1  // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2  /******************************************************************************
3   *
4   * Module Name: nsutils - Utilities for accessing ACPI namespace, accessing
5   *                        parents and siblings and Scope manipulation
6   *
7   * Copyright (C) 2000 - 2023, Intel Corp.
8   *
9   *****************************************************************************/
10  
11  #include <acpi/acpi.h>
12  #include "accommon.h"
13  #include "acnamesp.h"
14  #include "amlcode.h"
15  
16  #define _COMPONENT          ACPI_NAMESPACE
17  ACPI_MODULE_NAME("nsutils")
18  
19  /* Local prototypes */
20  #ifdef ACPI_OBSOLETE_FUNCTIONS
21  acpi_name acpi_ns_find_parent_name(struct acpi_namespace_node *node_to_search);
22  #endif
23  
24  /*******************************************************************************
25   *
26   * FUNCTION:    acpi_ns_print_node_pathname
27   *
28   * PARAMETERS:  node            - Object
29   *              message         - Prefix message
30   *
31   * DESCRIPTION: Print an object's full namespace pathname
32   *              Manages allocation/freeing of a pathname buffer
33   *
34   ******************************************************************************/
35  
36  void
acpi_ns_print_node_pathname(struct acpi_namespace_node * node,const char * message)37  acpi_ns_print_node_pathname(struct acpi_namespace_node *node,
38  			    const char *message)
39  {
40  	struct acpi_buffer buffer;
41  	acpi_status status;
42  
43  	if (!node) {
44  		acpi_os_printf("[NULL NAME]");
45  		return;
46  	}
47  
48  	/* Convert handle to full pathname and print it (with supplied message) */
49  
50  	buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;
51  
52  	status = acpi_ns_handle_to_pathname(node, &buffer, TRUE);
53  	if (ACPI_SUCCESS(status)) {
54  		if (message) {
55  			acpi_os_printf("%s ", message);
56  		}
57  
58  		acpi_os_printf("%s", (char *)buffer.pointer);
59  		ACPI_FREE(buffer.pointer);
60  	}
61  }
62  
63  /*******************************************************************************
64   *
65   * FUNCTION:    acpi_ns_get_type
66   *
67   * PARAMETERS:  node        - Parent Node to be examined
68   *
69   * RETURN:      Type field from Node whose handle is passed
70   *
71   * DESCRIPTION: Return the type of a Namespace node
72   *
73   ******************************************************************************/
74  
acpi_ns_get_type(struct acpi_namespace_node * node)75  acpi_object_type acpi_ns_get_type(struct acpi_namespace_node * node)
76  {
77  	ACPI_FUNCTION_TRACE(ns_get_type);
78  
79  	if (!node) {
80  		ACPI_WARNING((AE_INFO, "Null Node parameter"));
81  		return_UINT8(ACPI_TYPE_ANY);
82  	}
83  
84  	return_UINT8(node->type);
85  }
86  
87  /*******************************************************************************
88   *
89   * FUNCTION:    acpi_ns_local
90   *
91   * PARAMETERS:  type        - A namespace object type
92   *
93   * RETURN:      LOCAL if names must be found locally in objects of the
94   *              passed type, 0 if enclosing scopes should be searched
95   *
96   * DESCRIPTION: Returns scope rule for the given object type.
97   *
98   ******************************************************************************/
99  
acpi_ns_local(acpi_object_type type)100  u32 acpi_ns_local(acpi_object_type type)
101  {
102  	ACPI_FUNCTION_TRACE(ns_local);
103  
104  	if (!acpi_ut_valid_object_type(type)) {
105  
106  		/* Type code out of range  */
107  
108  		ACPI_WARNING((AE_INFO, "Invalid Object Type 0x%X", type));
109  		return_UINT32(ACPI_NS_NORMAL);
110  	}
111  
112  	return_UINT32(acpi_gbl_ns_properties[type] & ACPI_NS_LOCAL);
113  }
114  
115  /*******************************************************************************
116   *
117   * FUNCTION:    acpi_ns_get_internal_name_length
118   *
119   * PARAMETERS:  info            - Info struct initialized with the
120   *                                external name pointer.
121   *
122   * RETURN:      None
123   *
124   * DESCRIPTION: Calculate the length of the internal (AML) namestring
125   *              corresponding to the external (ASL) namestring.
