1/******************************************************************************
2 *
3 * Module Name: dswexec - Dispatcher method execution callbacks;
4 *                        dispatch to interpreter.
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2015, Intel Corp.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions, and the following disclaimer,
17 *    without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 *    substantially similar to the "NO WARRANTY" disclaimer below
20 *    ("Disclaimer") and any redistribution must be conditioned upon
21 *    including a substantially similar Disclaimer requirement for further
22 *    binary redistribution.
23 * 3. Neither the names of the above-listed copyright holders nor the names
24 *    of any contributors may be used to endorse or promote products derived
25 *    from this software without specific prior written permission.
26 *
27 * Alternatively, this software may be distributed under the terms of the
28 * GNU General Public License ("GPL") version 2 as published by the Free
29 * Software Foundation.
30 *
31 * NO WARRANTY
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGES.
43 */
44
45#include <acpi/acpi.h>
46#include "accommon.h"
47#include "acparser.h"
48#include "amlcode.h"
49#include "acdispat.h"
50#include "acinterp.h"
51#include "acnamesp.h"
52#include "acdebug.h"
53
54#define _COMPONENT          ACPI_DISPATCHER
55ACPI_MODULE_NAME("dswexec")
56
57/*
58 * Dispatch table for opcode classes
59 */
60static acpi_execute_op acpi_gbl_op_type_dispatch[] = {
61	acpi_ex_opcode_0A_0T_1R,
62	acpi_ex_opcode_1A_0T_0R,
63	acpi_ex_opcode_1A_0T_1R,
64	acpi_ex_opcode_1A_1T_0R,
65	acpi_ex_opcode_1A_1T_1R,
66	acpi_ex_opcode_2A_0T_0R,
67	acpi_ex_opcode_2A_0T_1R,
68	acpi_ex_opcode_2A_1T_1R,
69	acpi_ex_opcode_2A_2T_1R,
70	acpi_ex_opcode_3A_0T_0R,
71	acpi_ex_opcode_3A_1T_1R,
72	acpi_ex_opcode_6A_0T_1R
73};
74
75/*****************************************************************************
76 *
77 * FUNCTION:    acpi_ds_get_predicate_value
78 *
79 * PARAMETERS:  walk_state      - Current state of the parse tree walk
80 *              result_obj      - if non-zero, pop result from result stack
81 *
82 * RETURN:      Status
83 *
84 * DESCRIPTION: Get the result of a predicate evaluation
85 *
86 ****************************************************************************/
87
88acpi_status
89acpi_ds_get_predicate_value(struct acpi_walk_state *walk_state,
90			    union acpi_operand_object *result_obj)
91{
92	acpi_status status = AE_OK;
93	union acpi_operand_object *obj_desc;
94	union acpi_operand_object *local_obj_desc = NULL;
95
96	ACPI_FUNCTION_TRACE_PTR(ds_get_predicate_value, walk_state);
97
98	walk_state->control_state->common.state = 0;
99
100	if (result_obj) {
101		status = acpi_ds_result_pop(&obj_desc, walk_state);
102		if (ACPI_FAILURE(status)) {
103			ACPI_EXCEPTION((AE_INFO, status,
104					"Could not get result from predicate evaluation"));
105
106			return_ACPI_STATUS(status);
107		}
108	} else {
109		status = acpi_ds_create_operand(walk_state, walk_state->op, 0);
110		if (ACPI_FAILURE(status)) {
111			return_ACPI_STATUS(status);
112		}
113
114		status =
115		    acpi_ex_resolve_to_value(&walk_state->operands[0],
116					     walk_state);
117		if (ACPI_FAILURE(status)) {
118			return_ACPI_STATUS(status);
119		}
120
121		obj_desc = walk_state->operands[0];
122	}
123
124	if (!obj_desc) {
125		ACPI_ERROR((AE_INFO,
126			    "No predicate ObjDesc=%p State=%p",
127			    obj_desc, walk_state));
128
129		return_ACPI_STATUS(AE_AML_NO_OPERAND);
130	}
131
132	/*
133	 * Result of predicate evaluation must be an Integer
134	 * object. Implicitly convert the argument if necessary.
