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v3.1
  1/*******************************************************************************
  2 *
  3 * Module Name: nsxfeval - Public interfaces to the ACPI subsystem
  4 *                         ACPI Object evaluation interfaces
  5 *
  6 ******************************************************************************/
  7
  8/*
  9 * Copyright (C) 2000 - 2011, 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 "acinterp.h"
 49
 50#define _COMPONENT          ACPI_NAMESPACE
 51ACPI_MODULE_NAME("nsxfeval")
 52
 53/* Local prototypes */
 54static void acpi_ns_resolve_references(struct acpi_evaluate_info *info);
 55
 56/*******************************************************************************
 57 *
 58 * FUNCTION:    acpi_evaluate_object_typed
 59 *
 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
 68 *
 69 * RETURN:      Status
 70 *
 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)
 74 *
 75 ******************************************************************************/
 76
 77acpi_status
 78acpi_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)
 83{
 84	acpi_status status;
 85	u8 must_free = FALSE;
 86
 87	ACPI_FUNCTION_TRACE(acpi_evaluate_object_typed);
 88
 89	/* Return buffer must be valid */
 90
 91	if (!return_buffer) {
 92		return_ACPI_STATUS(AE_BAD_PARAMETER);
 93	}
 94
 95	if (return_buffer->length == ACPI_ALLOCATE_BUFFER) {
 96		must_free = TRUE;
 97	}
 98
 99	/* Evaluate the object */
100
101	status =
102	    acpi_evaluate_object(handle, pathname, external_params,
103				 return_buffer);
104	if (ACPI_FAILURE(status)) {
105		return_ACPI_STATUS(status);
106	}
107
108	/* Type ANY means "don't care" */
109
110	if (return_type == ACPI_TYPE_ANY) {
111		return_ACPI_STATUS(AE_OK);
112	}
113
114	if (return_buffer->length == 0) {
115
116		/* Error because caller specifically asked for a return value */
117
118		ACPI_ERROR((AE_INFO, "No return value"));
119		return_ACPI_STATUS(AE_NULL_OBJECT);
120	}
121
122	/* Examine the object type returned from evaluate_object */
123
124	if (((union acpi_object *)return_buffer->pointer)->type == return_type) {
125		return_ACPI_STATUS(AE_OK);
126	}
127
128	/* Return object type does not match requested type */
129
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)));
135
136	if (must_free) {
137
138		/* Caller used ACPI_ALLOCATE_BUFFER, free the return buffer */
139
140		ACPI_FREE(return_buffer->pointer);
141		return_buffer->pointer = NULL;
142	}
143
144	return_buffer->length = 0;
145	return_ACPI_STATUS(AE_TYPE);
146}
147
148ACPI_EXPORT_SYMBOL(acpi_evaluate_object_typed)
149
150/*******************************************************************************
151 *
152 * FUNCTION:    acpi_evaluate_object
153 *
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.
161 *
162 * RETURN:      Status
163 *
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)
167 *
168 ******************************************************************************/
169acpi_status
170acpi_evaluate_object(acpi_handle handle,
171		     acpi_string pathname,
172		     struct acpi_object_list *external_params,
173		     struct acpi_buffer *return_buffer)
174{
175	acpi_status status;
176	struct acpi_evaluate_info *info;
177	acpi_size buffer_space_needed;
178	u32 i;
179
180	ACPI_FUNCTION_TRACE(acpi_evaluate_object);
181
182	/* Allocate and initialize the evaluation information block */
183
184	info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
185	if (!info) {
186		return_ACPI_STATUS(AE_NO_MEMORY);
187	}
188
189	info->pathname = pathname;
190
191	/* Convert and validate the device handle */
192
193	info->prefix_node = acpi_ns_validate_handle(handle);
194	if (!info->prefix_node) {
195		status = AE_BAD_PARAMETER;
196		goto cleanup;
197	}
198
199	/*
200	 * If there are parameters to be passed to a control method, the external
201	 * objects must all be converted to internal objects
202	 */
203	if (external_params && external_params->count) {
204		/*
205		 * Allocate a new parameter block for the internal objects
206		 * Add 1 to count to allow for null terminated internal list
207		 */
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;
215		}
216
217		/* Convert each external object in the list to an internal object */
218
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;
227			}
228		}
229		info->parameters[external_params->count] = NULL;
230	}
231
232	/*
233	 * Three major cases:
234	 * 1) Fully qualified pathname
235	 * 2) No handle, not fully qualified pathname (error)
236	 * 3) Valid handle
237	 */
238	if ((pathname) && (acpi_ns_valid_root_prefix(pathname[0]))) {
239
240		/* The path is fully qualified, just evaluate by name */
241
242		info->prefix_node = NULL;
243		status = acpi_ns_evaluate(info);
244	} else if (!handle) {
245		/*
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
249		 */
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));
257		}
258
259		status = AE_BAD_PARAMETER;
260	} else {
261		/* We have a namespace a node and a possible relative path */
262
263		status = acpi_ns_evaluate(info);
264	}
265
266	/*
267	 * If we are expecting a return value, and all went well above,
268	 * copy the return value to an external object.
