xref: /linux/drivers/acpi/acpica/nsutils.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /******************************************************************************
2  *
3  * Module Name: nsutils - Utilities for accessing ACPI namespace, accessing
4  *                        parents and siblings and Scope manipulation
5  *
6  *****************************************************************************/
7 
8 /*
9  * Copyright (C) 2000 - 2017, 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 "acnamesp.h"
48 #include "amlcode.h"
49 
50 #define _COMPONENT          ACPI_NAMESPACE
51 ACPI_MODULE_NAME("nsutils")
52 
53 /* Local prototypes */
54 #ifdef ACPI_OBSOLETE_FUNCTIONS
55 acpi_name acpi_ns_find_parent_name(struct acpi_namespace_node *node_to_search);
56 #endif
57 
58 /*******************************************************************************
59  *
60  * FUNCTION:    acpi_ns_print_node_pathname
61  *
62  * PARAMETERS:  node            - Object
63  *              message         - Prefix message
64  *
65  * DESCRIPTION: Print an object's full namespace pathname
66  *              Manages allocation/freeing of a pathname buffer
67  *
68  ******************************************************************************/
69 
70 void
71 acpi_ns_print_node_pathname(struct acpi_namespace_node *node,
72 			    const char *message)
73 {
74 	struct acpi_buffer buffer;
75 	acpi_status status;
76 
77 	if (!node) {
78 		acpi_os_printf("[NULL NAME]");
79 		return;
80 	}
81 
82 	/* Convert handle to full pathname and print it (with supplied message) */
83 
84 	buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;
85 
86 	status = acpi_ns_handle_to_pathname(node, &buffer, TRUE);
87 	if (ACPI_SUCCESS(status)) {
88 		if (message) {
89 			acpi_os_printf("%s ", message);
90 		}
91 
92 		acpi_os_printf("[%s] (Node %p)", (char *)buffer.pointer, node);
93 		ACPI_FREE(buffer.pointer);
94 	}
95 }
96 
97 /*******************************************************************************
98  *
99  * FUNCTION:    acpi_ns_get_type
100  *
101  * PARAMETERS:  node        - Parent Node to be examined
102  *
103  * RETURN:      Type field from Node whose handle is passed
104  *
105  * DESCRIPTION: Return the type of a Namespace node
106  *
107  ******************************************************************************/
108 
109 acpi_object_type acpi_ns_get_type(struct acpi_namespace_node * node)
110 {
111 	ACPI_FUNCTION_TRACE(ns_get_type);
112 
113 	if (!node) {
114 		ACPI_WARNING((AE_INFO, "Null Node parameter"));
115 		return_UINT8(ACPI_TYPE_ANY);
116 	}
117 
118 	return_UINT8(node->type);
119 }
120 
121 /*******************************************************************************
122  *
123  * FUNCTION:    acpi_ns_local
124  *
125  * PARAMETERS:  type        - A namespace object type
126  *
127  * RETURN:      LOCAL if names must be found locally in objects of the
128  *              passed type, 0 if enclosing scopes should be searched
129  *
130  * DESCRIPTION: Returns scope rule for the given object type.
131  *
132  ******************************************************************************/
133 
134 u32 acpi_ns_local(acpi_object_type type)
135 {
136 	ACPI_FUNCTION_TRACE(ns_local);
137 
138 	if (!acpi_ut_valid_object_type(type)) {
139 
140 		/* Type code out of range  */
141 
142 		ACPI_WARNING((AE_INFO, "Invalid Object Type 0x%X", type));
143 		return_UINT32(ACPI_NS_NORMAL);
144 	}
145 
146 	return_UINT32(acpi_gbl_ns_properties[type] & ACPI_NS_LOCAL);
147 }
148 
149 /*******************************************************************************
150  *
151  * FUNCTION:    acpi_ns_get_internal_name_length
152  *
153  * PARAMETERS:  info            - Info struct initialized with the
154  *                                external name pointer.
155  *
156  * RETURN:      None
157  *
158  * DESCRIPTION: Calculate the length of the internal (AML) namestring
159  *              corresponding to the external (ASL) namestring.
