xref: /openbmc/linux/drivers/acpi/acpica/dswexec.c (revision 65844828)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3  *
4  * Module Name: dswexec - Dispatcher method execution callbacks;
5  *                        dispatch to interpreter.
6  *
7  * Copyright (C) 2000 - 2022, Intel Corp.
8  *
9  *****************************************************************************/
10 
11 #include <acpi/acpi.h>
12 #include "accommon.h"
13 #include "acparser.h"
14 #include "amlcode.h"
15 #include "acdispat.h"
16 #include "acinterp.h"
17 #include "acnamesp.h"
18 #include "acdebug.h"
19 #ifdef ACPI_EXEC_APP
20 #include "aecommon.h"
21 #endif
22 
23 #define _COMPONENT          ACPI_DISPATCHER
24 ACPI_MODULE_NAME("dswexec")
25 
26 /*
27  * Dispatch table for opcode classes
28  */
29 static acpi_execute_op acpi_gbl_op_type_dispatch[] = {
30 	acpi_ex_opcode_0A_0T_1R,
31 	acpi_ex_opcode_1A_0T_0R,
32 	acpi_ex_opcode_1A_0T_1R,
33 	NULL,			/* Was: acpi_ex_opcode_1A_0T_0R (Was for Load operator) */
34 	acpi_ex_opcode_1A_1T_1R,
35 	acpi_ex_opcode_2A_0T_0R,
36 	acpi_ex_opcode_2A_0T_1R,
37 	acpi_ex_opcode_2A_1T_1R,
38 	acpi_ex_opcode_2A_2T_1R,
39 	acpi_ex_opcode_3A_0T_0R,
40 	acpi_ex_opcode_3A_1T_1R,
41 	acpi_ex_opcode_6A_0T_1R
42 };
43 
44 /*****************************************************************************
45  *
46  * FUNCTION:    acpi_ds_get_predicate_value
47  *
48  * PARAMETERS:  walk_state      - Current state of the parse tree walk
49  *              result_obj      - if non-zero, pop result from result stack
50  *
51  * RETURN:      Status
52  *
53  * DESCRIPTION: Get the result of a predicate evaluation
54  *
55  ****************************************************************************/
56 
57 acpi_status
58 acpi_ds_get_predicate_value(struct acpi_walk_state *walk_state,
59 			    union acpi_operand_object *result_obj)
60 {
61 	acpi_status status = AE_OK;
62 	union acpi_operand_object *obj_desc;
63 	union acpi_operand_object *local_obj_desc = NULL;
64 
65 	ACPI_FUNCTION_TRACE_PTR(ds_get_predicate_value, walk_state);
66 
67 	walk_state->control_state->common.state = 0;
68 
69 	if (result_obj) {
70 		status = acpi_ds_result_pop(&obj_desc, walk_state);
71 		if (ACPI_FAILURE(status)) {
72 			ACPI_EXCEPTION((AE_INFO, status,
73 					"Could not get result from predicate evaluation"));
74 
75 			return_ACPI_STATUS(status);
76 		}
77 	} else {
78 		status = acpi_ds_create_operand(walk_state, walk_state->op, 0);
79 		if (ACPI_FAILURE(status)) {
80 			return_ACPI_STATUS(status);
81 		}
82 
83 		status =
84 		    acpi_ex_resolve_to_value(&walk_state->operands[0],
85 					     walk_state);
86 		if (ACPI_FAILURE(status)) {
87 			return_ACPI_STATUS(status);
88 		}
89 
90 		obj_desc = walk_state->operands[0];
91 	}
92 
93 	if (!obj_desc) {
94 		ACPI_ERROR((AE_INFO,
95 			    "No predicate ObjDesc=%p State=%p",
96 			    obj_desc, walk_state));
97 
98 		return_ACPI_STATUS(AE_AML_NO_OPERAND);
99 	}
100 
101 	/*
102 	 * Result of predicate evaluation must be an Integer
103 	 * object. Implicitly convert the argument if necessary.