269	 */
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) {
276				/*
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.
283				 */
284				status = AE_TYPE;
285				info->return_object = NULL;	/* No need to delete a NS Node */
286				return_buffer->length = 0;
287			}
288
289			if (ACPI_SUCCESS(status)) {
290
291				/* Dereference Index and ref_of references */
292
293				acpi_ns_resolve_references(info);
294
295				/* Get the size of the returned object */
296
297				status =
298				    acpi_ut_get_object_size(info->return_object,
299							    &buffer_space_needed);
300				if (ACPI_SUCCESS(status)) {
301
302					/* Validate/Allocate/Clear caller buffer */
303
304					status =
305					    acpi_ut_initialize_buffer
306					    (return_buffer,
307					     buffer_space_needed);
308					if (ACPI_FAILURE(status)) {
309						/*
310						 * Caller's buffer is too small or a new one can't
311						 * be allocated
312						 */
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 */
321
322						status =
323						    acpi_ut_copy_iobject_to_eobject
324						    (info->return_object,
325						     return_buffer);
326					}
327				}
328			}
329		}
330	}
331
332	if (info->return_object) {
333		/*
334		 * Delete the internal return object. NOTE: Interpreter must be
335		 * locked to avoid race condition.
336		 */
337		acpi_ex_enter_interpreter();
338
339		/* Remove one reference on the return object (should delete it) */
340
341		acpi_ut_remove_reference(info->return_object);
342		acpi_ex_exit_interpreter();
343	}
344
345      cleanup:
346
347	/* Free the input parameter list (if we created one) */
348
349	if (info->parameters) {
350
351		/* Free the allocated parameter block */
352
353		acpi_ut_delete_internal_object_list(info->parameters);
354	}
355
356	ACPI_FREE(info);
357	return_ACPI_STATUS(status);
358}
359
360ACPI_EXPORT_SYMBOL(acpi_evaluate_object)
361
362/*******************************************************************************
363 *
364 * FUNCTION:    acpi_ns_resolve_references
365 *
366 * PARAMETERS:  Info                    - Evaluation info block
367 *
368 * RETURN:      Info->return_object is replaced with the dereferenced object
369 *
370 * DESCRIPTION: Dereference certain reference objects. Called before an
371 *              internal return object is converted to an external union acpi_object.
372 *
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.
377 *
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.
380 *
381 ******************************************************************************/
382static void acpi_ns_resolve_references(struct acpi_evaluate_info *info)
383{
384	union acpi_operand_object *obj_desc = NULL;
385	struct acpi_namespace_node *node;
386
387	/* We are interested in reference objects only */
388
389	if ((info->return_object)->common.type != ACPI_TYPE_LOCAL_REFERENCE) {
390		return;
391	}
392
393	/*
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.
399	 */
400	switch (info->return_object->reference.class) {
401	case ACPI_REFCLASS_INDEX:
402
403		obj_desc = *(info->return_object->reference.where);
404		break;
405
406	case ACPI_REFCLASS_REFOF:
407
408		node = info->return_object->reference.object;
409		if (node) {
410			obj_desc = node->object;
411		}
412		break;
413
414	default:
415		return;
416	}
417
418	/* Replace the existing reference object */
419
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;
424	}
425
426	return;
427}
428
429/*******************************************************************************
430 *
431 * FUNCTION:    acpi_walk_namespace
432 *
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
443 *
444 * RETURNS      Return value from the user_function if terminated early.
