE_OK;
187     ACPI_PARSE_OBJECT       *Arg = NULL;
188 
189 
190     ACPI_FUNCTION_TRACE_PTR (PsBuildNamedOp, WalkState);
191 
192 
193     UnnamedOp->Common.Value.Arg = NULL;
194     UnnamedOp->Common.ArgListLength = 0;
195     UnnamedOp->Common.AmlOpcode = WalkState->Opcode;
196 
197     /*
198      * Get and append arguments until we find the node that contains
199      * the name (the type ARGP_NAME).
200      */
201     while (GET_CURRENT_ARG_TYPE (WalkState->ArgTypes) &&
202           (GET_CURRENT_ARG_TYPE (WalkState->ArgTypes) != ARGP_NAME))
203     {
204         Status = AcpiPsGetNextArg (WalkState, &(WalkState->ParserState),
205             GET_CURRENT_ARG_TYPE (WalkState->ArgTypes), &Arg);
206         if (ACPI_FAILURE (Status))
207         {
208             return_ACPI_STATUS (Status);
209         }
210 
211         AcpiPsAppendArg (UnnamedOp, Arg);
212         INCREMENT_ARG_LIST (WalkState->ArgTypes);
213     }
214 
215     /*
216      * Make sure that we found a NAME and didn't run out of arguments
217      */
218     if (!GET_CURRENT_ARG_TYPE (WalkState->ArgTypes))
219     {
220         return_ACPI_STATUS (AE_AML_NO_OPERAND);
221     }
222 
223     /* We know that this arg is a name, move to next arg */
224 
225     INCREMENT_ARG_LIST (WalkState->ArgTypes);
226 
227     /*
228      * Find the object. This will either insert the object into
229      * the namespace or simply look it up
230      */
231     WalkState->Op = NULL;
232 
233     Status = WalkState->DescendingCallback (WalkState, Op);
234     if (ACPI_FAILURE (Status))
235     {
236         if (Status != AE_CTRL_TERMINATE)
237         {
238             ACPI_EXCEPTION ((AE_INFO, Status, "During name lookup/catalog"));
239         }
240         return_ACPI_STATUS (Status);
241     }
242 
243     if (!*Op)
244     {
245         return_ACPI_STATUS (AE_CTRL_PARSE_CONTINUE);
246     }
247 
248     Status = AcpiPsNextParseState (WalkState, *Op, Status);
249     if (ACPI_FAILURE (Status))
250     {
251         if (Status == AE_CTRL_PENDING)
252         {
253             Status = AE_CTRL_PARSE_PENDING;
254         }
255         return_ACPI_STATUS (Status);
256     }
257 
258     AcpiPsAppendArg (*Op, UnnamedOp->Common.Value.Arg);
259 
260     if ((*Op)->Common.AmlOpcode == AML_REGION_OP ||
261         (*Op)->Common.AmlOpcode == AML_DATA_REGION_OP)
262     {
263         /*
264          * Defer final parsing of an OperationRegion body, because we don't
265          * have enough info in the first pass to parse it correctly (i.e.,
266          * there may be method calls within the TermArg elements of the body.)
267          *
268          * However, we must continue parsing because the opregion is not a
269          * standalone package -- we don't know where the end is at this point.
