MAINTAINERS: Update qib and ipath entries from QLogic to Intel
[linux/fpc-iii.git] / drivers / acpi / acpica / nsxfeval.c
blob71d15f61807ba312e9f60b617c215a23ce643f9e
1 /*******************************************************************************
3 * Module Name: nsxfeval - Public interfaces to the ACPI subsystem
4 * ACPI Object evaluation interfaces
6 ******************************************************************************/
8 /*
9 * Copyright (C) 2000 - 2012, Intel Corp.
10 * All rights reserved.
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.
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.
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.
45 #include <linux/export.h>
46 #include <acpi/acpi.h>
47 #include "accommon.h"
48 #include "acnamesp.h"
49 #include "acinterp.h"
51 #define _COMPONENT ACPI_NAMESPACE
52 ACPI_MODULE_NAME("nsxfeval")
54 /* Local prototypes */
55 static void acpi_ns_resolve_references(struct acpi_evaluate_info *info);
57 /*******************************************************************************
59 * FUNCTION: acpi_evaluate_object_typed
61 * PARAMETERS: Handle - Object handle (optional)
62 * Pathname - Object pathname (optional)
63 * external_params - List of parameters to pass to method,
64 * terminated by NULL. May be NULL
65 * if no parameters are being passed.
66 * return_buffer - Where to put method's return value (if
67 * any). If NULL, no value is returned.
68 * return_type - Expected type of return object
70 * RETURN: Status
72 * DESCRIPTION: Find and evaluate the given object, passing the given
73 * parameters if necessary. One of "Handle" or "Pathname" must
74 * be valid (non-null)
76 ******************************************************************************/
78 acpi_status
79 acpi_evaluate_object_typed(acpi_handle handle,
80 acpi_string pathname,
81 struct acpi_object_list *external_params,
82 struct acpi_buffer *return_buffer,
83 acpi_object_type return_type)
85 acpi_status status;
86 u8 must_free = FALSE;
88 ACPI_FUNCTION_TRACE(acpi_evaluate_object_typed);
90 /* Return buffer must be valid */
92 if (!return_buffer) {
93 return_ACPI_STATUS(AE_BAD_PARAMETER);
96 if (return_buffer->length == ACPI_ALLOCATE_BUFFER) {
97 must_free = TRUE;
100 /* Evaluate the object */
102 status =
103 acpi_evaluate_object(handle, pathname, external_params,
104 return_buffer);
105 if (ACPI_FAILURE(status)) {
106 return_ACPI_STATUS(status);
109 /* Type ANY means "don't care" */
111 if (return_type == ACPI_TYPE_ANY) {
112 return_ACPI_STATUS(AE_OK);
115 if (return_buffer->length == 0) {
117 /* Error because caller specifically asked for a return value */
119 ACPI_ERROR((AE_INFO, "No return value"));
120 return_ACPI_STATUS(AE_NULL_OBJECT);
123 /* Examine the object type returned from evaluate_object */
125 if (((union acpi_object *)return_buffer->pointer)->type == return_type) {
126 return_ACPI_STATUS(AE_OK);
129 /* Return object type does not match requested type */
131 ACPI_ERROR((AE_INFO,
132 "Incorrect return type [%s] requested [%s]",
133 acpi_ut_get_type_name(((union acpi_object *)return_buffer->
134 pointer)->type),
135 acpi_ut_get_type_name(return_type)));
137 if (must_free) {
139 /* Caller used ACPI_ALLOCATE_BUFFER, free the return buffer */
141 ACPI_FREE(return_buffer->pointer);
142 return_buffer->pointer = NULL;
145 return_buffer->length = 0;
146 return_ACPI_STATUS(AE_TYPE);
149 ACPI_EXPORT_SYMBOL(acpi_evaluate_object_typed)
151 /*******************************************************************************
153 * FUNCTION: acpi_evaluate_object
155 * PARAMETERS: Handle - Object handle (optional)
156 * Pathname - Object pathname (optional)
157 * external_params - List of parameters to pass to method,
158 * terminated by NULL. May be NULL
159 * if no parameters are being passed.
160 * return_buffer - Where to put method's return value (if
161 * any). If NULL, no value is returned.
