Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus
[linux-btrfs-devel.git] / drivers / acpi / acpica / nsxfeval.c
blobc53f0040e49016b041b364c8366ca8568d953a08
1 /*******************************************************************************
3 * Module Name: nsxfeval - Public interfaces to the ACPI subsystem
4 * ACPI Object evaluation interfaces
6 ******************************************************************************/
8 /*
9 * Copyright (C) 2000 - 2011, 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 <acpi/acpi.h>
46 #include "accommon.h"
47 #include "acnamesp.h"
48 #include "acinterp.h"
50 #define _COMPONENT ACPI_NAMESPACE
51 ACPI_MODULE_NAME("nsxfeval")
53 /* Local prototypes */
54 static void acpi_ns_resolve_references(struct acpi_evaluate_info *info);
56 /*******************************************************************************
58 * FUNCTION: acpi_evaluate_object_typed
60 * PARAMETERS: Handle - Object handle (optional)
61 * Pathname - Object pathname (optional)
62 * external_params - List of parameters to pass to method,
63 * terminated by NULL. May be NULL
64 * if no parameters are being passed.
65 * return_buffer - Where to put method's return value (if
66 * any). If NULL, no value is returned.
67 * return_type - Expected type of return object
69 * RETURN: Status
71 * DESCRIPTION: Find and evaluate the given object, passing the given
72 * parameters if necessary. One of "Handle" or "Pathname" must
73 * be valid (non-null)
75 ******************************************************************************/
77 acpi_status
78 acpi_evaluate_object_typed(acpi_handle handle,
79 acpi_string pathname,
80 struct acpi_object_list *external_params,
81 struct acpi_buffer *return_buffer,
82 acpi_object_type return_type)
84 acpi_status status;
85 u8 must_free = FALSE;
87 ACPI_FUNCTION_TRACE(acpi_evaluate_object_typed);
89 /* Return buffer must be valid */
91 if (!return_buffer) {
92 return_ACPI_STATUS(AE_BAD_PARAMETER);
95 if (return_buffer->length == ACPI_ALLOCATE_BUFFER) {
96 must_free = TRUE;
99 /* Evaluate the object */
101 status =
102 acpi_evaluate_object(handle, pathname, external_params,
103 return_buffer);
104 if (ACPI_FAILURE(status)) {
105 return_ACPI_STATUS(status);
108 /* Type ANY means "don't care" */
110 if (return_type == ACPI_TYPE_ANY) {
111 return_ACPI_STATUS(AE_OK);
114 if (return_buffer->length == 0) {
116 /* Error because caller specifically asked for a return value */
118 ACPI_ERROR((AE_INFO, "No return value"));
119 return_ACPI_STATUS(AE_NULL_OBJECT);
122 /* Examine the object type returned from evaluate_object */
124 if (((union acpi_object *)return_buffer->pointer)->type == return_type) {
125 return_ACPI_STATUS(AE_OK);
128 /* Return object type does not match requested type */
130 ACPI_ERROR((AE_INFO,
131 "Incorrect return type [%s] requested [%s]",
132 acpi_ut_get_type_name(((union acpi_object *)return_buffer->
133 pointer)->type),
134 acpi_ut_get_type_name(return_type)));
136 if (must_free) {
138 /* Caller used ACPI_ALLOCATE_BUFFER, free the return buffer */
140 ACPI_FREE(return_buffer->pointer);
141 return_buffer->pointer = NULL;
144 return_buffer->length = 0;
145 return_ACPI_STATUS(AE_TYPE);
148 ACPI_EXPORT_SYMBOL(acpi_evaluate_object_typed)
150 /*******************************************************************************
152 * FUNCTION: acpi_evaluate_object
154 * PARAMETERS: Handle - Object handle (optional)
155 * Pathname - Object pathname (optional)
156 * external_params - List of parameters to pass to method,
157 * terminated by NULL. May be NULL
158 * if no parameters are being passed.
159 * return_buffer - Where to put method's return value (if
160 * any). If NULL, no value is returned.
