xref: /openbmc/linux/drivers/acpi/acpica/dswload2.c (revision 4da722ca)
1 /******************************************************************************
2  *
3  * Module Name: dswload2 - Dispatcher second pass namespace load callbacks
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2017, 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/acpi.h>
45 #include "accommon.h"
46 #include "acparser.h"
47 #include "amlcode.h"
48 #include "acdispat.h"
49 #include "acinterp.h"
50 #include "acnamesp.h"
51 #include "acevents.h"
52 
53 #define _COMPONENT          ACPI_DISPATCHER
54 ACPI_MODULE_NAME("dswload2")
55 
56 /*******************************************************************************
57  *
58  * FUNCTION:    acpi_ds_load2_begin_op
59  *
60  * PARAMETERS:  walk_state      - Current state of the parse tree walk
61  *              out_op          - Wher to return op if a new one is created
62  *
63  * RETURN:      Status
64  *
65  * DESCRIPTION: Descending callback used during the loading of ACPI tables.
66  *
67  ******************************************************************************/
68 acpi_status
69 acpi_ds_load2_begin_op(struct acpi_walk_state *walk_state,
70 		       union acpi_parse_object **out_op)
71 {
72 	union acpi_parse_object *op;
73 	struct acpi_namespace_node *node;
74 	acpi_status status;
75 	acpi_object_type object_type;
76 	char *buffer_ptr;
77 	u32 flags;
78 
79 	ACPI_FUNCTION_TRACE(ds_load2_begin_op);
80 
81 	op = walk_state->op;
82 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Op=%p State=%p\n", op,
83 			  walk_state));
84 
85 	if (op) {
86 		if ((walk_state->control_state) &&
87 		    (walk_state->control_state->common.state ==
88 		     ACPI_CONTROL_CONDITIONAL_EXECUTING)) {
89 
90 			/* We are executing a while loop outside of a method */
91 
92 			status = acpi_ds_exec_begin_op(walk_state, out_op);
93 			return_ACPI_STATUS(status);
94 		}
95 
96 		/* We only care about Namespace opcodes here */
97 
98 		if ((!(walk_state->op_info->flags & AML_NSOPCODE) &&
99 		     (walk_state->opcode != AML_INT_NAMEPATH_OP)) ||
100 		    (!(walk_state->op_info->flags & AML_NAMED))) {
101 			return_ACPI_STATUS(AE_OK);
102 		}
103 
104 		/* Get the name we are going to enter or lookup in the namespace */
105 
106 		if (walk_state->opcode == AML_INT_NAMEPATH_OP) {
107 
108 			/* For Namepath op, get the path string */
109 
110 			buffer_ptr = op->common.value.string;
111 			if (!buffer_ptr) {
112 
113 				/* No name, just exit */
114 
115 				return_ACPI_STATUS(AE_OK);
116 			}
117 		} else {
118 			/* Get name from the op */
119 
120 			buffer_ptr = ACPI_CAST_PTR(char, &op->named.name);
121 		}
122 	} else {
123 		/* Get the namestring from the raw AML */
124 
125 		buffer_ptr =
126 		    acpi_ps_get_next_namestring(&walk_state->parser_state);
127 	}
128 
129 	/* Map the opcode into an internal object type */
130 
131 	object_type = walk_state->op_info->object_type;
132 
133 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
134 			  "State=%p Op=%p Type=%X\n", walk_state, op,
135 			  object_type));
136 
137 	switch (walk_state->opcode) {
138 	case AML_FIELD_OP:
139 	case AML_BANK_FIELD_OP:
140 	case AML_INDEX_FIELD_OP:
141 
142 		node = NULL;
143 		status = AE_OK;
144 		break;
145 
146 	case AML_INT_NAMEPATH_OP:
147 		/*
148 		 * The name_path is an object reference to an existing object.
149 		 * Don't enter the name into the namespace, but look it up
150 		 * for use later.
