xref: /titanic_52/usr/src/uts/intel/io/acpica/executer/exresop.c (revision ccdeb6b6d71f3c9aa7e78b688f7b34fff109a817)
1 /******************************************************************************
2  *
3  * Module Name: exresop - AML Interpreter operand/object resolution
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 "amlcode.h"
47 #include "acparser.h"
48 #include "acinterp.h"
49 #include "acnamesp.h"
50 
51 
52 #define _COMPONENT          ACPI_EXECUTER
53         ACPI_MODULE_NAME    ("exresop")
54 
55 /* Local prototypes */
56 
57 static ACPI_STATUS
58 AcpiExCheckObjectType (
59     ACPI_OBJECT_TYPE        TypeNeeded,
60     ACPI_OBJECT_TYPE        ThisType,
61     void                    *Object);
62 
63 
64 /*******************************************************************************
65  *
66  * FUNCTION:    AcpiExCheckObjectType
67  *
68  * PARAMETERS:  TypeNeeded          Object type needed
69  *              ThisType            Actual object type
70  *              Object              Object pointer
71  *
72  * RETURN:      Status
73  *
74  * DESCRIPTION: Check required type against actual type
75  *
76  ******************************************************************************/
77 
78 static ACPI_STATUS
79 AcpiExCheckObjectType (
80     ACPI_OBJECT_TYPE        TypeNeeded,
81     ACPI_OBJECT_TYPE        ThisType,
82     void                    *Object)
83 {
84     ACPI_FUNCTION_ENTRY ();
85 
86 
87     if (TypeNeeded == ACPI_TYPE_ANY)
88     {
89         /* All types OK, so we don't perform any typechecks */
90 
91         return (AE_OK);
92     }
93 
94     if (TypeNeeded == ACPI_TYPE_LOCAL_REFERENCE)
95     {
96         /*
97          * Allow the AML "Constant" opcodes (Zero, One, etc.) to be reference
98          * objects and thus allow them to be targets. (As per the ACPI
99          * specification, a store to a constant is a noop.)
100          */
101         if ((ThisType == ACPI_TYPE_INTEGER) &&
102             (((ACPI_OPERAND_OBJECT *) Object)->Common.Flags &
103                 AOPOBJ_AML_CONSTANT))
104         {
105             return (AE_OK);
106         }
107     }
108 
109     if (TypeNeeded != ThisType)
110     {
111         ACPI_ERROR ((AE_INFO,
112             "Needed type [%s], found [%s] %p",
113             AcpiUtGetTypeName (TypeNeeded),
114             AcpiUtGetTypeName (ThisType), Object));
115 
116         return (AE_AML_OPERAND_TYPE);
117     }
118 
119     return (AE_OK);
120 }
121 
122 
123 /*******************************************************************************
124  *
125  * FUNCTION:    AcpiExResolveOperands
126  *
127  * PARAMETERS:  Opcode              - Opcode being interpreted
128  *              StackPtr            - Pointer to the operand stack to be
129  *                                    resolved
130  *              WalkState           - Current state
131  *
132  * RETURN:      Status
133  *
134  * DESCRIPTION: Convert multiple input operands to the types required by the
135  *              target operator.
136  *
137  *      Each 5-bit group in ArgTypes represents one required
138  *      operand and indicates the required Type. The corresponding operand
139  *      will be converted to the required type if possible, otherwise we
140  *      abort with an exception.
141  *
142  ******************************************************************************/
143 
144 ACPI_STATUS
145 AcpiExResolveOperands (
146     UINT16                  Opcode,
147     ACPI_OPERAND_OBJECT     **StackPtr,
148     ACPI_WALK_STATE         *WalkState)
149 {
150     ACPI_OPERAND_OBJECT     *ObjDesc;
151     ACPI_STATUS             Status = AE_OK;
152     UINT8                   ObjectType;
153     UINT32                  ArgTypes;
154     const ACPI_OPCODE_INFO  *OpInfo;
155     UINT32                  ThisArgType;
156     ACPI_OBJECT_TYPE        TypeNeeded;
157     UINT16                  TargetOp = 0;
158 
159 
160     ACPI_FUNCTION_TRACE_U32 (ExResolveOperands, Opcode);
161 
162 
163     OpInfo = AcpiPsGetOpcodeInfo (Opcode);
164     if (OpInfo->Class == AML_CLASS_UNKNOWN)
165     {
166         return_ACPI_STATUS (AE_AML_BAD_OPCODE);
167     }
168 
169     ArgTypes = OpInfo->RuntimeArgs;
170     if (ArgTypes == ARGI_INVALID_OPCODE)
171     {
172         ACPI_ERROR ((AE_INFO, "Unknown AML opcode 0x%X",
173             Opcode));
174 
175         return_ACPI_STATUS (AE_AML_INTERNAL);
176     }
177 
178     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
179         "Opcode %X [%s] RequiredOperandTypes=%8.8X\n",
180         Opcode, OpInfo->Name, ArgTypes));
181 
182     /*
183      * Normal exit is with (ArgTypes == 0) at end of argument list.
