[mirror_ubuntu-zesty-kernel.git] / drivers / acpi / acpica / nswalk.c

/******************************************************************************
 *
 * Module Name: nswalk - Functions for walking the ACPI namespace
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2008, Intel Corp.
 * 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 "accommon.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nswalk")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_next_node
 *
 * PARAMETERS:  parent_node         - Parent node whose children we are
 *                                    getting
 *              child_node          - Previous child that was found.
 *                                    The NEXT child will be returned
 *
 * RETURN:      struct acpi_namespace_node - Pointer to the NEXT child or NULL if
 *                                    none is found.
 *
 * DESCRIPTION: Return the next peer node within the namespace.  If Handle
 *              is valid, Scope is ignored.  Otherwise, the first node
 *              within Scope is returned.
 *
 ******************************************************************************/
struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node
						  *parent_node,
						  struct acpi_namespace_node
						  *child_node)
{
	ACPI_FUNCTION_ENTRY();

	if (!child_node) {

		/* It's really the parent's _scope_ that we want */

		return parent_node->child;
	}

	/*
	 * Get the next node.
	 *
	 * If we are at the end of this peer list, return NULL
	 */
	if (child_node->flags & ANOBJ_END_OF_PEER_LIST) {
		return NULL;
	}

	/* Otherwise just return the next peer */

	return child_node->peer;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_next_node_typed
 *
 * PARAMETERS:  Type                - Type of node to be searched for
 *              parent_node         - Parent node whose children we are
 *                                    getting
 *              child_node          - Previous child that was found.
 *                                    The NEXT child will be returned
 *
 * RETURN:      struct acpi_namespace_node - Pointer to the NEXT child or NULL if
 *                                    none is found.
 *
 * DESCRIPTION: Return the next peer node within the namespace.  If Handle
 *              is valid, Scope is ignored.  Otherwise, the first node
 *              within Scope is returned.
 *
 ******************************************************************************/

struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type,
							struct
							acpi_namespace_node
							*parent_node,
							struct
							acpi_namespace_node
							*child_node)
{
	struct acpi_namespace_node *next_node = NULL;

	ACPI_FUNCTION_ENTRY();

	next_node = acpi_ns_get_next_node(parent_node, child_node);


	/* If any type is OK, we are done */

	if (type == ACPI_TYPE_ANY) {

		/* next_node is NULL if we are at the end-of-list */

		return (next_node);
	}

	/* Must search for the node -- but within this scope only */

	while (next_node) {

		/* If type matches, we are done */

		if (next_node->type == type) {
			return (next_node);
		}

		/* Otherwise, move on to the next node */

		next_node = acpi_ns_get_next_valid_node(next_node);
	}

	/* Not found */

	return (NULL);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_walk_namespace
 *
 * PARAMETERS:  Type                - acpi_object_type to search for
 *              start_node          - Handle in namespace where search begins
 *              max_depth           - Depth to which search is to reach
 *              Flags               - Whether to unlock the NS before invoking
 *                                    the callback routine
 *              user_function       - Called when an object of "Type" is found
 *              Context             - Passed to user function
 *              return_value        - from the user_function if terminated early.
 *                                    Otherwise, returns NULL.
 * RETURNS:     Status
 *
 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
 *              starting (and ending) at the node specified by start_handle.
 *              The user_function is called whenever a node 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_ns_walk_namespace(acpi_object_type type,
		       acpi_handle start_node,
		       u32 max_depth,
		       u32 flags,
		       acpi_walk_callback user_function,
		       void *context, void **return_value)
{
	acpi_status status;
	acpi_status mutex_status;
	struct acpi_namespace_node *child_node;
	struct acpi_namespace_node *parent_node;
	acpi_object_type child_type;
	u32 level;

	ACPI_FUNCTION_TRACE(ns_walk_namespace);

