xref: /haiku/src/add-ons/kernel/bus_managers/acpi/acpica/components/executer/exoparg2.c (revision 90ae2e54f6ccaca73c011a2aa4cdd660417108ad)
1 /******************************************************************************
2  *
3  * Module Name: exoparg2 - AML execution - opcodes with 2 arguments
4  *
5  *****************************************************************************/
6 
7 /******************************************************************************
8  *
9  * 1. Copyright Notice
10  *
11  * Some or all of this work - Copyright (c) 1999 - 2012, 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 
117 #define __EXOPARG2_C__
118 
119 #include "acpi.h"
120 #include "accommon.h"
121 #include "acparser.h"
122 #include "acinterp.h"
123 #include "acevents.h"
124 #include "amlcode.h"
125 
126 
127 #define _COMPONENT          ACPI_EXECUTER
128         ACPI_MODULE_NAME    ("exoparg2")
129 
130 
131 /*!
132  * Naming convention for AML interpreter execution routines.
133  *
134  * The routines that begin execution of AML opcodes are named with a common
135  * convention based upon the number of arguments, the number of target operands,
136  * and whether or not a value is returned:
137  *
138  *      AcpiExOpcode_xA_yT_zR
139  *
140  * Where:
141  *
142  * xA - ARGUMENTS:    The number of arguments (input operands) that are
143  *                    required for this opcode type (1 through 6 args).
144  * yT - TARGETS:      The number of targets (output operands) that are required
145  *                    for this opcode type (0, 1, or 2 targets).
146  * zR - RETURN VALUE: Indicates whether this opcode type returns a value
147  *                    as the function return (0 or 1).
148  *
149  * The AcpiExOpcode* functions are called via the Dispatcher component with
150  * fully resolved operands.
151 !*/
152 
153 
154 /*******************************************************************************
155  *
156  * FUNCTION:    AcpiExOpcode_2A_0T_0R
157  *
158  * PARAMETERS:  WalkState           - Current walk state
159  *
160  * RETURN:      Status
161  *
162  * DESCRIPTION: Execute opcode with two arguments, no target, and no return
163  *              value.
164  *
165  * ALLOCATION:  Deletes both operands
166  *
167  ******************************************************************************/
168 
169 ACPI_STATUS
170 AcpiExOpcode_2A_0T_0R (
171     ACPI_WALK_STATE         *WalkState)
172 {
173     ACPI_OPERAND_OBJECT     **Operand = &WalkState->Operands[0];
174     ACPI_NAMESPACE_NODE     *Node;
175     UINT32                  Value;
176     ACPI_STATUS             Status = AE_OK;
177 
178 
179     ACPI_FUNCTION_TRACE_STR (ExOpcode_2A_0T_0R,
180             AcpiPsGetOpcodeName (WalkState->Opcode));
181 
182 
183     /* Examine the opcode */
184 
185     switch (WalkState->Opcode)
186     {
187     case AML_NOTIFY_OP:         /* Notify (NotifyObject, NotifyValue) */
188 
189         /* The first operand is a namespace node */
190 
191         Node = (ACPI_NAMESPACE_NODE *) Operand[0];
192 
193         /* Second value is the notify value */
194 
195         Value = (UINT32) Operand[1]->Integer.Value;
196 
197         /* Are notifies allowed on this object? */
198 
199         if (!AcpiEvIsNotifyObject (Node))
200         {
201             ACPI_ERROR ((AE_INFO,
202                 "Unexpected notify object type [%s]",
203                 AcpiUtGetTypeName (Node->Type)));
204 
205             Status = AE_AML_OPERAND_TYPE;
206             break;
207         }
208 
209         /*
210          * Dispatch the notify to the appropriate handler
211          * NOTE: the request is queued for execution after this method
212          * completes. The notify handlers are NOT invoked synchronously
213          * from this thread -- because handlers may in turn run other
214          * control methods.