151 		 */
152 		status =
153 		    acpi_ns_lookup(walk_state->scope_info, buffer_ptr,
154 				   object_type, ACPI_IMODE_EXECUTE,
155 				   ACPI_NS_SEARCH_PARENT, walk_state, &(node));
156 		break;
157 
158 	case AML_SCOPE_OP:
159 
160 		/* Special case for Scope(\) -> refers to the Root node */
161 
162 		if (op && (op->named.node == acpi_gbl_root_node)) {
163 			node = op->named.node;
164 
165 			status =
166 			    acpi_ds_scope_stack_push(node, object_type,
167 						     walk_state);
168 			if (ACPI_FAILURE(status)) {
169 				return_ACPI_STATUS(status);
170 			}
171 		} else {
172 			/*
173 			 * The Path is an object reference to an existing object.
174 			 * Don't enter the name into the namespace, but look it up
175 			 * for use later.
176 			 */
177 			status =
178 			    acpi_ns_lookup(walk_state->scope_info, buffer_ptr,
179 					   object_type, ACPI_IMODE_EXECUTE,
180 					   ACPI_NS_SEARCH_PARENT, walk_state,
181 					   &(node));
182 			if (ACPI_FAILURE(status)) {
183 #ifdef ACPI_ASL_COMPILER
184 				if (status == AE_NOT_FOUND) {
185 					status = AE_OK;
186 				} else {
187 					ACPI_ERROR_NAMESPACE(buffer_ptr,
188 							     status);
189 				}
190 #else
191 				ACPI_ERROR_NAMESPACE(buffer_ptr, status);
192 #endif
193 				return_ACPI_STATUS(status);
194 			}
195 		}
196 
197 		/*
198 		 * We must check to make sure that the target is
199 		 * one of the opcodes that actually opens a scope
200 		 */
201 		switch (node->type) {
202 		case ACPI_TYPE_ANY:
203 		case ACPI_TYPE_LOCAL_SCOPE:	/* Scope */
204 		case ACPI_TYPE_DEVICE:
205 		case ACPI_TYPE_POWER:
206 		case ACPI_TYPE_PROCESSOR:
207 		case ACPI_TYPE_THERMAL:
208 
209 			/* These are acceptable types */
210 			break;
211 
212 		case ACPI_TYPE_INTEGER:
213 		case ACPI_TYPE_STRING:
214 		case ACPI_TYPE_BUFFER:
215 
216 			/*
217 			 * These types we will allow, but we will change the type.
218 			 * This enables some existing code of the form:
219 			 *
220 			 *  Name (DEB, 0)
221 			 *  Scope (DEB) { ... }
222 			 */
223 			ACPI_WARNING((AE_INFO,
224 				      "Type override - [%4.4s] had invalid type (%s) "
225 				      "for Scope operator, changed to type ANY",
226 				      acpi_ut_get_node_name(node),
227 				      acpi_ut_get_type_name(node->type)));
228 
229 			node->type = ACPI_TYPE_ANY;
230 			walk_state->scope_info->common.value = ACPI_TYPE_ANY;
231 			break;
232 
233 		case ACPI_TYPE_METHOD:
234 
235 			/*
236 			 * Allow scope change to root during execution of module-level
237 			 * code. Root is typed METHOD during this time.