104 	 */
105 	status = acpi_ex_convert_to_integer(obj_desc, &local_obj_desc,
106 					    ACPI_IMPLICIT_CONVERSION);
107 	if (ACPI_FAILURE(status)) {
108 		goto cleanup;
109 	}
110 
111 	if (local_obj_desc->common.type != ACPI_TYPE_INTEGER) {
112 		ACPI_ERROR((AE_INFO,
113 			    "Bad predicate (not an integer) ObjDesc=%p State=%p Type=0x%X",
114 			    obj_desc, walk_state, obj_desc->common.type));
115 
116 		status = AE_AML_OPERAND_TYPE;
117 		goto cleanup;
118 	}
119 
120 	/* Truncate the predicate to 32-bits if necessary */
121 
122 	(void)acpi_ex_truncate_for32bit_table(local_obj_desc);
123 
124 	/*
125 	 * Save the result of the predicate evaluation on
126 	 * the control stack
127 	 */
128 	if (local_obj_desc->integer.value) {
129 		walk_state->control_state->common.value = TRUE;
130 	} else {
131 		/*
132 		 * Predicate is FALSE, we will just toss the
133 		 * rest of the package
134 		 */
135 		walk_state->control_state->common.value = FALSE;
136 		status = AE_CTRL_FALSE;
137 	}
138 
139 	/* Predicate can be used for an implicit return value */
140 
141 	(void)acpi_ds_do_implicit_return(local_obj_desc, walk_state, TRUE);
142 
143 cleanup:
144 
145 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
146 			  "Completed a predicate eval=%X Op=%p\n",
147 			  walk_state->control_state->common.value,
148 			  walk_state->op));
149 
150 	/* Break to debugger to display result */
151 
152 	acpi_db_display_result_object(local_obj_desc, walk_state);
153 
154 	/*
155 	 * Delete the predicate result object (we know that
156 	 * we don't need it anymore)
157 	 */
158 	if (local_obj_desc != obj_desc) {
159 		acpi_ut_remove_reference(local_obj_desc);
160 	}
161 	acpi_ut_remove_reference(obj_desc);
162 
163 	walk_state->control_state->common.state = ACPI_CONTROL_NORMAL;
164 	return_ACPI_STATUS(status);
165 }
166 
167 /*****************************************************************************
168  *
169  * FUNCTION:    acpi_ds_exec_begin_op
170  *
171  * PARAMETERS:  walk_state      - Current state of the parse tree walk
172  *              out_op          - Where to return op if a new one is created
173  *
174  * RETURN:      Status
175  *
176  * DESCRIPTION: Descending callback used during the execution of control
177  *              methods. This is where most operators and operands are
178  *              dispatched to the interpreter.
179  *
180  ****************************************************************************/
181 
182 acpi_status
183 acpi_ds_exec_begin_op(struct acpi_walk_state *walk_state,
184 		      union acpi_parse_object **out_op)
185 {
186 	union acpi_parse_object *op;
187 	acpi_status status = AE_OK;
188 	u32 opcode_class;
189 
190 	ACPI_FUNCTION_TRACE_PTR(ds_exec_begin_op, walk_state);
191 
192 	op = walk_state->op;
193 	if (!op) {
194 		status = acpi_ds_load2_begin_op(walk_state, out_op);
195 		if (ACPI_FAILURE(status)) {
196 			goto error_exit;
197 		}
198 
199 		op = *out_op;
200 		walk_state->op = op;
201 		walk_state->opcode = op->common.aml_opcode;
202 		walk_state->op_info =
203 		    acpi_ps_get_opcode_info(op->common.aml_opcode);
204 
205 		if (acpi_ns_opens_scope(walk_state->op_info->object_type)) {
206 			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
207 					  "(%s) Popping scope for Op %p\n",
208 					  acpi_ut_get_type_name(walk_state->
209 								op_info->
210 								object_type),
211 					  op));
212 
213 			status = acpi_ds_scope_stack_pop(walk_state);
214 			if (ACPI_FAILURE(status)) {
215 				goto error_exit;
216 			}
217 		}
218 	}
219 
220 	if (op == walk_state->origin) {
221 		if (out_op) {
222 			*out_op = op;
223 		}
224 
225 		return_ACPI_STATUS(AE_OK);
226 	}
227 
228 	/*
229 	 * If the previous opcode was a conditional, this opcode
230 	 * must be the beginning of the associated predicate.
