xref: /openbmc/linux/drivers/acpi/acpica/nsaccess.c (revision 63705da3)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /*******************************************************************************
3  *
4  * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
5  *
6  ******************************************************************************/
7 
8 #include <acpi/acpi.h>
9 #include "accommon.h"
10 #include "amlcode.h"
11 #include "acnamesp.h"
12 #include "acdispat.h"
13 
14 #ifdef ACPI_ASL_COMPILER
15 #include "acdisasm.h"
16 #endif
17 
18 #define _COMPONENT          ACPI_NAMESPACE
19 ACPI_MODULE_NAME("nsaccess")
20 
21 /*******************************************************************************
22  *
23  * FUNCTION:    acpi_ns_root_initialize
24  *
25  * PARAMETERS:  None
26  *
27  * RETURN:      Status
28  *
29  * DESCRIPTION: Allocate and initialize the default root named objects
30  *
31  * MUTEX:       Locks namespace for entire execution
32  *
33  ******************************************************************************/
34 acpi_status acpi_ns_root_initialize(void)
35 {
36 	acpi_status status;
37 	const struct acpi_predefined_names *init_val = NULL;
38 	struct acpi_namespace_node *new_node;
39 	struct acpi_namespace_node *prev_node = NULL;
40 	union acpi_operand_object *obj_desc;
41 	acpi_string val = NULL;
42 
43 	ACPI_FUNCTION_TRACE(ns_root_initialize);
44 
45 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
46 	if (ACPI_FAILURE(status)) {
47 		return_ACPI_STATUS(status);
48 	}
49 
50 	/*
51 	 * The global root ptr is initially NULL, so a non-NULL value indicates
52 	 * that acpi_ns_root_initialize() has already been called; just return.
53 	 */
54 	if (acpi_gbl_root_node) {
55 		status = AE_OK;
56 		goto unlock_and_exit;
57 	}
58 
59 	/*
60 	 * Tell the rest of the subsystem that the root is initialized
61 	 * (This is OK because the namespace is locked)
62 	 */
63 	acpi_gbl_root_node = &acpi_gbl_root_node_struct;
64 
65 	/* Enter the predefined names in the name table */
66 
67 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
68 			  "Entering predefined entries into namespace\n"));
69 
70 	/*
71 	 * Create the initial (default) namespace.
72 	 * This namespace looks like something similar to this:
73 	 *
74 	 *   ACPI Namespace (from Namespace Root):
75 	 *    0  _GPE Scope        00203160 00
76 	 *    0  _PR_ Scope        002031D0 00
77 	 *    0  _SB_ Device       00203240 00 Notify Object: 0020ADD8
78 	 *    0  _SI_ Scope        002032B0 00
79 	 *    0  _TZ_ Device       00203320 00
80 	 *    0  _REV Integer      00203390 00 = 0000000000000002
81 	 *    0  _OS_ String       00203488 00 Len 14 "Microsoft Windows NT"
82 	 *    0  _GL_ Mutex        00203580 00 Object 002035F0
83 	 *    0  _OSI Method       00203678 00 Args 1 Len 0000 Aml 00000000
84 	 */
85 	for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
86 		status = AE_OK;
87 
88 		/* _OSI is optional for now, will be permanent later */
89 
90 		if (!strcmp(init_val->name, "_OSI")
91 		    && !acpi_gbl_create_osi_method) {
92 			continue;
93 		}
94 
95 		/*
96 		 * Create, init, and link the new predefined name
97 		 * Note: No need to use acpi_ns_lookup here because all the
98 		 * predefined names are at the root level. It is much easier to
99 		 * just create and link the new node(s) here.
100 		 */
101 		new_node =
102 		    acpi_ns_create_node(*ACPI_CAST_PTR(u32, init_val->name));
103 		if (!new_node) {
104 			status = AE_NO_MEMORY;
105 			goto unlock_and_exit;
106 		}
107 
108 		new_node->descriptor_type = ACPI_DESC_TYPE_NAMED;
109 		new_node->type = init_val->type;
110 
111 		if (!prev_node) {
112 			acpi_gbl_root_node_struct.child = new_node;
113 		} else {
114 			prev_node->peer = new_node;
115 		}
116 
117 		new_node->parent = &acpi_gbl_root_node_struct;
118 		prev_node = new_node;
119 
120 		/*
121 		 * Name entered successfully. If entry in pre_defined_names[] specifies
122 		 * an initial value, create the initial value.