238 			 */
239 			if ((node == acpi_gbl_root_node) &&
240 			    (walk_state->
241 			     parse_flags & ACPI_PARSE_MODULE_LEVEL)) {
242 				break;
243 			}
244 
245 			/*lint -fallthrough */
246 
247 		default:
248 
249 			/* All other types are an error */
250 
251 			ACPI_ERROR((AE_INFO,
252 				    "Invalid type (%s) for target of "
253 				    "Scope operator [%4.4s] (Cannot override)",
254 				    acpi_ut_get_type_name(node->type),
255 				    acpi_ut_get_node_name(node)));
256 
257 			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
258 		}
259 		break;
260 
261 	default:
262 
263 		/* All other opcodes */
264 
265 		if (op && op->common.node) {
266 
267 			/* This op/node was previously entered into the namespace */
268 
269 			node = op->common.node;
270 
271 			if (acpi_ns_opens_scope(object_type)) {
272 				status =
273 				    acpi_ds_scope_stack_push(node, object_type,
274 							     walk_state);
275 				if (ACPI_FAILURE(status)) {
276 					return_ACPI_STATUS(status);
277 				}
278 			}
279 
280 			return_ACPI_STATUS(AE_OK);
281 		}
282 
283 		/*
284 		 * Enter the named type into the internal namespace. We enter the name
285 		 * as we go downward in the parse tree. Any necessary subobjects that
286 		 * involve arguments to the opcode must be created as we go back up the
287 		 * parse tree later.
288 		 *
289 		 * Note: Name may already exist if we are executing a deferred opcode.
290 		 */
291 		if (walk_state->deferred_node) {
292 
293 			/* This name is already in the namespace, get the node */
294 
295 			node = walk_state->deferred_node;
296 			status = AE_OK;
297 			break;
298 		}
299 
300 		flags = ACPI_NS_NO_UPSEARCH;
301 		if (walk_state->pass_number == ACPI_IMODE_EXECUTE) {
302 
303 			/* Execution mode, node cannot already exist, node is temporary */
304 
305 			flags |= ACPI_NS_ERROR_IF_FOUND;
306 
307 			if (!
308 			    (walk_state->
309 			     parse_flags & ACPI_PARSE_MODULE_LEVEL)) {
310 				flags |= ACPI_NS_TEMPORARY;
311 			}
312 		}
313 #ifdef ACPI_ASL_COMPILER
314 
315 		/*
316 		 * Do not open a scope for AML_EXTERNAL_OP
317 		 * acpi_ns_lookup can open a new scope based on the object type
318 		 * of this op. AML_EXTERNAL_OP is a declaration rather than a
319 		 * definition. In the case that this external is a method object,
320 		 * acpi_ns_lookup will open a new scope. However, an AML_EXTERNAL_OP
321 		 * associated with the ACPI_TYPE_METHOD is a declaration, rather than
322 		 * a definition. Flags is set to avoid opening a scope for any
323 		 * AML_EXTERNAL_OP.
324 		 */
325 		if (walk_state->opcode == AML_EXTERNAL_OP) {
326 			flags |= ACPI_NS_DONT_OPEN_SCOPE;
327 		}
328 #endif
329 
330 		/* Add new entry or lookup existing entry */
331 
332 		status =
333 		    acpi_ns_lookup(walk_state->scope_info, buffer_ptr,
334 				   object_type, ACPI_IMODE_LOAD_PASS2, flags,
335 				   walk_state, &node);
336 
337 		if (ACPI_SUCCESS(status) && (flags & ACPI_NS_TEMPORARY)) {
338 			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
339 					  "***New Node [%4.4s] %p is temporary\n",
340 					  acpi_ut_get_node_name(node), node));
341 		}
342 		break;
343 	}
344 
345 	if (ACPI_FAILURE(status)) {
346 		ACPI_ERROR_NAMESPACE(buffer_ptr, status);
347 		return_ACPI_STATUS(status);
348 	}
349 
350 	if (!op) {
351 
352 		/* Create a new op */
353 
354 		op = acpi_ps_alloc_op(walk_state->opcode, walk_state->aml);
355 		if (!op) {
356 			return_ACPI_STATUS(AE_NO_MEMORY);
357 		}
358 
359 		/* Initialize the new op */
360 
361 		if (node) {
362 			op->named.name = node->name.integer;
363 		}
364 		*out_op = op;
365 	}
366 
367 	/*
368 	 * Put the Node in the "op" object that the parser uses, so we
369 	 * can get it again quickly when this scope is closed
370 	 */
371 	op->common.node = node;
372 	return_ACPI_STATUS(status);
373 }
374 
375 /*******************************************************************************
376  *
377  * FUNCTION:    acpi_ds_load2_end_op
378  *
379  * PARAMETERS:  walk_state      - Current state of the parse tree walk
380  *
381  * RETURN:      Status
382  *
383  * DESCRIPTION: Ascending callback used during the loading of the namespace,
384  *              both control methods and everything else.