160  *
161  ******************************************************************************/
162 
163 void acpi_ns_get_internal_name_length(struct acpi_namestring_info *info)
164 {
165 	const char *next_external_char;
166 	u32 i;
167 
168 	ACPI_FUNCTION_ENTRY();
169 
170 	next_external_char = info->external_name;
171 	info->num_carats = 0;
172 	info->num_segments = 0;
173 	info->fully_qualified = FALSE;
174 
175 	/*
176 	 * For the internal name, the required length is 4 bytes per segment,
177 	 * plus 1 each for root_prefix, multi_name_prefix_op, segment count,
178 	 * trailing null (which is not really needed, but no there's harm in
179 	 * putting it there)
180 	 *
181 	 * strlen() + 1 covers the first name_seg, which has no path separator
182 	 */
183 	if (ACPI_IS_ROOT_PREFIX(*next_external_char)) {
184 		info->fully_qualified = TRUE;
185 		next_external_char++;
186 
187 		/* Skip redundant root_prefix, like \\_SB.PCI0.SBRG.EC0 */
188 
189 		while (ACPI_IS_ROOT_PREFIX(*next_external_char)) {
190 			next_external_char++;
191 		}
192 	} else {
193 		/* Handle Carat prefixes */
194 
195 		while (ACPI_IS_PARENT_PREFIX(*next_external_char)) {
196 			info->num_carats++;
197 			next_external_char++;
198 		}
199 	}
200 
201 	/*
202 	 * Determine the number of ACPI name "segments" by counting the number of
203 	 * path separators within the string. Start with one segment since the
204 	 * segment count is [(# separators) + 1], and zero separators is ok.
205 	 */
206 	if (*next_external_char) {
207 		info->num_segments = 1;
208 		for (i = 0; next_external_char[i]; i++) {
209 			if (ACPI_IS_PATH_SEPARATOR(next_external_char[i])) {
210 				info->num_segments++;
211 			}
212 		}
213 	}
214 
215 	info->length = (ACPI_NAME_SIZE * info->num_segments) +
216 	    4 + info->num_carats;
217 
218 	info->next_external_char = next_external_char;
219 }
220 
221 /*******************************************************************************
222  *
223  * FUNCTION:    acpi_ns_build_internal_name
224  *
225  * PARAMETERS:  info            - Info struct fully initialized
226  *
227  * RETURN:      Status
228  *
229  * DESCRIPTION: Construct the internal (AML) namestring
230  *              corresponding to the external (ASL) namestring.
231  *
232  ******************************************************************************/
233 
234 acpi_status acpi_ns_build_internal_name(struct acpi_namestring_info *info)
235 {
236 	u32 num_segments = info->num_segments;
237 	char *internal_name = info->internal_name;
238 	const char *external_name = info->next_external_char;
239 	char *result = NULL;
240 	u32 i;
241 
242 	ACPI_FUNCTION_TRACE(ns_build_internal_name);
243 
244 	/* Setup the correct prefixes, counts, and pointers */
245 
246 	if (info->fully_qualified) {
247 		internal_name[0] = AML_ROOT_PREFIX;
248 
249 		if (num_segments <= 1) {
250 			result = &internal_name[1];
251 		} else if (num_segments == 2) {
252 			internal_name[1] = AML_DUAL_NAME_PREFIX;
253 			result = &internal_name[2];
254 		} else {
255 			internal_name[1] = AML_MULTI_NAME_PREFIX_OP;
256 			internal_name[2] = (char)num_segments;
257 			result = &internal_name[3];
258 		}
259 	} else {
260 		/*
261 		 * Not fully qualified.