	/* Special case for the namespace Root Node */

	if (start_node == ACPI_ROOT_OBJECT) {
		start_node = acpi_gbl_root_node;
	}

	/* Null child means "get first node" */

	parent_node = start_node;
	child_node = NULL;
	child_type = ACPI_TYPE_ANY;
	level = 1;

	/*
	 * Traverse the tree of nodes until we bubble back up to where we
	 * started. When Level is zero, the loop is done because we have
	 * bubbled up to (and passed) the original parent handle (start_entry)
	 */
	while (level > 0) {

		/* Get the next node in this scope.  Null if not found */

		status = AE_OK;
		child_node = acpi_ns_get_next_node(parent_node, child_node);
		if (child_node) {

			/* Found next child, get the type if we are not searching for ANY */

			if (type != ACPI_TYPE_ANY) {
				child_type = child_node->type;
			}

			/*
			 * Ignore all temporary namespace nodes (created during control
			 * method execution) unless told otherwise. These temporary nodes
			 * can cause a race condition because they can be deleted during
			 * the execution of the user function (if the namespace is
			 * unlocked before invocation of the user function.) Only the
			 * debugger namespace dump will examine the temporary nodes.
			 */
			if ((child_node->flags & ANOBJ_TEMPORARY) &&
			    !(flags & ACPI_NS_WALK_TEMP_NODES)) {
				status = AE_CTRL_DEPTH;
			}

			/* Type must match requested type */

			else if (child_type == type) {
				/*
				 * Found a matching node, invoke the user callback function.
				 * Unlock the namespace if flag is set.
				 */
				if (flags & ACPI_NS_WALK_UNLOCK) {
					mutex_status =
					    acpi_ut_release_mutex
					    (ACPI_MTX_NAMESPACE);
					if (ACPI_FAILURE(mutex_status)) {
						return_ACPI_STATUS
						    (mutex_status);
					}
				}

				status =
				    user_function(child_node, level, context,
						  return_value);

				if (flags & ACPI_NS_WALK_UNLOCK) {
					mutex_status =
					    acpi_ut_acquire_mutex
					    (ACPI_MTX_NAMESPACE);
					if (ACPI_FAILURE(mutex_status)) {
						return_ACPI_STATUS
						    (mutex_status);
					}
				}

				switch (status) {
				case AE_OK:
				case AE_CTRL_DEPTH:

					/* Just keep going */
					break;

				case AE_CTRL_TERMINATE:

					/* Exit now, with OK status */

					return_ACPI_STATUS(AE_OK);

				default:

					/* All others are valid exceptions */

					return_ACPI_STATUS(status);
				}
			}

			/*
			 * Depth first search: Attempt to go down another level in the
			 * namespace if we are allowed to.  Don't go any further if we have
			 * reached the caller specified maximum depth or if the user
			 * function has specified that the maximum depth has been reached.
			 */
			if ((level < max_depth) && (status != AE_CTRL_DEPTH)) {
				if (child_node->child) {

					/* There is at least one child of this node, visit it */

					level++;
					parent_node = child_node;
					child_node = NULL;
				}
			}
		} else {
			/*
			 * No more children of this node (acpi_ns_get_next_node failed), go
			 * back upwards in the namespace tree to the node's parent.
			 */
			level--;
			child_node = parent_node;
			parent_node = acpi_ns_get_parent_node(parent_node);
		}
	}