445 *              Otherwise, returns NULL.
446 *
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.
453 *
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.
459 *
460 ******************************************************************************/
461
462acpi_status
463acpi_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)
469{
470	acpi_status status;
471
472	ACPI_FUNCTION_TRACE(acpi_walk_namespace);
473
474	/* Parameter validation */
475
476	if ((type > ACPI_TYPE_LOCAL_MAX) ||
477	    (!max_depth) || (!pre_order_visit && !post_order_visit)) {
478		return_ACPI_STATUS(AE_BAD_PARAMETER);
479	}
480
481	/*
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.)
491	 */
492	status = acpi_ut_acquire_read_lock(&acpi_gbl_namespace_rw_lock);
493	if (ACPI_FAILURE(status)) {
494		return status;
495	}
496
497	/*
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.)
502	 */
503	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
504	if (ACPI_FAILURE(status)) {
505		goto unlock_and_exit;
506	}
507
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);
512
513	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
514
515      unlock_and_exit:
516	(void)acpi_ut_release_read_lock(&acpi_gbl_namespace_rw_lock);
517	return_ACPI_STATUS(status);
518}
519
520ACPI_EXPORT_SYMBOL(acpi_walk_namespace)
521
522/*******************************************************************************
523 *
524 * FUNCTION:    acpi_ns_get_device_callback
525 *
526 * PARAMETERS:  Callback from acpi_get_device
527 *
528 * RETURN:      Status
529 *
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.
533 *
534 ******************************************************************************/
535static acpi_status
536acpi_ns_get_device_callback(acpi_handle obj_handle,
537			    u32 nesting_level,
538			    void *context, void **return_value)
539{
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;
549
550	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
551	if (ACPI_FAILURE(status)) {
552		return (status);
553	}
554
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);
559	}
560
561	if (!node) {
562		return (AE_BAD_PARAMETER);
563	}
564
565	/*
566	 * First, filter based on the device HID and CID.
567	 *
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.
573	 *
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).
578	 */
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);
585		}
586
587		no_match = ACPI_STRCMP(hid->string, info->hid);
588		ACPI_FREE(hid);
589
590		if (no_match) {
591			/*
592			 * HID does not match, attempt match within the
593			 * list of Compatible IDs (CIDs)
594			 */
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);
600			}
601
602			/* Walk the CID list */
603
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;
610				}
611			}
612			ACPI_FREE(cid);
613			if (!found)
614				return (AE_OK);
615		}
616	}
617
618	/* Run _STA to determine if device is present */
619
620	status = acpi_ut_execute_STA(node, &flags);
621	if (ACPI_FAILURE(status)) {
622		return (AE_CTRL_DEPTH);
623	}
624
625	if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
626	    !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
627		/*
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.
631		 */
632		return (AE_CTRL_DEPTH);
633	}
634
635	/* We have a valid device, invoke the user function */
636
637	status = info->user_function(obj_handle, nesting_level, info->context,
638				     return_value);
639	return (status);
640}
641
642/*******************************************************************************
643 *
644 * FUNCTION:    acpi_get_devices
645 *
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
651 *
652 * RETURNS      Return value from the user_function if terminated early.
653 *              Otherwise, returns NULL.
654 *
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.
661 *
662 *              This is a wrapper for walk_namespace, but the callback performs
663 *              additional filtering. Please see acpi_ns_get_device_callback.
664 *
665 ******************************************************************************/
666
667acpi_status
668acpi_get_devices(const char *HID,
669		 acpi_walk_callback user_function,
670		 void *context, void **return_value)
671{
672	acpi_status status;
673	struct acpi_get_devices_info info;
674
675	ACPI_FUNCTION_TRACE(acpi_get_devices);
676
677	/* Parameter validation */
678
679	if (!user_function) {
680		return_ACPI_STATUS(AE_BAD_PARAMETER);
681	}
682
683	/*
684	 * We're going to call their callback from OUR callback, so we need
685	 * to know what it is, and their context parameter.