162 * RETURN: Status
164 * DESCRIPTION: Find and evaluate the given object, passing the given
165 * parameters if necessary. One of "Handle" or "Pathname" must
166 * be valid (non-null)
168 ******************************************************************************/
169 acpi_status
170 acpi_evaluate_object(acpi_handle handle,
171 acpi_string pathname,
172 struct acpi_object_list *external_params,
173 struct acpi_buffer *return_buffer)
175 acpi_status status;
176 struct acpi_evaluate_info *info;
177 acpi_size buffer_space_needed;
178 u32 i;
180 ACPI_FUNCTION_TRACE(acpi_evaluate_object);
182 /* Allocate and initialize the evaluation information block */
184 info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
185 if (!info) {
186 return_ACPI_STATUS(AE_NO_MEMORY);
189 info->pathname = pathname;
191 /* Convert and validate the device handle */
193 info->prefix_node = acpi_ns_validate_handle(handle);
194 if (!info->prefix_node) {
195 status = AE_BAD_PARAMETER;
196 goto cleanup;
200 * If there are parameters to be passed to a control method, the external
201 * objects must all be converted to internal objects
203 if (external_params && external_params->count) {
205 * Allocate a new parameter block for the internal objects
206 * Add 1 to count to allow for null terminated internal list
208 info->parameters = ACPI_ALLOCATE_ZEROED(((acpi_size)
209 external_params->
210 count +
211 1) * sizeof(void *));
212 if (!info->parameters) {
213 status = AE_NO_MEMORY;
214 goto cleanup;
217 /* Convert each external object in the list to an internal object */
219 for (i = 0; i < external_params->count; i++) {
220 status =
221 acpi_ut_copy_eobject_to_iobject(&external_params->
222 pointer[i],
223 &info->
224 parameters[i]);
225 if (ACPI_FAILURE(status)) {
226 goto cleanup;
229 info->parameters[external_params->count] = NULL;
233 * Three major cases:
234 * 1) Fully qualified pathname
235 * 2) No handle, not fully qualified pathname (error)
236 * 3) Valid handle
238 if ((pathname) && (acpi_ns_valid_root_prefix(pathname[0]))) {
240 /* The path is fully qualified, just evaluate by name */
242 info->prefix_node = NULL;
243 status = acpi_ns_evaluate(info);
244 } else if (!handle) {
246 * A handle is optional iff a fully qualified pathname is specified.
247 * Since we've already handled fully qualified names above, this is
248 * an error
250 if (!pathname) {
251 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
252 "Both Handle and Pathname are NULL"));
253 } else {
254 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
255 "Null Handle with relative pathname [%s]",
256 pathname));
259 status = AE_BAD_PARAMETER;
260 } else {
261 /* We have a namespace a node and a possible relative path */
263 status = acpi_ns_evaluate(info);
267 * If we are expecting a return value, and all went well above,
268 * copy the return value to an external object.
270 if (return_buffer) {
271 if (!info->return_object) {
272 return_buffer->length = 0;
273 } else {
274 if (ACPI_GET_DESCRIPTOR_TYPE(info->return_object) ==
275 ACPI_DESC_TYPE_NAMED) {
277 * If we received a NS Node as a return object, this means that
278 * the object we are evaluating has nothing interesting to
279 * return (such as a mutex, etc.) We return an error because
280 * these types are essentially unsupported by this interface.
281 * We don't check up front because this makes it easier to add
282 * support for various types at a later date if necessary.
284 status = AE_TYPE;
285 info->return_object = NULL; /* No need to delete a NS Node */
286 return_buffer->length = 0;
289 if (ACPI_SUCCESS(status)) {
291 /* Dereference Index and ref_of references */
293 acpi_ns_resolve_references(info);
295 /* Get the size of the returned object */
297 status =
298 acpi_ut_get_object_size(info->return_object,
299 &buffer_space_needed);
300 if (ACPI_SUCCESS(status)) {
302 /* Validate/Allocate/Clear caller buffer */
304 status =
305 acpi_ut_initialize_buffer
306 (return_buffer,
307 buffer_space_needed);
308 if (ACPI_FAILURE(status)) {
310 * Caller's buffer is too small or a new one can't
311 * be allocated
313 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
314 "Needed buffer size %X, %s\n",
315 (u32)
316 buffer_space_needed,
317 acpi_format_exception
318 (status)));
319 } else {
320 /* We have enough space for the object, build it */
322 status =
323 acpi_ut_copy_iobject_to_eobject
324 (info->return_object,
325 return_buffer);
332 if (info->return_object) {
334 * Delete the internal return object. NOTE: Interpreter must be
335 * locked to avoid race condition.