262 		 * Handle Carats first, then append the name segments
263 		 */
264 		i = 0;
265 		if (info->num_carats) {
266 			for (i = 0; i < info->num_carats; i++) {
267 				internal_name[i] = AML_PARENT_PREFIX;
268 			}
269 		}
270 
271 		if (num_segments <= 1) {
272 			result = &internal_name[i];
273 		} else if (num_segments == 2) {
274 			internal_name[i] = AML_DUAL_NAME_PREFIX;
275 			result = &internal_name[(acpi_size)i + 1];
276 		} else {
277 			internal_name[i] = AML_MULTI_NAME_PREFIX_OP;
278 			internal_name[(acpi_size)i + 1] = (char)num_segments;
279 			result = &internal_name[(acpi_size)i + 2];
280 		}
281 	}
282 
283 	/* Build the name (minus path separators) */
284 
285 	for (; num_segments; num_segments--) {
286 		for (i = 0; i < ACPI_NAME_SIZE; i++) {
287 			if (ACPI_IS_PATH_SEPARATOR(*external_name) ||
288 			    (*external_name == 0)) {
289 
290 				/* Pad the segment with underscore(s) if segment is short */
291 
292 				result[i] = '_';
293 			} else {
294 				/* Convert the character to uppercase and save it */
295 
296 				result[i] = (char)toupper((int)*external_name);
297 				external_name++;
298 			}
299 		}
300 
301 		/* Now we must have a path separator, or the pathname is bad */
302 
303 		if (!ACPI_IS_PATH_SEPARATOR(*external_name) &&
304 		    (*external_name != 0)) {
305 			return_ACPI_STATUS(AE_BAD_PATHNAME);
306 		}
307 
308 		/* Move on the next segment */
309 
310 		external_name++;
311 		result += ACPI_NAME_SIZE;
312 	}
313 
314 	/* Terminate the string */
315 
316 	*result = 0;
317 
318 	if (info->fully_qualified) {
319 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
320 				  "Returning [%p] (abs) \"\\%s\"\n",
321 				  internal_name, internal_name));
322 	} else {
323 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Returning [%p] (rel) \"%s\"\n",
324 				  internal_name, internal_name));
325 	}
326 
327 	return_ACPI_STATUS(AE_OK);
328 }
329 
330 /*******************************************************************************
331  *
332  * FUNCTION:    acpi_ns_internalize_name
333  *
334  * PARAMETERS:  *external_name          - External representation of name
335  *              **Converted name        - Where to return the resulting
336  *                                        internal represention of the name
337  *
338  * RETURN:      Status
339  *
340  * DESCRIPTION: Convert an external representation (e.g. "\_PR_.CPU0")
341  *              to internal form (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
342  *
343  *******************************************************************************/
344 
345 acpi_status
346 acpi_ns_internalize_name(const char *external_name, char **converted_name)
347 {
348 	char *internal_name;
349 	struct acpi_namestring_info info;
350 	acpi_status status;
351 
352 	ACPI_FUNCTION_TRACE(ns_internalize_name);
353 
354 	if ((!external_name) || (*external_name == 0) || (!converted_name)) {
355 		return_ACPI_STATUS(AE_BAD_PARAMETER);
356 	}
357 
358 	/* Get the length of the new internal name */
359 
360 	info.external_name = external_name;
361 	acpi_ns_get_internal_name_length(&info);
362 
363 	/* We need a segment to store the internal  name */
364 
365 	internal_name = ACPI_ALLOCATE_ZEROED(info.length);
366 	if (!internal_name) {
367 		return_ACPI_STATUS(AE_NO_MEMORY);
368 	}
369 
370 	/* Build the name */
371 
372 	info.internal_name = internal_name;
373 	status = acpi_ns_build_internal_name(&info);
374 	if (ACPI_FAILURE(status)) {
375 		ACPI_FREE(internal_name);
376 		return_ACPI_STATUS(status);
377 	}
378 
379 	*converted_name = internal_name;
380 	return_ACPI_STATUS(AE_OK);
381 }
382 
383 /*******************************************************************************
384  *
385  * FUNCTION:    acpi_ns_externalize_name
386  *
387  * PARAMETERS:  internal_name_length - Lenth of the internal name below
388  *              internal_name       - Internal representation of name
389  *              converted_name_length - Where the length is returned
390  *              converted_name      - Where the resulting external name
391  *                                    is returned
392  *
393  * RETURN:      Status
394  *
395  * DESCRIPTION: Convert internal name (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
396  *              to its external (printable) form (e.g. "\_PR_.CPU0")
397  *
398  ******************************************************************************/
399 
400 acpi_status
401 acpi_ns_externalize_name(u32 internal_name_length,
402 			 const char *internal_name,
403 			 u32 * converted_name_length, char **converted_name)
404 {
405 	u32 names_index = 0;
406 	u32 num_segments = 0;
407 	u32 required_length;
408 	u32 prefix_length = 0;
409 	u32 i = 0;
410 	u32 j = 0;
411 
412 	ACPI_FUNCTION_TRACE(ns_externalize_name);
413 
414 	if (!internal_name_length || !internal_name || !converted_name) {
415 		return_ACPI_STATUS(AE_BAD_PARAMETER);
416 	}
417 
418 	/* Check for a prefix (one '\' | one or more '^') */
419 
420 	switch (internal_name[0]) {
421 	case AML_ROOT_PREFIX:
422 
423 		prefix_length = 1;
424 		break;
425 
426 	case AML_PARENT_PREFIX:
427 
428 		for (i = 0; i < internal_name_length; i++) {
429 			if (ACPI_IS_PARENT_PREFIX(internal_name[i])) {
430 				prefix_length = i + 1;
431 			} else {
432 				break;
433 			}
434 		}
435 
436 		if (i == internal_name_length) {
437 			prefix_length = i;
438 		}
439 
440 		break;
441 
442 	default:
443 
444 		break;
445 	}
446 
447 	/*
448 	 * Check for object names. Note that there could be 0-255 of these
449 	 * 4-byte elements.