686	 */
687	info.hid = HID;
688	info.context = context;
689	info.user_function = user_function;
690
691	/*
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.
696	 */
697	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
698	if (ACPI_FAILURE(status)) {
699		return_ACPI_STATUS(status);
700	}
701
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);
706
707	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
708	return_ACPI_STATUS(status);
709}
710
711ACPI_EXPORT_SYMBOL(acpi_get_devices)
712
713/*******************************************************************************
714 *
715 * FUNCTION:    acpi_attach_data
716 *
717 * PARAMETERS:  obj_handle          - Namespace node
718 *              Handler             - Handler for this attachment
719 *              Data                - Pointer to data to be attached
720 *
721 * RETURN:      Status
722 *
723 * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
724 *
725 ******************************************************************************/
726acpi_status
727acpi_attach_data(acpi_handle obj_handle,
728		 acpi_object_handler handler, void *data)
729{
730	struct acpi_namespace_node *node;
731	acpi_status status;
732
733	/* Parameter validation */
734
735	if (!obj_handle || !handler || !data) {
736		return (AE_BAD_PARAMETER);
737	}
738
739	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
740	if (ACPI_FAILURE(status)) {
741		return (status);
742	}
743
744	/* Convert and validate the handle */
745
746	node = acpi_ns_validate_handle(obj_handle);
747	if (!node) {
748		status = AE_BAD_PARAMETER;
749		goto unlock_and_exit;
750	}
751
752	status = acpi_ns_attach_data(node, handler, data);
753
754      unlock_and_exit:
755	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
756	return (status);
757}
758
759ACPI_EXPORT_SYMBOL(acpi_attach_data)
760
761/*******************************************************************************
762 *
763 * FUNCTION:    acpi_detach_data
764 *
765 * PARAMETERS:  obj_handle          - Namespace node handle
766 *              Handler             - Handler used in call to acpi_attach_data
767 *
768 * RETURN:      Status
769 *
770 * DESCRIPTION: Remove data that was previously attached to a node.
771 *
772 ******************************************************************************/
773acpi_status
774acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
775{
776	struct acpi_namespace_node *node;
777	acpi_status status;
778
779	/* Parameter validation */
780
781	if (!obj_handle || !handler) {
782		return (AE_BAD_PARAMETER);
783	}
784
785	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
786	if (ACPI_FAILURE(status)) {
787		return (status);
788	}
789
790	/* Convert and validate the handle */
791
792	node = acpi_ns_validate_handle(obj_handle);
793	if (!node) {
794		status = AE_BAD_PARAMETER;
795		goto unlock_and_exit;
796	}
797
798	status = acpi_ns_detach_data(node, handler);
799
800      unlock_and_exit:
801	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
802	return (status);
803}
804
805ACPI_EXPORT_SYMBOL(acpi_detach_data)
806
807/*******************************************************************************
808 *
809 * FUNCTION:    acpi_get_data
810 *
811 * PARAMETERS:  obj_handle          - Namespace node
812 *              Handler             - Handler used in call to attach_data
813 *              Data                - Where the data is returned
814 *
815 * RETURN:      Status
816 *
817 * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
818 *
819 ******************************************************************************/
820acpi_status
821acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
822{
823	struct acpi_namespace_node *node;
824	acpi_status status;
825
826	/* Parameter validation */
827
828	if (!obj_handle || !handler || !data) {
829		return (AE_BAD_PARAMETER);
830	}
831
832	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
833	if (ACPI_FAILURE(status)) {
834		return (status);
835	}
836
837	/* Convert and validate the handle */
838
839	node = acpi_ns_validate_handle(obj_handle);
840	if (!node) {
841		status = AE_BAD_PARAMETER;
842		goto unlock_and_exit;
843	}
844
845	status = acpi_ns_get_attached_data(node, handler, data);
846
847      unlock_and_exit:
848	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
849	return (status);
850}
851
852ACPI_EXPORT_SYMBOL(acpi_get_data)
v3.5.6
  1/*******************************************************************************
  2 *
  3 * Module Name: nsxfeval - Public interfaces to the ACPI subsystem
  4 *                         ACPI Object evaluation interfaces
  5 *
  6 ******************************************************************************/
  7
  8/*
  9 * Copyright (C) 2000 - 2012, 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 <linux/export.h>
 46#include <acpi/acpi.h>