123 		 */
124 		if (init_val->val) {
125 			status = acpi_os_predefined_override(init_val, &val);
126 			if (ACPI_FAILURE(status)) {
127 				ACPI_ERROR((AE_INFO,
128 					    "Could not override predefined %s",
129 					    init_val->name));
130 			}
131 
132 			if (!val) {
133 				val = init_val->val;
134 			}
135 
136 			/*
137 			 * Entry requests an initial value, allocate a
138 			 * descriptor for it.
139 			 */
140 			obj_desc =
141 			    acpi_ut_create_internal_object(init_val->type);
142 			if (!obj_desc) {
143 				status = AE_NO_MEMORY;
144 				goto unlock_and_exit;
145 			}
146 
147 			/*
148 			 * Convert value string from table entry to
149 			 * internal representation. Only types actually
150 			 * used for initial values are implemented here.
151 			 */
152 			switch (init_val->type) {
153 			case ACPI_TYPE_METHOD:
154 
155 				obj_desc->method.param_count =
156 				    (u8) ACPI_TO_INTEGER(val);
157 				obj_desc->common.flags |= AOPOBJ_DATA_VALID;
158 
159 #if defined (ACPI_ASL_COMPILER)
160 
161 				/* Save the parameter count for the iASL compiler */
162 
163 				new_node->value = obj_desc->method.param_count;
164 #else
165 				/* Mark this as a very SPECIAL method (_OSI) */
166 
167 				obj_desc->method.info_flags =
168 				    ACPI_METHOD_INTERNAL_ONLY;
169 				obj_desc->method.dispatch.implementation =
170 				    acpi_ut_osi_implementation;
171 #endif
172 				break;
173 
174 			case ACPI_TYPE_INTEGER:
175 
176 				obj_desc->integer.value = ACPI_TO_INTEGER(val);
177 				break;
178 
179 			case ACPI_TYPE_STRING:
180 
181 				/* Build an object around the static string */
182 
183 				obj_desc->string.length = (u32)strlen(val);
184 				obj_desc->string.pointer = val;
185 				obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
186 				break;
187 
188 			case ACPI_TYPE_MUTEX:
189 
190 				obj_desc->mutex.node = new_node;
191 				obj_desc->mutex.sync_level =
192 				    (u8) (ACPI_TO_INTEGER(val) - 1);
193 
194 				/* Create a mutex */
195 
196 				status =
197 				    acpi_os_create_mutex(&obj_desc->mutex.
198 							 os_mutex);
199 				if (ACPI_FAILURE(status)) {
200 					acpi_ut_remove_reference(obj_desc);
201 					goto unlock_and_exit;
202 				}
203 
204 				/* Special case for ACPI Global Lock */
205 
206 				if (strcmp(init_val->name, "_GL_") == 0) {
207 					acpi_gbl_global_lock_mutex = obj_desc;
208 
209 					/* Create additional counting semaphore for global lock */
210 
211 					status =
212 					    acpi_os_create_semaphore(1, 0,
213 								     &acpi_gbl_global_lock_semaphore);
214 					if (ACPI_FAILURE(status)) {
215 						acpi_ut_remove_reference
216 						    (obj_desc);
217 						goto unlock_and_exit;
218 					}
219 				}
220 				break;
221 
222 			default:
223 
224 				ACPI_ERROR((AE_INFO,
225 					    "Unsupported initial type value 0x%X",
226 					    init_val->type));
227 				acpi_ut_remove_reference(obj_desc);
228 				obj_desc = NULL;
229 				continue;
230 			}
231 
232 			/* Store pointer to value descriptor in the Node */
233 
234 			status = acpi_ns_attach_object(new_node, obj_desc,
235 						       obj_desc->common.type);
236 
237 			/* Remove local reference to the object */
238 
239 			acpi_ut_remove_reference(obj_desc);
240 		}
241 	}
242 
243 unlock_and_exit:
244 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
245 
246 	/* Save a handle to "_GPE", it is always present */
247 
248 	if (ACPI_SUCCESS(status)) {
249 		status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
250 					  &acpi_gbl_fadt_gpe_device);
251 	}
252 
253 	return_ACPI_STATUS(status);
254 }
255 
256 /*******************************************************************************
257  *
258  * FUNCTION:    acpi_ns_lookup
259  *
260  * PARAMETERS:  scope_info      - Current scope info block
261  *              pathname        - Search pathname, in internal format
262  *                                (as represented in the AML stream)
263  *              type            - Type associated with name
264  *              interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
265  *              flags           - Flags describing the search restrictions
266  *              walk_state      - Current state of the walk
267  *              return_node     - Where the Node is placed (if found
268  *                                or created successfully)
269  *
270  * RETURN:      Status
271  *
272  * DESCRIPTION: Find or enter the passed name in the name space.