385  *
386  ******************************************************************************/
387 
388 acpi_status acpi_ds_load2_end_op(struct acpi_walk_state *walk_state)
389 {
390 	union acpi_parse_object *op;
391 	acpi_status status = AE_OK;
392 	acpi_object_type object_type;
393 	struct acpi_namespace_node *node;
394 	union acpi_parse_object *arg;
395 	struct acpi_namespace_node *new_node;
396 #ifndef ACPI_NO_METHOD_EXECUTION
397 	u32 i;
398 	u8 region_space;
399 #endif
400 
401 	ACPI_FUNCTION_TRACE(ds_load2_end_op);
402 
403 	op = walk_state->op;
404 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Opcode [%s] Op %p State %p\n",
405 			  walk_state->op_info->name, op, walk_state));
406 
407 	/* Check if opcode had an associated namespace object */
408 
409 	if (!(walk_state->op_info->flags & AML_NSOBJECT)) {
410 		return_ACPI_STATUS(AE_OK);
411 	}
412 
413 	if (op->common.aml_opcode == AML_SCOPE_OP) {
414 		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
415 				  "Ending scope Op=%p State=%p\n", op,
416 				  walk_state));
417 	}
418 
419 	object_type = walk_state->op_info->object_type;
420 
421 	/*
422 	 * Get the Node/name from the earlier lookup
423 	 * (It was saved in the *op structure)
424 	 */
425 	node = op->common.node;
426 
427 	/*
428 	 * Put the Node on the object stack (Contains the ACPI Name of
429 	 * this object)
430 	 */
431 	walk_state->operands[0] = (void *)node;
432 	walk_state->num_operands = 1;
433 
434 	/* Pop the scope stack */
435 
436 	if (acpi_ns_opens_scope(object_type) &&
437 	    (op->common.aml_opcode != AML_INT_METHODCALL_OP)) {
438 		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
439 				  "(%s) Popping scope for Op %p\n",
440 				  acpi_ut_get_type_name(object_type), op));
441 
442 		status = acpi_ds_scope_stack_pop(walk_state);
443 		if (ACPI_FAILURE(status)) {
444 			goto cleanup;
445 		}
446 	}
447 
448 	/*
449 	 * Named operations are as follows:
450 	 *
451 	 * AML_ALIAS
452 	 * AML_BANKFIELD
453 	 * AML_CREATEBITFIELD
454 	 * AML_CREATEBYTEFIELD
455 	 * AML_CREATEDWORDFIELD
456 	 * AML_CREATEFIELD
457 	 * AML_CREATEQWORDFIELD
458 	 * AML_CREATEWORDFIELD
459 	 * AML_DATA_REGION
460 	 * AML_DEVICE
461 	 * AML_EVENT
462 	 * AML_FIELD
463 	 * AML_INDEXFIELD
464 	 * AML_METHOD
465 	 * AML_METHODCALL
466 	 * AML_MUTEX
467 	 * AML_NAME
468 	 * AML_NAMEDFIELD
469 	 * AML_OPREGION
470 	 * AML_POWERRES
471 	 * AML_PROCESSOR
472 	 * AML_SCOPE
473 	 * AML_THERMALZONE
474 	 */
475 
476 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
477 			  "Create-Load [%s] State=%p Op=%p NamedObj=%p\n",
478 			  acpi_ps_get_opcode_name(op->common.aml_opcode),
479 			  walk_state, op, node));
480 
481 	/* Decode the opcode */
482 
483 	arg = op->common.value.arg;
484 
485 	switch (walk_state->op_info->type) {
486 #ifndef ACPI_NO_METHOD_EXECUTION
487 
488 	case AML_TYPE_CREATE_FIELD:
489 		/*
490 		 * Create the field object, but the field buffer and index must
491 		 * be evaluated later during the execution phase
492 		 */
493 		status = acpi_ds_create_buffer_field(op, walk_state);
494 		break;
495 
496 	case AML_TYPE_NAMED_FIELD:
497 		/*
498 		 * If we are executing a method, initialize the field
499 		 */
500 		if (walk_state->method_node) {
501 			status = acpi_ds_init_field_objects(op, walk_state);
502 		}
503 
504 		switch (op->common.aml_opcode) {
505 		case AML_INDEX_FIELD_OP:
506 
507 			status =
508 			    acpi_ds_create_index_field(op,
509 						       (acpi_handle)arg->common.
