xref: /linux/drivers/acpi/acpica/dswload2.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /******************************************************************************
2  *
3  * Module Name: dswload2 - Dispatcher second pass namespace load callbacks
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2015, 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 
314 		/* Add new entry or lookup existing entry */
315 
316 		status =
317 		    acpi_ns_lookup(walk_state->scope_info, buffer_ptr,
318 				   object_type, ACPI_IMODE_LOAD_PASS2, flags,
319 				   walk_state, &node);
320 
321 		if (ACPI_SUCCESS(status) && (flags & ACPI_NS_TEMPORARY)) {
322 			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
323 					  "***New Node [%4.4s] %p is temporary\n",
324 					  acpi_ut_get_node_name(node), node));
325 		}
326 		break;
327 	}
328 
329 	if (ACPI_FAILURE(status)) {
330 		ACPI_ERROR_NAMESPACE(buffer_ptr, status);
331 		return_ACPI_STATUS(status);
332 	}
333 
334 	if (!op) {
335 
336 		/* Create a new op */
337 
338 		op = acpi_ps_alloc_op(walk_state->opcode, walk_state->aml);
339 		if (!op) {
340 			return_ACPI_STATUS(AE_NO_MEMORY);
341 		}
342 
343 		/* Initialize the new op */
344 
345 		if (node) {
346 			op->named.name = node->name.integer;
347 		}
348 		*out_op = op;
349 	}
350 
351 	/*
352 	 * Put the Node in the "op" object that the parser uses, so we
353 	 * can get it again quickly when this scope is closed
354 	 */
355 	op->common.node = node;
356 	return_ACPI_STATUS(status);
357 }
358 
359 /*******************************************************************************
360  *
361  * FUNCTION:    acpi_ds_load2_end_op
362  *
363  * PARAMETERS:  walk_state      - Current state of the parse tree walk
364  *
365  * RETURN:      Status
366  *
367  * DESCRIPTION: Ascending callback used during the loading of the namespace,
368  *              both control methods and everything else.
369  *
370  ******************************************************************************/
371 
372 acpi_status acpi_ds_load2_end_op(struct acpi_walk_state *walk_state)
373 {
374 	union acpi_parse_object *op;
375 	acpi_status status = AE_OK;
376 	acpi_object_type object_type;
377 	struct acpi_namespace_node *node;
378 	union acpi_parse_object *arg;
379 	struct acpi_namespace_node *new_node;
380 #ifndef ACPI_NO_METHOD_EXECUTION
381 	u32 i;
382 	u8 region_space;
383 #endif
384 
385 	ACPI_FUNCTION_TRACE(ds_load2_end_op);
386 
387 	op = walk_state->op;
388 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Opcode [%s] Op %p State %p\n",
389 			  walk_state->op_info->name, op, walk_state));
390 
391 	/* Check if opcode had an associated namespace object */
392 
393 	if (!(walk_state->op_info->flags & AML_NSOBJECT)) {
394 		return_ACPI_STATUS(AE_OK);
395 	}
396 
397 	if (op->common.aml_opcode == AML_SCOPE_OP) {
398 		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
399 				  "Ending scope Op=%p State=%p\n", op,
400 				  walk_state));
401 	}
402 
403 	object_type = walk_state->op_info->object_type;
404 
405 	/*
406 	 * Get the Node/name from the earlier lookup
407 	 * (It was saved in the *op structure)
408 	 */
409 	node = op->common.node;
410 
411 	/*
412 	 * Put the Node on the object stack (Contains the ACPI Name of
413 	 * this object)
414 	 */
415 	walk_state->operands[0] = (void *)node;
416 	walk_state->num_operands = 1;
417 
418 	/* Pop the scope stack */
419 
420 	if (acpi_ns_opens_scope(object_type) &&
421 	    (op->common.aml_opcode != AML_INT_METHODCALL_OP)) {
422 		ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
423 				  "(%s) Popping scope for Op %p\n",