450 	 */
451 	if (prefix_length < internal_name_length) {
452 		switch (internal_name[prefix_length]) {
453 		case AML_MULTI_NAME_PREFIX_OP:
454 
455 			/* <count> 4-byte names */
456 
457 			names_index = prefix_length + 2;
458 			num_segments = (u8)
459 			    internal_name[(acpi_size)prefix_length + 1];
460 			break;
461 
462 		case AML_DUAL_NAME_PREFIX:
463 
464 			/* Two 4-byte names */
465 
466 			names_index = prefix_length + 1;
467 			num_segments = 2;
468 			break;
469 
470 		case 0:
471 
472 			/* null_name */
473 
474 			names_index = 0;
475 			num_segments = 0;
476 			break;
477 
478 		default:
479 
480 			/* one 4-byte name */
481 
482 			names_index = prefix_length;
483 			num_segments = 1;
484 			break;
485 		}
486 	}
487 
488 	/*
489 	 * Calculate the length of converted_name, which equals the length
490 	 * of the prefix, length of all object names, length of any required
491 	 * punctuation ('.') between object names, plus the NULL terminator.
492 	 */
493 	required_length = prefix_length + (4 * num_segments) +
494 	    ((num_segments > 0) ? (num_segments - 1) : 0) + 1;
495 
496 	/*
497 	 * Check to see if we're still in bounds. If not, there's a problem
498 	 * with internal_name (invalid format).
499 	 */
500 	if (required_length > internal_name_length) {
501 		ACPI_ERROR((AE_INFO, "Invalid internal name"));
502 		return_ACPI_STATUS(AE_BAD_PATHNAME);
503 	}
504 
505 	/* Build the converted_name */
506 
507 	*converted_name = ACPI_ALLOCATE_ZEROED(required_length);
508 	if (!(*converted_name)) {
509 		return_ACPI_STATUS(AE_NO_MEMORY);
510 	}
511 
512 	j = 0;
513 
514 	for (i = 0; i < prefix_length; i++) {
515 		(*converted_name)[j++] = internal_name[i];
516 	}
517 
518 	if (num_segments > 0) {
519 		for (i = 0; i < num_segments; i++) {
520 			if (i > 0) {
521 				(*converted_name)[j++] = '.';
522 			}
523 
524 			/* Copy and validate the 4-char name segment */
525 
526 			ACPI_MOVE_NAME(&(*converted_name)[j],
527 				       &internal_name[names_index]);
528 			acpi_ut_repair_name(&(*converted_name)[j]);
529 
530 			j += ACPI_NAME_SIZE;
531 			names_index += ACPI_NAME_SIZE;
532 		}
533 	}
534 
535 	if (converted_name_length) {
536 		*converted_name_length = (u32) required_length;
537 	}
538 
539 	return_ACPI_STATUS(AE_OK);
540 }
541 
542 /*******************************************************************************
543  *
544  * FUNCTION:    acpi_ns_validate_handle
545  *
546  * PARAMETERS:  handle          - Handle to be validated and typecast to a
547  *                                namespace node.