273  *              Log an error if name not found in Exec mode.
274  *
275  * MUTEX:       Assumes namespace is locked.
276  *
277  ******************************************************************************/
278 
279 acpi_status
280 acpi_ns_lookup(union acpi_generic_state *scope_info,
281 	       char *pathname,
282 	       acpi_object_type type,
283 	       acpi_interpreter_mode interpreter_mode,
284 	       u32 flags,
285 	       struct acpi_walk_state *walk_state,
286 	       struct acpi_namespace_node **return_node)
287 {
288 	acpi_status status;
289 	char *path = pathname;
290 	char *external_path;
291 	struct acpi_namespace_node *prefix_node;
292 	struct acpi_namespace_node *current_node = NULL;
293 	struct acpi_namespace_node *this_node = NULL;
294 	u32 num_segments;
295 	u32 num_carats;
296 	acpi_name simple_name;
297 	acpi_object_type type_to_check_for;
298 	acpi_object_type this_search_type;
299 	u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
300 	u32 local_flags;
301 	acpi_interpreter_mode local_interpreter_mode;
302 
303 	ACPI_FUNCTION_TRACE(ns_lookup);
304 
305 	if (!return_node) {
306 		return_ACPI_STATUS(AE_BAD_PARAMETER);
307 	}
308 
309 	local_flags = flags &
310 	    ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_OVERRIDE_IF_FOUND |
311 	      ACPI_NS_SEARCH_PARENT);
312 	*return_node = ACPI_ENTRY_NOT_FOUND;
313 	acpi_gbl_ns_lookup_count++;
314 
315 	if (!acpi_gbl_root_node) {
316 		return_ACPI_STATUS(AE_NO_NAMESPACE);
317 	}
318 
319 	/* Get the prefix scope. A null scope means use the root scope */
320 
321 	if ((!scope_info) || (!scope_info->scope.node)) {
322 		ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
323 				  "Null scope prefix, using root node (%p)\n",
324 				  acpi_gbl_root_node));
325 
326 		prefix_node = acpi_gbl_root_node;
327 	} else {
328 		prefix_node = scope_info->scope.node;
329 		if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
330 		    ACPI_DESC_TYPE_NAMED) {
331 			ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
332 				    prefix_node,
333 				    acpi_ut_get_descriptor_name(prefix_node)));
334 			return_ACPI_STATUS(AE_AML_INTERNAL);
335 		}
336 
337 		if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
338 			/*
339 			 * This node might not be a actual "scope" node (such as a
340 			 * Device/Method, etc.)  It could be a Package or other object
341 			 * node. Backup up the tree to find the containing scope node.
342 			 */
343 			while (!acpi_ns_opens_scope(prefix_node->type) &&
344 			       prefix_node->type != ACPI_TYPE_ANY) {
345 				prefix_node = prefix_node->parent;
346 			}
347 		}
348 	}
349 
350 	/* Save type. TBD: may be no longer necessary */
351 
352 	type_to_check_for = type;
353 
354 	/*
355 	 * Begin examination of the actual pathname
356 	 */
357 	if (!pathname) {
358 
359 		/* A Null name_path is allowed and refers to the root */
360 
361 		num_segments = 0;
362 		this_node = acpi_gbl_root_node;
363 		path = "";
364 
365 		ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
366 				  "Null Pathname (Zero segments), Flags=%X\n",
367 				  flags));
368 	} else {
369 		/*
370 		 * Name pointer is valid (and must be in internal name format)
371 		 *
372 		 * Check for scope prefixes:
373 		 *
374 		 * As represented in the AML stream, a namepath consists of an
375 		 * optional scope prefix followed by a name segment part.
