xref: /illumos-gate/usr/src/common/acpica/parser/psloop.c (revision 35786f6866ae52207d0f1a25fe7ca5f652f32ce0)
1 /******************************************************************************
2  *
3  * Module Name: psloop - Main AML parse loop
4  *
5  *****************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2018, 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 /*
153  * Parse the AML and build an operation tree as most interpreters, (such as
154  * Perl) do. Parsing is done by hand rather than with a YACC generated parser
155  * to tightly constrain stack and dynamic memory usage. Parsing is kept
156  * flexible and the code fairly compact by parsing based on a list of AML
157  * opcode templates in AmlOpInfo[].
158  */
159 
160 #include "acpi.h"
161 #include "accommon.h"
162 #include "acinterp.h"
163 #include "acparser.h"
164 #include "acdispat.h"
165 #include "amlcode.h"
166 #include "acconvert.h"
167 #include "acnamesp.h"
168 
169 #define _COMPONENT          ACPI_PARSER
170         ACPI_MODULE_NAME    ("psloop")
171 
172 
173 /* Local prototypes */
174 
175 static ACPI_STATUS
176 AcpiPsGetArguments (
177     ACPI_WALK_STATE         *WalkState,
178     UINT8                   *AmlOpStart,
179     ACPI_PARSE_OBJECT       *Op);
180 
181 static void
182 AcpiPsLinkModuleCode (
183     ACPI_PARSE_OBJECT       *ParentOp,
184     UINT8                   *AmlStart,
185     UINT32                  AmlLength,
186     ACPI_OWNER_ID           OwnerId);
187 
188 
189 /*******************************************************************************
190  *
191  * FUNCTION:    AcpiPsGetArguments
192  *
193  * PARAMETERS:  WalkState           - Current state
194  *              AmlOpStart          - Op start in AML
195  *              Op                  - Current Op
196  *
197  * RETURN:      Status
198  *
199  * DESCRIPTION: Get arguments for passed Op.
200  *
201  ******************************************************************************/
202 
203 static ACPI_STATUS
AcpiPsGetArguments(ACPI_WALK_STATE * WalkState,UINT8 * AmlOpStart,ACPI_PARSE_OBJECT * Op)204 AcpiPsGetArguments (
205     ACPI_WALK_STATE         *WalkState,
206     UINT8                   *AmlOpStart,
207     ACPI_PARSE_OBJECT       *Op)
208 {
209     ACPI_STATUS             Status = AE_OK;
210     ACPI_PARSE_OBJECT       *Arg = NULL;
211     const ACPI_OPCODE_INFO  *OpInfo;
212 
213 
214     ACPI_FUNCTION_TRACE_PTR (PsGetArguments, WalkState);
215 
216 
217     ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
218         "Get arguments for opcode [%s]\n", Op->Common.AmlOpName));
219 
220     switch (Op->Common.AmlOpcode)
221     {
222     case AML_BYTE_OP:       /* AML_BYTEDATA_ARG */
223     case AML_WORD_OP:       /* AML_WORDDATA_ARG */
224     case AML_DWORD_OP:      /* AML_DWORDATA_ARG */
225     case AML_QWORD_OP:      /* AML_QWORDATA_ARG */
226     case AML_STRING_OP:     /* AML_ASCIICHARLIST_ARG */
227 
228         /* Fill in constant or string argument directly */
229 
230         AcpiPsGetNextSimpleArg (&(WalkState->ParserState),
231             GET_CURRENT_ARG_TYPE (WalkState->ArgTypes), Op);
232         break;
233 
234     case AML_INT_NAMEPATH_OP:   /* AML_NAMESTRING_ARG */
235 
236         Status = AcpiPsGetNextNamepath (WalkState,
237             &(WalkState->ParserState), Op, ACPI_POSSIBLE_METHOD_CALL);
238         if (ACPI_FAILURE (Status))
239         {
240             return_ACPI_STATUS (Status);
241         }
242 
243         WalkState->ArgTypes = 0;
244         break;
245 
246     default:
247         /*
248          * Op is not a constant or string, append each argument to the Op
249          */
250         while (GET_CURRENT_ARG_TYPE (WalkState->ArgTypes) &&
251             !WalkState->ArgCount)
252         {
253             WalkState->Aml = WalkState->ParserState.Aml;
254 
255             switch (Op->Common.AmlOpcode)
256             {
257             case AML_METHOD_OP:
258             case AML_BUFFER_OP:
259             case AML_PACKAGE_OP:
260             case AML_VARIABLE_PACKAGE_OP:
261             case AML_WHILE_OP:
262 
263                 break;
264 
265             default:
266 
267                 ASL_CV_CAPTURE_COMMENTS (WalkState);
268                 break;
269             }
270 
271             Status = AcpiPsGetNextArg (WalkState, &(WalkState->ParserState),
272                 GET_CURRENT_ARG_TYPE (WalkState->ArgTypes), &Arg);
273             if (ACPI_FAILURE (Status))
274             {
275                 return_ACPI_STATUS (Status);
276             }
277 
278             if (Arg)
279             {
280                 AcpiPsAppendArg (Op, Arg);
281             }
282 
283             INCREMENT_ARG_LIST (WalkState->ArgTypes);
284         }
285 
286         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
287             "Final argument count: %8.8X pass %u\n",
288             WalkState->ArgCount, WalkState->PassNumber));
289 
290         /*
291          * This case handles the legacy option that groups all module-level
292          * code blocks together and defers execution until all of the tables
293          * are loaded. Execute all of these blocks at this time.