135	 */
136	status = acpi_ex_convert_to_integer(obj_desc, &local_obj_desc, 16);
137	if (ACPI_FAILURE(status)) {
138		goto cleanup;
139	}
140
141	if (local_obj_desc->common.type != ACPI_TYPE_INTEGER) {
142		ACPI_ERROR((AE_INFO,
143			    "Bad predicate (not an integer) ObjDesc=%p State=%p Type=0x%X",
144			    obj_desc, walk_state, obj_desc->common.type));
145
146		status = AE_AML_OPERAND_TYPE;
147		goto cleanup;
148	}
149
150	/* Truncate the predicate to 32-bits if necessary */
151
152	(void)acpi_ex_truncate_for32bit_table(local_obj_desc);
153
154	/*
155	 * Save the result of the predicate evaluation on
156	 * the control stack
157	 */
158	if (local_obj_desc->integer.value) {
159		walk_state->control_state->common.value = TRUE;
160	} else {
161		/*
162		 * Predicate is FALSE, we will just toss the
163		 * rest of the package
164		 */
165		walk_state->control_state->common.value = FALSE;
166		status = AE_CTRL_FALSE;
167	}
168
169	/* Predicate can be used for an implicit return value */
170
171	(void)acpi_ds_do_implicit_return(local_obj_desc, walk_state, TRUE);
172
173cleanup:
174
175	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Completed a predicate eval=%X Op=%p\n",
176			  walk_state->control_state->common.value,
177			  walk_state->op));
178
179	/* Break to debugger to display result */
180
181	ACPI_DEBUGGER_EXEC(acpi_db_display_result_object
182			   (local_obj_desc, walk_state));
183
184	/*
185	 * Delete the predicate result object (we know that
186	 * we don't need it anymore)
187	 */
188	if (local_obj_desc != obj_desc) {
189		acpi_ut_remove_reference(local_obj_desc);
190	}
191	acpi_ut_remove_reference(obj_desc);
192
193	walk_state->control_state->common.state = ACPI_CONTROL_NORMAL;
194	return_ACPI_STATUS(status);
195}
196
197/*****************************************************************************
198 *
199 * FUNCTION:    acpi_ds_exec_begin_op
200 *
201 * PARAMETERS:  walk_state      - Current state of the parse tree walk
202 *              out_op          - Where to return op if a new one is created
203 *
204 * RETURN:      Status
205 *
206 * DESCRIPTION: Descending callback used during the execution of control
207 *              methods. This is where most operators and operands are
208 *              dispatched to the interpreter.
209 *
210 ****************************************************************************/
211
212acpi_status
213acpi_ds_exec_begin_op(struct acpi_walk_state *walk_state,
214		      union acpi_parse_object **out_op)
215{
216	union acpi_parse_object *op;
217	acpi_status status = AE_OK;
218	u32 opcode_class;
219
220	ACPI_FUNCTION_TRACE_PTR(ds_exec_begin_op, walk_state);
221
222	op = walk_state->op;
223	if (!op) {
224		status = acpi_ds_load2_begin_op(walk_state, out_op);
225		if (ACPI_FAILURE(status)) {
226			goto error_exit;
227		}
228
229		op = *out_op;
230		walk_state->op = op;
231		walk_state->opcode = op->common.aml_opcode;
232		walk_state->op_info =
233		    acpi_ps_get_opcode_info(op->common.aml_opcode);
234
235		if (acpi_ns_opens_scope(walk_state->op_info->object_type)) {
236			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
237					  "(%s) Popping scope for Op %p\n",
238					  acpi_ut_get_type_name(walk_state->
239								op_info->
240								object_type),
241					  op));
242
243			status = acpi_ds_scope_stack_pop(walk_state);
244			if (ACPI_FAILURE(status)) {
245				goto error_exit;
246			}
247		}
248	}
249
250	if (op == walk_state->origin) {
251		if (out_op) {
252			*out_op = op;
253		}
254
255		return_ACPI_STATUS(AE_OK);
256	}
257
258	/*
259	 * If the previous opcode was a conditional, this opcode
260	 * must be the beginning of the associated predicate.