231 	 * Save this knowledge in the current scope descriptor
232 	 */
233 	if ((walk_state->control_state) &&
234 	    (walk_state->control_state->common.state ==
235 	     ACPI_CONTROL_CONDITIONAL_EXECUTING)) {
236 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
237 				  "Exec predicate Op=%p State=%p\n",
238 				  op, walk_state));
239 
240 		walk_state->control_state->common.state =
241 		    ACPI_CONTROL_PREDICATE_EXECUTING;
242 
243 		/* Save start of predicate */
244 
245 		walk_state->control_state->control.predicate_op = op;
246 	}
247 
248 	opcode_class = walk_state->op_info->class;
249 
250 	/* We want to send namepaths to the load code */
251 
252 	if (op->common.aml_opcode == AML_INT_NAMEPATH_OP) {
253 		opcode_class = AML_CLASS_NAMED_OBJECT;
254 	}
255 
256 	/*
257 	 * Handle the opcode based upon the opcode type
258 	 */
259 	switch (opcode_class) {
260 	case AML_CLASS_CONTROL:
261 
262 		status = acpi_ds_exec_begin_control_op(walk_state, op);
263 		break;
264 
265 	case AML_CLASS_NAMED_OBJECT:
266 
267 		if (walk_state->walk_type & ACPI_WALK_METHOD) {
268 			/*
269 			 * Found a named object declaration during method execution;
270 			 * we must enter this object into the namespace. The created
271 			 * object is temporary and will be deleted upon completion of
272 			 * the execution of this method.
273 			 *
274 			 * Note 10/2010: Except for the Scope() op. This opcode does
275 			 * not actually create a new object, it refers to an existing
276 			 * object. However, for Scope(), we want to indeed open a
277 			 * new scope.
278 			 */
279 			if (op->common.aml_opcode != AML_SCOPE_OP) {
280 				status =
281 				    acpi_ds_load2_begin_op(walk_state, NULL);
282 			} else {
283 				status =
284 				    acpi_ds_scope_stack_push(op->named.node,
285 							     op->named.node->
286 							     type, walk_state);
287 				if (ACPI_FAILURE(status)) {
288 					return_ACPI_STATUS(status);
289 				}
290 			}
291 		}
292 		break;
293 
294 	case AML_CLASS_EXECUTE:
295 	case AML_CLASS_CREATE:
296 
297 		break;
298 
299 	default:
300 
301 		break;
302 	}
303 
304 	/* Nothing to do here during method execution */
305 
306 	return_ACPI_STATUS(status);
307 
308 error_exit:
309 	status = acpi_ds_method_error(status, walk_state);
310 	return_ACPI_STATUS(status);
311 }
312 
313 /*****************************************************************************
314  *
315  * FUNCTION:    acpi_ds_exec_end_op
316  *
317  * PARAMETERS:  walk_state      - Current state of the parse tree walk
318  *
319  * RETURN:      Status
320  *
321  * DESCRIPTION: Ascending callback used during the execution of control
322  *              methods. The only thing we really need to do here is to
323  *              notice the beginning of IF, ELSE, and WHILE blocks.