126   *
127   ******************************************************************************/
128  
acpi_ns_get_internal_name_length(struct acpi_namestring_info * info)129  void acpi_ns_get_internal_name_length(struct acpi_namestring_info *info)
130  {
131  	const char *next_external_char;
132  	u32 i;
133  
134  	ACPI_FUNCTION_ENTRY();
135  
136  	next_external_char = info->external_name;
137  	info->num_carats = 0;
138  	info->num_segments = 0;
139  	info->fully_qualified = FALSE;
140  
141  	/*
142  	 * For the internal name, the required length is 4 bytes per segment,
143  	 * plus 1 each for root_prefix, multi_name_prefix_op, segment count,
144  	 * trailing null (which is not really needed, but no there's harm in
145  	 * putting it there)
146  	 *
147  	 * strlen() + 1 covers the first name_seg, which has no path separator
148  	 */
149  	if (ACPI_IS_ROOT_PREFIX(*next_external_char)) {
150  		info->fully_qualified = TRUE;
151  		next_external_char++;
152  
153  		/* Skip redundant root_prefix, like \\_SB.PCI0.SBRG.EC0 */
154  
155  		while (ACPI_IS_ROOT_PREFIX(*next_external_char)) {
156  			next_external_char++;
157  		}
158  	} else {
159  		/* Handle Carat prefixes */
160  
161  		while (ACPI_IS_PARENT_PREFIX(*next_external_char)) {
162  			info->num_carats++;
163  			next_external_char++;
164  		}
165  	}
166  
167  	/*
168  	 * Determine the number of ACPI name "segments" by counting the number of
169  	 * path separators within the string. Start with one segment since the
170  	 * segment count is [(# separators) + 1], and zero separators is ok.
171  	 */
172  	if (*next_external_char) {
173  		info->num_segments = 1;
174  		for (i = 0; next_external_char[i]; i++) {
175  			if (ACPI_IS_PATH_SEPARATOR(next_external_char[i])) {
176  				info->num_segments++;
177  			}
178  		}
179  	}
180  
181  	info->length = (ACPI_NAMESEG_SIZE * info->num_segments) +
182  	    4 + info->num_carats;
183  
184  	info->next_external_char = next_external_char;
185  }
186  
187  /*******************************************************************************
188   *
189   * FUNCTION:    acpi_ns_build_internal_name
190   *
191   * PARAMETERS:  info            - Info struct fully initialized
192   *
193   * RETURN:      Status
194   *
195   * DESCRIPTION: Construct the internal (AML) namestring
196   *              corresponding to the external (ASL) namestring.
197   *
198   ******************************************************************************/
199  
acpi_ns_build_internal_name(struct acpi_namestring_info * info)200  acpi_status acpi_ns_build_internal_name(struct acpi_namestring_info *info)
201  {
202  	u32 num_segments = info->num_segments;
203  	char *internal_name = info->internal_name;
204  	const char *external_name = info->next_external_char;
205  	char *result = NULL;
206  	u32 i;
207  
208  	ACPI_FUNCTION_TRACE(ns_build_internal_name);
209  
210  	/* Setup the correct prefixes, counts, and pointers */
211  
212  	if (info->fully_qualified) {
213  		internal_name[0] = AML_ROOT_PREFIX;
214  
215  		if (num_segments <= 1) {
216  			result = &internal_name[1];
217  		} else if (num_segments == 2) {
218  			internal_name[1] = AML_DUAL_NAME_PREFIX;
219  			result = &internal_name[2];
220  		} else {
221  			internal_name[1] = AML_MULTI_NAME_PREFIX;
222  			internal_name[2] = (char)num_segments;
223  			result = &internal_name[3];
224  		}
225  	} else {
226  		/*
227  		 * Not fully qualified.