215          */
216         Status = AcpiEvQueueNotifyRequest (Node, Value);
217         break;
218 
219 
220     default:
221 
222         ACPI_ERROR ((AE_INFO, "Unknown AML opcode 0x%X",
223             WalkState->Opcode));
224         Status = AE_AML_BAD_OPCODE;
225     }
226 
227     return_ACPI_STATUS (Status);
228 }
229 
230 
231 /*******************************************************************************
232  *
233  * FUNCTION:    AcpiExOpcode_2A_2T_1R
234  *
235  * PARAMETERS:  WalkState           - Current walk state
236  *
237  * RETURN:      Status
238  *
239  * DESCRIPTION: Execute a dyadic operator (2 operands) with 2 output targets
240  *              and one implicit return value.
241  *
242  ******************************************************************************/
243 
244 ACPI_STATUS
245 AcpiExOpcode_2A_2T_1R (
246     ACPI_WALK_STATE         *WalkState)
247 {
248     ACPI_OPERAND_OBJECT     **Operand = &WalkState->Operands[0];
249     ACPI_OPERAND_OBJECT     *ReturnDesc1 = NULL;
250     ACPI_OPERAND_OBJECT     *ReturnDesc2 = NULL;
251     ACPI_STATUS             Status;
252 
253 
254     ACPI_FUNCTION_TRACE_STR (ExOpcode_2A_2T_1R,
255         AcpiPsGetOpcodeName (WalkState->Opcode));
256 
257 
258     /* Execute the opcode */
259 
260     switch (WalkState->Opcode)
261     {
262     case AML_DIVIDE_OP:
263 
264         /* Divide (Dividend, Divisor, RemainderResult QuotientResult) */
265 
266         ReturnDesc1 = AcpiUtCreateInternalObject (ACPI_TYPE_INTEGER);
267         if (!ReturnDesc1)
268         {
269             Status = AE_NO_MEMORY;
270             goto Cleanup;
271         }
272 
273         ReturnDesc2 = AcpiUtCreateInternalObject (ACPI_TYPE_INTEGER);
274         if (!ReturnDesc2)
275         {
276             Status = AE_NO_MEMORY;
277             goto Cleanup;
278         }
279 
280         /* Quotient to ReturnDesc1, remainder to ReturnDesc2 */
281 
282         Status = AcpiUtDivide (Operand[0]->Integer.Value,
283                                Operand[1]->Integer.Value,
284                                &ReturnDesc1->Integer.Value,
285                                &ReturnDesc2->Integer.Value);
286         if (ACPI_FAILURE (Status))
287         {
288             goto Cleanup;
289         }
290         break;
291 
292 
293     default:
294 
295         ACPI_ERROR ((AE_INFO, "Unknown AML opcode 0x%X",
296             WalkState->Opcode));
297         Status = AE_AML_BAD_OPCODE;
298         goto Cleanup;
299     }
300 
301     /* Store the results to the target reference operands */
302 
303     Status = AcpiExStore (ReturnDesc2, Operand[2], WalkState);
304     if (ACPI_FAILURE (Status))
305     {
306         goto Cleanup;
307     }
308 
309     Status = AcpiExStore (ReturnDesc1, Operand[3], WalkState);
310     if (ACPI_FAILURE (Status))
311     {
312         goto Cleanup;
313     }
314 
315 Cleanup:
316     /*
317      * Since the remainder is not returned indirectly, remove a reference to
318      * it. Only the quotient is returned indirectly.
319      */
320     AcpiUtRemoveReference (ReturnDesc2);
321 
322     if (ACPI_FAILURE (Status))
323     {
324         /* Delete the return object */
325 
326         AcpiUtRemoveReference (ReturnDesc1);
327     }
328 
329     /* Save return object (the remainder) on success */
330 
331     else
332     {
333         WalkState->ResultObj = ReturnDesc1;
334     }
335 
336     return_ACPI_STATUS (Status);
337 }
338 
339 
340 /*******************************************************************************
341  *
342  * FUNCTION:    AcpiExOpcode_2A_1T_1R
343  *
344  * PARAMETERS:  WalkState           - Current walk state
345  *
346  * RETURN:      Status
347  *
348  * DESCRIPTION: Execute opcode with two arguments, one target, and a return
349  *              value.