261	 * Save this knowledge in the current scope descriptor
262	 */
263	if ((walk_state->control_state) &&
264	    (walk_state->control_state->common.state ==
265	     ACPI_CONTROL_CONDITIONAL_EXECUTING)) {
266		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
267				  "Exec predicate Op=%p State=%p\n", op,
268				  walk_state));
269
270		walk_state->control_state->common.state =
271		    ACPI_CONTROL_PREDICATE_EXECUTING;
272
273		/* Save start of predicate */
274
275		walk_state->control_state->control.predicate_op = op;
276	}
277
278	opcode_class = walk_state->op_info->class;
279
280	/* We want to send namepaths to the load code */
281
282	if (op->common.aml_opcode == AML_INT_NAMEPATH_OP) {
283		opcode_class = AML_CLASS_NAMED_OBJECT;
284	}
285
286	/*
287	 * Handle the opcode based upon the opcode type
288	 */
289	switch (opcode_class) {
290	case AML_CLASS_CONTROL:
291
292		status = acpi_ds_exec_begin_control_op(walk_state, op);
293		break;
294
295	case AML_CLASS_NAMED_OBJECT:
296
297		if (walk_state->walk_type & ACPI_WALK_METHOD) {
298			/*
299			 * Found a named object declaration during method execution;
300			 * we must enter this object into the namespace. The created
301			 * object is temporary and will be deleted upon completion of
302			 * the execution of this method.
303			 *
304			 * Note 10/2010: Except for the Scope() op. This opcode does
305			 * not actually create a new object, it refers to an existing
306			 * object. However, for Scope(), we want to indeed open a
307			 * new scope.
308			 */
309			if (op->common.aml_opcode != AML_SCOPE_OP) {
310				status =
311				    acpi_ds_load2_begin_op(walk_state, NULL);
312			} else {
313				status =
314				    acpi_ds_scope_stack_push(op->named.node,
315							     op->named.node->
316							     type, walk_state);
317				if (ACPI_FAILURE(status)) {
318					return_ACPI_STATUS(status);
319				}
320			}
321		}
322		break;
323
324	case AML_CLASS_EXECUTE:
325	case AML_CLASS_CREATE:
326
327		break;
328
329	default:
330
331		break;
332	}
333
334	/* Nothing to do here during method execution */
335
336	return_ACPI_STATUS(status);
337
338error_exit:
339	status = acpi_ds_method_error(status, walk_state);
340	return_ACPI_STATUS(status);
341}
342
343/*****************************************************************************
344 *
345 * FUNCTION:    acpi_ds_exec_end_op
346 *
347 * PARAMETERS:  walk_state      - Current state of the parse tree walk
348 *
349 * RETURN:      Status
350 *
351 * DESCRIPTION: Ascending callback used during the execution of control
352 *              methods. The only thing we really need to do here is to
353 *              notice the beginning of IF, ELSE, and WHILE blocks.
