aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/acpi/namespace/nsxfeval.c
blob: f39fbc6b9237687a3ffd0c1b387499bb6ad0714c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
/*******************************************************************************
 *
 * Module Name: nsxfeval - Public interfaces to the ACPI subsystem
 *                         ACPI Object evaluation interfaces
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2007, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include <acpi/acnamesp.h>
#include <acpi/acinterp.h>

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nsxfeval")
#ifdef ACPI_FUTURE_USAGE
/*******************************************************************************
 *
 * FUNCTION:    acpi_evaluate_object_typed
 *
 * PARAMETERS:  Handle              - Object handle (optional)
 *              Pathname            - Object pathname (optional)
 *              external_params     - List of parameters to pass to method,
 *                                    terminated by NULL.  May be NULL
 *                                    if no parameters are being passed.
 *              return_buffer       - Where to put method's return value (if
 *                                    any).  If NULL, no value is returned.
 *              return_type         - Expected type of return object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Find and evaluate the given object, passing the given
 *              parameters if necessary.  One of "Handle" or "Pathname" must
 *              be valid (non-null)
 *
 ******************************************************************************/
acpi_status
acpi_evaluate_object_typed(acpi_handle handle,
			   acpi_string pathname,
			   struct acpi_object_list *external_params,
			   struct acpi_buffer *return_buffer,
			   acpi_object_type return_type)
{
	acpi_status status;
	u8 must_free = FALSE;

	ACPI_FUNCTION_TRACE(acpi_evaluate_object_typed);

	/* Return buffer must be valid */

	if (!return_buffer) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	if (return_buffer->length == ACPI_ALLOCATE_BUFFER) {
		must_free = TRUE;
	}

	/* Evaluate the object */

	status =
	    acpi_evaluate_object(handle, pathname, external_params,
				 return_buffer);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/* Type ANY means "don't care" */

	if (return_type == ACPI_TYPE_ANY) {
		return_ACPI_STATUS(AE_OK);
	}

	if (return_buffer->length == 0) {

		/* Error because caller specifically asked for a return value */

		ACPI_ERROR((AE_INFO, "No return value"));
		return_ACPI_STATUS(AE_NULL_OBJECT);
	}

	/* Examine the object type returned from evaluate_object */

	if (((union acpi_object *)return_buffer->pointer)->type == return_type) {
		return_ACPI_STATUS(AE_OK);
	}

	/* Return object type does not match requested type */

	ACPI_ERROR((AE_INFO,
		    "Incorrect return type [%s] requested [%s]",
		    acpi_ut_get_type_name(((union acpi_object *)return_buffer->
					   pointer)->type),
		    acpi_ut_get_type_name(return_type)));

	if (must_free) {

		/* Caller used ACPI_ALLOCATE_BUFFER, free the return buffer */

		ACPI_FREE(return_buffer->pointer);
		return_buffer->pointer = NULL;
	}

	return_buffer->length = 0;
	return_ACPI_STATUS(AE_TYPE);
}

ACPI_EXPORT_SYMBOL(acpi_evaluate_object_typed)
#endif				/*  ACPI_FUTURE_USAGE  */
/*******************************************************************************
 *
 * FUNCTION:    acpi_evaluate_object
 *
 * PARAMETERS:  Handle              - Object handle (optional)
 *              Pathname            - Object pathname (optional)
 *              external_params     - List of parameters to pass to method,
 *                                    terminated by NULL.  May be NULL
 *                                    if no parameters are being passed.
 *              return_buffer       - Where to put method's return value (if
 *                                    any).  If NULL, no value is returned.
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Find and evaluate the given object, passing the given
 *              parameters if necessary.  One of "Handle" or "Pathname" must
 *              be valid (non-null)
 *
 ******************************************************************************/
acpi_status
acpi_evaluate_object(acpi_handle handle,
		     acpi_string pathname,
		     struct acpi_object_list *external_params,
		     struct acpi_buffer *return_buffer)
{
	acpi_status status;
	struct acpi_evaluate_info *info;
	acpi_size buffer_space_needed;
	u32 i;

	ACPI_FUNCTION_TRACE(acpi_evaluate_object);

	/* Allocate and initialize the evaluation information block */

	info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
	if (!info) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	info->pathname = pathname;
	info->parameter_type = ACPI_PARAM_ARGS;