	/* Complete walk, not terminated by user function */

	return_ACPI_STATUS(AE_OK);
}
Commit	Line	Data
1da177e4 LT	1	/******************************************************************************
	2	*
	3	* Module Name: nswalk - Functions for walking the ACPI namespace
	4	*
	5	*****************************************************************************/
	6
	7	/*
75a44ce0	8	* Copyright (C) 2000 - 2008, Intel Corp.
1da177e4 LT	9	* All rights reserved.
	10	*
	11	* Redistribution and use in source and binary forms, with or without
	12	* modification, are permitted provided that the following conditions
	13	* are met:
	14	* 1. Redistributions of source code must retain the above copyright
	15	* notice, this list of conditions, and the following disclaimer,
	16	* without modification.
	17	* 2. Redistributions in binary form must reproduce at minimum a disclaimer
	18	* substantially similar to the "NO WARRANTY" disclaimer below
	19	* ("Disclaimer") and any redistribution must be conditioned upon
	20	* including a substantially similar Disclaimer requirement for further
	21	* binary redistribution.
	22	* 3. Neither the names of the above-listed copyright holders nor the names
	23	* of any contributors may be used to endorse or promote products derived
	24	* from this software without specific prior written permission.
	25	*
	26	* Alternatively, this software may be distributed under the terms of the
	27	* GNU General Public License ("GPL") version 2 as published by the Free
	28	* Software Foundation.
	29	*
	30	* NO WARRANTY
	31	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	32	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	33	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
	34	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	35	* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	36	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	37	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	38	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	39	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	40	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	41	* POSSIBILITY OF SUCH DAMAGES.
	42	*/
	43
1da177e4	44	#include <acpi/acpi.h>
e2f7a777 LB	45	#include "accommon.h"
e2f7a777 LB	46	#include "acnamesp.h"
1da177e4	47
1da177e4	48	#define _COMPONENT ACPI_NAMESPACE
4be44fcd	49	ACPI_MODULE_NAME("nswalk")
1da177e4 LT	50
	51	/*******************************************************************************
	52	*
	53	* FUNCTION: acpi_ns_get_next_node
	54	*
8c725bf9	55	* PARAMETERS: parent_node - Parent node whose children we are
44f6c012	56	* getting
1da177e4 LT	57	* child_node - Previous child that was found.
	58	* The NEXT child will be returned
	59	*
	60	* RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if
	61	* none is found.
	62	*
	63	* DESCRIPTION: Return the next peer node within the namespace. If Handle
	64	* is valid, Scope is ignored. Otherwise, the first node
	65	* within Scope is returned.
	66	*
	67	******************************************************************************/
8c725bf9 BM	68	struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node
	69	*parent_node,
	70	struct acpi_namespace_node
4be44fcd	71	*child_node)
1da177e4	72	{
4be44fcd	73	ACPI_FUNCTION_ENTRY();
1da177e4 LT	74
1da177e4 LT	75	if (!child_node) {
52fc0b02	76
1da177e4 LT	77	/* It's really the parent's _scope_ that we want */
1da177e4 LT	78
8c725bf9	79	return parent_node->child;
1da177e4 LT	80	}
1da177e4 LT	81
8c725bf9 BM	82	/*
	83	* Get the next node.
	84	*
	85	* If we are at the end of this peer list, return NULL
	86	*/
	87	if (child_node->flags & ANOBJ_END_OF_PEER_LIST) {
	88	return NULL;
1da177e4 LT	89	}
1da177e4 LT	90
8c725bf9 BM	91	/* Otherwise just return the next peer */
	92
	93	return child_node->peer;
	94	}
	95