228  		 * Handle Carats first, then append the name segments
229  		 */
230  		i = 0;
231  		if (info->num_carats) {
232  			for (i = 0; i < info->num_carats; i++) {
233  				internal_name[i] = AML_PARENT_PREFIX;
234  			}
235  		}
236  
237  		if (num_segments <= 1) {
238  			result = &internal_name[i];
239  		} else if (num_segments == 2) {
240  			internal_name[i] = AML_DUAL_NAME_PREFIX;
241  			result = &internal_name[(acpi_size)i + 1];
242  		} else {
243  			internal_name[i] = AML_MULTI_NAME_PREFIX;
244  			internal_name[(acpi_size)i + 1] = (char)num_segments;
245  			result = &internal_name[(acpi_size)i + 2];
246  		}
247  	}
248  
249  	/* Build the name (minus path separators) */
250  
251  	for (; num_segments; num_segments--) {
252  		for (i = 0; i < ACPI_NAMESEG_SIZE; i++) {
253  			if (ACPI_IS_PATH_SEPARATOR(*external_name) ||
254  			    (*external_name == 0)) {
255  
256  				/* Pad the segment with underscore(s) if segment is short */
257  
258  				result[i] = '_';
259  			} else {
260  				/* Convert the character to uppercase and save it */
261  
262  				result[i] = (char)toupper((int)*external_name);
263  				external_name++;
264  			}
265  		}
266  
267  		/* Now we must have a path separator, or the pathname is bad */
268  
269  		if (!ACPI_IS_PATH_SEPARATOR(*external_name) &&
270  		    (*external_name != 0)) {
271  			return_ACPI_STATUS(AE_BAD_PATHNAME);
272  		}
273  
274  		/* Move on the next segment */
275  
276  		external_name++;
277  		result += ACPI_NAMESEG_SIZE;
278  	}
279  
280  	/* Terminate the string */
281  
282  	*result = 0;
283  
284  	if (info->fully_qualified) {
285  		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
286  				  "Returning [%p] (abs) \"\\%s\"\n",
287  				  internal_name, internal_name));
288  	} else {
289  		ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Returning [%p] (rel) \"%s\"\n",
290  				  internal_name, internal_name));
291  	}
292  
293  	return_ACPI_STATUS(AE_OK);
294  }
295  
296  /*******************************************************************************
297   *
298   * FUNCTION:    acpi_ns_internalize_name
299   *
300   * PARAMETERS:  *external_name          - External representation of name
301   *              **Converted name        - Where to return the resulting
302   *                                        internal represention of the name
303   *
304   * RETURN:      Status
305   *
306   * DESCRIPTION: Convert an external representation (e.g. "\_PR_.CPU0")
307   *              to internal form (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
308   *
309   *******************************************************************************/
310  
311  acpi_status
acpi_ns_internalize_name(const char * external_name,char ** converted_name)312  acpi_ns_internalize_name(const char *external_name, char **converted_name)
313  {
314  	char *internal_name;
315  	struct acpi_namestring_info info;
316  	acpi_status status;
317  
318  	ACPI_FUNCTION_TRACE(ns_internalize_name);
319  
320  	if ((!external_name) || (*external_name == 0) || (!converted_name)) {
321  		return_ACPI_STATUS(AE_BAD_PARAMETER);
322  	}
323  
324  	/* Get the length of the new internal name */
325  
326  	info.external_name = external_name;
327  	acpi_ns_get_internal_name_length(&info);
328  
329  	/* We need a segment to store the internal  name */
330  
331  	internal_name = ACPI_ALLOCATE_ZEROED(info.length);
332  	if (!internal_name) {
333  		return_ACPI_STATUS(AE_NO_MEMORY);
334  	}
335  
336  	/* Build the name */
337  
338  	info.internal_name = internal_name;
339  	status = acpi_ns_build_internal_name(&info);
340  	if (ACPI_FAILURE(status)) {
341  		ACPI_FREE(internal_name);
342  		return_ACPI_STATUS(status);
343  	}
344  
345  	*converted_name = internal_name;
346  	return_ACPI_STATUS(AE_OK);
347  }
348  
349  /*******************************************************************************
350   *
351   * FUNCTION:    acpi_ns_externalize_name
352   *
353   * PARAMETERS:  internal_name_length - Length of the internal name below
354   *              internal_name       - Internal representation of name
355   *              converted_name_length - Where the length is returned
356   *              converted_name      - Where the resulting external name