548  *
549  * RETURN:      A pointer to a namespace node
550  *
551  * DESCRIPTION: Convert a namespace handle to a namespace node. Handles special
552  *              cases for the root node.
553  *
554  * NOTE: Real integer handles would allow for more verification
555  *       and keep all pointers within this subsystem - however this introduces
556  *       more overhead and has not been necessary to this point. Drivers
557  *       holding handles are typically notified before a node becomes invalid
558  *       due to a table unload.
559  *
560  ******************************************************************************/
561 
562 struct acpi_namespace_node *acpi_ns_validate_handle(acpi_handle handle)
563 {
564 
565 	ACPI_FUNCTION_ENTRY();
566 
567 	/* Parameter validation */
568 
569 	if ((!handle) || (handle == ACPI_ROOT_OBJECT)) {
570 		return (acpi_gbl_root_node);
571 	}
572 
573 	/* We can at least attempt to verify the handle */
574 
575 	if (ACPI_GET_DESCRIPTOR_TYPE(handle) != ACPI_DESC_TYPE_NAMED) {
576 		return (NULL);
577 	}
578 
579 	return (ACPI_CAST_PTR(struct acpi_namespace_node, handle));
580 }
581 
582 /*******************************************************************************
583  *
584  * FUNCTION:    acpi_ns_terminate
585  *
586  * PARAMETERS:  none
587  *
588  * RETURN:      none
589  *
590  * DESCRIPTION: free memory allocated for namespace and ACPI table storage.
591  *
592  ******************************************************************************/
593 
594 void acpi_ns_terminate(void)
595 {
596 	acpi_status status;
597 
598 	ACPI_FUNCTION_TRACE(ns_terminate);
599 
600 #ifdef ACPI_EXEC_APP
601 	{
602 		union acpi_operand_object *prev;
603 		union acpi_operand_object *next;
604 
605 		/* Delete any module-level code blocks */
606 
607 		next = acpi_gbl_module_code_list;
608 		while (next) {
609 			prev = next;
610 			next = next->method.mutex;
611 			prev->method.mutex = NULL;	/* Clear the Mutex (cheated) field */
612 			acpi_ut_remove_reference(prev);
613 		}
614 	}
615 #endif
616 
617 	/*
618 	 * Free the entire namespace -- all nodes and all objects
619 	 * attached to the nodes
620 	 */
621 	acpi_ns_delete_namespace_subtree(acpi_gbl_root_node);
622 
623 	/* Delete any objects attached to the root node */
624 
625 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
626 	if (ACPI_FAILURE(status)) {
627 		return_VOID;
628 	}
629 
630 	acpi_ns_delete_node(acpi_gbl_root_node);
631 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
632 
633 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Namespace freed\n"));
634 	return_VOID;
635 }
636 
637 /*******************************************************************************
638  *
639  * FUNCTION:    acpi_ns_opens_scope
640  *
641  * PARAMETERS:  type        - A valid namespace type
642  *
643  * RETURN:      NEWSCOPE if the passed type "opens a name scope" according
644  *              to the ACPI specification, else 0
645  *
646  ******************************************************************************/
647 
648 u32 acpi_ns_opens_scope(acpi_object_type type)
649 {
650 	ACPI_FUNCTION_ENTRY();
651 
652 	if (type > ACPI_TYPE_LOCAL_MAX) {
653 
654 		/* type code out of range  */
655 
656 		ACPI_WARNING((AE_INFO, "Invalid Object Type 0x%X", type));
657 		return (ACPI_NS_NORMAL);
658 	}
659 
660 	return (((u32)acpi_gbl_ns_properties[type]) & ACPI_NS_NEWSCOPE);
661 }
662 
663 /*******************************************************************************
664  *
665  * FUNCTION:    acpi_ns_get_node_unlocked
666  *
667  * PARAMETERS:  *pathname   - Name to be found, in external (ASL) format. The
668  *                            \ (backslash) and ^ (carat) prefixes, and the
669  *                            . (period) to separate segments are supported.