 47#include "accommon.h"
 48#include "acnamesp.h"
 49#include "acinterp.h"
 50
 51#define _COMPONENT          ACPI_NAMESPACE
 52ACPI_MODULE_NAME("nsxfeval")
 53
 54/* Local prototypes */
 55static void acpi_ns_resolve_references(struct acpi_evaluate_info *info);
 56
 57/*******************************************************************************
 58 *
 59 * FUNCTION:    acpi_evaluate_object_typed
 60 *
 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
 69 *
 70 * RETURN:      Status
 71 *
 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)
 75 *
 76 ******************************************************************************/
 77
 78acpi_status
 79acpi_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)
 84{
 85	acpi_status status;
 86	u8 must_free = FALSE;
 87
 88	ACPI_FUNCTION_TRACE(acpi_evaluate_object_typed);
 89
 90	/* Return buffer must be valid */
 91
 92	if (!return_buffer) {
 93		return_ACPI_STATUS(AE_BAD_PARAMETER);
 94	}
 95
 96	if (return_buffer->length == ACPI_ALLOCATE_BUFFER) {
 97		must_free = TRUE;
 98	}
 99
100	/* Evaluate the object */
101
102	status =
103	    acpi_evaluate_object(handle, pathname, external_params,
104				 return_buffer);
105	if (ACPI_FAILURE(status)) {
106		return_ACPI_STATUS(status);
107	}
108
109	/* Type ANY means "don't care" */
110
111	if (return_type == ACPI_TYPE_ANY) {
112		return_ACPI_STATUS(AE_OK);
113	}
114
115	if (return_buffer->length == 0) {
116
117		/* Error because caller specifically asked for a return value */
118
119		ACPI_ERROR((AE_INFO, "No return value"));
120		return_ACPI_STATUS(AE_NULL_OBJECT);
121	}
122
123	/* Examine the object type returned from evaluate_object */
124
125	if (((union acpi_object *)return_buffer->pointer)->type == return_type) {
126		return_ACPI_STATUS(AE_OK);
127	}
128
129	/* Return object type does not match requested type */
130
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)));
136
137	if (must_free) {
138
139		/* Caller used ACPI_ALLOCATE_BUFFER, free the return buffer */
140
141		ACPI_FREE(return_buffer->pointer);
142		return_buffer->pointer = NULL;
143	}
144
145	return_buffer->length = 0;
146	return_ACPI_STATUS(AE_TYPE);
147}
148
149ACPI_EXPORT_SYMBOL(acpi_evaluate_object_typed)
150
151/*******************************************************************************
152 *
153 * FUNCTION:    acpi_evaluate_object
154 *
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.
162 *
163 * RETURN:      Status
164 *
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)
168 *
169 ******************************************************************************/
170acpi_status
171acpi_evaluate_object(acpi_handle handle,
172		     acpi_string pathname,
173		     struct acpi_object_list *external_params,
174		     struct acpi_buffer *return_buffer)
175{
176	acpi_status status;
177	struct acpi_evaluate_info *info;
178	acpi_size buffer_space_needed;
179	u32 i;
180
181	ACPI_FUNCTION_TRACE(acpi_evaluate_object);
182
183	/* Allocate and initialize the evaluation information block */
184
185	info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
186	if (!info) {
187		return_ACPI_STATUS(AE_NO_MEMORY);
188	}
189
190	info->pathname = pathname;
191
192	/* Convert and validate the device handle */
193
194	info->prefix_node = acpi_ns_validate_handle(handle);
195	if (!info->prefix_node) {
196		status = AE_BAD_PARAMETER;
197		goto cleanup;
198	}
199
200	/*
201	 * If there are parameters to be passed to a control method, the external
202	 * objects must all be converted to internal objects
203	 */
204	if (external_params && external_params->count) {
205		/*
206		 * Allocate a new parameter block for the internal objects
207		 * Add 1 to count to allow for null terminated internal list
208		 */
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;
216		}
217
218		/* Convert each external object in the list to an internal object */
219
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;
228			}
229		}
230		info->parameters[external_params->count] = NULL;
231	}
232
233	/*
234	 * Three major cases:
235	 * 1) Fully qualified pathname
236	 * 2) No handle, not fully qualified pathname (error)
237	 * 3) Valid handle
238	 */
239	if ((pathname) && (acpi_ns_valid_root_prefix(pathname[0]))) {
240
241		/* The path is fully qualified, just evaluate by name */
242
243		info->prefix_node = NULL;
244		status = acpi_ns_evaluate(info);
245	} else if (!handle) {
246		/*
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
250		 */
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));
258		}
259
260		status = AE_BAD_PARAMETER;
261	} else {
262		/* We have a namespace a node and a possible relative path */
263
264		status = acpi_ns_evaluate(info);
265	}
266
267	/*
268	 * If we are expecting a return value, and all went well above,
269	 * copy the return value to an external object.