324  *
325  ****************************************************************************/
326 
327 acpi_status acpi_ds_exec_end_op(struct acpi_walk_state *walk_state)
328 {
329 	union acpi_parse_object *op;
330 	acpi_status status = AE_OK;
331 	u32 op_type;
332 	u32 op_class;
333 	union acpi_parse_object *next_op;
334 	union acpi_parse_object *first_arg;
335 #ifdef ACPI_EXEC_APP
336 	char *namepath;
337 	union acpi_operand_object *obj_desc;
338 #endif
339 
340 	ACPI_FUNCTION_TRACE_PTR(ds_exec_end_op, walk_state);
341 
342 	op = walk_state->op;
343 	op_type = walk_state->op_info->type;
344 	op_class = walk_state->op_info->class;
345 
346 	if (op_class == AML_CLASS_UNKNOWN) {
347 		ACPI_ERROR((AE_INFO, "Unknown opcode 0x%X",
348 			    op->common.aml_opcode));
349 		return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
350 	}
351 
352 	first_arg = op->common.value.arg;
353 
354 	/* Init the walk state */
355 
356 	walk_state->num_operands = 0;
357 	walk_state->operand_index = 0;
358 	walk_state->return_desc = NULL;
359 	walk_state->result_obj = NULL;
360 
361 	/* Call debugger for single step support (DEBUG build only) */
362 
363 	status = acpi_db_single_step(walk_state, op, op_class);
364 	if (ACPI_FAILURE(status)) {
365 		return_ACPI_STATUS(status);
366 	}
367 
368 	/* Decode the Opcode Class */
369 
370 	switch (op_class) {
371 	case AML_CLASS_ARGUMENT:	/* Constants, literals, etc. */
372 
373 		if (walk_state->opcode == AML_INT_NAMEPATH_OP) {
374 			status = acpi_ds_evaluate_name_path(walk_state);
375 			if (ACPI_FAILURE(status)) {
376 				goto cleanup;
377 			}
378 		}
379 		break;
380 
381 	case AML_CLASS_EXECUTE:	/* Most operators with arguments */
382 
383 		/* Build resolved operand stack */
384 
385 		status = acpi_ds_create_operands(walk_state, first_arg);
386 		if (ACPI_FAILURE(status)) {
387 			goto cleanup;
388 		}
389 
390 		/*
391 		 * All opcodes require operand resolution, with the only exceptions
392 		 * being the object_type and size_of operators as well as opcodes that
393 		 * take no arguments.
394 		 */
395 		if (!(walk_state->op_info->flags & AML_NO_OPERAND_RESOLVE) &&
396 		    (walk_state->op_info->flags & AML_HAS_ARGS)) {
397 
398 			/* Resolve all operands */
399 
400 			status = acpi_ex_resolve_operands(walk_state->opcode,
401 							  &(walk_state->
402 							    operands
403 							    [walk_state->
404 							     num_operands - 1]),
405 							  walk_state);
406 		}
407 
408 		if (ACPI_SUCCESS(status)) {
409 			/*
410 			 * Dispatch the request to the appropriate interpreter handler
411 			 * routine. There is one routine per opcode "type" based upon the
412 			 * number of opcode arguments and return type.
413 			 */
414 			status =
415 			    acpi_gbl_op_type_dispatch[op_type] (walk_state);
416 		} else {
417 			/*
418 			 * Treat constructs of the form "Store(LocalX,LocalX)" as noops when the
419 			 * Local is uninitialized.