510 						       node, walk_state);
511 			break;
512 
513 		case AML_BANK_FIELD_OP:
514 
515 			status =
516 			    acpi_ds_create_bank_field(op, arg->common.node,
517 						      walk_state);
518 			break;
519 
520 		case AML_FIELD_OP:
521 
522 			status =
523 			    acpi_ds_create_field(op, arg->common.node,
524 						 walk_state);
525 			break;
526 
527 		default:
528 
529 			/* All NAMED_FIELD opcodes must be handled above */
530 			break;
531 		}
532 		break;
533 
534 	case AML_TYPE_NAMED_SIMPLE:
535 
536 		status = acpi_ds_create_operands(walk_state, arg);
537 		if (ACPI_FAILURE(status)) {
538 			goto cleanup;
539 		}
540 
541 		switch (op->common.aml_opcode) {
542 		case AML_PROCESSOR_OP:
543 
544 			status = acpi_ex_create_processor(walk_state);
545 			break;
546 
547 		case AML_POWER_RESOURCE_OP:
548 
549 			status = acpi_ex_create_power_resource(walk_state);
550 			break;
551 
552 		case AML_MUTEX_OP:
553 
554 			status = acpi_ex_create_mutex(walk_state);
555 			break;
556 
557 		case AML_EVENT_OP:
558 
559 			status = acpi_ex_create_event(walk_state);
560 			break;
561 
562 		case AML_ALIAS_OP:
563 
564 			status = acpi_ex_create_alias(walk_state);
565 			break;
566 
567 		default:
568 
569 			/* Unknown opcode */
570 
571 			status = AE_OK;
572 			goto cleanup;
573 		}
574 
575 		/* Delete operands */
576 
577 		for (i = 1; i < walk_state->num_operands; i++) {
578 			acpi_ut_remove_reference(walk_state->operands[i]);
579 			walk_state->operands[i] = NULL;
580 		}
581 
582 		break;
583 #endif				/* ACPI_NO_METHOD_EXECUTION */
584 
585 	case AML_TYPE_NAMED_COMPLEX:
586 
587 		switch (op->common.aml_opcode) {
588 #ifndef ACPI_NO_METHOD_EXECUTION
589 		case AML_REGION_OP:
590 		case AML_DATA_REGION_OP:
591 
592 			if (op->common.aml_opcode == AML_REGION_OP) {
593 				region_space = (acpi_adr_space_type)
594 				    ((op->common.value.arg)->common.value.
595 				     integer);
596 			} else {
597 				region_space = ACPI_ADR_SPACE_DATA_TABLE;
598 			}
599 
600 			/*
601 			 * The op_region is not fully parsed at this time. The only valid
602 			 * argument is the space_id. (We must save the address of the
603 			 * AML of the address and length operands)
604 			 *
605 			 * If we have a valid region, initialize it. The namespace is
606 			 * unlocked at this point.
607 			 *
608 			 * Need to unlock interpreter if it is locked (if we are running
609 			 * a control method), in order to allow _REG methods to be run
610 			 * during acpi_ev_initialize_region.