350  *
351  ******************************************************************************/
352 
353 ACPI_STATUS
354 AcpiExOpcode_2A_1T_1R (
355     ACPI_WALK_STATE         *WalkState)
356 {
357     ACPI_OPERAND_OBJECT     **Operand = &WalkState->Operands[0];
358     ACPI_OPERAND_OBJECT     *ReturnDesc = NULL;
359     UINT64                  Index;
360     ACPI_STATUS             Status = AE_OK;
361     ACPI_SIZE               Length;
362 
363 
364     ACPI_FUNCTION_TRACE_STR (ExOpcode_2A_1T_1R,
365         AcpiPsGetOpcodeName (WalkState->Opcode));
366 
367 
368     /* Execute the opcode */
369 
370     if (WalkState->OpInfo->Flags & AML_MATH)
371     {
372         /* All simple math opcodes (add, etc.) */
373 
374         ReturnDesc = AcpiUtCreateInternalObject (ACPI_TYPE_INTEGER);
375         if (!ReturnDesc)
376         {
377             Status = AE_NO_MEMORY;
378             goto Cleanup;
379         }
380 
381         ReturnDesc->Integer.Value = AcpiExDoMathOp (WalkState->Opcode,
382                                                 Operand[0]->Integer.Value,
383                                                 Operand[1]->Integer.Value);
384         goto StoreResultToTarget;
385     }
386 
387     switch (WalkState->Opcode)
388     {
389     case AML_MOD_OP: /* Mod (Dividend, Divisor, RemainderResult (ACPI 2.0) */
390 
391         ReturnDesc = AcpiUtCreateInternalObject (ACPI_TYPE_INTEGER);
392         if (!ReturnDesc)
393         {
394             Status = AE_NO_MEMORY;
395             goto Cleanup;
396         }
397 
398         /* ReturnDesc will contain the remainder */
399 
400         Status = AcpiUtDivide (Operand[0]->Integer.Value,
401                                Operand[1]->Integer.Value,
402                                NULL,
403                                &ReturnDesc->Integer.Value);
404         break;
405 
406 
407     case AML_CONCAT_OP: /* Concatenate (Data1, Data2, Result) */
408 
409         Status = AcpiExDoConcatenate (Operand[0], Operand[1],
410                     &ReturnDesc, WalkState);
411         break;
412 
413 
414     case AML_TO_STRING_OP: /* ToString (Buffer, Length, Result) (ACPI 2.0) */
415 
416         /*
417          * Input object is guaranteed to be a buffer at this point (it may have
418          * been converted.)  Copy the raw buffer data to a new object of
419          * type String.
420          */
421 
422         /*
423          * Get the length of the new string. It is the smallest of:
424          * 1) Length of the input buffer
425          * 2) Max length as specified in the ToString operator
426          * 3) Length of input buffer up to a zero byte (null terminator)
427          *
428          * NOTE: A length of zero is ok, and will create a zero-length, null
429          *       terminated string.
430          */
431         Length = 0;
432         while ((Length < Operand[0]->Buffer.Length) &&
433                (Length < Operand[1]->Integer.Value) &&
434                (Operand[0]->Buffer.Pointer[Length]))
435         {
436             Length++;
437         }
438 
439         /* Allocate a new string object */
440 
441         ReturnDesc = AcpiUtCreateStringObject (Length);
442         if (!ReturnDesc)
443         {
444             Status = AE_NO_MEMORY;
445             goto Cleanup;
446         }
447 
448         /*
449          * Copy the raw buffer data with no transform.