163 * RETURN: Status
165 * DESCRIPTION: Find and evaluate the given object, passing the given
166 * parameters if necessary. One of "Handle" or "Pathname" must
167 * be valid (non-null)
169 ******************************************************************************/
170 acpi_status
171 acpi_evaluate_object(acpi_handle handle,
172 acpi_string pathname,
173 struct acpi_object_list *external_params,
174 struct acpi_buffer *return_buffer)
176 acpi_status status;
177 struct acpi_evaluate_info *info;
178 acpi_size buffer_space_needed;
179 u32 i;
181 ACPI_FUNCTION_TRACE(acpi_evaluate_object);
183 /* Allocate and initialize the evaluation information block */
185 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
186 if (!info) {
187 return_ACPI_STATUS(AE_NO_MEMORY);
190 info->pathname = pathname;
192 /* Convert and validate the device handle */
194 info->prefix_node = acpi_ns_validate_handle(handle);
195 if (!info->prefix_node) {
196 status = AE_BAD_PARAMETER;
197 goto cleanup;
201 * If there are parameters to be passed to a control method, the external
202 * objects must all be converted to internal objects
204 if (external_params && external_params->count) {
206 * Allocate a new parameter block for the internal objects
207 * Add 1 to count to allow for null terminated internal list
209 info->parameters = ACPI_ALLOCATE_ZEROED(((acpi_size)
210 external_params->
211 count +
212 1) * sizeof(void *));
213 if (!info->parameters) {
214 status = AE_NO_MEMORY;
215 goto cleanup;
218 /* Convert each external object in the list to an internal object */
220 for (i = 0; i < external_params->count; i++) {
221 status =
222 acpi_ut_copy_eobject_to_iobject(&external_params->
223 pointer[i],
224 &info->
225 parameters[i]);
226 if (ACPI_FAILURE(status)) {
227 goto cleanup;
230 info->parameters[external_params->count] = NULL;
234 * Three major cases:
235 * 1) Fully qualified pathname
236 * 2) No handle, not fully qualified pathname (error)
237 * 3) Valid handle
239 if ((pathname) && (acpi_ns_valid_root_prefix(pathname[0]))) {
241 /* The path is fully qualified, just evaluate by name */
243 info->prefix_node = NULL;
244 status = acpi_ns_evaluate(info);
245 } else if (!handle) {
247 * A handle is optional iff a fully qualified pathname is specified.
248 * Since we've already handled fully qualified names above, this is
249 * an error
251 if (!pathname) {
252 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
253 "Both Handle and Pathname are NULL"));
254 } else {
255 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
256 "Null Handle with relative pathname [%s]",
257 pathname));
260 status = AE_BAD_PARAMETER;
261 } else {
262 /* We have a namespace a node and a possible relative path */
264 status = acpi_ns_evaluate(info);
268 * If we are expecting a return value, and all went well above,
269 * copy the return value to an external object.
271 if (return_buffer) {
272 if (!info->return_object) {
273 return_buffer->length = 0;
274 } else {
275 if (ACPI_GET_DESCRIPTOR_TYPE(info->return_object) ==
276 ACPI_DESC_TYPE_NAMED) {
278 * If we received a NS Node as a return object, this means that
279 * the object we are evaluating has nothing interesting to
280 * return (such as a mutex, etc.) We return an error because
281 * these types are essentially unsupported by this interface.
282 * We don't check up front because this makes it easier to add
283 * support for various types at a later date if necessary.
285 status = AE_TYPE;
286 info->return_object = NULL; /* No need to delete a NS Node */
287 return_buffer->length = 0;
290 if (ACPI_SUCCESS(status)) {
292 /* Dereference Index and ref_of references */
294 acpi_ns_resolve_references(info);
296 /* Get the size of the returned object */
298 status =
299 acpi_ut_get_object_size(info->return_object,
300 &buffer_space_needed);
301 if (ACPI_SUCCESS(status)) {
303 /* Validate/Allocate/Clear caller buffer */
305 status =
306 acpi_ut_initialize_buffer
307 (return_buffer,
308 buffer_space_needed);
309 if (ACPI_FAILURE(status)) {
311 * Caller's buffer is too small or a new one can't
312 * be allocated
314 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
315 "Needed buffer size %X, %s\n",
316 (u32)
317 buffer_space_needed,
318 acpi_format_exception
319 (status)));
320 } else {
321 /* We have enough space for the object, build it */
323 status =
324 acpi_ut_copy_iobject_to_eobject
325 (info->return_object,
326 return_buffer);
333 if (info->return_object) {
335 * Delete the internal return object. NOTE: Interpreter must be
336 * locked to avoid race condition.