376 		 *
377 		 * If present, the scope prefix is either a Root Prefix (in
378 		 * which case the name is fully qualified), or one or more
379 		 * Parent Prefixes (in which case the name's scope is relative
380 		 * to the current scope).
381 		 */
382 		if (*path == (u8) AML_ROOT_PREFIX) {
383 
384 			/* Pathname is fully qualified, start from the root */
385 
386 			this_node = acpi_gbl_root_node;
387 			search_parent_flag = ACPI_NS_NO_UPSEARCH;
388 
389 			/* Point to name segment part */
390 
391 			path++;
392 
393 			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
394 					  "Path is absolute from root [%p]\n",
395 					  this_node));
396 		} else {
397 			/* Pathname is relative to current scope, start there */
398 
399 			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
400 					  "Searching relative to prefix scope [%4.4s] (%p)\n",
401 					  acpi_ut_get_node_name(prefix_node),
402 					  prefix_node));
403 
404 			/*
405 			 * Handle multiple Parent Prefixes (carat) by just getting
406 			 * the parent node for each prefix instance.
407 			 */
408 			this_node = prefix_node;
409 			num_carats = 0;
410 			while (*path == (u8) AML_PARENT_PREFIX) {
411 
412 				/* Name is fully qualified, no search rules apply */
413 
414 				search_parent_flag = ACPI_NS_NO_UPSEARCH;
415 
416 				/*
417 				 * Point past this prefix to the name segment
418 				 * part or the next Parent Prefix
419 				 */
420 				path++;
421 
422 				/* Backup to the parent node */
423 
424 				num_carats++;
425 				this_node = this_node->parent;
426 				if (!this_node) {
427 					/*
428 					 * Current scope has no parent scope. Externalize
429 					 * the internal path for error message.
430 					 */
431 					status =
432 					    acpi_ns_externalize_name
433 					    (ACPI_UINT32_MAX, pathname, NULL,
434 					     &external_path);
435 					if (ACPI_SUCCESS(status)) {
436 						ACPI_ERROR((AE_INFO,
437 							    "%s: Path has too many parent prefixes (^)",
438 							    external_path));
439 
440 						ACPI_FREE(external_path);
441 					}
442 
443 					return_ACPI_STATUS(AE_NOT_FOUND);
444 				}
445 			}
446 
447 			if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
448 				ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
449 						  "Search scope is [%4.4s], path has %u carat(s)\n",
450 						  acpi_ut_get_node_name
451 						  (this_node), num_carats));
452 			}
453 		}
454 
455 		/*
456 		 * Determine the number of ACPI name segments in this pathname.
457 		 *
458 		 * The segment part consists of either:
459 		 *  - A Null name segment (0)
460 		 *  - A dual_name_prefix followed by two 4-byte name segments
461 		 *  - A multi_name_prefix followed by a byte indicating the
462 		 *      number of segments and the segments themselves.
463 		 *  - A single 4-byte name segment
464 		 *
465 		 * Examine the name prefix opcode, if any, to determine the number of
466 		 * segments.
467 		 */
468 		switch (*path) {
469 		case 0:
470 			/*
471 			 * Null name after a root or parent prefixes. We already
472 			 * have the correct target node and there are no name segments.
473 			 */
474 			num_segments = 0;
475 			type = this_node->type;
476 
477 			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
478 					  "Prefix-only Pathname (Zero name segments), Flags=%X\n",
479 					  flags));
480 			break;
481 
482 		case AML_DUAL_NAME_PREFIX:
483 
484 			/* More than one name_seg, search rules do not apply */
485 
486 			search_parent_flag = ACPI_NS_NO_UPSEARCH;
487 
488 			/* Two segments, point to first name segment */
489 
490 			num_segments = 2;
491 			path++;
492 
493 			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
494 					  "Dual Pathname (2 segments, Flags=%X)\n",
495 					  flags));
496 			break;
497 
498 		case AML_MULTI_NAME_PREFIX:
499 
500 			/* More than one name_seg, search rules do not apply */
501 
502 			search_parent_flag = ACPI_NS_NO_UPSEARCH;
503 
504 			/* Extract segment count, point to first name segment */
505 
506 			path++;
507 			num_segments = (u32) (u8) * path;
508 			path++;
509 
510 			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
511 					  "Multi Pathname (%u Segments, Flags=%X)\n",
512 					  num_segments, flags));
513 			break;
514 
515 		default:
516 			/*
517 			 * Not a Null name, no Dual or Multi prefix, hence there is
518 			 * only one name segment and Pathname is already pointing to it.