357   *                                    is returned
358   *
359   * RETURN:      Status
360   *
361   * DESCRIPTION: Convert internal name (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
362   *              to its external (printable) form (e.g. "\_PR_.CPU0")
363   *
364   ******************************************************************************/
365  
366  acpi_status
acpi_ns_externalize_name(u32 internal_name_length,const char * internal_name,u32 * converted_name_length,char ** converted_name)367  acpi_ns_externalize_name(u32 internal_name_length,
368  			 const char *internal_name,
369  			 u32 * converted_name_length, char **converted_name)
370  {
371  	u32 names_index = 0;
372  	u32 num_segments = 0;
373  	u32 required_length;
374  	u32 prefix_length = 0;
375  	u32 i = 0;
376  	u32 j = 0;
377  
378  	ACPI_FUNCTION_TRACE(ns_externalize_name);
379  
380  	if (!internal_name_length || !internal_name || !converted_name) {
381  		return_ACPI_STATUS(AE_BAD_PARAMETER);
382  	}
383  
384  	/* Check for a prefix (one '\' | one or more '^') */
385  
386  	switch (internal_name[0]) {
387  	case AML_ROOT_PREFIX:
388  
389  		prefix_length = 1;
390  		break;
391  
392  	case AML_PARENT_PREFIX:
393  
394  		for (i = 0; i < internal_name_length; i++) {
395  			if (ACPI_IS_PARENT_PREFIX(internal_name[i])) {
396  				prefix_length = i + 1;
397  			} else {
398  				break;
399  			}
400  		}
401  
402  		if (i == internal_name_length) {
403  			prefix_length = i;
404  		}
405  
406  		break;
407  
408  	default:
409  
410  		break;
411  	}
412  
413  	/*
414  	 * Check for object names. Note that there could be 0-255 of these
415  	 * 4-byte elements.
416  	 */
417  	if (prefix_length < internal_name_length) {
418  		switch (internal_name[prefix_length]) {
419  		case AML_MULTI_NAME_PREFIX:
420  
421  			/* <count> 4-byte names */
422  
423  			names_index = prefix_length + 2;
424  			num_segments = (u8)
425  			    internal_name[(acpi_size)prefix_length + 1];
426  			break;
427  
428  		case AML_DUAL_NAME_PREFIX:
429  
430  			/* Two 4-byte names */
431  
432  			names_index = prefix_length + 1;
433  			num_segments = 2;
434  			break;
435  
436  		case 0:
437  
438  			/* null_name */
439  
440  			names_index = 0;
441  			num_segments = 0;
442  			break;
443  
444  		default:
445  
446  			/* one 4-byte name */
447  
448  			names_index = prefix_length;
449  			num_segments = 1;
450  			break;
451  		}
452  	}
453  
454  	/*
455  	 * Calculate the length of converted_name, which equals the length
456  	 * of the prefix, length of all object names, length of any required
457  	 * punctuation ('.') between object names, plus the NULL terminator.
458  	 */
459  	required_length = prefix_length + (4 * num_segments) +
460  	    ((num_segments > 0) ? (num_segments - 1) : 0) + 1;
461  
462  	/*
463  	 * Check to see if we're still in bounds. If not, there's a problem
464  	 * with internal_name (invalid format).
465  	 */
466  	if (required_length > internal_name_length) {
467  		ACPI_ERROR((AE_INFO, "Invalid internal name"));
468  		return_ACPI_STATUS(AE_BAD_PATHNAME);
469  	}
470  
471  	/* Build the converted_name */
472  
473  	*converted_name = ACPI_ALLOCATE_ZEROED(required_length);
474  	if (!(*converted_name)) {
475  		return_ACPI_STATUS(AE_NO_MEMORY);
476  	}
477  
478  	j = 0;
479  
480  	for (i = 0; i < prefix_length; i++) {
481  		(*converted_name)[j++] = internal_name[i];
482  	}
483  
484  	if (num_segments > 0) {
485  		for (i = 0; i < num_segments; i++) {
486  			if (i > 0) {
487  				(*converted_name)[j++] = '.';
488  			}
489  
490  			/* Copy and validate the 4-char name segment */
491  
492  			ACPI_COPY_NAMESEG(&(*converted_name)[j],
493  					  &internal_name[names_index]);
494  			acpi_ut_repair_name(&(*converted_name)[j]);
495  
496  			j += ACPI_NAMESEG_SIZE;
497  			names_index += ACPI_NAMESEG_SIZE;
498  		}
499  	}
500  
501  	if (converted_name_length) {
502  		*converted_name_length = (u32) required_length;
503  	}
504  
505  	return_ACPI_STATUS(AE_OK);
506  }
507  
508  /*******************************************************************************
509   *
510   * FUNCTION:    acpi_ns_validate_handle
511   *
512   * PARAMETERS:  handle          - Handle to be validated and typecast to a
513   *                                namespace node.