450          * (NULL terminated already)
451          */
452         ACPI_MEMCPY (ReturnDesc->String.Pointer,
453             Operand[0]->Buffer.Pointer, Length);
454         break;
455 
456 
457     case AML_CONCAT_RES_OP:
458 
459         /* ConcatenateResTemplate (Buffer, Buffer, Result) (ACPI 2.0) */
460 
461         Status = AcpiExConcatTemplate (Operand[0], Operand[1],
462                     &ReturnDesc, WalkState);
463         break;
464 
465 
466     case AML_INDEX_OP:              /* Index (Source Index Result) */
467 
468         /* Create the internal return object */
469 
470         ReturnDesc = AcpiUtCreateInternalObject (ACPI_TYPE_LOCAL_REFERENCE);
471         if (!ReturnDesc)
472         {
473             Status = AE_NO_MEMORY;
474             goto Cleanup;
475         }
476 
477         /* Initialize the Index reference object */
478 
479         Index = Operand[1]->Integer.Value;
480         ReturnDesc->Reference.Value = (UINT32) Index;
481         ReturnDesc->Reference.Class = ACPI_REFCLASS_INDEX;
482 
483         /*
484          * At this point, the Source operand is a String, Buffer, or Package.
485          * Verify that the index is within range.
486          */
487         switch ((Operand[0])->Common.Type)
488         {
489         case ACPI_TYPE_STRING:
490 
491             if (Index >= Operand[0]->String.Length)
492             {
493                 Status = AE_AML_STRING_LIMIT;
494             }
495 
496             ReturnDesc->Reference.TargetType = ACPI_TYPE_BUFFER_FIELD;
497             break;
498 
499         case ACPI_TYPE_BUFFER:
500 
501             if (Index >= Operand[0]->Buffer.Length)
502             {
503                 Status = AE_AML_BUFFER_LIMIT;
504             }
505 
506             ReturnDesc->Reference.TargetType = ACPI_TYPE_BUFFER_FIELD;
507             break;
508 
509         case ACPI_TYPE_PACKAGE:
510 
511             if (Index >= Operand[0]->Package.Count)
512             {
513                 Status = AE_AML_PACKAGE_LIMIT;
514             }
515 
516             ReturnDesc->Reference.TargetType = ACPI_TYPE_PACKAGE;
517             ReturnDesc->Reference.Where = &Operand[0]->Package.Elements [Index];
518             break;
519 
520         default:
521 
522             Status = AE_AML_INTERNAL;
523             goto Cleanup;
524         }
525 
526         /* Failure means that the Index was beyond the end of the object */
527 
528         if (ACPI_FAILURE (Status))
529         {
530             ACPI_EXCEPTION ((AE_INFO, Status,
531                 "Index (0x%8.8X%8.8X) is beyond end of object",
532                 ACPI_FORMAT_UINT64 (Index)));
533             goto Cleanup;
534         }
535 
536         /*
537          * Save the target object and add a reference to it for the life
538          * of the index
539          */
540         ReturnDesc->Reference.Object = Operand[0];
541         AcpiUtAddReference (Operand[0]);
542 
543         /* Store the reference to the Target */
544 
545         Status = AcpiExStore (ReturnDesc, Operand[2], WalkState);
546 
547         /* Return the reference */
548 
549         WalkState->ResultObj = ReturnDesc;
550         goto Cleanup;
551 
552 
553     default:
554 
555         ACPI_ERROR ((AE_INFO, "Unknown AML opcode 0x%X",
556             WalkState->Opcode));
557         Status = AE_AML_BAD_OPCODE;
558         break;
559     }
560 
561 
562 StoreResultToTarget:
563 
564     if (ACPI_SUCCESS (Status))
565     {
566         /*
567          * Store the result of the operation (which is now in ReturnDesc) into
568          * the Target descriptor.