337 acpi_ex_enter_interpreter();
339 /* Remove one reference on the return object (should delete it) */
341 acpi_ut_remove_reference(info->return_object);
342 acpi_ex_exit_interpreter();
345 cleanup:
347 /* Free the input parameter list (if we created one) */
349 if (info->parameters) {
351 /* Free the allocated parameter block */
353 acpi_ut_delete_internal_object_list(info->parameters);
356 ACPI_FREE(info);
357 return_ACPI_STATUS(status);
360 ACPI_EXPORT_SYMBOL(acpi_evaluate_object)
362 /*******************************************************************************
364 * FUNCTION: acpi_ns_resolve_references
366 * PARAMETERS: Info - Evaluation info block
368 * RETURN: Info->return_object is replaced with the dereferenced object
370 * DESCRIPTION: Dereference certain reference objects. Called before an
371 * internal return object is converted to an external union acpi_object.
373 * Performs an automatic dereference of Index and ref_of reference objects.
374 * These reference objects are not supported by the union acpi_object, so this is a
375 * last resort effort to return something useful. Also, provides compatibility
376 * with other ACPI implementations.
378 * NOTE: does not handle references within returned package objects or nested
379 * references, but this support could be added later if found to be necessary.
381 ******************************************************************************/
382 static void acpi_ns_resolve_references(struct acpi_evaluate_info *info)
384 union acpi_operand_object *obj_desc = NULL;
385 struct acpi_namespace_node *node;
387 /* We are interested in reference objects only */
389 if ((info->return_object)->common.type != ACPI_TYPE_LOCAL_REFERENCE) {
390 return;
394 * Two types of references are supported - those created by Index and
395 * ref_of operators. A name reference (AML_NAMEPATH_OP) can be converted
396 * to an union acpi_object, so it is not dereferenced here. A ddb_handle
397 * (AML_LOAD_OP) cannot be dereferenced, nor can it be converted to
398 * an union acpi_object.
400 switch (info->return_object->reference.class) {
401 case ACPI_REFCLASS_INDEX:
403 obj_desc = *(info->return_object->reference.where);
404 break;
406 case ACPI_REFCLASS_REFOF:
408 node = info->return_object->reference.object;
409 if (node) {
410 obj_desc = node->object;
412 break;
414 default:
415 return;
418 /* Replace the existing reference object */
420 if (obj_desc) {
421 acpi_ut_add_reference(obj_desc);
422 acpi_ut_remove_reference(info->return_object);
423 info->return_object = obj_desc;
426 return;
429 /*******************************************************************************
431 * FUNCTION: acpi_walk_namespace
433 * PARAMETERS: Type - acpi_object_type to search for
434 * start_object - Handle in namespace where search begins
435 * max_depth - Depth to which search is to reach
436 * pre_order_visit - Called during tree pre-order visit
437 * when an object of "Type" is found
438 * post_order_visit - Called during tree post-order visit
439 * when an object of "Type" is found
440 * Context - Passed to user function(s) above
441 * return_value - Location where return value of
442 * user_function is put if terminated early
444 * RETURNS Return value from the user_function if terminated early.
445 * Otherwise, returns NULL.
447 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
448 * starting (and ending) at the object specified by start_handle.
449 * The callback function is called whenever an object that matches
450 * the type parameter is found. If the callback function returns
451 * a non-zero value, the search is terminated immediately and this
452 * value is returned to the caller.
454 * The point of this procedure is to provide a generic namespace
455 * walk routine that can be called from multiple places to
456 * provide multiple services; the callback function(s) can be
457 * tailored to each task, whether it is a print function,
458 * a compare function, etc.
460 ******************************************************************************/
462 acpi_status
463 acpi_walk_namespace(acpi_object_type type,
464 acpi_handle start_object,
465 u32 max_depth,
466 acpi_walk_callback pre_order_visit,
467 acpi_walk_callback post_order_visit,
468 void *context, void **return_value)
470 acpi_status status;
472 ACPI_FUNCTION_TRACE(acpi_walk_namespace);
474 /* Parameter validation */
476 if ((type > ACPI_TYPE_LOCAL_MAX) ||
477 (!max_depth) || (!pre_order_visit && !post_order_visit)) {
478 return_ACPI_STATUS(AE_BAD_PARAMETER);
482 * Need to acquire the namespace reader lock to prevent interference
483 * with any concurrent table unloads (which causes the deletion of
484 * namespace objects). We cannot allow the deletion of a namespace node
485 * while the user function is using it. The exception to this are the
486 * nodes created and deleted during control method execution -- these
487 * nodes are marked as temporary nodes and are ignored by the namespace
488 * walk. Thus, control methods can be executed while holding the
489 * namespace deletion lock (and the user function can execute control
490 * methods.)