514   *
515   * RETURN:      A pointer to a namespace node
516   *
517   * DESCRIPTION: Convert a namespace handle to a namespace node. Handles special
518   *              cases for the root node.
519   *
520   * NOTE: Real integer handles would allow for more verification
521   *       and keep all pointers within this subsystem - however this introduces
522   *       more overhead and has not been necessary to this point. Drivers
523   *       holding handles are typically notified before a node becomes invalid
524   *       due to a table unload.
525   *
526   ******************************************************************************/
527  
acpi_ns_validate_handle(acpi_handle handle)528  struct acpi_namespace_node *acpi_ns_validate_handle(acpi_handle handle)
529  {
530  
531  	ACPI_FUNCTION_ENTRY();
532  
533  	/* Parameter validation */
534  
535  	if ((!handle) || (handle == ACPI_ROOT_OBJECT)) {
536  		return (acpi_gbl_root_node);
537  	}
538  
539  	/* We can at least attempt to verify the handle */
540  
541  	if (ACPI_GET_DESCRIPTOR_TYPE(handle) != ACPI_DESC_TYPE_NAMED) {
542  		return (NULL);
543  	}
544  
545  	return (ACPI_CAST_PTR(struct acpi_namespace_node, handle));
546  }
547  
548  /*******************************************************************************
549   *
550   * FUNCTION:    acpi_ns_terminate
551   *
552   * PARAMETERS:  none
553   *
554   * RETURN:      none
555   *
556   * DESCRIPTION: free memory allocated for namespace and ACPI table storage.
557   *
558   ******************************************************************************/
559  
acpi_ns_terminate(void)560  void acpi_ns_terminate(void)
561  {
562  	acpi_status status;
563  
564  	ACPI_FUNCTION_TRACE(ns_terminate);
565  
566  	/*
567  	 * Free the entire namespace -- all nodes and all objects
568  	 * attached to the nodes
569  	 */
570  	acpi_ns_delete_namespace_subtree(acpi_gbl_root_node);
571  
572  	/* Delete any objects attached to the root node */
573  
574  	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
575  	if (ACPI_FAILURE(status)) {
576  		return_VOID;
577  	}
578  
579  	acpi_ns_delete_node(acpi_gbl_root_node);
580  	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
581  
582  	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Namespace freed\n"));
583  	return_VOID;
584  }
585  
586  /*******************************************************************************
587   *
588   * FUNCTION:    acpi_ns_opens_scope
589   *
590   * PARAMETERS:  type        - A valid namespace type
591   *
592   * RETURN:      NEWSCOPE if the passed type "opens a name scope" according
593   *              to the ACPI specification, else 0
594   *
595   ******************************************************************************/
596  
acpi_ns_opens_scope(acpi_object_type type)597  u32 acpi_ns_opens_scope(acpi_object_type type)
598  {
599  	ACPI_FUNCTION_ENTRY();
600  
601  	if (type > ACPI_TYPE_LOCAL_MAX) {
602  
603  		/* type code out of range  */
604  
605  		ACPI_WARNING((AE_INFO, "Invalid Object Type 0x%X", type));
606  		return (ACPI_NS_NORMAL);
607  	}
608  
609  	return (((u32)acpi_gbl_ns_properties[type]) & ACPI_NS_NEWSCOPE);
610  }
611  
612  /*******************************************************************************
613   *
614   * FUNCTION:    acpi_ns_get_node_unlocked
615   *
616   * PARAMETERS:  *pathname   - Name to be found, in external (ASL) format. The
617   *                            \ (backslash) and ^ (carat) prefixes, and the
618   *                            . (period) to separate segments are supported.
619   *              prefix_node  - Root of subtree to be searched, or NS_ALL for the
620   *                            root of the name space. If Name is fully
621   *                            qualified (first s8 is '\'), the passed value
622   *                            of Scope will not be accessed.
623   *              flags       - Used to indicate whether to perform upsearch or
624   *                            not.