569          */
570         Status = AcpiExStore (ReturnDesc, Operand[2], WalkState);
571         if (ACPI_FAILURE (Status))
572         {
573             goto Cleanup;
574         }
575 
576         if (!WalkState->ResultObj)
577         {
578             WalkState->ResultObj = ReturnDesc;
579         }
580     }
581 
582 
583 Cleanup:
584 
585     /* Delete return object on error */
586 
587     if (ACPI_FAILURE (Status))
588     {
589         AcpiUtRemoveReference (ReturnDesc);
590         WalkState->ResultObj = NULL;
591     }
592 
593     return_ACPI_STATUS (Status);
594 }
595 
596 
597 /*******************************************************************************
598  *
599  * FUNCTION:    AcpiExOpcode_2A_0T_1R
600  *
601  * PARAMETERS:  WalkState           - Current walk state
602  *
603  * RETURN:      Status
604  *
605  * DESCRIPTION: Execute opcode with 2 arguments, no target, and a return value
606  *
607  ******************************************************************************/
608 
609 ACPI_STATUS
610 AcpiExOpcode_2A_0T_1R (
611     ACPI_WALK_STATE         *WalkState)
612 {
613     ACPI_OPERAND_OBJECT     **Operand = &WalkState->Operands[0];
614     ACPI_OPERAND_OBJECT     *ReturnDesc = NULL;
615     ACPI_STATUS             Status = AE_OK;
616     BOOLEAN                 LogicalResult = FALSE;
617 
618 
619     ACPI_FUNCTION_TRACE_STR (ExOpcode_2A_0T_1R,
620         AcpiPsGetOpcodeName (WalkState->Opcode));
621 
622 
623     /* Create the internal return object */
624 
625     ReturnDesc = AcpiUtCreateInternalObject (ACPI_TYPE_INTEGER);
626     if (!ReturnDesc)
627     {
628         Status = AE_NO_MEMORY;
629         goto Cleanup;
630     }
631 
632     /* Execute the Opcode */
633 
634     if (WalkState->OpInfo->Flags & AML_LOGICAL_NUMERIC)
635     {
636         /* LogicalOp  (Operand0, Operand1) */
637 
638         Status = AcpiExDoLogicalNumericOp (WalkState->Opcode,
639                         Operand[0]->Integer.Value, Operand[1]->Integer.Value,
640                         &LogicalResult);
641         goto StoreLogicalResult;
642     }
643     else if (WalkState->OpInfo->Flags & AML_LOGICAL)
644     {
645         /* LogicalOp  (Operand0, Operand1) */
646 
647         Status = AcpiExDoLogicalOp (WalkState->Opcode, Operand[0],
648                     Operand[1], &LogicalResult);
649         goto StoreLogicalResult;
650     }
651 
652     switch (WalkState->Opcode)
653     {
654     case AML_ACQUIRE_OP:            /* Acquire (MutexObject, Timeout) */
655 
656         Status = AcpiExAcquireMutex (Operand[1], Operand[0], WalkState);
657         if (Status == AE_TIME)
658         {
659             LogicalResult = TRUE;       /* TRUE = Acquire timed out */
660             Status = AE_OK;
661         }
662         break;
663 
664 
665     case AML_WAIT_OP:               /* Wait (EventObject, Timeout) */
666 
667         Status = AcpiExSystemWaitEvent (Operand[1], Operand[0]);
668         if (Status == AE_TIME)
669         {
670             LogicalResult = TRUE;       /* TRUE, Wait timed out */
671             Status = AE_OK;
672         }
673         break;
674 
675 
676     default:
677 
678         ACPI_ERROR ((AE_INFO, "Unknown AML opcode 0x%X",
679             WalkState->Opcode));
680         Status = AE_AML_BAD_OPCODE;
681         goto Cleanup;
682     }
683 
684 
685 StoreLogicalResult:
686     /*
687      * Set return value to according to LogicalResult. logical TRUE (all ones)
688      * Default is FALSE (zero)
689      */
690     if (LogicalResult)
691     {
692         ReturnDesc->Integer.Value = ACPI_UINT64_MAX;
693     }
694 
695 Cleanup:
696 
697     /* Delete return object on error */
698 
699     if (ACPI_FAILURE (Status))
700     {
701         AcpiUtRemoveReference (ReturnDesc);
702     }
703 
704     /* Save return object on success */
705 
706     else
707     {
708         WalkState->ResultObj = ReturnDesc;
709     }
710 
711     return_ACPI_STATUS (Status);
712 }
713