184      * Function will return an exception from within the loop upon
185      * finding an entry which is not (or cannot be converted
186      * to) the required type; if stack underflows; or upon
187      * finding a NULL stack entry (which should not happen).
188      */
189     while (GET_CURRENT_ARG_TYPE (ArgTypes))
190     {
191         if (!StackPtr || !*StackPtr)
192         {
193             ACPI_ERROR ((AE_INFO, "Null stack entry at %p",
194                 StackPtr));
195 
196             return_ACPI_STATUS (AE_AML_INTERNAL);
197         }
198 
199         /* Extract useful items */
200 
201         ObjDesc = *StackPtr;
202 
203         /* Decode the descriptor type */
204 
205         switch (ACPI_GET_DESCRIPTOR_TYPE (ObjDesc))
206         {
207         case ACPI_DESC_TYPE_NAMED:
208 
209             /* Namespace Node */
210 
211             ObjectType = ((ACPI_NAMESPACE_NODE *) ObjDesc)->Type;
212 
213             /*
214              * Resolve an alias object. The construction of these objects
215              * guarantees that there is only one level of alias indirection;
216              * thus, the attached object is always the aliased namespace node
217              */
218             if (ObjectType == ACPI_TYPE_LOCAL_ALIAS)
219             {
220                 ObjDesc = AcpiNsGetAttachedObject (
221                     (ACPI_NAMESPACE_NODE *) ObjDesc);
222                 *StackPtr = ObjDesc;
223                 ObjectType = ((ACPI_NAMESPACE_NODE *) ObjDesc)->Type;
224             }
225             break;
226 
227         case ACPI_DESC_TYPE_OPERAND:
228 
229             /* ACPI internal object */
230 
231             ObjectType = ObjDesc->Common.Type;
232 
233             /* Check for bad ACPI_OBJECT_TYPE */
234 
235             if (!AcpiUtValidObjectType (ObjectType))
236             {
237                 ACPI_ERROR ((AE_INFO,
238                     "Bad operand object type [0x%X]", ObjectType));
239 
240                 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
241             }
242 
243             if (ObjectType == (UINT8) ACPI_TYPE_LOCAL_REFERENCE)
244             {
245                 /* Validate the Reference */
246 
247                 switch (ObjDesc->Reference.Class)
248                 {
249                 case ACPI_REFCLASS_DEBUG:
250 
251                     TargetOp = AML_DEBUG_OP;
252 
253                     /*lint -fallthrough */
254 
255                 case ACPI_REFCLASS_ARG:
256                 case ACPI_REFCLASS_LOCAL:
257                 case ACPI_REFCLASS_INDEX:
258                 case ACPI_REFCLASS_REFOF:
259                 case ACPI_REFCLASS_TABLE:    /* DdbHandle from LOAD_OP or LOAD_TABLE_OP */
260                 case ACPI_REFCLASS_NAME:     /* Reference to a named object */
261 
262                     ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
263                         "Operand is a Reference, Class [%s] %2.2X\n",
264                         AcpiUtGetReferenceName (ObjDesc),
265                         ObjDesc->Reference.Class));
266                     break;
267 
268                 default:
269 
270                     ACPI_ERROR ((AE_INFO,
271                         "Unknown Reference Class 0x%2.2X in %p",
272                         ObjDesc->Reference.Class, ObjDesc));
273 
274                     return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
275                 }
276             }
277             break;
278 
279         default:
280 
281             /* Invalid descriptor */
282 
283             ACPI_ERROR ((AE_INFO, "Invalid descriptor %p [%s]",
284                 ObjDesc, AcpiUtGetDescriptorName (ObjDesc)));
285 
286             return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
287         }
288 
289         /* Get one argument type, point to the next */
290 
291         ThisArgType = GET_CURRENT_ARG_TYPE (ArgTypes);
292         INCREMENT_ARG_LIST (ArgTypes);
293 
294         /*
295          * Handle cases where the object does not need to be
296          * resolved to a value
297          */
298         switch (ThisArgType)
299         {
300         case ARGI_REF_OR_STRING:        /* Can be a String or Reference */
301 
302             if ((ACPI_GET_DESCRIPTOR_TYPE (ObjDesc) ==
303                 ACPI_DESC_TYPE_OPERAND) &&
304                 (ObjDesc->Common.Type == ACPI_TYPE_STRING))
305             {
306                 /*
307                  * String found - the string references a named object and
308                  * must be resolved to a node