519 			 */
520 			num_segments = 1;
521 
522 			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
523 					  "Simple Pathname (1 segment, Flags=%X)\n",
524 					  flags));
525 			break;
526 		}
527 
528 		ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
529 	}
530 
531 	/*
532 	 * Search namespace for each segment of the name. Loop through and
533 	 * verify (or add to the namespace) each name segment.
534 	 *
535 	 * The object type is significant only at the last name
536 	 * segment. (We don't care about the types along the path, only
537 	 * the type of the final target object.)
538 	 */
539 	this_search_type = ACPI_TYPE_ANY;
540 	current_node = this_node;
541 
542 	while (num_segments && current_node) {
543 		num_segments--;
544 		if (!num_segments) {
545 
546 			/* This is the last segment, enable typechecking */
547 
548 			this_search_type = type;
549 
550 			/*
551 			 * Only allow automatic parent search (search rules) if the caller
552 			 * requested it AND we have a single, non-fully-qualified name_seg
553 			 */
554 			if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
555 			    (flags & ACPI_NS_SEARCH_PARENT)) {
556 				local_flags |= ACPI_NS_SEARCH_PARENT;
557 			}
558 
559 			/* Set error flag according to caller */
560 
561 			if (flags & ACPI_NS_ERROR_IF_FOUND) {
562 				local_flags |= ACPI_NS_ERROR_IF_FOUND;
563 			}
564 
565 			/* Set override flag according to caller */
566 
567 			if (flags & ACPI_NS_OVERRIDE_IF_FOUND) {
568 				local_flags |= ACPI_NS_OVERRIDE_IF_FOUND;
569 			}
570 		}
571 
572 		/* Handle opcodes that create a new name_seg via a full name_path */
573 
574 		local_interpreter_mode = interpreter_mode;
575 		if ((flags & ACPI_NS_PREFIX_MUST_EXIST) && (num_segments > 0)) {
576 
577 			/* Every element of the path must exist (except for the final name_seg) */
578 
579 			local_interpreter_mode = ACPI_IMODE_EXECUTE;
580 		}
581 
582 		/* Extract one ACPI name from the front of the pathname */
583 
584 		ACPI_MOVE_32_TO_32(&simple_name, path);
585 
586 		/* Try to find the single (4 character) ACPI name */
587 
588 		status =
589 		    acpi_ns_search_and_enter(simple_name, walk_state,
590 					     current_node,
591 					     local_interpreter_mode,
592 					     this_search_type, local_flags,
593 					     &this_node);
594 		if (ACPI_FAILURE(status)) {
595 			if (status == AE_NOT_FOUND) {
596 #if !defined ACPI_ASL_COMPILER	/* Note: iASL reports this error by itself, not needed here */
597 				if (flags & ACPI_NS_PREFIX_MUST_EXIST) {
598 					acpi_os_printf(ACPI_MSG_BIOS_ERROR
599 						       "Object does not exist: %4.4s\n",
600 						       (char *)&simple_name);
601 				}
602 #endif
603 				/* Name not found in ACPI namespace */
604 
605 				ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
606 						  "Name [%4.4s] not found in scope [%4.4s] %p\n",
607 						  (char *)&simple_name,
608 						  (char *)&current_node->name,
609 						  current_node));
610 			}
611 #ifdef ACPI_EXEC_APP
612 			if ((status == AE_ALREADY_EXISTS) &&
613 			    (this_node->flags & ANOBJ_NODE_EARLY_INIT)) {
614 				this_node->flags &= ~ANOBJ_NODE_EARLY_INIT;
615 				status = AE_OK;
616 			}
617 #endif
618 
619 #ifdef ACPI_ASL_COMPILER
620 			/*
621 			 * If this ACPI name already exists within the namespace as an
622 			 * external declaration, then mark the external as a conflicting
623 			 * declaration and proceed to process the current node as if it did
624 			 * not exist in the namespace. If this node is not processed as
625 			 * normal, then it could cause improper namespace resolution
626 			 * by failing to open a new scope.