338 acpi_ex_enter_interpreter();
340 /* Remove one reference on the return object (should delete it) */
342 acpi_ut_remove_reference(info->return_object);
343 acpi_ex_exit_interpreter();
346 cleanup:
348 /* Free the input parameter list (if we created one) */
350 if (info->parameters) {
352 /* Free the allocated parameter block */
354 acpi_ut_delete_internal_object_list(info->parameters);
357 ACPI_FREE(info);
358 return_ACPI_STATUS(status);
361 ACPI_EXPORT_SYMBOL(acpi_evaluate_object)
363 /*******************************************************************************
365 * FUNCTION: acpi_ns_resolve_references
367 * PARAMETERS: Info - Evaluation info block
369 * RETURN: Info->return_object is replaced with the dereferenced object
371 * DESCRIPTION: Dereference certain reference objects. Called before an
372 * internal return object is converted to an external union acpi_object.
374 * Performs an automatic dereference of Index and ref_of reference objects.
375 * These reference objects are not supported by the union acpi_object, so this is a
376 * last resort effort to return something useful. Also, provides compatibility
377 * with other ACPI implementations.
379 * NOTE: does not handle references within returned package objects or nested
380 * references, but this support could be added later if found to be necessary.
382 ******************************************************************************/
383 static void acpi_ns_resolve_references(struct acpi_evaluate_info *info)
385 union acpi_operand_object *obj_desc = NULL;
386 struct acpi_namespace_node *node;
388 /* We are interested in reference objects only */
390 if ((info->return_object)->common.type != ACPI_TYPE_LOCAL_REFERENCE) {
391 return;
395 * Two types of references are supported - those created by Index and
396 * ref_of operators. A name reference (AML_NAMEPATH_OP) can be converted
397 * to an union acpi_object, so it is not dereferenced here. A ddb_handle
398 * (AML_LOAD_OP) cannot be dereferenced, nor can it be converted to
399 * an union acpi_object.
401 switch (info->return_object->reference.class) {
402 case ACPI_REFCLASS_INDEX:
404 obj_desc = *(info->return_object->reference.where);
405 break;
407 case ACPI_REFCLASS_REFOF:
409 node = info->return_object->reference.object;
410 if (node) {
411 obj_desc = node->object;
413 break;
415 default:
416 return;
419 /* Replace the existing reference object */
421 if (obj_desc) {
422 acpi_ut_add_reference(obj_desc);
423 acpi_ut_remove_reference(info->return_object);
424 info->return_object = obj_desc;
427 return;
430 /*******************************************************************************
432 * FUNCTION: acpi_walk_namespace
434 * PARAMETERS: Type - acpi_object_type to search for
435 * start_object - Handle in namespace where search begins
436 * max_depth - Depth to which search is to reach
437 * pre_order_visit - Called during tree pre-order visit
438 * when an object of "Type" is found
439 * post_order_visit - Called during tree post-order visit
440 * when an object of "Type" is found
441 * Context - Passed to user function(s) above
442 * return_value - Location where return value of
443 * user_function is put if terminated early
445 * RETURNS Return value from the user_function if terminated early.
446 * Otherwise, returns NULL.
448 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
449 * starting (and ending) at the object specified by start_handle.
450 * The callback function is called whenever an object that matches
451 * the type parameter is found. If the callback function returns
452 * a non-zero value, the search is terminated immediately and this
453 * value is returned to the caller.
455 * The point of this procedure is to provide a generic namespace
456 * walk routine that can be called from multiple places to
457 * provide multiple services; the callback function(s) can be
458 * tailored to each task, whether it is a print function,
459 * a compare function, etc.
461 ******************************************************************************/
463 acpi_status
464 acpi_walk_namespace(acpi_object_type type,
465 acpi_handle start_object,
466 u32 max_depth,
467 acpi_walk_callback pre_order_visit,
468 acpi_walk_callback post_order_visit,
469 void *context, void **return_value)
471 acpi_status status;
473 ACPI_FUNCTION_TRACE(acpi_walk_namespace);
475 /* Parameter validation */
477 if ((type > ACPI_TYPE_LOCAL_MAX) ||
478 (!max_depth) || (!pre_order_visit && !post_order_visit)) {
479 return_ACPI_STATUS(AE_BAD_PARAMETER);
483 * Need to acquire the namespace reader lock to prevent interference
484 * with any concurrent table unloads (which causes the deletion of
485 * namespace objects). We cannot allow the deletion of a namespace node
486 * while the user function is using it. The exception to this are the
487 * nodes created and deleted during control method execution -- these
488 * nodes are marked as temporary nodes and are ignored by the namespace
489 * walk. Thus, control methods can be executed while holding the
490 * namespace deletion lock (and the user function can execute control
491 * methods.)