294          * Execute any module-level code that was detected during the table
295          * load phase.
296          *
297          * Note: this option is deprecated and will be eliminated in the
298          * future. Use of this option can cause problems with AML code that
299          * depends upon in-order immediate execution of module-level code.
300          */
301         if (AcpiGbl_GroupModuleLevelCode &&
302             (WalkState->PassNumber <= ACPI_IMODE_LOAD_PASS2) &&
303             ((WalkState->ParseFlags & ACPI_PARSE_DISASSEMBLE) == 0))
304         {
305             /*
306              * We want to skip If/Else/While constructs during Pass1 because we
307              * want to actually conditionally execute the code during Pass2.
308              *
309              * Except for disassembly, where we always want to walk the
310              * If/Else/While packages
311              */
312             switch (Op->Common.AmlOpcode)
313             {
314             case AML_IF_OP:
315             case AML_ELSE_OP:
316             case AML_WHILE_OP:
317                 /*
318                  * Currently supported module-level opcodes are:
319                  * IF/ELSE/WHILE. These appear to be the most common,
320                  * and easiest to support since they open an AML
321                  * package.
322                  */
323                 if (WalkState->PassNumber == ACPI_IMODE_LOAD_PASS1)
324                 {
325                     AcpiPsLinkModuleCode (Op->Common.Parent, AmlOpStart,
326                         (UINT32) (WalkState->ParserState.PkgEnd - AmlOpStart),
327                         WalkState->OwnerId);
328                 }
329 
330                 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
331                     "Pass1: Skipping an If/Else/While body\n"));
332 
333                 /* Skip body of if/else/while in pass 1 */
334 
335                 WalkState->ParserState.Aml = WalkState->ParserState.PkgEnd;
336                 WalkState->ArgCount = 0;
337                 break;
338 
339             default:
340                 /*
341                  * Check for an unsupported executable opcode at module
342                  * level. We must be in PASS1, the parent must be a SCOPE,
343                  * The opcode class must be EXECUTE, and the opcode must
344                  * not be an argument to another opcode.
345                  */
346                 if ((WalkState->PassNumber == ACPI_IMODE_LOAD_PASS1) &&
347                     (Op->Common.Parent->Common.AmlOpcode == AML_SCOPE_OP))
348                 {
349                     OpInfo = AcpiPsGetOpcodeInfo (Op->Common.AmlOpcode);
350                     if ((OpInfo->Class == AML_CLASS_EXECUTE) &&
351                         (!Arg))
352                     {
353                         ACPI_WARNING ((AE_INFO,
354                             "Unsupported module-level executable opcode "
355                             "0x%.2X at table offset 0x%.4X",
356                             Op->Common.AmlOpcode,
357                             (UINT32) (ACPI_PTR_DIFF (AmlOpStart,
358                                 WalkState->ParserState.AmlStart) +
359                                 sizeof (ACPI_TABLE_HEADER))));
360                     }
361                 }
362                 break;
363             }
364         }
365 
366         /* Special processing for certain opcodes */
367 
368         switch (Op->Common.AmlOpcode)
369         {
370         case AML_METHOD_OP:
371             /*
372              * Skip parsing of control method because we don't have enough
373              * info in the first pass to parse it correctly.