	96	/*******************************************************************************
	97	*
	98	* FUNCTION: acpi_ns_get_next_node_typed
	99	*
	100	* PARAMETERS: Type - Type of node to be searched for
	101	* parent_node - Parent node whose children we are
	102	* getting
	103	* child_node - Previous child that was found.
	104	* The NEXT child will be returned
	105	*
	106	* RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if
	107	* none is found.
	108	*
	109	* DESCRIPTION: Return the next peer node within the namespace. If Handle
	110	* is valid, Scope is ignored. Otherwise, the first node
	111	* within Scope is returned.
	112	*
	113	******************************************************************************/
	114
	115	struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type,
	116	struct
	117	acpi_namespace_node
	118	*parent_node,
	119	struct
	120	acpi_namespace_node
	121	*child_node)
	122	{
	123	struct acpi_namespace_node *next_node = NULL;
	124
	125	ACPI_FUNCTION_ENTRY();
	126
	127	next_node = acpi_ns_get_next_node(parent_node, child_node);
	128
	129
1da177e4 LT	130	/* If any type is OK, we are done */
	131
	132	if (type == ACPI_TYPE_ANY) {
52fc0b02	133
1da177e4 LT	134	/* next_node is NULL if we are at the end-of-list */
	135
	136	return (next_node);
	137	}
	138
	139	/* Must search for the node -- but within this scope only */
	140
	141	while (next_node) {
52fc0b02	142
1da177e4 LT	143	/* If type matches, we are done */
	144
	145	if (next_node->type == type) {
	146	return (next_node);
	147	}
	148
	149	/* Otherwise, move on to the next node */
	150
4be44fcd	151	next_node = acpi_ns_get_next_valid_node(next_node);
1da177e4 LT	152	}
	153
	154	/* Not found */
	155
	156	return (NULL);
	157	}
	158
1da177e4 LT	159	/*******************************************************************************
	160	*
	161	* FUNCTION: acpi_ns_walk_namespace
	162	*
	163	* PARAMETERS: Type - acpi_object_type to search for
	164	* start_node - Handle in namespace where search begins
	165	* max_depth - Depth to which search is to reach
d1fdda83	166	* Flags - Whether to unlock the NS before invoking
1da177e4 LT	167	* the callback routine
	168	* user_function - Called when an object of "Type" is found
	169	* Context - Passed to user function
	170	* return_value - from the user_function if terminated early.
	171	* Otherwise, returns NULL.
	172	* RETURNS: Status
	173	*
	174	* DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
	175	* starting (and ending) at the node specified by start_handle.
	176	* The user_function is called whenever a node that matches
	177	* the type parameter is found. If the user function returns
d4913dc6 BM	178	* a non-zero value, the search is terminated immediately and
d4913dc6 BM	179	* this value is returned to the caller.
1da177e4 LT	180	*
	181	* The point of this procedure is to provide a generic namespace
	182	* walk routine that can be called from multiple places to
	183	* provide multiple services; the User Function can be tailored
	184	* to each task, whether it is a print function, a compare
	185	* function, etc.
	186	*
	187	******************************************************************************/
	188
	189	acpi_status
4be44fcd LB	190	acpi_ns_walk_namespace(acpi_object_type type,
	191	acpi_handle start_node,
	192	u32 max_depth,
d1fdda83	193	u32 flags,
4be44fcd LB	194	acpi_walk_callback user_function,
4be44fcd LB	195	void context, void *return_value)
1da177e4	196	{
4be44fcd LB	197	acpi_status status;
	198	acpi_status mutex_status;
	199	struct acpi_namespace_node *child_node;
	200	struct acpi_namespace_node *parent_node;
	201	acpi_object_type child_type;
	202	u32 level;
1da177e4	203
b229cf92	204	ACPI_FUNCTION_TRACE(ns_walk_namespace);
1da177e4 LT	205
	206	/* Special case for the namespace Root Node */
	207
	208	if (start_node == ACPI_ROOT_OBJECT) {