309                  */
310                 goto NextOperand;
311             }
312 
313             /*
314              * Else not a string - fall through to the normal Reference
315              * case below
316              */
317             /*lint -fallthrough */
318 
319         case ARGI_REFERENCE:            /* References: */
320         case ARGI_INTEGER_REF:
321         case ARGI_OBJECT_REF:
322         case ARGI_DEVICE_REF:
323         case ARGI_TARGETREF:     /* Allows implicit conversion rules before store */
324         case ARGI_FIXED_TARGET:  /* No implicit conversion before store to target */
325         case ARGI_SIMPLE_TARGET: /* Name, Local, or Arg - no implicit conversion  */
326         case ARGI_STORE_TARGET:
327 
328             /*
329              * Need an operand of type ACPI_TYPE_LOCAL_REFERENCE
330              * A Namespace Node is OK as-is
331              */
332             if (ACPI_GET_DESCRIPTOR_TYPE (ObjDesc) == ACPI_DESC_TYPE_NAMED)
333             {
334                 goto NextOperand;
335             }
336 
337             Status = AcpiExCheckObjectType (
338                 ACPI_TYPE_LOCAL_REFERENCE, ObjectType, ObjDesc);
339             if (ACPI_FAILURE (Status))
340             {
341                 return_ACPI_STATUS (Status);
342             }
343             goto NextOperand;
344 
345         case ARGI_DATAREFOBJ:  /* Store operator only */
346             /*
347              * We don't want to resolve IndexOp reference objects during
348              * a store because this would be an implicit DeRefOf operation.
349              * Instead, we just want to store the reference object.
350              * -- All others must be resolved below.
351              */
352             if ((Opcode == AML_STORE_OP) &&
353                 ((*StackPtr)->Common.Type == ACPI_TYPE_LOCAL_REFERENCE) &&
354                 ((*StackPtr)->Reference.Class == ACPI_REFCLASS_INDEX))
355             {
356                 goto NextOperand;
357             }
358             break;
359 
360         default:
361 
362             /* All cases covered above */
363 
364             break;
365         }
366 
367         /*
368          * Resolve this object to a value
369          */
370         Status = AcpiExResolveToValue (StackPtr, WalkState);
371         if (ACPI_FAILURE (Status))
372         {
373             return_ACPI_STATUS (Status);
374         }
375 
376         /* Get the resolved object */
377 
378         ObjDesc = *StackPtr;
379 
380         /*
381          * Check the resulting object (value) type
382          */
383         switch (ThisArgType)
384         {
385         /*
386          * For the simple cases, only one type of resolved object
387          * is allowed
388          */
389         case ARGI_MUTEX:
390 
391             /* Need an operand of type ACPI_TYPE_MUTEX */
392 
393             TypeNeeded = ACPI_TYPE_MUTEX;
394             break;
395 
396         case ARGI_EVENT:
397 
398             /* Need an operand of type ACPI_TYPE_EVENT */
399 
400             TypeNeeded = ACPI_TYPE_EVENT;
401             break;
402 
403         case ARGI_PACKAGE:   /* Package */
404 
405             /* Need an operand of type ACPI_TYPE_PACKAGE */
406 
407             TypeNeeded = ACPI_TYPE_PACKAGE;
408             break;
409 
410         case ARGI_ANYTYPE:
411 
412             /* Any operand type will do */
413 
414             TypeNeeded = ACPI_TYPE_ANY;
415             break;
416 
417         case ARGI_DDBHANDLE:
418 
419             /* Need an operand of type ACPI_TYPE_DDB_HANDLE */
420 
421             TypeNeeded = ACPI_TYPE_LOCAL_REFERENCE;
422             break;
423 
424 
425         /*
426          * The more complex cases allow multiple resolved object types
427          */
428         case ARGI_INTEGER:
429 
430             /*
431              * Need an operand of type ACPI_TYPE_INTEGER,
432              * But we can implicitly convert from a STRING or BUFFER
433              * Aka - "Implicit Source Operand Conversion"
434              */
435             Status = AcpiExConvertToInteger (ObjDesc, StackPtr, 16);
436             if (ACPI_FAILURE (Status))
437             {
438                 if (Status == AE_TYPE)
439                 {
440                     ACPI_ERROR ((AE_INFO,
441                         "Needed [Integer/String/Buffer], found [%s] %p",
442                         AcpiUtGetObjectTypeName (ObjDesc), ObjDesc));
443 
444                     return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
445                 }
446 