627 			 */
628 			if (acpi_gbl_disasm_flag &&
629 			    (status == AE_ALREADY_EXISTS) &&
630 			    ((this_node->flags & ANOBJ_IS_EXTERNAL) ||
631 			     (walk_state
632 			      && walk_state->opcode == AML_EXTERNAL_OP))) {
633 				this_node->flags &= ~ANOBJ_IS_EXTERNAL;
634 				this_node->type = (u8)this_search_type;
635 				if (walk_state->opcode != AML_EXTERNAL_OP) {
636 					acpi_dm_mark_external_conflict
637 					    (this_node);
638 				}
639 				break;
640 			}
641 #endif
642 
643 			*return_node = this_node;
644 			return_ACPI_STATUS(status);
645 		}
646 
647 		/* More segments to follow? */
648 
649 		if (num_segments > 0) {
650 			/*
651 			 * If we have an alias to an object that opens a scope (such as a
652 			 * device or processor), we need to dereference the alias here so
653 			 * that we can access any children of the original node (via the
654 			 * remaining segments).
655 			 */
656 			if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
657 				if (!this_node->object) {
658 					return_ACPI_STATUS(AE_NOT_EXIST);
659 				}
660 
661 				if (acpi_ns_opens_scope
662 				    (((struct acpi_namespace_node *)
663 				      this_node->object)->type)) {
664 					this_node =
665 					    (struct acpi_namespace_node *)
666 					    this_node->object;
667 				}
668 			}
669 		}
670 
671 		/* Special handling for the last segment (num_segments == 0) */
672 
673 		else {
674 			/*
675 			 * Sanity typecheck of the target object:
676 			 *
677 			 * If 1) This is the last segment (num_segments == 0)
678 			 *    2) And we are looking for a specific type
679 			 *       (Not checking for TYPE_ANY)
680 			 *    3) Which is not an alias
681 			 *    4) Which is not a local type (TYPE_SCOPE)
682 			 *    5) And the type of target object is known (not TYPE_ANY)
683 			 *    6) And target object does not match what we are looking for
684 			 *
685 			 * Then we have a type mismatch. Just warn and ignore it.
686 			 */
687 			if ((type_to_check_for != ACPI_TYPE_ANY) &&
688 			    (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
689 			    (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)
690 			    && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)
691 			    && (this_node->type != ACPI_TYPE_ANY)
692 			    && (this_node->type != type_to_check_for)) {
693 
694 				/* Complain about a type mismatch */
695 
696 				ACPI_WARNING((AE_INFO,
697 					      "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
698 					      ACPI_CAST_PTR(char, &simple_name),
699 					      acpi_ut_get_type_name(this_node->
700 								    type),
701 					      acpi_ut_get_type_name
702 					      (type_to_check_for)));
703 			}
704 
705 			/*
706 			 * If this is the last name segment and we are not looking for a
707 			 * specific type, but the type of found object is known, use that
708 			 * type to (later) see if it opens a scope.
709 			 */
710 			if (type == ACPI_TYPE_ANY) {
711 				type = this_node->type;
712 			}
713 		}
714 
715 		/* Point to next name segment and make this node current */
716 
717 		path += ACPI_NAMESEG_SIZE;
718 		current_node = this_node;
719 	}
720 
721 	/* Always check if we need to open a new scope */
722 
723 	if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
724 		/*
725 		 * If entry is a type which opens a scope, push the new scope on the
726 		 * scope stack.
727 		 */
728 		if (acpi_ns_opens_scope(type)) {
729 			status =
730 			    acpi_ds_scope_stack_push(this_node, type,
731 						     walk_state);
732 			if (ACPI_FAILURE(status)) {
733 				return_ACPI_STATUS(status);
734 			}
735 		}
736 	}
737 #ifdef ACPI_EXEC_APP
738 	if (flags & ACPI_NS_EARLY_INIT) {
739 		this_node->flags |= ANOBJ_NODE_EARLY_INIT;
740 	}
741 #endif
742 
743 	*return_node = this_node;
744 	return_ACPI_STATUS(AE_OK);
745 }
746