492 status = acpi_ut_acquire_read_lock(&acpi_gbl_namespace_rw_lock);
493 if (ACPI_FAILURE(status)) {
494 return status;
498 * Lock the namespace around the walk. The namespace will be
499 * unlocked/locked around each call to the user function - since the user
500 * function must be allowed to make ACPICA calls itself (for example, it
501 * will typically execute control methods during device enumeration.)
503 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
504 if (ACPI_FAILURE(status)) {
505 goto unlock_and_exit;
508 status = acpi_ns_walk_namespace(type, start_object, max_depth,
509 ACPI_NS_WALK_UNLOCK, pre_order_visit,
510 post_order_visit, context,
511 return_value);
513 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
515 unlock_and_exit:
516 (void)acpi_ut_release_read_lock(&acpi_gbl_namespace_rw_lock);
517 return_ACPI_STATUS(status);
520 ACPI_EXPORT_SYMBOL(acpi_walk_namespace)
522 /*******************************************************************************
524 * FUNCTION: acpi_ns_get_device_callback
526 * PARAMETERS: Callback from acpi_get_device
528 * RETURN: Status
530 * DESCRIPTION: Takes callbacks from walk_namespace and filters out all non-
531 * present devices, or if they specified a HID, it filters based
532 * on that.
534 ******************************************************************************/
535 static acpi_status
536 acpi_ns_get_device_callback(acpi_handle obj_handle,
537 u32 nesting_level,
538 void *context, void **return_value)
540 struct acpi_get_devices_info *info = context;
541 acpi_status status;
542 struct acpi_namespace_node *node;
543 u32 flags;
544 struct acpica_device_id *hid;
545 struct acpica_device_id_list *cid;
546 u32 i;
547 u8 found;
548 int no_match;
550 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
551 if (ACPI_FAILURE(status)) {
552 return (status);
555 node = acpi_ns_validate_handle(obj_handle);
556 status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
557 if (ACPI_FAILURE(status)) {
558 return (status);
561 if (!node) {
562 return (AE_BAD_PARAMETER);
566 * First, filter based on the device HID and CID.
568 * 01/2010: For this case where a specific HID is requested, we don't
569 * want to run _STA until we have an actual HID match. Thus, we will
570 * not unnecessarily execute _STA on devices for which the caller
571 * doesn't care about. Previously, _STA was executed unconditionally
572 * on all devices found here.
574 * A side-effect of this change is that now we will continue to search
575 * for a matching HID even under device trees where the parent device
576 * would have returned a _STA that indicates it is not present or
577 * not functioning (thus aborting the search on that branch).
579 if (info->hid != NULL) {
580 status = acpi_ut_execute_HID(node, &hid);
581 if (status == AE_NOT_FOUND) {
582 return (AE_OK);
583 } else if (ACPI_FAILURE(status)) {
584 return (AE_CTRL_DEPTH);
587 no_match = ACPI_STRCMP(hid->string, info->hid);
588 ACPI_FREE(hid);
590 if (no_match) {
592 * HID does not match, attempt match within the
593 * list of Compatible IDs (CIDs)
595 status = acpi_ut_execute_CID(node, &cid);
596 if (status == AE_NOT_FOUND) {
597 return (AE_OK);
598 } else if (ACPI_FAILURE(status)) {
599 return (AE_CTRL_DEPTH);
602 /* Walk the CID list */
604 found = 0;
605 for (i = 0; i < cid->count; i++) {
606 if (ACPI_STRCMP(cid->ids[i].string, info->hid)
607 == 0) {
608 found = 1;
609 break;
612 ACPI_FREE(cid);
613 if (!found)
614 return (AE_OK);
618 /* Run _STA to determine if device is present */
620 status = acpi_ut_execute_STA(node, &flags);
621 if (ACPI_FAILURE(status)) {
622 return (AE_CTRL_DEPTH);
625 if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
626 !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
628 * Don't examine the children of the device only when the
629 * device is neither present nor functional. See ACPI spec,
630 * description of _STA for more information.
632 return (AE_CTRL_DEPTH);
635 /* We have a valid device, invoke the user function */
637 status = info->user_function(obj_handle, nesting_level, info->context,
638 return_value);
639 return (status);
642 /*******************************************************************************
644 * FUNCTION: acpi_get_devices
646 * PARAMETERS: HID - HID to search for. Can be NULL.
647 * user_function - Called when a matching object is found
648 * Context - Passed to user function
649 * return_value - Location where return value of
650 * user_function is put if terminated early
652 * RETURNS Return value from the user_function if terminated early.
653 * Otherwise, returns NULL.
655 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
656 * starting (and ending) at the object specified by start_handle.