424 				  acpi_ut_get_type_name(object_type), op));
425 
426 		status = acpi_ds_scope_stack_pop(walk_state);
427 		if (ACPI_FAILURE(status)) {
428 			goto cleanup;
429 		}
430 	}
431 
432 	/*
433 	 * Named operations are as follows:
434 	 *
435 	 * AML_ALIAS
436 	 * AML_BANKFIELD
437 	 * AML_CREATEBITFIELD
438 	 * AML_CREATEBYTEFIELD
439 	 * AML_CREATEDWORDFIELD
440 	 * AML_CREATEFIELD
441 	 * AML_CREATEQWORDFIELD
442 	 * AML_CREATEWORDFIELD
443 	 * AML_DATA_REGION
444 	 * AML_DEVICE
445 	 * AML_EVENT
446 	 * AML_FIELD
447 	 * AML_INDEXFIELD
448 	 * AML_METHOD
449 	 * AML_METHODCALL
450 	 * AML_MUTEX
451 	 * AML_NAME
452 	 * AML_NAMEDFIELD
453 	 * AML_OPREGION
454 	 * AML_POWERRES
455 	 * AML_PROCESSOR
456 	 * AML_SCOPE
457 	 * AML_THERMALZONE
458 	 */
459 
460 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
461 			  "Create-Load [%s] State=%p Op=%p NamedObj=%p\n",
462 			  acpi_ps_get_opcode_name(op->common.aml_opcode),
463 			  walk_state, op, node));
464 
465 	/* Decode the opcode */
466 
467 	arg = op->common.value.arg;
468 
469 	switch (walk_state->op_info->type) {
470 #ifndef ACPI_NO_METHOD_EXECUTION
471 
472 	case AML_TYPE_CREATE_FIELD:
473 		/*
474 		 * Create the field object, but the field buffer and index must
475 		 * be evaluated later during the execution phase
476 		 */
477 		status = acpi_ds_create_buffer_field(op, walk_state);
478 		break;
479 
480 	case AML_TYPE_NAMED_FIELD:
481 		/*
482 		 * If we are executing a method, initialize the field
483 		 */
484 		if (walk_state->method_node) {
485 			status = acpi_ds_init_field_objects(op, walk_state);
486 		}
487 
488 		switch (op->common.aml_opcode) {
489 		case AML_INDEX_FIELD_OP:
490 
491 			status =
492 			    acpi_ds_create_index_field(op,
493 						       (acpi_handle) arg->
494 						       common.node, walk_state);
495 			break;
496 
497 		case AML_BANK_FIELD_OP:
498 
499 			status =
500 			    acpi_ds_create_bank_field(op, arg->common.node,
501 						      walk_state);
502 			break;
503 
504 		case AML_FIELD_OP:
505 
506 			status =
507 			    acpi_ds_create_field(op, arg->common.node,
508 						 walk_state);
509 			break;
510 
511 		default:
512 
513 			/* All NAMED_FIELD opcodes must be handled above */
514 			break;
515 		}
516 		break;
517 
518 	case AML_TYPE_NAMED_SIMPLE:
519 
520 		status = acpi_ds_create_operands(walk_state, arg);
521 		if (ACPI_FAILURE(status)) {
522 			goto cleanup;
523 		}
524 
525 		switch (op->common.aml_opcode) {
526 		case AML_PROCESSOR_OP:
527 
528 			status = acpi_ex_create_processor(walk_state);
529 			break;
530 
531 		case AML_POWER_RES_OP:
532 
533 			status = acpi_ex_create_power_resource(walk_state);
534 			break;
535 
536 		case AML_MUTEX_OP:
537 
538 			status = acpi_ex_create_mutex(walk_state);
539 			break;
540 
541 		case AML_EVENT_OP:
542 
543 			status = acpi_ex_create_event(walk_state);
544 			break;
545 
546 		case AML_ALIAS_OP:
547 
548 			status = acpi_ex_create_alias(walk_state);
549 			break;
550 
551 		default:
552 
553 			/* Unknown opcode */
554 
555 			status = AE_OK;
556 			goto cleanup;
557 		}
558 
559 		/* Delete operands */
560 
561 		for (i = 1; i < walk_state->num_operands; i++) {
562 			acpi_ut_remove_reference(walk_state->operands[i]);
563 			walk_state->operands[i] = NULL;
564 		}
565 
566 		break;
567 #endif				/* ACPI_NO_METHOD_EXECUTION */
568 
569 	case AML_TYPE_NAMED_COMPLEX:
570 
571 		switch (op->common.aml_opcode) {
572 #ifndef ACPI_NO_METHOD_EXECUTION
573 		case AML_REGION_OP:
574 		case AML_DATA_REGION_OP:
575 
576 			if (op->common.aml_opcode == AML_REGION_OP) {
577 				region_space = (acpi_adr_space_type)
578 				    ((op->common.value.arg)->common.value.