	/* Convert and validate the device handle */

	info->prefix_node = acpi_ns_map_handle_to_node(handle);
	if (!info->prefix_node) {
		status = AE_BAD_PARAMETER;
		goto cleanup;
	}

	/*
	 * If there are parameters to be passed to a control method, the external
	 * objects must all be converted to internal objects
	 */
	if (external_params && external_params->count) {
		/*
		 * Allocate a new parameter block for the internal objects
		 * Add 1 to count to allow for null terminated internal list
		 */
		info->parameters = ACPI_ALLOCATE_ZEROED(((acpi_size)
							 external_params->
							 count +
							 1) * sizeof(void *));
		if (!info->parameters) {
			status = AE_NO_MEMORY;
			goto cleanup;
		}

		/* Convert each external object in the list to an internal object */

		for (i = 0; i < external_params->count; i++) {
			status =
			    acpi_ut_copy_eobject_to_iobject(&external_params->
							    pointer[i],
							    &info->
							    parameters[i]);
			if (ACPI_FAILURE(status)) {
				goto cleanup;
			}
		}
		info->parameters[external_params->count] = NULL;
	}

	/*
	 * Three major cases:
	 * 1) Fully qualified pathname
	 * 2) No handle, not fully qualified pathname (error)
	 * 3) Valid handle
	 */
	if ((pathname) && (acpi_ns_valid_root_prefix(pathname[0]))) {

		/* The path is fully qualified, just evaluate by name */

		info->prefix_node = NULL;
		status = acpi_ns_evaluate(info);
	} else if (!handle) {
		/*
		 * A handle is optional iff a fully qualified pathname is specified.
		 * Since we've already handled fully qualified names above, this is
		 * an error
		 */
		if (!pathname) {
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					  "Both Handle and Pathname are NULL"));
		} else {
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					  "Null Handle with relative pathname [%s]",
					  pathname));
		}

		status = AE_BAD_PARAMETER;
	} else {
		/* We have a namespace a node and a possible relative path */

		status = acpi_ns_evaluate(info);
	}

	/*
	 * If we are expecting a return value, and all went well above,
	 * copy the return value to an external object.
	 */
	if (return_buffer) {
		if (!info->return_object) {
			return_buffer->length = 0;
		} else {
			if (ACPI_GET_DESCRIPTOR_TYPE(info->return_object) ==
			    ACPI_DESC_TYPE_NAMED) {
				/*
				 * If we received a NS Node as a return object, this means that
				 * the object we are evaluating has nothing interesting to
				 * return (such as a mutex, etc.)  We return an error because
				 * these types are essentially unsupported by this interface.
				 * We don't check up front because this makes it easier to add
				 * support for various types at a later date if necessary.
				 */
				status = AE_TYPE;
				info->return_object = NULL;	/* No need to delete a NS Node */
				return_buffer->length = 0;
			}

			if (ACPI_SUCCESS(status)) {

				/* Get the size of the returned object */

				status =
				    acpi_ut_get_object_size(info->return_object,
							    &buffer_space_needed);
				if (ACPI_SUCCESS(status)) {

					/* Validate/Allocate/Clear caller buffer */

					status =
					    acpi_ut_initialize_buffer
					    (return_buffer,
					     buffer_space_needed);
					if (ACPI_FAILURE(status)) {
						/*
						 * Caller's buffer is too small or a new one can't
						 * be allocated
						 */
						ACPI_DEBUG_PRINT((ACPI_DB_INFO,
								  "Needed buffer size %X, %s\n",
								  (u32)
								  buffer_space_needed,
								  acpi_format_exception
								  (status)));
					} else {
						/* We have enough space for the object, build it */

						status =
						    acpi_ut_copy_iobject_to_eobject
						    (info->return_object,
						     return_buffer);
					}
				}
			}
		}
	}

	if (info->return_object) {
		/*
		 * Delete the internal return object. NOTE: Interpreter must be
		 * locked to avoid race condition.
		 */
		acpi_ex_enter_interpreter();

		/* Remove one reference on the return object (should delete it) */

		acpi_ut_remove_reference(info->return_object);
		acpi_ex_exit_interpreter();
	}

      cleanup:

	/* Free the input parameter list (if we created one) */

	if (info->parameters) {

		/* Free the allocated parameter block */

		acpi_ut_delete_internal_object_list(info->parameters);
	}

	ACPI_FREE(info);
	return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_evaluate_object)