625   *              return_node - Where the Node is returned
626   *
627   * DESCRIPTION: Look up a name relative to a given scope and return the
628   *              corresponding Node. NOTE: Scope can be null.
629   *
630   * MUTEX:       Doesn't locks namespace
631   *
632   ******************************************************************************/
633  
634  acpi_status
acpi_ns_get_node_unlocked(struct acpi_namespace_node * prefix_node,const char * pathname,u32 flags,struct acpi_namespace_node ** return_node)635  acpi_ns_get_node_unlocked(struct acpi_namespace_node *prefix_node,
636  			  const char *pathname,
637  			  u32 flags, struct acpi_namespace_node **return_node)
638  {
639  	union acpi_generic_state scope_info;
640  	acpi_status status;
641  	char *internal_path;
642  
643  	ACPI_FUNCTION_TRACE_PTR(ns_get_node_unlocked,
644  				ACPI_CAST_PTR(char, pathname));
645  
646  	/* Simplest case is a null pathname */
647  
648  	if (!pathname) {
649  		*return_node = prefix_node;
650  		if (!prefix_node) {
651  			*return_node = acpi_gbl_root_node;
652  		}
653  
654  		return_ACPI_STATUS(AE_OK);
655  	}
656  
657  	/* Quick check for a reference to the root */
658  
659  	if (ACPI_IS_ROOT_PREFIX(pathname[0]) && (!pathname[1])) {
660  		*return_node = acpi_gbl_root_node;
661  		return_ACPI_STATUS(AE_OK);
662  	}
663  
664  	/* Convert path to internal representation */
665  
666  	status = acpi_ns_internalize_name(pathname, &internal_path);
667  	if (ACPI_FAILURE(status)) {
668  		return_ACPI_STATUS(status);
669  	}
670  
671  	/* Setup lookup scope (search starting point) */
672  
673  	scope_info.scope.node = prefix_node;
674  
675  	/* Lookup the name in the namespace */
676  
677  	status = acpi_ns_lookup(&scope_info, internal_path, ACPI_TYPE_ANY,
678  				ACPI_IMODE_EXECUTE,
679  				(flags | ACPI_NS_DONT_OPEN_SCOPE), NULL,
680  				return_node);
681  	if (ACPI_FAILURE(status)) {
682  		ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s, %s\n",
683  				  pathname, acpi_format_exception(status)));
684  	}
685  
686  	ACPI_FREE(internal_path);
687  	return_ACPI_STATUS(status);
688  }
689  
690  /*******************************************************************************
691   *
692   * FUNCTION:    acpi_ns_get_node
693   *
694   * PARAMETERS:  *pathname   - Name to be found, in external (ASL) format. The
695   *                            \ (backslash) and ^ (carat) prefixes, and the
696   *                            . (period) to separate segments are supported.
697   *              prefix_node  - Root of subtree to be searched, or NS_ALL for the
698   *                            root of the name space. If Name is fully
699   *                            qualified (first s8 is '\'), the passed value
700   *                            of Scope will not be accessed.
701   *              flags       - Used to indicate whether to perform upsearch or
702   *                            not.
703   *              return_node - Where the Node is returned
704   *
705   * DESCRIPTION: Look up a name relative to a given scope and return the
706   *              corresponding Node. NOTE: Scope can be null.
707   *
708   * MUTEX:       Locks namespace
709   *
710   ******************************************************************************/
711  
712  acpi_status
acpi_ns_get_node(struct acpi_namespace_node * prefix_node,const char * pathname,u32 flags,struct acpi_namespace_node ** return_node)713  acpi_ns_get_node(struct acpi_namespace_node *prefix_node,
714  		 const char *pathname,
715  		 u32 flags, struct acpi_namespace_node **return_node)
716  {
717  	acpi_status status;
718  
719  	ACPI_FUNCTION_TRACE_PTR(ns_get_node, ACPI_CAST_PTR(char, pathname));
720  
721  	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
722  	if (ACPI_FAILURE(status)) {
723  		return_ACPI_STATUS(status);
724  	}
725  
726  	status = acpi_ns_get_node_unlocked(prefix_node, pathname,
727  					   flags, return_node);
728  
729  	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
730  	return_ACPI_STATUS(status);
731  }
732