374              *
375              * Save the length and address of the body
376              */
377             Op->Named.Data = WalkState->ParserState.Aml;
378             Op->Named.Length = (UINT32)
379                 (WalkState->ParserState.PkgEnd - WalkState->ParserState.Aml);
380 
381             /* Skip body of method */
382 
383             WalkState->ParserState.Aml = WalkState->ParserState.PkgEnd;
384             WalkState->ArgCount = 0;
385             break;
386 
387         case AML_BUFFER_OP:
388         case AML_PACKAGE_OP:
389         case AML_VARIABLE_PACKAGE_OP:
390 
391             if ((Op->Common.Parent) &&
392                 (Op->Common.Parent->Common.AmlOpcode == AML_NAME_OP) &&
393                 (WalkState->PassNumber <= ACPI_IMODE_LOAD_PASS2))
394             {
395                 ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
396                     "Setup Package/Buffer: Pass %u, AML Ptr: %p\n",
397                     WalkState->PassNumber, AmlOpStart));
398 
399                 /*
400                  * Skip parsing of Buffers and Packages because we don't have
401                  * enough info in the first pass to parse them correctly.
402                  */
403                 Op->Named.Data = AmlOpStart;
404                 Op->Named.Length = (UINT32)
405                     (WalkState->ParserState.PkgEnd - AmlOpStart);
406 
407                 /* Skip body */
408 
409                 WalkState->ParserState.Aml = WalkState->ParserState.PkgEnd;
410                 WalkState->ArgCount = 0;
411             }
412             break;
413 
414         case AML_WHILE_OP:
415 
416             if (WalkState->ControlState)
417             {
418                 WalkState->ControlState->Control.PackageEnd =
419                     WalkState->ParserState.PkgEnd;
420             }
421             break;
422 
423         default:
424 
425             /* No action for all other opcodes */
426 
427             break;
428         }
429 
430         break;
431     }
432 
433     return_ACPI_STATUS (AE_OK);
434 }
435 
436 
437 /*******************************************************************************
438  *
439  * FUNCTION:    AcpiPsLinkModuleCode
440  *
441  * PARAMETERS:  ParentOp            - Parent parser op
442  *              AmlStart            - Pointer to the AML
443  *              AmlLength           - Length of executable AML
444  *              OwnerId             - OwnerId of module level code
445  *
446  * RETURN:      None.
447  *
448  * DESCRIPTION: Wrap the module-level code with a method object and link the
449  *              object to the global list. Note, the mutex field of the method
450  *              object is used to link multiple module-level code objects.
451  *
452  * NOTE: In this legacy option, each block of detected executable AML
453  * code that is outside of any control method is wrapped with a temporary
454  * control method object and placed on a global list below.
455  *
456  * This function executes the module-level code for all tables only after
457  * all of the tables have been loaded. It is a legacy option and is
458  * not compatible with other ACPI implementations. See AcpiNsLoadTable.
459  *
460  * This function will be removed when the legacy option is removed.
461  *
462  ******************************************************************************/
463 
464 static void
AcpiPsLinkModuleCode(ACPI_PARSE_OBJECT * ParentOp,UINT8 * AmlStart,UINT32 AmlLength,ACPI_OWNER_ID OwnerId)465 AcpiPsLinkModuleCode (
466     ACPI_PARSE_OBJECT       *ParentOp,
467     UINT8                   *AmlStart,
468     UINT32                  AmlLength,
469     ACPI_OWNER_ID           OwnerId)
470 {
471     ACPI_OPERAND_OBJECT     *Prev;
472     ACPI_OPERAND_OBJECT     *Next;
473     ACPI_OPERAND_OBJECT     *MethodObj;
474     ACPI_NAMESPACE_NODE     *ParentNode;
475 
476 
477     ACPI_FUNCTION_TRACE (PsLinkModuleCode);
478 
479 
480     /* Get the tail of the list */
481 
482     Prev = Next = AcpiGbl_ModuleCodeList;
483     while (Next)
484     {
485         Prev = Next;
486         Next = Next->Method.Mutex;
487     }
488 
489     /*
490      * Insert the module level code into the list. Merge it if it is
491      * adjacent to the previous element.