670  *              prefix_node  - Root of subtree to be searched, or NS_ALL for the
671  *                            root of the name space. If Name is fully
672  *                            qualified (first s8 is '\'), the passed value
673  *                            of Scope will not be accessed.
674  *              flags       - Used to indicate whether to perform upsearch or
675  *                            not.
676  *              return_node - Where the Node is returned
677  *
678  * DESCRIPTION: Look up a name relative to a given scope and return the
679  *              corresponding Node. NOTE: Scope can be null.
680  *
681  * MUTEX:       Doesn't locks namespace
682  *
683  ******************************************************************************/
684 
685 acpi_status
686 acpi_ns_get_node_unlocked(struct acpi_namespace_node *prefix_node,
687 			  const char *pathname,
688 			  u32 flags, struct acpi_namespace_node **return_node)
689 {
690 	union acpi_generic_state scope_info;
691 	acpi_status status;
692 	char *internal_path;
693 
694 	ACPI_FUNCTION_TRACE_PTR(ns_get_node_unlocked,
695 				ACPI_CAST_PTR(char, pathname));
696 
697 	/* Simplest case is a null pathname */
698 
699 	if (!pathname) {
700 		*return_node = prefix_node;
701 		if (!prefix_node) {
702 			*return_node = acpi_gbl_root_node;
703 		}
704 
705 		return_ACPI_STATUS(AE_OK);
706 	}
707 
708 	/* Quick check for a reference to the root */
709 
710 	if (ACPI_IS_ROOT_PREFIX(pathname[0]) && (!pathname[1])) {
711 		*return_node = acpi_gbl_root_node;
712 		return_ACPI_STATUS(AE_OK);
713 	}
714 
715 	/* Convert path to internal representation */
716 
717 	status = acpi_ns_internalize_name(pathname, &internal_path);
718 	if (ACPI_FAILURE(status)) {
719 		return_ACPI_STATUS(status);
720 	}
721 
722 	/* Setup lookup scope (search starting point) */
723 
724 	scope_info.scope.node = prefix_node;
725 
726 	/* Lookup the name in the namespace */
727 
728 	status = acpi_ns_lookup(&scope_info, internal_path, ACPI_TYPE_ANY,
729 				ACPI_IMODE_EXECUTE,
730 				(flags | ACPI_NS_DONT_OPEN_SCOPE), NULL,
731 				return_node);
732 	if (ACPI_FAILURE(status)) {
733 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s, %s\n",
734 				  pathname, acpi_format_exception(status)));
735 	}
736 
737 	ACPI_FREE(internal_path);
738 	return_ACPI_STATUS(status);
739 }
740 
741 /*******************************************************************************
742  *
743  * FUNCTION:    acpi_ns_get_node
744  *
745  * PARAMETERS:  *pathname   - Name to be found, in external (ASL) format. The
746  *                            \ (backslash) and ^ (carat) prefixes, and the
747  *                            . (period) to separate segments are supported.
748  *              prefix_node  - Root of subtree to be searched, or NS_ALL for the
749  *                            root of the name space. If Name is fully
750  *                            qualified (first s8 is '\'), the passed value
751  *                            of Scope will not be accessed.
752  *              flags       - Used to indicate whether to perform upsearch or
753  *                            not.
754  *              return_node - Where the Node is returned
755  *
756  * DESCRIPTION: Look up a name relative to a given scope and return the
757  *              corresponding Node. NOTE: Scope can be null.
758  *
759  * MUTEX:       Locks namespace
760  *
761  ******************************************************************************/
762 
763 acpi_status
764 acpi_ns_get_node(struct acpi_namespace_node *prefix_node,
765 		 const char *pathname,
766 		 u32 flags, struct acpi_namespace_node **return_node)
767 {
768 	acpi_status status;
769 
770 	ACPI_FUNCTION_TRACE_PTR(ns_get_node, ACPI_CAST_PTR(char, pathname));
771 
772 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
773 	if (ACPI_FAILURE(status)) {
774 		return_ACPI_STATUS(status);
775 	}
776 
777 	status = acpi_ns_get_node_unlocked(prefix_node, pathname,
778 					   flags, return_node);
779 
780 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
781 	return_ACPI_STATUS(status);
782 }
783