/*******************************************************************************
 *
 * FUNCTION:    acpi_walk_namespace
 *
 * PARAMETERS:  Type                - acpi_object_type to search for
 *              start_object        - Handle in namespace where search begins
 *              max_depth           - Depth to which search is to reach
 *              user_function       - Called when an object of "Type" is found
 *              Context             - Passed to user function
 *              return_value        - Location where return value of
 *                                    user_function is put if terminated early
 *
 * RETURNS      Return value from the user_function if terminated early.
 *              Otherwise, returns NULL.
 *
 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
 *              starting (and ending) at the object specified by start_handle.
 *              The user_function is called whenever an object that matches
 *              the type parameter is found.  If the user function returns
 *              a non-zero value, the search is terminated immediately and this
 *              value is returned to the caller.
 *
 *              The point of this procedure is to provide a generic namespace
 *              walk routine that can be called from multiple places to
 *              provide multiple services;  the User Function can be tailored
 *              to each task, whether it is a print function, a compare
 *              function, etc.
 *
 ******************************************************************************/
acpi_status
acpi_walk_namespace(acpi_object_type type,
		    acpi_handle start_object,
		    u32 max_depth,
		    acpi_walk_callback user_function,
		    void *context, void **return_value)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(acpi_walk_namespace);

	/* Parameter validation */

	if ((type > ACPI_TYPE_LOCAL_MAX) || (!max_depth) || (!user_function)) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/*
	 * Lock the namespace around the walk.
	 * The namespace will be unlocked/locked around each call
	 * to the user function - since this function
	 * must be allowed to make Acpi calls itself.
	 */
	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	status = acpi_ns_walk_namespace(type, start_object, max_depth,
					ACPI_NS_WALK_UNLOCK,
					user_function, context, return_value);

	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
	return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_walk_namespace)

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_device_callback
 *
 * PARAMETERS:  Callback from acpi_get_device
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Takes callbacks from walk_namespace and filters out all non-
 *              present devices, or if they specified a HID, it filters based
 *              on that.
 *
 ******************************************************************************/
static acpi_status
acpi_ns_get_device_callback(acpi_handle obj_handle,
			    u32 nesting_level,
			    void *context, void **return_value)
{
	struct acpi_get_devices_info *info = context;
	acpi_status status;
	struct acpi_namespace_node *node;
	u32 flags;
	struct acpica_device_id hid;
	struct acpi_compatible_id_list *cid;
	acpi_native_uint i;

	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		return (status);
	}

	node = acpi_ns_map_handle_to_node(obj_handle);
	status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		return (status);
	}

	if (!node) {
		return (AE_BAD_PARAMETER);
	}

	/* Run _STA to determine if device is present */

	status = acpi_ut_execute_STA(node, &flags);
	if (ACPI_FAILURE(status)) {
		return (AE_CTRL_DEPTH);
	}

	if (!(flags & ACPI_STA_DEVICE_PRESENT)) {

		/* Don't examine children of the device if not present */

		return (AE_CTRL_DEPTH);
	}

	/* Filter based on device HID & CID */

	if (info->hid != NULL) {
		status = acpi_ut_execute_HID(node, &hid);
		if (status == AE_NOT_FOUND) {
			return (AE_OK);
		} else if (ACPI_FAILURE(status)) {
			return (AE_CTRL_DEPTH);
		}

		if (ACPI_STRNCMP(hid.value, info->hid, sizeof(hid.value)) != 0) {

			/* Get the list of Compatible IDs */

			status = acpi_ut_execute_CID(node, &cid);
			if (status == AE_NOT_FOUND) {
				return (AE_OK);
			} else if (ACPI_FAILURE(status)) {
				return (AE_CTRL_DEPTH);
			}