492      */
493     if (!Prev ||
494        ((Prev->Method.AmlStart + Prev->Method.AmlLength) != AmlStart))
495     {
496         /* Create, initialize, and link a new temporary method object */
497 
498         MethodObj = AcpiUtCreateInternalObject (ACPI_TYPE_METHOD);
499         if (!MethodObj)
500         {
501             return_VOID;
502         }
503 
504         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
505             "Create/Link new code block: %p\n", MethodObj));
506 
507         if (ParentOp->Common.Node)
508         {
509             ParentNode = ParentOp->Common.Node;
510         }
511         else
512         {
513             ParentNode = AcpiGbl_RootNode;
514         }
515 
516         MethodObj->Method.AmlStart = AmlStart;
517         MethodObj->Method.AmlLength = AmlLength;
518         MethodObj->Method.OwnerId = OwnerId;
519         MethodObj->Method.InfoFlags |= ACPI_METHOD_MODULE_LEVEL;
520 
521         /*
522          * Save the parent node in NextObject. This is cheating, but we
523          * don't want to expand the method object.
524          */
525         MethodObj->Method.NextObject =
526             ACPI_CAST_PTR (ACPI_OPERAND_OBJECT, ParentNode);
527 
528         if (!Prev)
529         {
530             AcpiGbl_ModuleCodeList = MethodObj;
531         }
532         else
533         {
534             Prev->Method.Mutex = MethodObj;
535         }
536     }
537     else
538     {
539         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
540             "Appending to existing code block: %p\n", Prev));
541 
542         Prev->Method.AmlLength += AmlLength;
543     }
544 
545     return_VOID;
546 }
547 
548 /*******************************************************************************
549  *
550  * FUNCTION:    AcpiPsParseLoop
551  *
552  * PARAMETERS:  WalkState           - Current state
553  *
554  * RETURN:      Status
555  *
556  * DESCRIPTION: Parse AML (pointed to by the current parser state) and return
557  *              a tree of ops.
558  *
559  ******************************************************************************/
560 
561 ACPI_STATUS
AcpiPsParseLoop(ACPI_WALK_STATE * WalkState)562 AcpiPsParseLoop (
563     ACPI_WALK_STATE         *WalkState)
564 {
565     ACPI_STATUS             Status = AE_OK;
566     ACPI_PARSE_OBJECT       *Op = NULL;     /* current op */
567     ACPI_PARSE_STATE        *ParserState;
568     UINT8                   *AmlOpStart = NULL;
569 
570 
571     ACPI_FUNCTION_TRACE_PTR (PsParseLoop, WalkState);
572 
573 
574     if (WalkState->DescendingCallback == NULL)
575     {
576         return_ACPI_STATUS (AE_BAD_PARAMETER);
577     }
578 
579     ParserState = &WalkState->ParserState;
580     WalkState->ArgTypes = 0;
581 
582 #if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))
583 
584     if (WalkState->WalkType & ACPI_WALK_METHOD_RESTART)
585     {
586         /* We are restarting a preempted control method */
587 
588         if (AcpiPsHasCompletedScope (ParserState))
589         {
590             /*
591              * We must check if a predicate to an IF or WHILE statement
592              * was just completed
593              */
594             if ((ParserState->Scope->ParseScope.Op) &&
595                ((ParserState->Scope->ParseScope.Op->Common.AmlOpcode == AML_IF_OP) ||
596                 (ParserState->Scope->ParseScope.Op->Common.AmlOpcode == AML_WHILE_OP)) &&
597                 (WalkState->ControlState) &&
598                 (WalkState->ControlState->Common.State ==
599                     ACPI_CONTROL_PREDICATE_EXECUTING))
600             {
601                 /*
602                  * A predicate was just completed, get the value of the
603                  * predicate and branch based on that value
604                  */
605                 WalkState->Op = NULL;
606                 Status = AcpiDsGetPredicateValue (WalkState, ACPI_TO_POINTER (TRUE));
607                 if (ACPI_FAILURE (Status) &&
608                     ((Status & AE_CODE_MASK) != AE_CODE_CONTROL))
609                 {
610                     if (Status == AE_AML_NO_RETURN_VALUE)
611                     {
612                         ACPI_EXCEPTION ((AE_INFO, Status,
613                             "Invoked method did not return a value"));
614                     }
615 
616                     ACPI_EXCEPTION ((AE_INFO, Status, "GetPredicate Failed"));
617                     return_ACPI_STATUS (Status);
618                 }
619 
620                 Status = AcpiPsNextParseState (WalkState, Op, Status);
621             }
622 
623             AcpiPsPopScope (ParserState, &Op,
624                 &WalkState->ArgTypes, &WalkState->ArgCount);
625             ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "Popped scope, Op=%p\n", Op));
626         }
627         else if (WalkState->PrevOp)
628         {
629             /* We were in the middle of an op */
630 
631             Op = WalkState->PrevOp;
632             WalkState->ArgTypes = WalkState->PrevArgTypes;
633         }
634     }
635 #endif
636 
637     /* Iterative parsing loop, while there is more AML to process: */
638 
639     while ((ParserState->Aml < ParserState->AmlEnd) || (Op))
640     {
641         ASL_CV_CAPTURE_COMMENTS (WalkState);
642 
643         AmlOpStart = ParserState->Aml;
644         if (!Op)
645         {
646             Status = AcpiPsCreateOp (WalkState, AmlOpStart, &Op);
647             if (ACPI_FAILURE (Status))
648             {
649                 /*
650                  * ACPI_PARSE_MODULE_LEVEL means that we are loading a table by
651                  * executing it as a control method. However, if we encounter
652                  * an error while loading the table, we need to keep trying to
653                  * load the table rather than aborting the table load. Set the
654                  * status to AE_OK to proceed with the table load.