579 				     integer);
580 			} else {
581 				region_space = ACPI_ADR_SPACE_DATA_TABLE;
582 			}
583 
584 			/*
585 			 * The op_region is not fully parsed at this time. The only valid
586 			 * argument is the space_id. (We must save the address of the
587 			 * AML of the address and length operands)
588 			 *
589 			 * If we have a valid region, initialize it. The namespace is
590 			 * unlocked at this point.
591 			 *
592 			 * Need to unlock interpreter if it is locked (if we are running
593 			 * a control method), in order to allow _REG methods to be run
594 			 * during acpi_ev_initialize_region.
595 			 */
596 			if (walk_state->method_node) {
597 				/*
598 				 * Executing a method: initialize the region and unlock
599 				 * the interpreter
600 				 */
601 				status =
602 				    acpi_ex_create_region(op->named.data,
603 							  op->named.length,
604 							  region_space,
605 							  walk_state);
606 				if (ACPI_FAILURE(status)) {
607 					return_ACPI_STATUS(status);
608 				}
609 
610 				acpi_ex_exit_interpreter();
611 			}
612 
613 			status =
614 			    acpi_ev_initialize_region
615 			    (acpi_ns_get_attached_object(node), FALSE);
616 			if (walk_state->method_node) {
617 				acpi_ex_enter_interpreter();
618 			}
619 
620 			if (ACPI_FAILURE(status)) {
621 				/*
622 				 *  If AE_NOT_EXIST is returned, it is not fatal
623 				 *  because many regions get created before a handler
624 				 *  is installed for said region.
625 				 */
626 				if (AE_NOT_EXIST == status) {
627 					status = AE_OK;
628 				}
629 			}
630 			break;
631 
632 		case AML_NAME_OP:
633 
634 			status = acpi_ds_create_node(walk_state, node, op);
635 			break;
636 
637 		case AML_METHOD_OP:
638 			/*
639 			 * method_op pkg_length name_string method_flags term_list
640 			 *
641 			 * Note: We must create the method node/object pair as soon as we
642 			 * see the method declaration. This allows later pass1 parsing
643 			 * of invocations of the method (need to know the number of
644 			 * arguments.)
645 			 */
646 			ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
647 					  "LOADING-Method: State=%p Op=%p NamedObj=%p\n",
648 					  walk_state, op, op->named.node));
649 
650 			if (!acpi_ns_get_attached_object(op->named.node)) {
651 				walk_state->operands[0] =
652 				    ACPI_CAST_PTR(void, op->named.node);
653 				walk_state->num_operands = 1;
654 
655 				status =
656 				    acpi_ds_create_operands(walk_state,
657 							    op->common.value.
658 							    arg);
659 				if (ACPI_SUCCESS(status)) {
660 					status =
661 					    acpi_ex_create_method(op->named.
662 								  data,
663 								  op->named.
664 								  length,
665 								  walk_state);
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