420 			 */
421 			if ((status == AE_AML_UNINITIALIZED_LOCAL) &&
422 			    (walk_state->opcode == AML_STORE_OP) &&
423 			    (walk_state->operands[0]->common.type ==
424 			     ACPI_TYPE_LOCAL_REFERENCE)
425 			    && (walk_state->operands[1]->common.type ==
426 				ACPI_TYPE_LOCAL_REFERENCE)
427 			    && (walk_state->operands[0]->reference.class ==
428 				walk_state->operands[1]->reference.class)
429 			    && (walk_state->operands[0]->reference.value ==
430 				walk_state->operands[1]->reference.value)) {
431 				status = AE_OK;
432 			} else {
433 				ACPI_EXCEPTION((AE_INFO, status,
434 						"While resolving operands for [%s]",
435 						acpi_ps_get_opcode_name
436 						(walk_state->opcode)));
437 			}
438 		}
439 
440 		/* Always delete the argument objects and clear the operand stack */
441 
442 		acpi_ds_clear_operands(walk_state);
443 
444 		/*
445 		 * If a result object was returned from above, push it on the
446 		 * current result stack
447 		 */
448 		if (ACPI_SUCCESS(status) && walk_state->result_obj) {
449 			status =
450 			    acpi_ds_result_push(walk_state->result_obj,
451 						walk_state);
452 		}
453 		break;
454 
455 	default:
456 
457 		switch (op_type) {
458 		case AML_TYPE_CONTROL:	/* Type 1 opcode, IF/ELSE/WHILE/NOOP */
459 
460 			/* 1 Operand, 0 external_result, 0 internal_result */
461 
462 			status = acpi_ds_exec_end_control_op(walk_state, op);
463 
464 			break;
465 
466 		case AML_TYPE_METHOD_CALL:
467 			/*
468 			 * If the method is referenced from within a package
469 			 * declaration, it is not a invocation of the method, just
470 			 * a reference to it.
471 			 */
472 			if ((op->asl.parent) &&
473 			    ((op->asl.parent->asl.aml_opcode == AML_PACKAGE_OP)
474 			     || (op->asl.parent->asl.aml_opcode ==
475 				 AML_VARIABLE_PACKAGE_OP))) {
476 				ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
477 						  "Method Reference in a Package, Op=%p\n",
478 						  op));
479 
480 				op->common.node = (struct acpi_namespace_node *)
481 				    op->asl.value.arg->asl.node;
482 				acpi_ut_add_reference(op->asl.value.arg->asl.
483 						      node->object);
484 				return_ACPI_STATUS(AE_OK);
485 			}
486 
487 			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
488 					  "Method invocation, Op=%p\n", op));
489 
490 			/*
491 			 * (AML_METHODCALL) Op->Asl.Value.Arg->Asl.Node contains
492 			 * the method Node pointer
493 			 */
494 			/* next_op points to the op that holds the method name */
495 
496 			next_op = first_arg;
497 
498 			/* next_op points to first argument op */
499 
500 			next_op = next_op->common.next;
501 
502 			/*
503 			 * Get the method's arguments and put them on the operand stack
504 			 */
505 			status = acpi_ds_create_operands(walk_state, next_op);
506 			if (ACPI_FAILURE(status)) {
507 				break;
508 			}
509 
510 			/*
511 			 * Since the operands will be passed to another control method,
512 			 * we must resolve all local references here (Local variables,
513 			 * arguments to *this* method, etc.)
514 			 */
515 			status = acpi_ds_resolve_operands(walk_state);
516 			if (ACPI_FAILURE(status)) {
517 
518 				/* On error, clear all resolved operands */
519 
520 				acpi_ds_clear_operands(walk_state);
521 				break;
522 			}
523 
524 			/*
525 			 * Tell the walk loop to preempt this running method and
526 			 * execute the new method
527 			 */
528 			status = AE_CTRL_TRANSFER;
529 
530 			/*
531 			 * Return now; we don't want to disturb anything,
532 			 * especially the operand count!
533 			 */
534 			return_ACPI_STATUS(status);
535 
536 		case AML_TYPE_CREATE_FIELD:
537 
538 			ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
539 					  "Executing CreateField Buffer/Index Op=%p\n",
540 					  op));
541 
542 			status = acpi_ds_load2_end_op(walk_state);
543 			if (ACPI_FAILURE(status)) {
544 				break;
545 			}
546 
547 			status =
548 			    acpi_ds_eval_buffer_field_operands(walk_state, op);
549 			if (ACPI_FAILURE(status)) {
550 				break;
551 			}
552 #ifdef ACPI_EXEC_APP
553 			/*
554 			 * acpi_exec support for namespace initialization file (initialize
555 			 * buffer_fields in this code.)