270          *
271          * (Length is unknown until parse of the body complete)
272          */
273         (*Op)->Named.Data = AmlOpStart;
274         (*Op)->Named.Length = 0;
275     }
276 
277     return_ACPI_STATUS (AE_OK);
278 }
279 
280 
281 /*******************************************************************************
282  *
283  * FUNCTION:    AcpiPsCreateOp
284  *
285  * PARAMETERS:  WalkState           - Current state
286  *              AmlOpStart          - Op start in AML
287  *              NewOp               - Returned Op
288  *
289  * RETURN:      Status
290  *
291  * DESCRIPTION: Get Op from AML
292  *
293  ******************************************************************************/
294 
295 ACPI_STATUS
AcpiPsCreateOp(ACPI_WALK_STATE * WalkState,UINT8 * AmlOpStart,ACPI_PARSE_OBJECT ** NewOp)296 AcpiPsCreateOp (
297     ACPI_WALK_STATE         *WalkState,
298     UINT8                   *AmlOpStart,
299     ACPI_PARSE_OBJECT       **NewOp)
300 {
301     ACPI_STATUS             Status = AE_OK;
302     ACPI_PARSE_OBJECT       *Op;
303     ACPI_PARSE_OBJECT       *NamedOp = NULL;
304     ACPI_PARSE_OBJECT       *ParentScope;
305     UINT8                   ArgumentCount;
306     const ACPI_OPCODE_INFO  *OpInfo;
307 
308 
309     ACPI_FUNCTION_TRACE_PTR (PsCreateOp, WalkState);
310 
311 
312     Status = AcpiPsGetAmlOpcode (WalkState);
313     if (Status == AE_CTRL_PARSE_CONTINUE)
314     {
315         return_ACPI_STATUS (AE_CTRL_PARSE_CONTINUE);
316     }
317 
318     /* Create Op structure and append to parent's argument list */
319 
320     WalkState->OpInfo = AcpiPsGetOpcodeInfo (WalkState->Opcode);
321     Op = AcpiPsAllocOp (WalkState->Opcode, AmlOpStart);
322     if (!Op)
323     {
324         return_ACPI_STATUS (AE_NO_MEMORY);
325     }
326 
327     if (WalkState->OpInfo->Flags & AML_NAMED)
328     {
329         Status = AcpiPsBuildNamedOp (WalkState, AmlOpStart, Op, &NamedOp);
330         AcpiPsFreeOp (Op);
331         if (ACPI_FAILURE (Status))
332         {
333             return_ACPI_STATUS (Status);
334         }
335 
336         *NewOp = NamedOp;
337         return_ACPI_STATUS (AE_OK);
338     }
339 
340     /* Not a named opcode, just allocate Op and append to parent */
341 
342     if (WalkState->OpInfo->Flags & AML_CREATE)
343     {
344         /*
345          * Backup to beginning of CreateXXXfield declaration
346          * BodyLength is unknown until we parse the body
347          */
348         Op->Named.Data = AmlOpStart;
349         Op->Named.Length = 0;
350     }
351 
352     if (WalkState->Opcode == AML_BANK_FIELD_OP)
353     {
354         /*
355          * Backup to beginning of BankField declaration
356          * BodyLength is unknown until we parse the body
357          */
358         Op->Named.Data = AmlOpStart;
359         Op->Named.Length = 0;
360     }
361 
362     ParentScope = AcpiPsGetParentScope (&(WalkState->ParserState));
363     AcpiPsAppendArg (ParentScope, Op);
364 
365     if (ParentScope)
366     {
367         OpInfo = AcpiPsGetOpcodeInfo (ParentScope->Common.AmlOpcode);
368         if (OpInfo->Flags & AML_HAS_TARGET)
369         {
370             ArgumentCount = AcpiPsGetArgumentCount (OpInfo->Type);
371             if (ParentScope->Common.ArgListLength > ArgumentCount)
372             {
373                 Op->Common.Flags |= ACPI_PARSEOP_TARGET;
374             }
375         }
376         else if (ParentScope->Common.AmlOpcode == AML_INCREMENT_OP)
377         {
378             Op->Common.Flags |= ACPI_PARSEOP_TARGET;
379         }
380     }
381 
382     if (WalkState->DescendingCallback != NULL)
383     {
384         /*
385          * Find the object. This will either insert the object into
386          * the namespace or simply look it up
387          */
388         WalkState->Op = *NewOp = Op;
389 
390         Status = WalkState->DescendingCallback (WalkState, &Op);
391         Status = AcpiPsNextParseState (WalkState, Op, Status);
392         if (Status == AE_CTRL_PENDING)
393         {
394             Status = AE_CTRL_PARSE_PENDING;
395         }
396     }
397 
398     return_ACPI_STATUS (Status);
399 }
400 
401 
402 /*******************************************************************************
403  *
404  * FUNCTION:    AcpiPsCompleteOp
405  *
406  * PARAMETERS:  WalkState           - Current state
407  *              Op                  - Returned Op
408  *              Status              - Parse status before complete Op
409  *
410  * RETURN:      Status
411  *
412  * DESCRIPTION: Complete Op
413  *
414  ******************************************************************************/
415 
416 ACPI_STATUS
AcpiPsCompleteOp(ACPI_WALK_STATE * WalkState,ACPI_PARSE_OBJECT ** Op,ACPI_STATUS Status)417 AcpiPsCompleteOp (
418     ACPI_WALK_STATE         *WalkState,
419     ACPI_PARSE_OBJECT       **Op,
420     ACPI_STATUS             Status)
421 {
422     ACPI_STATUS             Status2;
423 
424 
425     ACPI_FUNCTION_TRACE_PTR (PsCompleteOp, WalkState);
426 
427 
428     /*