611 			 */
612 			if (walk_state->method_node) {
613 				/*
614 				 * Executing a method: initialize the region and unlock
615 				 * the interpreter
616 				 */
617 				status = acpi_ex_create_region(op->named.data,
618 							       op->named.length,
619 							       region_space,
620 							       walk_state);
621 				if (ACPI_FAILURE(status)) {
622 					return_ACPI_STATUS(status);
623 				}
624 			}
625 
626 			status =
627 			    acpi_ev_initialize_region
628 			    (acpi_ns_get_attached_object(node));
629 			break;
630 
631 		case AML_NAME_OP:
632 
633 			status = acpi_ds_create_node(walk_state, node, op);
634 			break;
635 
636 		case AML_METHOD_OP:
637 			/*
638 			 * method_op pkg_length name_string method_flags term_list
639 			 *
640 			 * Note: We must create the method node/object pair as soon as we
641 			 * see the method declaration. This allows later pass1 parsing
642 			 * of invocations of the method (need to know the number of
643 			 * arguments.)
644 			 */
645 			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
646 					  "LOADING-Method: State=%p Op=%p NamedObj=%p\n",
647 					  walk_state, op, op->named.node));
648 
649 			if (!acpi_ns_get_attached_object(op->named.node)) {
650 				walk_state->operands[0] =
651 				    ACPI_CAST_PTR(void, op->named.node);
652 				walk_state->num_operands = 1;
653 
654 				status =
655 				    acpi_ds_create_operands(walk_state,
656 							    op->common.value.
657 							    arg);
658 				if (ACPI_SUCCESS(status)) {
659 					status =
660 					    acpi_ex_create_method(op->named.
661 								  data,
662 								  op->named.
663 								  length,
664 								  walk_state);
665 				}
666 
667 				walk_state->operands[0] = NULL;
668 				walk_state->num_operands = 0;
669 
670 				if (ACPI_FAILURE(status)) {
671 					return_ACPI_STATUS(status);
672 				}
673 			}
674 			break;
675 
676 #endif				/* ACPI_NO_METHOD_EXECUTION */
677 
678 		default:
679 
680 			/* All NAMED_COMPLEX opcodes must be handled above */
681 			break;
682 		}
683 		break;
684 
685 	case AML_CLASS_INTERNAL:
686 
687 		/* case AML_INT_NAMEPATH_OP: */
688 		break;
689 
690 	case AML_CLASS_METHOD_CALL:
691 
692 		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
693 				  "RESOLVING-MethodCall: State=%p Op=%p NamedObj=%p\n",
694 				  walk_state, op, node));
695 
696 		/*
697 		 * Lookup the method name and save the Node
698 		 */
699 		status =
700 		    acpi_ns_lookup(walk_state->scope_info,
701 				   arg->common.value.string, ACPI_TYPE_ANY,
702 				   ACPI_IMODE_LOAD_PASS2,
703 				   ACPI_NS_SEARCH_PARENT |
704 				   ACPI_NS_DONT_OPEN_SCOPE, walk_state,
705 				   &(new_node));
706 		if (ACPI_SUCCESS(status)) {
707 			/*
708 			 * Make sure that what we found is indeed a method
709 			 * We didn't search for a method on purpose, to see if the name
710 			 * would resolve
711 			 */
712 			if (new_node->type != ACPI_TYPE_METHOD) {
713 				status = AE_AML_OPERAND_TYPE;
714 			}
715 
716 			/* We could put the returned object (Node) on the object stack for
717 			 * later, but for now, we will put it in the "op" object that the
718 			 * parser uses, so we can get it again at the end of this scope
719 			 */
720 			op->common.node = new_node;
721 		} else {
722 			ACPI_ERROR_NAMESPACE(arg->common.value.string, status);
723 		}
724 		break;
725 
726 	default:
727 
728 		break;
729 	}
730 
731 cleanup:
732 
733 	/* Remove the Node pushed at the very beginning */
734 
735 	walk_state->operands[0] = NULL;
736 	walk_state->num_operands = 0;
737 	return_ACPI_STATUS(status);
738 }
739