354 *
355 ****************************************************************************/
356
357acpi_status acpi_ds_exec_end_op(struct acpi_walk_state *walk_state)
358{
359	union acpi_parse_object *op;
360	acpi_status status = AE_OK;
361	u32 op_type;
362	u32 op_class;
363	union acpi_parse_object *next_op;
364	union acpi_parse_object *first_arg;
365
366	ACPI_FUNCTION_TRACE_PTR(ds_exec_end_op, walk_state);
367
368	op = walk_state->op;
369	op_type = walk_state->op_info->type;
370	op_class = walk_state->op_info->class;
371
372	if (op_class == AML_CLASS_UNKNOWN) {
373		ACPI_ERROR((AE_INFO, "Unknown opcode 0x%X",
374			    op->common.aml_opcode));
375		return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
376	}
377
378	first_arg = op->common.value.arg;
379
380	/* Init the walk state */
381
382	walk_state->num_operands = 0;
383	walk_state->operand_index = 0;
384	walk_state->return_desc = NULL;
385	walk_state->result_obj = NULL;
386
387	/* Call debugger for single step support (DEBUG build only) */
388
389	ACPI_DEBUGGER_EXEC(status =
390			   acpi_db_single_step(walk_state, op, op_class));
391	ACPI_DEBUGGER_EXEC(if (ACPI_FAILURE(status)) {
392			   return_ACPI_STATUS(status);}
393	) ;
394
395	/* Decode the Opcode Class */
396
397	switch (op_class) {
398	case AML_CLASS_ARGUMENT:	/* Constants, literals, etc. */
399
400		if (walk_state->opcode == AML_INT_NAMEPATH_OP) {
401			status = acpi_ds_evaluate_name_path(walk_state);
402			if (ACPI_FAILURE(status)) {
403				goto cleanup;
404			}
405		}
406		break;
407
408	case AML_CLASS_EXECUTE:	/* Most operators with arguments */
409
410		/* Build resolved operand stack */
411
412		status = acpi_ds_create_operands(walk_state, first_arg);
413		if (ACPI_FAILURE(status)) {
414			goto cleanup;
415		}
416
417		/*
418		 * All opcodes require operand resolution, with the only exceptions
419		 * being the object_type and size_of operators.
420		 */
421		if (!(walk_state->op_info->flags & AML_NO_OPERAND_RESOLVE)) {
422
423			/* Resolve all operands */
424
425			status = acpi_ex_resolve_operands(walk_state->opcode,
426							  &(walk_state->
427							    operands
428							    [walk_state->
429							     num_operands - 1]),
430							  walk_state);
431		}
432
433		if (ACPI_SUCCESS(status)) {
434			/*
435			 * Dispatch the request to the appropriate interpreter handler
436			 * routine. There is one routine per opcode "type" based upon the
437			 * number of opcode arguments and return type.
438			 */
439			status =
440			    acpi_gbl_op_type_dispatch[op_type] (walk_state);
441		} else {
442			/*
443			 * Treat constructs of the form "Store(LocalX,LocalX)" as noops when the
444			 * Local is uninitialized.
445			 */
446			if ((status == AE_AML_UNINITIALIZED_LOCAL) &&
447			    (walk_state->opcode == AML_STORE_OP) &&
448			    (walk_state->operands[0]->common.type ==
449			     ACPI_TYPE_LOCAL_REFERENCE)
450			    && (walk_state->operands[1]->common.type ==
451				ACPI_TYPE_LOCAL_REFERENCE)
452			    && (walk_state->operands[0]->reference.class ==
453				walk_state->operands[1]->reference.class)
454			    && (walk_state->operands[0]->reference.value ==
455				walk_state->operands[1]->reference.value)) {
456				status = AE_OK;
457			} else {
458				ACPI_EXCEPTION((AE_INFO, status,
459						"While resolving operands for [%s]",
460						acpi_ps_get_opcode_name
461						(walk_state->opcode)));
462			}
463		}
464
465		/* Always delete the argument objects and clear the operand stack */
466
467		acpi_ds_clear_operands(walk_state);
468
469		/*
470		 * If a result object was returned from above, push it on the
471		 * current result stack
472		 */
473		if (ACPI_SUCCESS(status) && walk_state->result_obj) {
474			status =
475			    acpi_ds_result_push(walk_state->result_obj,
476						walk_state);
477		}
478		break;
479
480	default:
481
482		switch (op_type) {
483		case AML_TYPE_CONTROL:	/* Type 1 opcode, IF/ELSE/WHILE/NOOP */
484
485			/* 1 Operand, 0 external_result, 0 internal_result */
486
487			status = acpi_ds_exec_end_control_op(walk_state, op);
488
489			break;
490
491		case AML_TYPE_METHOD_CALL:
492			/*
493			 * If the method is referenced from within a package
494			 * declaration, it is not a invocation of the method, just
495			 * a reference to it.