429      * Finished one argument of the containing scope
430      */
431     WalkState->ParserState.Scope->ParseScope.ArgCount--;
432 
433     /* Close this Op (will result in parse subtree deletion) */
434 
435     Status2 = AcpiPsCompleteThisOp (WalkState, *Op);
436     if (ACPI_FAILURE (Status2))
437     {
438         return_ACPI_STATUS (Status2);
439     }
440 
441     *Op = NULL;
442 
443     switch (Status)
444     {
445     case AE_OK:
446 
447         break;
448 
449     case AE_CTRL_TRANSFER:
450 
451         /* We are about to transfer to a called method */
452 
453         WalkState->PrevOp = NULL;
454         WalkState->PrevArgTypes = WalkState->ArgTypes;
455         return_ACPI_STATUS (Status);
456 
457     case AE_CTRL_END:
458 
459         AcpiPsPopScope (&(WalkState->ParserState), Op,
460             &WalkState->ArgTypes, &WalkState->ArgCount);
461 
462         if (*Op)
463         {
464             WalkState->Op = *Op;
465             WalkState->OpInfo = AcpiPsGetOpcodeInfo ((*Op)->Common.AmlOpcode);
466             WalkState->Opcode = (*Op)->Common.AmlOpcode;
467 
468             Status = WalkState->AscendingCallback (WalkState);
469             Status = AcpiPsNextParseState (WalkState, *Op, Status);
470 
471             Status2 = AcpiPsCompleteThisOp (WalkState, *Op);
472             if (ACPI_FAILURE (Status2))
473             {
474                 return_ACPI_STATUS (Status2);
475             }
476         }
477 
478         Status = AE_OK;
479         break;
480 
481     case AE_CTRL_BREAK:
482     case AE_CTRL_CONTINUE:
483 
484         /* Pop off scopes until we find the While */
485 
486         while (!(*Op) || ((*Op)->Common.AmlOpcode != AML_WHILE_OP))
487         {
488             AcpiPsPopScope (&(WalkState->ParserState), Op,
489                 &WalkState->ArgTypes, &WalkState->ArgCount);
490         }
491 
492         /* Close this iteration of the While loop */
493 
494         WalkState->Op = *Op;
495         WalkState->OpInfo = AcpiPsGetOpcodeInfo ((*Op)->Common.AmlOpcode);
496         WalkState->Opcode = (*Op)->Common.AmlOpcode;
497 
498         Status = WalkState->AscendingCallback (WalkState);
499         Status = AcpiPsNextParseState (WalkState, *Op, Status);
500 
501         Status2 = AcpiPsCompleteThisOp (WalkState, *Op);
502         if (ACPI_FAILURE (Status2))
503         {
504             return_ACPI_STATUS (Status2);
505         }
506 
507         Status = AE_OK;
508         break;
509 
510     case AE_CTRL_TERMINATE:
511 
512         /* Clean up */
513         do
514         {
515             if (*Op)
516             {
517                 Status2 = AcpiPsCompleteThisOp (WalkState, *Op);
518                 if (ACPI_FAILURE (Status2))
519                 {
520                     return_ACPI_STATUS (Status2);
521                 }
522 
523                 AcpiUtDeleteGenericState (
524                     AcpiUtPopGenericState (&WalkState->ControlState));
525             }
526 
527             AcpiPsPopScope (&(WalkState->ParserState), Op,
528                 &WalkState->ArgTypes, &WalkState->ArgCount);
529 
530         } while (*Op);
531 
532         return_ACPI_STATUS (AE_OK);
533 
534     default:  /* All other non-AE_OK status */
535 
536         do
537         {
538             if (*Op)
539             {
540                 Status2 = AcpiPsCompleteThisOp (WalkState, *Op);
541                 if (ACPI_FAILURE (Status2))
542                 {
543                     return_ACPI_STATUS (Status2);
544                 }
545             }
546 
547             AcpiPsPopScope (&(WalkState->ParserState), Op,
548                 &WalkState->ArgTypes, &WalkState->ArgCount);
549 
550         } while (*Op);
551 
552 
553 #if 0
554         /*
555          * TBD: Cleanup parse ops on error
556          */
557         if (*Op == NULL)
558         {
559             AcpiPsPopScope (ParserState, Op,
560                 &WalkState->ArgTypes, &WalkState->ArgCount);
561         }
562 #endif
563         WalkState->PrevOp = NULL;
564         WalkState->PrevArgTypes = WalkState->ArgTypes;
565         return_ACPI_STATUS (Status);
566     }
567 
568     /* This scope complete? */
569 
570     if (AcpiPsHasCompletedScope (&(WalkState->ParserState)))
571     {
572         AcpiPsPopScope (&(WalkState->ParserState), Op,
573             &WalkState->ArgTypes, &WalkState->ArgCount);
574         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "Popped scope, Op=%p\n", *Op));
575     }
576     else
577     {
578         *Op = NULL;
579     }
580 
581     return_ACPI_STATUS (AE_OK);
582 }
583 
584 
585 /*******************************************************************************
586  *
587  * FUNCTION:    AcpiPsCompleteFinalOp
588  *
589  * PARAMETERS:  WalkState           - Current state
590  *              Op                  - Current Op
591  *              Status              - Current parse status before complete last
592  *                                    Op
593  *
594  * RETURN:      Status
595  *
596  * DESCRIPTION: Complete last Op.