655                  */
656                 if ((WalkState->ParseFlags & ACPI_PARSE_MODULE_LEVEL) &&
657                     Status == AE_ALREADY_EXISTS)
658                 {
659                     Status = AE_OK;
660                 }
661                 if (Status == AE_CTRL_PARSE_CONTINUE)
662                 {
663                     continue;
664                 }
665 
666                 if (Status == AE_CTRL_PARSE_PENDING)
667                 {
668                     Status = AE_OK;
669                 }
670 
671                 if (Status == AE_CTRL_TERMINATE)
672                 {
673                     return_ACPI_STATUS (Status);
674                 }
675 
676                 Status = AcpiPsCompleteOp (WalkState, &Op, Status);
677                 if (ACPI_FAILURE (Status))
678                 {
679                     return_ACPI_STATUS (Status);
680                 }
681                 if (AcpiNsOpensScope (
682                     AcpiPsGetOpcodeInfo (WalkState->Opcode)->ObjectType))
683                 {
684                     /*
685                      * If the scope/device op fails to parse, skip the body of
686                      * the scope op because the parse failure indicates that
687                      * the device may not exist.
688                      */
689                     ACPI_ERROR ((AE_INFO, "Skip parsing opcode %s",
690                         AcpiPsGetOpcodeName (WalkState->Opcode)));
691                     WalkState->ParserState.Aml = WalkState->Aml + 1;
692                     WalkState->ParserState.Aml =
693                         AcpiPsGetNextPackageEnd(&WalkState->ParserState);
694                     WalkState->Aml = WalkState->ParserState.Aml;
695                 }
696 
697                 continue;
698             }
699 
700             AcpiExStartTraceOpcode (Op, WalkState);
701         }
702 
703         /*
704          * Start ArgCount at zero because we don't know if there are
705          * any args yet
706          */
707         WalkState->ArgCount = 0;
708 
709         switch (Op->Common.AmlOpcode)
710         {
711         case AML_BYTE_OP:
712         case AML_WORD_OP:
713         case AML_DWORD_OP:
714         case AML_QWORD_OP:
715 
716             break;
717 
718         default:
719 
720             ASL_CV_CAPTURE_COMMENTS (WalkState);
721             break;
722         }
723 
724         /* Are there any arguments that must be processed? */
725 
726         if (WalkState->ArgTypes)
727         {
728             /* Get arguments */
729 
730             Status = AcpiPsGetArguments (WalkState, AmlOpStart, Op);
731             if (ACPI_FAILURE (Status))
732             {
733                 Status = AcpiPsCompleteOp (WalkState, &Op, Status);
734                 if (ACPI_FAILURE (Status))
735                 {
736                     return_ACPI_STATUS (Status);
737                 }
738                 if ((WalkState->ControlState) &&
739                     ((WalkState->ControlState->Control.Opcode == AML_IF_OP) ||
740                     (WalkState->ControlState->Control.Opcode == AML_WHILE_OP)))
741                 {
742                     /*
743                      * If the if/while op fails to parse, we will skip parsing
744                      * the body of the op.