270	 */
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) {
277				/*
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.
284				 */
285				status = AE_TYPE;
286				info->return_object = NULL;	/* No need to delete a NS Node */
287				return_buffer->length = 0;
288			}
289
290			if (ACPI_SUCCESS(status)) {
291
292				/* Dereference Index and ref_of references */
293
294				acpi_ns_resolve_references(info);
295
296				/* Get the size of the returned object */
297
298				status =
299				    acpi_ut_get_object_size(info->return_object,
300							    &buffer_space_needed);
301				if (ACPI_SUCCESS(status)) {
302
303					/* Validate/Allocate/Clear caller buffer */
304
305					status =
306					    acpi_ut_initialize_buffer
307					    (return_buffer,
308					     buffer_space_needed);
309					if (ACPI_FAILURE(status)) {
310						/*
311						 * Caller's buffer is too small or a new one can't
312						 * be allocated
313						 */
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 */
322
323						status =
324						    acpi_ut_copy_iobject_to_eobject
325						    (info->return_object,
326						     return_buffer);
327					}
328				}
329			}
330		}
331	}
332
333	if (info->return_object) {
334		/*
335		 * Delete the internal return object. NOTE: Interpreter must be
336		 * locked to avoid race condition.
337		 */
338		acpi_ex_enter_interpreter();
339
340		/* Remove one reference on the return object (should delete it) */
341
342		acpi_ut_remove_reference(info->return_object);
343		acpi_ex_exit_interpreter();
344	}
345
346      cleanup:
347
348	/* Free the input parameter list (if we created one) */
349
350	if (info->parameters) {
351
352		/* Free the allocated parameter block */
353
354		acpi_ut_delete_internal_object_list(info->parameters);
355	}
356
357	ACPI_FREE(info);
358	return_ACPI_STATUS(status);
359}
360
361ACPI_EXPORT_SYMBOL(acpi_evaluate_object)
362
363/*******************************************************************************
364 *
365 * FUNCTION:    acpi_ns_resolve_references
366 *
367 * PARAMETERS:  Info                    - Evaluation info block
368 *
369 * RETURN:      Info->return_object is replaced with the dereferenced object
370 *
371 * DESCRIPTION: Dereference certain reference objects. Called before an
372 *              internal return object is converted to an external union acpi_object.
373 *
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.
378 *
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.
381 *
382 ******************************************************************************/
383static void acpi_ns_resolve_references(struct acpi_evaluate_info *info)
384{
385	union acpi_operand_object *obj_desc = NULL;
386	struct acpi_namespace_node *node;
387
388	/* We are interested in reference objects only */
389
390	if ((info->return_object)->common.type != ACPI_TYPE_LOCAL_REFERENCE) {
391		return;
392	}
393
394	/*
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.
400	 */
401	switch (info->return_object->reference.class) {
402	case ACPI_REFCLASS_INDEX:
403
404		obj_desc = *(info->return_object->reference.where);
405		break;
406
407	case ACPI_REFCLASS_REFOF:
408
409		node = info->return_object->reference.object;
410		if (node) {
411			obj_desc = node->object;
412		}
413		break;
414
415	default:
416		return;
417	}
418
419	/* Replace the existing reference object */
420
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;
425	}
426
427	return;
428}
429
430/*******************************************************************************
431 *
432 * FUNCTION:    acpi_walk_namespace
433 *
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
444 *
445 * RETURNS      Return value from the user_function if terminated early.