597  *
598  ******************************************************************************/
599 
600 ACPI_STATUS
AcpiPsCompleteFinalOp(ACPI_WALK_STATE * WalkState,ACPI_PARSE_OBJECT * Op,ACPI_STATUS Status)601 AcpiPsCompleteFinalOp (
602     ACPI_WALK_STATE         *WalkState,
603     ACPI_PARSE_OBJECT       *Op,
604     ACPI_STATUS             Status)
605 {
606     ACPI_STATUS             Status2;
607 
608 
609     ACPI_FUNCTION_TRACE_PTR (PsCompleteFinalOp, WalkState);
610 
611 
612     /*
613      * Complete the last Op (if not completed), and clear the scope stack.
614      * It is easily possible to end an AML "package" with an unbounded number
615      * of open scopes (such as when several ASL blocks are closed with
616      * sequential closing braces). We want to terminate each one cleanly.
617      */
618     ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "AML package complete at Op %p\n", Op));
619     do
620     {
621         if (Op)
622         {
623             if (WalkState->AscendingCallback != NULL)
624             {
625                 WalkState->Op = Op;
626                 WalkState->OpInfo = AcpiPsGetOpcodeInfo (Op->Common.AmlOpcode);
627                 WalkState->Opcode = Op->Common.AmlOpcode;
628 
629                 Status = WalkState->AscendingCallback (WalkState);
630                 Status = AcpiPsNextParseState (WalkState, Op, Status);
631                 if (Status == AE_CTRL_PENDING)
632                 {
633                     Status = AcpiPsCompleteOp (WalkState, &Op, AE_OK);
634                     if (ACPI_FAILURE (Status))
635                     {
636                         return_ACPI_STATUS (Status);
637                     }
638                 }
639 
640                 if (Status == AE_CTRL_TERMINATE)
641                 {
642                     Status = AE_OK;
643 
644                     /* Clean up */
645                     do
646                     {
647                         if (Op)
648                         {
649                             Status2 = AcpiPsCompleteThisOp (WalkState, Op);
650                             if (ACPI_FAILURE (Status2))
651                             {
652                                 return_ACPI_STATUS (Status2);
653                             }
654                         }
655 
656                         AcpiPsPopScope (&(WalkState->ParserState), &Op,
657                             &WalkState->ArgTypes, &WalkState->ArgCount);
658 
659                     } while (Op);
660 
661                     return_ACPI_STATUS (Status);
662                 }
663 
664                 else if (ACPI_FAILURE (Status))
665                 {
666                     /* First error is most important */
667 
668                     (void) AcpiPsCompleteThisOp (WalkState, Op);
669                     return_ACPI_STATUS (Status);
670                 }
671             }
672 
673             Status2 = AcpiPsCompleteThisOp (WalkState, Op);
674             if (ACPI_FAILURE (Status2))
675             {
676                 return_ACPI_STATUS (Status2);
677             }
678         }
679 
680         AcpiPsPopScope (&(WalkState->ParserState), &Op, &WalkState->ArgTypes,
681             &WalkState->ArgCount);
682 
683     } while (Op);
684 
685     return_ACPI_STATUS (Status);
686 }
687