657 * The user_function is called whenever an object of type
658 * Device is found. If the user function returns
659 * a non-zero value, the search is terminated immediately and this
660 * value is returned to the caller.
662 * This is a wrapper for walk_namespace, but the callback performs
663 * additional filtering. Please see acpi_ns_get_device_callback.
665 ******************************************************************************/
667 acpi_status
668 acpi_get_devices(const char *HID,
669 acpi_walk_callback user_function,
670 void *context, void **return_value)
672 acpi_status status;
673 struct acpi_get_devices_info info;
675 ACPI_FUNCTION_TRACE(acpi_get_devices);
677 /* Parameter validation */
679 if (!user_function) {
680 return_ACPI_STATUS(AE_BAD_PARAMETER);
684 * We're going to call their callback from OUR callback, so we need
685 * to know what it is, and their context parameter.
687 info.hid = HID;
688 info.context = context;
689 info.user_function = user_function;
692 * Lock the namespace around the walk.
693 * The namespace will be unlocked/locked around each call
694 * to the user function - since this function
695 * must be allowed to make Acpi calls itself.
697 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
698 if (ACPI_FAILURE(status)) {
699 return_ACPI_STATUS(status);
702 status = acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
703 ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
704 acpi_ns_get_device_callback, NULL,
705 &info, return_value);
707 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
708 return_ACPI_STATUS(status);
711 ACPI_EXPORT_SYMBOL(acpi_get_devices)
713 /*******************************************************************************
715 * FUNCTION: acpi_attach_data
717 * PARAMETERS: obj_handle - Namespace node
718 * Handler - Handler for this attachment
719 * Data - Pointer to data to be attached
721 * RETURN: Status
723 * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
725 ******************************************************************************/
726 acpi_status
727 acpi_attach_data(acpi_handle obj_handle,
728 acpi_object_handler handler, void *data)
730 struct acpi_namespace_node *node;
731 acpi_status status;
733 /* Parameter validation */
735 if (!obj_handle || !handler || !data) {
736 return (AE_BAD_PARAMETER);
739 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
740 if (ACPI_FAILURE(status)) {
741 return (status);
744 /* Convert and validate the handle */
746 node = acpi_ns_validate_handle(obj_handle);
747 if (!node) {
748 status = AE_BAD_PARAMETER;
749 goto unlock_and_exit;
752 status = acpi_ns_attach_data(node, handler, data);
754 unlock_and_exit:
755 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
756 return (status);
759 ACPI_EXPORT_SYMBOL(acpi_attach_data)
761 /*******************************************************************************
763 * FUNCTION: acpi_detach_data
765 * PARAMETERS: obj_handle - Namespace node handle
766 * Handler - Handler used in call to acpi_attach_data
768 * RETURN: Status
770 * DESCRIPTION: Remove data that was previously attached to a node.
772 ******************************************************************************/
773 acpi_status
774 acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
776 struct acpi_namespace_node *node;
777 acpi_status status;
779 /* Parameter validation */
781 if (!obj_handle || !handler) {
782 return (AE_BAD_PARAMETER);
785 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
786 if (ACPI_FAILURE(status)) {
787 return (status);
790 /* Convert and validate the handle */
792 node = acpi_ns_validate_handle(obj_handle);
793 if (!node) {
794 status = AE_BAD_PARAMETER;
795 goto unlock_and_exit;
798 status = acpi_ns_detach_data(node, handler);
800 unlock_and_exit:
801 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
802 return (status);
805 ACPI_EXPORT_SYMBOL(acpi_detach_data)
807 /*******************************************************************************
809 * FUNCTION: acpi_get_data
811 * PARAMETERS: obj_handle - Namespace node
812 * Handler - Handler used in call to attach_data
813 * Data - Where the data is returned
815 * RETURN: Status
817 * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
819 ******************************************************************************/
820 acpi_status
821 acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
823 struct acpi_namespace_node *node;
824 acpi_status status;
826 /* Parameter validation */
828 if (!obj_handle || !handler || !data) {
829 return (AE_BAD_PARAMETER);
832 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
833 if (ACPI_FAILURE(status)) {
834 return (status);
837 /* Convert and validate the handle */
839 node = acpi_ns_validate_handle(obj_handle);
840 if (!node) {
841 status = AE_BAD_PARAMETER;
842 goto unlock_and_exit;
845 status = acpi_ns_get_attached_data(node, handler, data);
847 unlock_and_exit:
848 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
849 return (status);
852 ACPI_EXPORT_SYMBOL(acpi_get_data)