			/* Walk the CID list */

			for (i = 0; i < cid->count; i++) {
				if (ACPI_STRNCMP(cid->id[i].value, info->hid,
						 sizeof(struct
							acpi_compatible_id)) !=
				    0) {
					ACPI_FREE(cid);
					return (AE_OK);
				}
			}
			ACPI_FREE(cid);
		}
	}

	status = info->user_function(obj_handle, nesting_level, info->context,
				     return_value);
	return (status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_get_devices
 *
 * PARAMETERS:  HID                 - HID to search for. Can be NULL.
 *              user_function       - Called when a matching object is found
 *              Context             - Passed to user function
 *              return_value        - Location where return value of
 *                                    user_function is put if terminated early
 *
 * RETURNS      Return value from the user_function if terminated early.
 *              Otherwise, returns NULL.
 *
 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
 *              starting (and ending) at the object specified by start_handle.
 *              The user_function is called whenever an object of type
 *              Device is found.  If the user function returns
 *              a non-zero value, the search is terminated immediately and this
 *              value is returned to the caller.
 *
 *              This is a wrapper for walk_namespace, but the callback performs
 *              additional filtering. Please see acpi_get_device_callback.
 *
 ******************************************************************************/

acpi_status
acpi_get_devices(const char *HID,
		 acpi_walk_callback user_function,
		 void *context, void **return_value)
{
	acpi_status status;
	struct acpi_get_devices_info info;

	ACPI_FUNCTION_TRACE(acpi_get_devices);

	/* Parameter validation */

	if (!user_function) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/*
	 * We're going to call their callback from OUR callback, so we need
	 * to know what it is, and their context parameter.
	 */
	info.hid = HID;
	info.context = context;
	info.user_function = user_function;

	/*
	 * Lock the namespace around the walk.
	 * The namespace will be unlocked/locked around each call
	 * to the user function - since this function
	 * must be allowed to make Acpi calls itself.
	 */
	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	status = acpi_ns_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
					ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
					acpi_ns_get_device_callback, &info,
					return_value);

	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
	return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_get_devices)

/*******************************************************************************
 *
 * FUNCTION:    acpi_attach_data
 *
 * PARAMETERS:  obj_handle          - Namespace node
 *              Handler             - Handler for this attachment
 *              Data                - Pointer to data to be attached
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
 *
 ******************************************************************************/
acpi_status
acpi_attach_data(acpi_handle obj_handle,
		 acpi_object_handler handler, void *data)
{
	struct acpi_namespace_node *node;
	acpi_status status;

	/* Parameter validation */

	if (!obj_handle || !handler || !data) {
		return (AE_BAD_PARAMETER);
	}

	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		return (status);
	}

	/* Convert and validate the handle */

	node = acpi_ns_map_handle_to_node(obj_handle);
	if (!node) {
		status = AE_BAD_PARAMETER;
		goto unlock_and_exit;
	}

	status = acpi_ns_attach_data(node, handler, data);

      unlock_and_exit:
	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
	return (status);
}

ACPI_EXPORT_SYMBOL(acpi_attach_data)

/*******************************************************************************
 *
 * FUNCTION:    acpi_detach_data
 *
 * PARAMETERS:  obj_handle          - Namespace node handle
 *              Handler             - Handler used in call to acpi_attach_data
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Remove data that was previously attached to a node.
 *
 ******************************************************************************/
acpi_status
acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
{
	struct acpi_namespace_node *node;
	acpi_status status;

	/* Parameter validation */

	if (!obj_handle || !handler) {
		return (AE_BAD_PARAMETER);
	}

	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		return (status);
	}

	/* Convert and validate the handle */

	node = acpi_ns_map_handle_to_node(obj_handle);
	if (!node) {
		status = AE_BAD_PARAMETER;
		goto unlock_and_exit;
	}

	status = acpi_ns_detach_data(node, handler);

      unlock_and_exit:
	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
	return (status);
}

ACPI_EXPORT_SYMBOL(acpi_detach_data)

/*******************************************************************************
 *
 * FUNCTION:    acpi_get_data
 *
 * PARAMETERS:  obj_handle          - Namespace node
 *              Handler             - Handler used in call to attach_data
 *              Data                - Where the data is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
 *
 ******************************************************************************/
acpi_status
acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
{
	struct acpi_namespace_node *node;
	acpi_status status;

	/* Parameter validation */

	if (!obj_handle || !handler || !data) {
		return (AE_BAD_PARAMETER);
	}

	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		return (status);
	}

	/* Convert and validate the handle */

	node = acpi_ns_map_handle_to_node(obj_handle);
	if (!node) {
		status = AE_BAD_PARAMETER;
		goto unlock_and_exit;
	}

	status = acpi_ns_get_attached_data(node, handler, data);

      unlock_and_exit:
	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
	return (status);
}

ACPI_EXPORT_SYMBOL(acpi_get_data)