745                      */
746                     ParserState->Aml =
747                         WalkState->ControlState->Control.AmlPredicateStart + 1;
748                     ParserState->Aml =
749                         AcpiPsGetNextPackageEnd (ParserState);
750                     WalkState->Aml = ParserState->Aml;
751 
752                     ACPI_ERROR ((AE_INFO, "Skipping While/If block"));
753                     if (*WalkState->Aml == AML_ELSE_OP)
754                     {
755                         ACPI_ERROR ((AE_INFO, "Skipping Else block"));
756                         WalkState->ParserState.Aml = WalkState->Aml + 1;
757                         WalkState->ParserState.Aml =
758                             AcpiPsGetNextPackageEnd (ParserState);
759                         WalkState->Aml = ParserState->Aml;
760                     }
761                     ACPI_FREE(AcpiUtPopGenericState (&WalkState->ControlState));
762                 }
763                 Op = NULL;
764                 continue;
765             }
766         }
767 
768         /* Check for arguments that need to be processed */
769 
770         ACPI_DEBUG_PRINT ((ACPI_DB_PARSE,
771             "Parseloop: argument count: %8.8X\n", WalkState->ArgCount));
772 
773         if (WalkState->ArgCount)
774         {
775             /*
776              * There are arguments (complex ones), push Op and
777              * prepare for argument
778              */
779             Status = AcpiPsPushScope (ParserState, Op,
780                 WalkState->ArgTypes, WalkState->ArgCount);
781             if (ACPI_FAILURE (Status))
782             {
783                 Status = AcpiPsCompleteOp (WalkState, &Op, Status);
784                 if (ACPI_FAILURE (Status))
785                 {
786                     return_ACPI_STATUS (Status);
787                 }
788 
789                 continue;
790             }
791 
792             Op = NULL;
793             continue;
794         }
795 
796         /*
797          * All arguments have been processed -- Op is complete,
798          * prepare for next
799          */
800         WalkState->OpInfo = AcpiPsGetOpcodeInfo (Op->Common.AmlOpcode);
801         if (WalkState->OpInfo->Flags & AML_NAMED)
802         {
803             if (Op->Common.AmlOpcode == AML_REGION_OP ||
804                 Op->Common.AmlOpcode == AML_DATA_REGION_OP)
805             {
806                 /*
807                  * Skip parsing of control method or opregion body,
808                  * because we don't have enough info in the first pass
809                  * to parse them correctly.
810                  *
811                  * Completed parsing an OpRegion declaration, we now
812                  * know the length.
813                  */
814                 Op->Named.Length = (UINT32) (ParserState->Aml - Op->Named.Data);
815             }
816         }
817 
818         if (WalkState->OpInfo->Flags & AML_CREATE)
819         {
820             /*
821              * Backup to beginning of CreateXXXfield declaration (1 for
822              * Opcode)
823              *
824              * BodyLength is unknown until we parse the body
825              */
826             Op->Named.Length = (UINT32) (ParserState->Aml - Op->Named.Data);
827         }
828 
829         if (Op->Common.AmlOpcode == AML_BANK_FIELD_OP)
830         {
831             /*
832              * Backup to beginning of BankField declaration
833              *
834              * BodyLength is unknown until we parse the body
835              */
836             Op->Named.Length = (UINT32) (ParserState->Aml - Op->Named.Data);
837         }
838 
839         /* This op complete, notify the dispatcher */
840 
841         if (WalkState->AscendingCallback != NULL)
842         {
843             WalkState->Op = Op;
844             WalkState->Opcode = Op->Common.AmlOpcode;
845 
846             Status = WalkState->AscendingCallback (WalkState);
847             Status = AcpiPsNextParseState (WalkState, Op, Status);
848             if (Status == AE_CTRL_PENDING)
849             {
850                 Status = AE_OK;
851             }
852             else if ((WalkState->ParseFlags & ACPI_PARSE_MODULE_LEVEL) &&
853                 (ACPI_AML_EXCEPTION(Status) || Status == AE_ALREADY_EXISTS ||
854                 Status == AE_NOT_FOUND))
855             {
856                 /*
857                  * ACPI_PARSE_MODULE_LEVEL flag means that we are currently
858                  * loading a table by executing it as a control method.
859                  * However, if we encounter an error while loading the table,
860                  * we need to keep trying to load the table rather than
861                  * aborting the table load (setting the status to AE_OK
862                  * continues the table load). If we get a failure at this
863                  * point, it means that the dispatcher got an error while
864                  * trying to execute the Op.
865                  */
866                 Status = AE_OK;
867             }
868         }
869 
870         Status = AcpiPsCompleteOp (WalkState, &Op, Status);
871         if (ACPI_FAILURE (Status))
872         {
873             return_ACPI_STATUS (Status);
874         }
875 
876     } /* while ParserState->Aml */
877 
878     Status = AcpiPsCompleteFinalOp (WalkState, Op, Status);
879     return_ACPI_STATUS (Status);
880 }
881