493 status = acpi_ut_acquire_read_lock(&acpi_gbl_namespace_rw_lock);
494 if (ACPI_FAILURE(status)) {
495 return status;
499 * Lock the namespace around the walk. The namespace will be
500 * unlocked/locked around each call to the user function - since the user
501 * function must be allowed to make ACPICA calls itself (for example, it
502 * will typically execute control methods during device enumeration.)
504 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
505 if (ACPI_FAILURE(status)) {
506 goto unlock_and_exit;
509 status = acpi_ns_walk_namespace(type, start_object, max_depth,
510 ACPI_NS_WALK_UNLOCK, pre_order_visit,
511 post_order_visit, context,
512 return_value);
514 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
516 unlock_and_exit:
517 (void)acpi_ut_release_read_lock(&acpi_gbl_namespace_rw_lock);
518 return_ACPI_STATUS(status);
521 ACPI_EXPORT_SYMBOL(acpi_walk_namespace)
523 /*******************************************************************************
525 * FUNCTION: acpi_ns_get_device_callback
527 * PARAMETERS: Callback from acpi_get_device
529 * RETURN: Status
531 * DESCRIPTION: Takes callbacks from walk_namespace and filters out all non-
532 * present devices, or if they specified a HID, it filters based
533 * on that.
535 ******************************************************************************/
536 static acpi_status
537 acpi_ns_get_device_callback(acpi_handle obj_handle,
538 u32 nesting_level,
539 void *context, void **return_value)
541 struct acpi_get_devices_info *info = context;
542 acpi_status status;
543 struct acpi_namespace_node *node;
544 u32 flags;
545 struct acpica_device_id *hid;
546 struct acpica_device_id_list *cid;
547 u32 i;
548 u8 found;
549 int no_match;
551 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
552 if (ACPI_FAILURE(status)) {
553 return (status);
556 node = acpi_ns_validate_handle(obj_handle);
557 status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
558 if (ACPI_FAILURE(status)) {
559 return (status);
562 if (!node) {
563 return (AE_BAD_PARAMETER);
567 * First, filter based on the device HID and CID.
569 * 01/2010: For this case where a specific HID is requested, we don't
570 * want to run _STA until we have an actual HID match. Thus, we will
571 * not unnecessarily execute _STA on devices for which the caller
572 * doesn't care about. Previously, _STA was executed unconditionally
573 * on all devices found here.
575 * A side-effect of this change is that now we will continue to search
576 * for a matching HID even under device trees where the parent device
577 * would have returned a _STA that indicates it is not present or
578 * not functioning (thus aborting the search on that branch).
580 if (info->hid != NULL) {
581 status = acpi_ut_execute_HID(node, &hid);
582 if (status == AE_NOT_FOUND) {
583 return (AE_OK);
584 } else if (ACPI_FAILURE(status)) {
585 return (AE_CTRL_DEPTH);
588 no_match = ACPI_STRCMP(hid->string, info->hid);
589 ACPI_FREE(hid);
591 if (no_match) {
593 * HID does not match, attempt match within the
594 * list of Compatible IDs (CIDs)
596 status = acpi_ut_execute_CID(node, &cid);
597 if (status == AE_NOT_FOUND) {
598 return (AE_OK);
599 } else if (ACPI_FAILURE(status)) {
600 return (AE_CTRL_DEPTH);
603 /* Walk the CID list */
605 found = 0;
606 for (i = 0; i < cid->count; i++) {
607 if (ACPI_STRCMP(cid->ids[i].string, info->hid)
608 == 0) {
609 found = 1;
610 break;
613 ACPI_FREE(cid);
614 if (!found)
615 return (AE_OK);
619 /* Run _STA to determine if device is present */
621 status = acpi_ut_execute_STA(node, &flags);
622 if (ACPI_FAILURE(status)) {
623 return (AE_CTRL_DEPTH);
626 if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
627 !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
629 * Don't examine the children of the device only when the
630 * device is neither present nor functional. See ACPI spec,
631 * description of _STA for more information.
633 return (AE_CTRL_DEPTH);
636 /* We have a valid device, invoke the user function */
638 status = info->user_function(obj_handle, nesting_level, info->context,
639 return_value);
640 return (status);
643 /*******************************************************************************
645 * FUNCTION: acpi_get_devices
647 * PARAMETERS: HID - HID to search for. Can be NULL.
648 * user_function - Called when a matching object is found
649 * Context - Passed to user function
650 * return_value - Location where return value of
651 * user_function is put if terminated early
653 * RETURNS Return value from the user_function if terminated early.
654 * Otherwise, returns NULL.
656 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
657 * starting (and ending) at the object specified by start_handle.