447                 return_ACPI_STATUS (Status);
448             }
449 
450             if (ObjDesc != *StackPtr)
451             {
452                 AcpiUtRemoveReference (ObjDesc);
453             }
454             goto NextOperand;
455 
456         case ARGI_BUFFER:
457             /*
458              * Need an operand of type ACPI_TYPE_BUFFER,
459              * But we can implicitly convert from a STRING or INTEGER
460              * Aka - "Implicit Source Operand Conversion"
461              */
462             Status = AcpiExConvertToBuffer (ObjDesc, StackPtr);
463             if (ACPI_FAILURE (Status))
464             {
465                 if (Status == AE_TYPE)
466                 {
467                     ACPI_ERROR ((AE_INFO,
468                         "Needed [Integer/String/Buffer], found [%s] %p",
469                         AcpiUtGetObjectTypeName (ObjDesc), ObjDesc));
470 
471                     return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
472                 }
473 
474                 return_ACPI_STATUS (Status);
475             }
476 
477             if (ObjDesc != *StackPtr)
478             {
479                 AcpiUtRemoveReference (ObjDesc);
480             }
481             goto NextOperand;
482 
483         case ARGI_STRING:
484             /*
485              * Need an operand of type ACPI_TYPE_STRING,
486              * But we can implicitly convert from a BUFFER or INTEGER
487              * Aka - "Implicit Source Operand Conversion"
488              */
489             Status = AcpiExConvertToString (
490                 ObjDesc, StackPtr, ACPI_IMPLICIT_CONVERT_HEX);
491             if (ACPI_FAILURE (Status))
492             {
493                 if (Status == AE_TYPE)
494                 {
495                     ACPI_ERROR ((AE_INFO,
496                         "Needed [Integer/String/Buffer], found [%s] %p",
497                         AcpiUtGetObjectTypeName (ObjDesc), ObjDesc));
498 
499                     return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
500                 }
501 
502                 return_ACPI_STATUS (Status);
503             }
504 
505             if (ObjDesc != *StackPtr)
506             {
507                 AcpiUtRemoveReference (ObjDesc);
508             }
509             goto NextOperand;
510 
511         case ARGI_COMPUTEDATA:
512 
513             /* Need an operand of type INTEGER, STRING or BUFFER */
514 
515             switch (ObjDesc->Common.Type)
516             {
517             case ACPI_TYPE_INTEGER:
518             case ACPI_TYPE_STRING:
519             case ACPI_TYPE_BUFFER:
520 
521                 /* Valid operand */
522                break;
523 
524             default:
525                 ACPI_ERROR ((AE_INFO,
526                     "Needed [Integer/String/Buffer], found [%s] %p",
527                     AcpiUtGetObjectTypeName (ObjDesc), ObjDesc));
528 
529                 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
530             }
531             goto NextOperand;
532 
533         case ARGI_BUFFER_OR_STRING:
534 
535             /* Need an operand of type STRING or BUFFER */
536 
537             switch (ObjDesc->Common.Type)
538             {
539             case ACPI_TYPE_STRING:
540             case ACPI_TYPE_BUFFER:
541 
542                 /* Valid operand */
543                break;
544 
545             case ACPI_TYPE_INTEGER:
546 
547                 /* Highest priority conversion is to type Buffer */
548 
549                 Status = AcpiExConvertToBuffer (ObjDesc, StackPtr);
550                 if (ACPI_FAILURE (Status))
551                 {
552                     return_ACPI_STATUS (Status);
553                 }
554 
555                 if (ObjDesc != *StackPtr)
556                 {
557                     AcpiUtRemoveReference (ObjDesc);
558                 }
559                 break;
560 
561             default:
562                 ACPI_ERROR ((AE_INFO,
563                     "Needed [Integer/String/Buffer], found [%s] %p",
564                     AcpiUtGetObjectTypeName (ObjDesc), ObjDesc));
565 
566                 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
567             }
568             goto NextOperand;
569 
570         case ARGI_DATAOBJECT:
571             /*
572              * ARGI_DATAOBJECT is only used by the SizeOf operator.
573              * Need a buffer, string, package, or RefOf reference.
574              *
575              * The only reference allowed here is a direct reference to
576              * a namespace node.