496			 */
497			if ((op->asl.parent) &&
498			    ((op->asl.parent->asl.aml_opcode == AML_PACKAGE_OP)
499			     || (op->asl.parent->asl.aml_opcode ==
500				 AML_VAR_PACKAGE_OP))) {
501				ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
502						  "Method Reference in a Package, Op=%p\n",
503						  op));
504
505				op->common.node =
506				    (struct acpi_namespace_node *)op->asl.value.
507				    arg->asl.node;
508				acpi_ut_add_reference(op->asl.value.arg->asl.
509						      node->object);
510				return_ACPI_STATUS(AE_OK);
511			}
512
513			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
514					  "Method invocation, Op=%p\n", op));
515
516			/*
517			 * (AML_METHODCALL) Op->Asl.Value.Arg->Asl.Node contains
518			 * the method Node pointer
519			 */
520			/* next_op points to the op that holds the method name */
521
522			next_op = first_arg;
523
524			/* next_op points to first argument op */
525
526			next_op = next_op->common.next;
527
528			/*
529			 * Get the method's arguments and put them on the operand stack
530			 */
531			status = acpi_ds_create_operands(walk_state, next_op);
532			if (ACPI_FAILURE(status)) {
533				break;
534			}
535
536			/*
537			 * Since the operands will be passed to another control method,
538			 * we must resolve all local references here (Local variables,
539			 * arguments to *this* method, etc.)
540			 */
541			status = acpi_ds_resolve_operands(walk_state);
542			if (ACPI_FAILURE(status)) {
543
544				/* On error, clear all resolved operands */
545
546				acpi_ds_clear_operands(walk_state);
547				break;
548			}
549
550			/*
551			 * Tell the walk loop to preempt this running method and
552			 * execute the new method
553			 */
554			status = AE_CTRL_TRANSFER;
555
556			/*
557			 * Return now; we don't want to disturb anything,
558			 * especially the operand count!
559			 */
560			return_ACPI_STATUS(status);
561
562		case AML_TYPE_CREATE_FIELD:
563
564			ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
565					  "Executing CreateField Buffer/Index Op=%p\n",
566					  op));
567
568			status = acpi_ds_load2_end_op(walk_state);
569			if (ACPI_FAILURE(status)) {
570				break;
571			}
572
573			status =
574			    acpi_ds_eval_buffer_field_operands(walk_state, op);
575			break;
576
577		case AML_TYPE_CREATE_OBJECT:
578
579			ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
580					  "Executing CreateObject (Buffer/Package) Op=%p\n",
581					  op));
582
583			switch (op->common.parent->common.aml_opcode) {
584			case AML_NAME_OP:
585				/*
586				 * Put the Node on the object stack (Contains the ACPI Name
587				 * of this object)
588				 */
589				walk_state->operands[0] =
590				    (void *)op->common.parent->common.node;
591				walk_state->num_operands = 1;
592
593				status = acpi_ds_create_node(walk_state,
594							     op->common.parent->
595							     common.node,
596							     op->common.parent);
597				if (ACPI_FAILURE(status)) {
598					break;
599				}
600
601				/* Fall through */
602				/*lint -fallthrough */
603
604			case AML_INT_EVAL_SUBTREE_OP:
605
606				status =
607				    acpi_ds_eval_data_object_operands
608				    (walk_state, op,
609				     acpi_ns_get_attached_object(op->common.
610								 parent->common.