556 			 */
557 			namepath =
558 			    acpi_ns_get_external_pathname(op->common.node);
559 			status = ae_lookup_init_file_entry(namepath, &obj_desc);
560 			if (ACPI_SUCCESS(status)) {
561 				status =
562 				    acpi_ex_write_data_to_field(obj_desc,
563 								op->common.
564 								node->object,
565 								NULL);
566 				if (ACPI_FAILURE(status)) {
567 					ACPI_EXCEPTION((AE_INFO, status,
568 							"While writing to buffer field"));
569 				}
570 			}
571 			ACPI_FREE(namepath);
572 			status = AE_OK;
573 #endif
574 			break;
575 
576 		case AML_TYPE_CREATE_OBJECT:
577 
578 			ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
579 					  "Executing CreateObject (Buffer/Package) Op=%p Child=%p ParentOpcode=%4.4X\n",
580 					  op, op->named.value.arg,
581 					  op->common.parent->common.
582 					  aml_opcode));
583 
584 			switch (op->common.parent->common.aml_opcode) {
585 			case AML_NAME_OP:
586 				/*
587 				 * Put the Node on the object stack (Contains the ACPI Name
588 				 * of this object)
589 				 */
590 				walk_state->operands[0] = (void *)
591 				    op->common.parent->common.node;
592 				walk_state->num_operands = 1;
593 
594 				status = acpi_ds_create_node(walk_state,
595 							     op->common.parent->
596 							     common.node,
597 							     op->common.parent);
598 				if (ACPI_FAILURE(status)) {
599 					break;
600 				}
601 
602 				ACPI_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 "
696 				    "type=0x%X Opcode=0x%X Op=%p",
697 				    op_class, op_type, op->common.aml_opcode,
698 				    op));
699 
700 			status = AE_NOT_IMPLEMENTED;
701 			break;
702 		}
703 	}
704 
705 	/*
706 	 * ACPI 2.0 support for 64-bit integers: Truncate numeric
707 	 * result value if we are executing from a 32-bit ACPI table
708 	 */
709 	(void)acpi_ex_truncate_for32bit_table(walk_state->result_obj);
710 
711 	/*
712 	 * Check if we just completed the evaluation of a
713 	 * conditional predicate
714 	 */
715 	if ((ACPI_SUCCESS(status)) &&
716 	    (walk_state->control_state) &&
717 	    (walk_state->control_state->common.state ==
718 	     ACPI_CONTROL_PREDICATE_EXECUTING) &&
719 	    (walk_state->control_state->control.predicate_op == op)) {
720 		status =
721 		    acpi_ds_get_predicate_value(walk_state,
722 						walk_state->result_obj);
723 		walk_state->result_obj = NULL;
724 	}
725 
726 cleanup:
727 
728 	if (walk_state->result_obj) {
729 
730 		/* Break to debugger to display result */
731 
732 		acpi_db_display_result_object(walk_state->result_obj,
733 					      walk_state);
734 
735 		/*
736 		 * Delete the result op if and only if:
737 		 * Parent will not use the result -- such as any
738 		 * non-nested type2 op in a method (parent will be method)
739 		 */
740 		acpi_ds_delete_result_if_not_used(op, walk_state->result_obj,
741 						  walk_state);
742 	}
743 #ifdef _UNDER_DEVELOPMENT
744 
745 	if (walk_state->parser_state.aml == walk_state->parser_state.aml_end) {
746 		acpi_db_method_end(walk_state);
747 	}
748 #endif
749 
750 	/* Invoke exception handler on error */
751 
752 	if (ACPI_FAILURE(status)) {
753 		status = acpi_ds_method_error(status, walk_state);
754 	}
755 
756 	/* Always clear the object stack */
757 
758 	walk_state->num_operands = 0;
759 	return_ACPI_STATUS(status);
760 }
761