658 * The user_function is called whenever an object of type
659 * Device is found. If the user function returns
660 * a non-zero value, the search is terminated immediately and this
661 * value is returned to the caller.
663 * This is a wrapper for walk_namespace, but the callback performs
664 * additional filtering. Please see acpi_ns_get_device_callback.
666 ******************************************************************************/
668 acpi_status
669 acpi_get_devices(const char *HID,
670 acpi_walk_callback user_function,
671 void *context, void **return_value)
673 acpi_status status;
674 struct acpi_get_devices_info info;
676 ACPI_FUNCTION_TRACE(acpi_get_devices);
678 /* Parameter validation */
680 if (!user_function) {
681 return_ACPI_STATUS(AE_BAD_PARAMETER);
685 * We're going to call their callback from OUR callback, so we need
686 * to know what it is, and their context parameter.
688 info.hid = HID;
689 info.context = context;
690 info.user_function = user_function;
693 * Lock the namespace around the walk.
694 * The namespace will be unlocked/locked around each call
695 * to the user function - since this function
696 * must be allowed to make Acpi calls itself.
698 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
699 if (ACPI_FAILURE(status)) {
700 return_ACPI_STATUS(status);
703 status = acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
704 ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
705 acpi_ns_get_device_callback, NULL,
706 &info, return_value);
708 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
709 return_ACPI_STATUS(status);
712 ACPI_EXPORT_SYMBOL(acpi_get_devices)
714 /*******************************************************************************
716 * FUNCTION: acpi_attach_data
718 * PARAMETERS: obj_handle - Namespace node
719 * Handler - Handler for this attachment
720 * Data - Pointer to data to be attached
722 * RETURN: Status
724 * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
726 ******************************************************************************/
727 acpi_status
728 acpi_attach_data(acpi_handle obj_handle,
729 acpi_object_handler handler, void *data)
731 struct acpi_namespace_node *node;
732 acpi_status status;
734 /* Parameter validation */
736 if (!obj_handle || !handler || !data) {
737 return (AE_BAD_PARAMETER);
740 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
741 if (ACPI_FAILURE(status)) {
742 return (status);
745 /* Convert and validate the handle */
747 node = acpi_ns_validate_handle(obj_handle);
748 if (!node) {
749 status = AE_BAD_PARAMETER;
750 goto unlock_and_exit;
753 status = acpi_ns_attach_data(node, handler, data);
755 unlock_and_exit:
756 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
757 return (status);
760 ACPI_EXPORT_SYMBOL(acpi_attach_data)
762 /*******************************************************************************
764 * FUNCTION: acpi_detach_data
766 * PARAMETERS: obj_handle - Namespace node handle
767 * Handler - Handler used in call to acpi_attach_data
769 * RETURN: Status
771 * DESCRIPTION: Remove data that was previously attached to a node.
773 ******************************************************************************/
774 acpi_status
775 acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
777 struct acpi_namespace_node *node;
778 acpi_status status;
780 /* Parameter validation */
782 if (!obj_handle || !handler) {
783 return (AE_BAD_PARAMETER);
786 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
787 if (ACPI_FAILURE(status)) {
788 return (status);
791 /* Convert and validate the handle */
793 node = acpi_ns_validate_handle(obj_handle);
794 if (!node) {
795 status = AE_BAD_PARAMETER;
796 goto unlock_and_exit;
799 status = acpi_ns_detach_data(node, handler);
801 unlock_and_exit:
802 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
803 return (status);
806 ACPI_EXPORT_SYMBOL(acpi_detach_data)
808 /*******************************************************************************
810 * FUNCTION: acpi_get_data
812 * PARAMETERS: obj_handle - Namespace node
813 * Handler - Handler used in call to attach_data
814 * Data - Where the data is returned
816 * RETURN: Status
818 * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
820 ******************************************************************************/
821 acpi_status
822 acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
824 struct acpi_namespace_node *node;
825 acpi_status status;
827 /* Parameter validation */
829 if (!obj_handle || !handler || !data) {
830 return (AE_BAD_PARAMETER);
833 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
834 if (ACPI_FAILURE(status)) {
835 return (status);
838 /* Convert and validate the handle */
840 node = acpi_ns_validate_handle(obj_handle);
841 if (!node) {
842 status = AE_BAD_PARAMETER;
843 goto unlock_and_exit;
846 status = acpi_ns_get_attached_data(node, handler, data);
848 unlock_and_exit:
849 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
850 return (status);
853 ACPI_EXPORT_SYMBOL(acpi_get_data)