611								 node));
612				break;
613
614			default:
615
616				status =
617				    acpi_ds_eval_data_object_operands
618				    (walk_state, op, NULL);
619				break;
620			}
621
622			/*
623			 * If a result object was returned from above, push it on the
624			 * current result stack
625			 */
626			if (walk_state->result_obj) {
627				status =
628				    acpi_ds_result_push(walk_state->result_obj,
629							walk_state);
630			}
631			break;
632
633		case AML_TYPE_NAMED_FIELD:
634		case AML_TYPE_NAMED_COMPLEX:
635		case AML_TYPE_NAMED_SIMPLE:
636		case AML_TYPE_NAMED_NO_OBJ:
637
638			status = acpi_ds_load2_end_op(walk_state);
639			if (ACPI_FAILURE(status)) {
640				break;
641			}
642
643			if (op->common.aml_opcode == AML_REGION_OP) {
644				ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
645						  "Executing OpRegion Address/Length Op=%p\n",
646						  op));
647
648				status =
649				    acpi_ds_eval_region_operands(walk_state,
650								 op);
651				if (ACPI_FAILURE(status)) {
652					break;
653				}
654			} else if (op->common.aml_opcode == AML_DATA_REGION_OP) {
655				ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
656						  "Executing DataTableRegion Strings Op=%p\n",
657						  op));
658
659				status =
660				    acpi_ds_eval_table_region_operands
661				    (walk_state, op);
662				if (ACPI_FAILURE(status)) {
663					break;
664				}
665			} else if (op->common.aml_opcode == AML_BANK_FIELD_OP) {
666				ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
667						  "Executing BankField Op=%p\n",
668						  op));
669
670				status =
671				    acpi_ds_eval_bank_field_operands(walk_state,
672								     op);
673				if (ACPI_FAILURE(status)) {
674					break;
675				}
676			}
677			break;
678
679		case AML_TYPE_UNDEFINED:
680
681			ACPI_ERROR((AE_INFO,
682				    "Undefined opcode type Op=%p", op));
683			return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
684
685		case AML_TYPE_BOGUS:
686
687			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
688					  "Internal opcode=%X type Op=%p\n",
689					  walk_state->opcode, op));
690			break;
691
692		default:
693
694			ACPI_ERROR((AE_INFO,
695				    "Unimplemented opcode, class=0x%X type=0x%X Opcode=0x%X Op=%p",
696				    op_class, op_type, op->common.aml_opcode,
697				    op));
698
699			status = AE_NOT_IMPLEMENTED;
700			break;
701		}
702	}
703
704	/*
705	 * ACPI 2.0 support for 64-bit integers: Truncate numeric
706	 * result value if we are executing from a 32-bit ACPI table
707	 */
708	(void)acpi_ex_truncate_for32bit_table(walk_state->result_obj);
709
710	/*
711	 * Check if we just completed the evaluation of a
712	 * conditional predicate
713	 */
714	if ((ACPI_SUCCESS(status)) &&
715	    (walk_state->control_state) &&
716	    (walk_state->control_state->common.state ==
717	     ACPI_CONTROL_PREDICATE_EXECUTING) &&
718	    (walk_state->control_state->control.predicate_op == op)) {
719		status =
720		    acpi_ds_get_predicate_value(walk_state,
721						walk_state->result_obj);
722		walk_state->result_obj = NULL;
723	}
724
725cleanup:
726
727	if (walk_state->result_obj) {
728
729		/* Break to debugger to display result */
730
731		ACPI_DEBUGGER_EXEC(acpi_db_display_result_object
732				   (walk_state->result_obj, walk_state));
733
734		/*
735		 * Delete the result op if and only if:
736		 * Parent will not use the result -- such as any
737		 * non-nested type2 op in a method (parent will be method)
738		 */
739		acpi_ds_delete_result_if_not_used(op, walk_state->result_obj,
740						  walk_state);
741	}
742#ifdef _UNDER_DEVELOPMENT
743
744	if (walk_state->parser_state.aml == walk_state->parser_state.aml_end) {
745		acpi_db_method_end(walk_state);
746	}
747#endif
748
749	/* Invoke exception handler on error */
750
751	if (ACPI_FAILURE(status)) {
752		status = acpi_ds_method_error(status, walk_state);
753	}
754
755	/* Always clear the object stack */
756
757	walk_state->num_operands = 0;
758	return_ACPI_STATUS(status);
759}
760