446 *              Otherwise, returns NULL.
447 *
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.
454 *
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.
460 *
461 ******************************************************************************/
462
463acpi_status
464acpi_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)
470{
471	acpi_status status;
472
473	ACPI_FUNCTION_TRACE(acpi_walk_namespace);
474
475	/* Parameter validation */
476
477	if ((type > ACPI_TYPE_LOCAL_MAX) ||
478	    (!max_depth) || (!pre_order_visit && !post_order_visit)) {
479		return_ACPI_STATUS(AE_BAD_PARAMETER);
480	}
481
482	/*
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.)
492	 */
493	status = acpi_ut_acquire_read_lock(&acpi_gbl_namespace_rw_lock);
494	if (ACPI_FAILURE(status)) {
495		return status;
496	}
497
498	/*
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.)
503	 */
504	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
505	if (ACPI_FAILURE(status)) {
506		goto unlock_and_exit;
507	}
508
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);
513
514	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
515
516      unlock_and_exit:
517	(void)acpi_ut_release_read_lock(&acpi_gbl_namespace_rw_lock);
518	return_ACPI_STATUS(status);
519}
520
521ACPI_EXPORT_SYMBOL(acpi_walk_namespace)
522
523/*******************************************************************************
524 *
525 * FUNCTION:    acpi_ns_get_device_callback
526 *
527 * PARAMETERS:  Callback from acpi_get_device
528 *
529 * RETURN:      Status
530 *
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.
534 *
535 ******************************************************************************/
536static acpi_status
537acpi_ns_get_device_callback(acpi_handle obj_handle,
538			    u32 nesting_level,
539			    void *context, void **return_value)
540{
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;
550
551	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
552	if (ACPI_FAILURE(status)) {
553		return (status);
554	}
555
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);
560	}
561
562	if (!node) {
563		return (AE_BAD_PARAMETER);
564	}
565
566	/*
567	 * First, filter based on the device HID and CID.
568	 *
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.
574	 *
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).
579	 */
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);
586		}
587
588		no_match = ACPI_STRCMP(hid->string, info->hid);
589		ACPI_FREE(hid);
590
591		if (no_match) {
592			/*
593			 * HID does not match, attempt match within the
594			 * list of Compatible IDs (CIDs)
595			 */
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);
601			}
602
603			/* Walk the CID list */
604
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;
611				}
612			}
613			ACPI_FREE(cid);
614			if (!found)
615				return (AE_OK);
616		}
617	}
618
619	/* Run _STA to determine if device is present */
620
621	status = acpi_ut_execute_STA(node, &flags);
622	if (ACPI_FAILURE(status)) {
623		return (AE_CTRL_DEPTH);
624	}
625
626	if (!(flags & ACPI_STA_DEVICE_PRESENT) &&
627	    !(flags & ACPI_STA_DEVICE_FUNCTIONING)) {
628		/*
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.
632		 */
633		return (AE_CTRL_DEPTH);
634	}
635
636	/* We have a valid device, invoke the user function */
637
638	status = info->user_function(obj_handle, nesting_level, info->context,
639				     return_value);
640	return (status);
641}
642
643/*******************************************************************************
644 *
645 * FUNCTION:    acpi_get_devices
646 *
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
652 *
653 * RETURNS      Return value from the user_function if terminated early.
654 *              Otherwise, returns NULL.
655 *
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.
662 *
663 *              This is a wrapper for walk_namespace, but the callback performs
664 *              additional filtering. Please see acpi_ns_get_device_callback.
665 *
666 ******************************************************************************/
667
668acpi_status
669acpi_get_devices(const char *HID,
670		 acpi_walk_callback user_function,
671		 void *context, void **return_value)
672{
673	acpi_status status;
674	struct acpi_get_devices_info info;
675
676	ACPI_FUNCTION_TRACE(acpi_get_devices);
677
678	/* Parameter validation */
679
680	if (!user_function) {
681		return_ACPI_STATUS(AE_BAD_PARAMETER);
682	}
683
684	/*
685	 * We're going to call their callback from OUR callback, so we need
686	 * to know what it is, and their context parameter.