577              */
578             switch (ObjDesc->Common.Type)
579             {
580             case ACPI_TYPE_PACKAGE:
581             case ACPI_TYPE_STRING:
582             case ACPI_TYPE_BUFFER:
583             case ACPI_TYPE_LOCAL_REFERENCE:
584 
585                 /* Valid operand */
586                 break;
587 
588             default:
589 
590                 ACPI_ERROR ((AE_INFO,
591                     "Needed [Buffer/String/Package/Reference], found [%s] %p",
592                     AcpiUtGetObjectTypeName (ObjDesc), ObjDesc));
593 
594                 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
595             }
596             goto NextOperand;
597 
598         case ARGI_COMPLEXOBJ:
599 
600             /* Need a buffer or package or (ACPI 2.0) String */
601 
602             switch (ObjDesc->Common.Type)
603             {
604             case ACPI_TYPE_PACKAGE:
605             case ACPI_TYPE_STRING:
606             case ACPI_TYPE_BUFFER:
607 
608                 /* Valid operand */
609                 break;
610 
611             default:
612 
613                 ACPI_ERROR ((AE_INFO,
614                     "Needed [Buffer/String/Package], found [%s] %p",
615                     AcpiUtGetObjectTypeName (ObjDesc), ObjDesc));
616 
617                 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
618             }
619             goto NextOperand;
620 
621         case ARGI_REGION_OR_BUFFER: /* Used by Load() only */
622 
623             /*
624              * Need an operand of type REGION or a BUFFER
625              * (which could be a resolved region field)
626              */
627             switch (ObjDesc->Common.Type)
628             {
629             case ACPI_TYPE_BUFFER:
630             case ACPI_TYPE_REGION:
631 
632                 /* Valid operand */
633                 break;
634 
635             default:
636 
637                 ACPI_ERROR ((AE_INFO,
638                     "Needed [Region/Buffer], found [%s] %p",
639                     AcpiUtGetObjectTypeName (ObjDesc), ObjDesc));
640 
641                 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
642             }
643             goto NextOperand;
644 
645         case ARGI_DATAREFOBJ:
646 
647             /* Used by the Store() operator only */
648 
649             switch (ObjDesc->Common.Type)
650             {
651             case ACPI_TYPE_INTEGER:
652             case ACPI_TYPE_PACKAGE:
653             case ACPI_TYPE_STRING:
654             case ACPI_TYPE_BUFFER:
655             case ACPI_TYPE_BUFFER_FIELD:
656             case ACPI_TYPE_LOCAL_REFERENCE:
657             case ACPI_TYPE_LOCAL_REGION_FIELD:
658             case ACPI_TYPE_LOCAL_BANK_FIELD:
659             case ACPI_TYPE_LOCAL_INDEX_FIELD:
660             case ACPI_TYPE_DDB_HANDLE:
661 
662                 /* Valid operand */
663                 break;
664 
665             default:
666 
667                 if (AcpiGbl_EnableInterpreterSlack)
668                 {
669                     /*
670                      * Enable original behavior of Store(), allowing any
671                      * and all objects as the source operand. The ACPI
672                      * spec does not allow this, however.
673                      */
674                     break;
675                 }
676 
677                 if (TargetOp == AML_DEBUG_OP)
678                 {
679                     /* Allow store of any object to the Debug object */
680 
681                     break;
682                 }
683 
684                 ACPI_ERROR ((AE_INFO,
685                     "Needed Integer/Buffer/String/Package/Ref/Ddb]"
686                     ", found [%s] %p",
687                     AcpiUtGetObjectTypeName (ObjDesc), ObjDesc));
688 
689                 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
690             }
691             goto NextOperand;
692 
693         default:
694 
695             /* Unknown type */
696 
697             ACPI_ERROR ((AE_INFO,
698                 "Internal - Unknown ARGI (required operand) type 0x%X",
699                 ThisArgType));
700 
701             return_ACPI_STATUS (AE_BAD_PARAMETER);
702         }
703 
704         /*
705          * Make sure that the original object was resolved to the
706          * required object type (Simple cases only).
707          */
708         Status = AcpiExCheckObjectType (
709             TypeNeeded, (*StackPtr)->Common.Type, *StackPtr);
710         if (ACPI_FAILURE (Status))
711         {
712             return_ACPI_STATUS (Status);
713         }
714 
715 NextOperand:
716         /*
717          * If more operands needed, decrement StackPtr to point
718          * to next operand on stack
719          */
720         if (GET_CURRENT_ARG_TYPE (ArgTypes))
721         {
722             StackPtr--;
723         }
724     }
725 
726     ACPI_DUMP_OPERANDS (WalkState->Operands,
727         AcpiPsGetOpcodeName (Opcode), WalkState->NumOperands);
728 
729     return_ACPI_STATUS (Status);
730 }
731