	209	start_node = acpi_gbl_root_node;
	210	}
	211
	212	/* Null child means "get first node" */
	213
	214	parent_node = start_node;
4be44fcd LB	215	child_node = NULL;
	216	child_type = ACPI_TYPE_ANY;
	217	level = 1;
1da177e4 LT	218
	219	/*
	220	* Traverse the tree of nodes until we bubble back up to where we
	221	* started. When Level is zero, the loop is done because we have
	222	* bubbled up to (and passed) the original parent handle (start_entry)
	223	*/
	224	while (level > 0) {
52fc0b02	225
1da177e4 LT	226	/* Get the next node in this scope. Null if not found */
	227
	228	status = AE_OK;
8c725bf9	229	child_node = acpi_ns_get_next_node(parent_node, child_node);
1da177e4	230	if (child_node) {
3effba32	231
c1014629	232	/* Found next child, get the type if we are not searching for ANY */
3effba32	233
1da177e4 LT	234	if (type != ACPI_TYPE_ANY) {
	235	child_type = child_node->type;
	236	}
	237
3effba32	238	/*
c1014629 BM	239	* Ignore all temporary namespace nodes (created during control
c1014629 BM	240	* method execution) unless told otherwise. These temporary nodes
d4913dc6 BM	241	* can cause a race condition because they can be deleted during
	242	* the execution of the user function (if the namespace is
	243	* unlocked before invocation of the user function.) Only the
	244	* debugger namespace dump will examine the temporary nodes.
3effba32	245	*/
c1014629 BM	246	if ((child_node->flags & ANOBJ_TEMPORARY) &&
	247	!(flags & ACPI_NS_WALK_TEMP_NODES)) {
	248	status = AE_CTRL_DEPTH;
	249	}
	250
	251	/* Type must match requested type */
	252
	253	else if (child_type == type) {
1da177e4	254	/*
3effba32 BM	255	* Found a matching node, invoke the user callback function.
3effba32 BM	256	* Unlock the namespace if flag is set.
1da177e4	257	*/
d1fdda83	258	if (flags & ACPI_NS_WALK_UNLOCK) {
4be44fcd LB	259	mutex_status =
	260	acpi_ut_release_mutex
	261	(ACPI_MTX_NAMESPACE);
	262	if (ACPI_FAILURE(mutex_status)) {
	263	return_ACPI_STATUS
	264	(mutex_status);
1da177e4 LT	265	}
	266	}
	267
3effba32 BM	268	status =
	269	user_function(child_node, level, context,
	270	return_value);
1da177e4	271
d1fdda83	272	if (flags & ACPI_NS_WALK_UNLOCK) {
4be44fcd LB	273	mutex_status =
	274	acpi_ut_acquire_mutex
	275	(ACPI_MTX_NAMESPACE);
	276	if (ACPI_FAILURE(mutex_status)) {
	277	return_ACPI_STATUS
	278	(mutex_status);
1da177e4 LT	279	}
	280	}
	281
	282	switch (status) {
	283	case AE_OK:
	284	case AE_CTRL_DEPTH:
	285
	286	/* Just keep going */
	287	break;
	288
	289	case AE_CTRL_TERMINATE:
	290
	291	/* Exit now, with OK status */
	292
4be44fcd	293	return_ACPI_STATUS(AE_OK);
1da177e4 LT	294
	295	default:
	296
	297	/* All others are valid exceptions */
	298
4be44fcd	299	return_ACPI_STATUS(status);
1da177e4 LT	300	}
	301	}
	302
	303	/*
3effba32 BM	304	* Depth first search: Attempt to go down another level in the
	305	* namespace if we are allowed to. Don't go any further if we have
	306	* reached the caller specified maximum depth or if the user
	307	* function has specified that the maximum depth has been reached.
1da177e4 LT	308	*/
1da177e4 LT	309	if ((level < max_depth) && (status != AE_CTRL_DEPTH)) {
8c725bf9	310	if (child_node->child) {
3effba32 BM	311
	312	/* There is at least one child of this node, visit it */
	313
1da177e4 LT	314	level++;
	315	parent_node = child_node;
	316	child_node = NULL;
	317	}
	318	}
4be44fcd	319	} else {
1da177e4	320	/*
3effba32 BM	321	* No more children of this node (acpi_ns_get_next_node failed), go
3effba32 BM	322	* back upwards in the namespace tree to the node's parent.
1da177e4 LT	323	*/
	324	level--;
	325	child_node = parent_node;
4be44fcd	326	parent_node = acpi_ns_get_parent_node(parent_node);
1da177e4 LT	327	}
	328	}
	329
	330	/* Complete walk, not terminated by user function */
	331
4be44fcd	332	return_ACPI_STATUS(AE_OK);
1da177e4	333	}