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 - 2016, 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
acpi_ns_print_node_pathname(struct acpi_namespace_node * node,const char * message)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
acpi_ns_get_type(struct acpi_namespace_node * node)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
acpi_ns_local(acpi_object_type type)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
acpi_ns_get_internal_name_length(struct acpi_namestring_info * info)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
acpi_ns_build_internal_name(struct acpi_namestring_info * info)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
acpi_ns_internalize_name(const char * external_name,char ** converted_name)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
acpi_ns_externalize_name(u32 internal_name_length,const char * internal_name,u32 * converted_name_length,char ** converted_name)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
acpi_ns_validate_handle(acpi_handle handle)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
acpi_ns_terminate(void)594 void acpi_ns_terminate(void)
595 {
596 acpi_status status;
597 union acpi_operand_object *prev;
598 union acpi_operand_object *next;
599
600 ACPI_FUNCTION_TRACE(ns_terminate);
601
602 /* Delete any module-level code blocks */
603
604 next = acpi_gbl_module_code_list;
605 while (next) {
606 prev = next;
607 next = next->method.mutex;
608 prev->method.mutex = NULL; /* Clear the Mutex (cheated) field */
609 acpi_ut_remove_reference(prev);
610 }
611
612 /*
613 * Free the entire namespace -- all nodes and all objects
614 * attached to the nodes
615 */
616 acpi_ns_delete_namespace_subtree(acpi_gbl_root_node);
617
618 /* Delete any objects attached to the root node */
619
620 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
621 if (ACPI_FAILURE(status)) {
622 return_VOID;
623 }
624
625 acpi_ns_delete_node(acpi_gbl_root_node);
626 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
627
628 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Namespace freed\n"));
629 return_VOID;
630 }
631
632 /*******************************************************************************
633 *
634 * FUNCTION: acpi_ns_opens_scope
635 *
636 * PARAMETERS: type - A valid namespace type
637 *
638 * RETURN: NEWSCOPE if the passed type "opens a name scope" according
639 * to the ACPI specification, else 0
640 *
641 ******************************************************************************/
642
acpi_ns_opens_scope(acpi_object_type type)643 u32 acpi_ns_opens_scope(acpi_object_type type)
644 {
645 ACPI_FUNCTION_ENTRY();
646
647 if (type > ACPI_TYPE_LOCAL_MAX) {
648
649 /* type code out of range */
650
651 ACPI_WARNING((AE_INFO, "Invalid Object Type 0x%X", type));
652 return (ACPI_NS_NORMAL);
653 }
654
655 return (((u32)acpi_gbl_ns_properties[type]) & ACPI_NS_NEWSCOPE);
656 }
657
658 /*******************************************************************************
659 *
660 * FUNCTION: acpi_ns_get_node_unlocked
661 *
662 * PARAMETERS: *pathname - Name to be found, in external (ASL) format. The
663 * \ (backslash) and ^ (carat) prefixes, and the
664 * . (period) to separate segments are supported.
665 * prefix_node - Root of subtree to be searched, or NS_ALL for the
666 * root of the name space. If Name is fully
667 * qualified (first s8 is '\'), the passed value
668 * of Scope will not be accessed.
669 * flags - Used to indicate whether to perform upsearch or
670 * not.
671 * return_node - Where the Node is returned
672 *
673 * DESCRIPTION: Look up a name relative to a given scope and return the
674 * corresponding Node. NOTE: Scope can be null.
675 *
676 * MUTEX: Doesn't locks namespace
677 *
678 ******************************************************************************/
679
680 acpi_status
acpi_ns_get_node_unlocked(struct acpi_namespace_node * prefix_node,const char * pathname,u32 flags,struct acpi_namespace_node ** return_node)681 acpi_ns_get_node_unlocked(struct acpi_namespace_node *prefix_node,
682 const char *pathname,
683 u32 flags, struct acpi_namespace_node **return_node)
684 {
685 union acpi_generic_state scope_info;
686 acpi_status status;
687 char *internal_path;
688
689 ACPI_FUNCTION_TRACE_PTR(ns_get_node_unlocked,
690 ACPI_CAST_PTR(char, pathname));
691
692 /* Simplest case is a null pathname */
693
694 if (!pathname) {
695 *return_node = prefix_node;
696 if (!prefix_node) {
697 *return_node = acpi_gbl_root_node;
698 }
699
700 return_ACPI_STATUS(AE_OK);
701 }
702
703 /* Quick check for a reference to the root */
704
705 if (ACPI_IS_ROOT_PREFIX(pathname[0]) && (!pathname[1])) {
706 *return_node = acpi_gbl_root_node;
707 return_ACPI_STATUS(AE_OK);
708 }
709
710 /* Convert path to internal representation */
711
712 status = acpi_ns_internalize_name(pathname, &internal_path);
713 if (ACPI_FAILURE(status)) {
714 return_ACPI_STATUS(status);
715 }
716
717 /* Setup lookup scope (search starting point) */
718
719 scope_info.scope.node = prefix_node;
720
721 /* Lookup the name in the namespace */
722
723 status = acpi_ns_lookup(&scope_info, internal_path, ACPI_TYPE_ANY,
724 ACPI_IMODE_EXECUTE,
725 (flags | ACPI_NS_DONT_OPEN_SCOPE), NULL,
726 return_node);
727 if (ACPI_FAILURE(status)) {
728 ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s, %s\n",
729 pathname, acpi_format_exception(status)));
730 }
731
732 ACPI_FREE(internal_path);
733 return_ACPI_STATUS(status);
734 }
735
736 /*******************************************************************************
737 *
738 * FUNCTION: acpi_ns_get_node
739 *
740 * PARAMETERS: *pathname - Name to be found, in external (ASL) format. The
741 * \ (backslash) and ^ (carat) prefixes, and the
742 * . (period) to separate segments are supported.
743 * prefix_node - Root of subtree to be searched, or NS_ALL for the
744 * root of the name space. If Name is fully
745 * qualified (first s8 is '\'), the passed value
746 * of Scope will not be accessed.
747 * flags - Used to indicate whether to perform upsearch or
748 * not.
749 * return_node - Where the Node is returned
750 *
751 * DESCRIPTION: Look up a name relative to a given scope and return the
752 * corresponding Node. NOTE: Scope can be null.
753 *
754 * MUTEX: Locks namespace
755 *
756 ******************************************************************************/
757
758 acpi_status
acpi_ns_get_node(struct acpi_namespace_node * prefix_node,const char * pathname,u32 flags,struct acpi_namespace_node ** return_node)759 acpi_ns_get_node(struct acpi_namespace_node *prefix_node,
760 const char *pathname,
761 u32 flags, struct acpi_namespace_node **return_node)
762 {
763 acpi_status status;
764
765 ACPI_FUNCTION_TRACE_PTR(ns_get_node, ACPI_CAST_PTR(char, pathname));
766
767 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
768 if (ACPI_FAILURE(status)) {
769 return_ACPI_STATUS(status);
770 }
771
772 status = acpi_ns_get_node_unlocked(prefix_node, pathname,
773 flags, return_node);
774
775 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
776 return_ACPI_STATUS(status);
777 }
778