687	 */
688	info.hid = HID;
689	info.context = context;
690	info.user_function = user_function;
691
692	/*
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.
697	 */
698	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
699	if (ACPI_FAILURE(status)) {
700		return_ACPI_STATUS(status);
701	}
702
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);
707
708	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
709	return_ACPI_STATUS(status);
710}
711
712ACPI_EXPORT_SYMBOL(acpi_get_devices)
713
714/*******************************************************************************
715 *
716 * FUNCTION:    acpi_attach_data
717 *
718 * PARAMETERS:  obj_handle          - Namespace node
719 *              Handler             - Handler for this attachment
720 *              Data                - Pointer to data to be attached
721 *
722 * RETURN:      Status
723 *
724 * DESCRIPTION: Attach arbitrary data and handler to a namespace node.
725 *
726 ******************************************************************************/
727acpi_status
728acpi_attach_data(acpi_handle obj_handle,
729		 acpi_object_handler handler, void *data)
730{
731	struct acpi_namespace_node *node;
732	acpi_status status;
733
734	/* Parameter validation */
735
736	if (!obj_handle || !handler || !data) {
737		return (AE_BAD_PARAMETER);
738	}
739
740	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
741	if (ACPI_FAILURE(status)) {
742		return (status);
743	}
744
745	/* Convert and validate the handle */
746
747	node = acpi_ns_validate_handle(obj_handle);
748	if (!node) {
749		status = AE_BAD_PARAMETER;
750		goto unlock_and_exit;
751	}
752
753	status = acpi_ns_attach_data(node, handler, data);
754
755      unlock_and_exit:
756	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
757	return (status);
758}
759
760ACPI_EXPORT_SYMBOL(acpi_attach_data)
761
762/*******************************************************************************
763 *
764 * FUNCTION:    acpi_detach_data
765 *
766 * PARAMETERS:  obj_handle          - Namespace node handle
767 *              Handler             - Handler used in call to acpi_attach_data
768 *
769 * RETURN:      Status
770 *
771 * DESCRIPTION: Remove data that was previously attached to a node.
772 *
773 ******************************************************************************/
774acpi_status
775acpi_detach_data(acpi_handle obj_handle, acpi_object_handler handler)
776{
777	struct acpi_namespace_node *node;
778	acpi_status status;
779
780	/* Parameter validation */
781
782	if (!obj_handle || !handler) {
783		return (AE_BAD_PARAMETER);
784	}
785
786	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
787	if (ACPI_FAILURE(status)) {
788		return (status);
789	}
790
791	/* Convert and validate the handle */
792
793	node = acpi_ns_validate_handle(obj_handle);
794	if (!node) {
795		status = AE_BAD_PARAMETER;
796		goto unlock_and_exit;
797	}
798
799	status = acpi_ns_detach_data(node, handler);
800
801      unlock_and_exit:
802	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
803	return (status);
804}
805
806ACPI_EXPORT_SYMBOL(acpi_detach_data)
807
808/*******************************************************************************
809 *
810 * FUNCTION:    acpi_get_data
811 *
812 * PARAMETERS:  obj_handle          - Namespace node
813 *              Handler             - Handler used in call to attach_data
814 *              Data                - Where the data is returned
815 *
816 * RETURN:      Status
817 *
818 * DESCRIPTION: Retrieve data that was previously attached to a namespace node.
819 *
820 ******************************************************************************/
821acpi_status
822acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)
823{
824	struct acpi_namespace_node *node;
825	acpi_status status;
826
827	/* Parameter validation */
828
829	if (!obj_handle || !handler || !data) {
830		return (AE_BAD_PARAMETER);
831	}
832
833	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
834	if (ACPI_FAILURE(status)) {
835		return (status);
836	}
837
838	/* Convert and validate the handle */
839
840	node = acpi_ns_validate_handle(obj_handle);
841	if (!node) {
842		status = AE_BAD_PARAMETER;
843		goto unlock_and_exit;
844	}
845
846	status = acpi_ns_get_attached_data(node, handler, data);
847
848      unlock_and_exit:
849	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
850	return (status);
851}
852
853ACPI_EXPORT_SYMBOL(acpi_get_data)