[deliverable/linux.git] / drivers / acpi / namespace / nssearch.c

/*******************************************************************************
 *
 * Module Name: nssearch - Namespace search
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2006, 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>

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nssearch")

/* Local prototypes */
static acpi_status
acpi_ns_search_parent_tree(u32 target_name,
			   struct acpi_namespace_node *node,
			   acpi_object_type type,
			   struct acpi_namespace_node **return_node);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_search_node
 *
 * PARAMETERS:  target_name     - Ascii ACPI name to search for
 *              Node            - Starting node where search will begin
 *              Type            - Object type to match
 *              return_node     - Where the matched Named obj is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Search a single level of the namespace.  Performs a
 *              simple search of the specified level, and does not add
 *              entries or search parents.
 *
 *
 *      Named object lists are built (and subsequently dumped) in the
 *      order in which the names are encountered during the namespace load;
 *
 *      All namespace searching is linear in this implementation, but
 *      could be easily modified to support any improved search
 *      algorithm.  However, the linear search was chosen for simplicity
 *      and because the trees are small and the other interpreter
 *      execution overhead is relatively high.
 *
 ******************************************************************************/

acpi_status
acpi_ns_search_node(u32 target_name,
		    struct acpi_namespace_node *node,
		    acpi_object_type type,
		    struct acpi_namespace_node **return_node)
{
	struct acpi_namespace_node *next_node;

	ACPI_FUNCTION_TRACE("ns_search_node");

#ifdef ACPI_DEBUG_OUTPUT
	if (ACPI_LV_NAMES & acpi_dbg_level) {
		char *scope_name;

		scope_name = acpi_ns_get_external_pathname(node);
		if (scope_name) {
			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
					  "Searching %s (%p) For [%4.4s] (%s)\n",
					  scope_name, node, ACPI_CAST_PTR(char,
									  &target_name),
					  acpi_ut_get_type_name(type)));

			ACPI_MEM_FREE(scope_name);
		}
	}
#endif

	/*
	 * Search for name at this namespace level, which is to say that we
	 * must search for the name among the children of this object
	 */
	next_node = node->child;
	while (next_node) {
		/* Check for match against the name */

		if (next_node->name.integer == target_name) {
			/* Resolve a control method alias if any */

			if (acpi_ns_get_type(next_node) ==
			    ACPI_TYPE_LOCAL_METHOD_ALIAS) {
				next_node =
				    ACPI_CAST_PTR(struct acpi_namespace_node,
						  next_node->object);
			}

			/*
			 * Found matching entry.
			 */
			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
					  "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",
					  ACPI_CAST_PTR(char, &target_name),
					  acpi_ut_get_type_name(next_node->
								type),
					  next_node,
					  acpi_ut_get_node_name(node), node));

			*return_node = next_node;
			return_ACPI_STATUS(AE_OK);
		}

		/*
		 * The last entry in the list points back to the parent,
		 * so a flag is used to indicate the end-of-list
		 */
		if (next_node->flags & ANOBJ_END_OF_PEER_LIST) {
			/* Searched entire list, we are done */

			break;
		}

		/* Didn't match name, move on to the next peer object */

		next_node = next_node->peer;
	}

	/* Searched entire namespace level, not found */

	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
			  "Name [%4.4s] (%s) not found in search in scope [%4.4s] %p first child %p\n",
			  ACPI_CAST_PTR(char, &target_name),
			  acpi_ut_get_type_name(type),
			  acpi_ut_get_node_name(node), node, node->child));

	return_ACPI_STATUS(AE_NOT_FOUND);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_search_parent_tree
 *
 * PARAMETERS:  target_name     - Ascii ACPI name to search for
 *              Node            - Starting node where search will begin
 *              Type            - Object type to match
 *              return_node     - Where the matched Node is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Called when a name has not been found in the current namespace
 *              level.  Before adding it or giving up, ACPI scope rules require
 *              searching enclosing scopes in cases identified by acpi_ns_local().
 *
 *              "A name is located by finding the matching name in the current
 *              name space, and then in the parent name space. If the parent
 *              name space does not contain the name, the search continues
 *              recursively until either the name is found or the name space
 *              does not have a parent (the root of the name space).  This
 *              indicates that the name is not found" (From ACPI Specification,
 *              section 5.3)
 *
 ******************************************************************************/

static acpi_status
acpi_ns_search_parent_tree(u32 target_name,
			   struct acpi_namespace_node *node,
			   acpi_object_type type,
			   struct acpi_namespace_node **return_node)
{
	acpi_status status;
	struct acpi_namespace_node *parent_node;

	ACPI_FUNCTION_TRACE("ns_search_parent_tree");

	parent_node = acpi_ns_get_parent_node(node);

	/*
	 * If there is no parent (i.e., we are at the root) or type is "local",
	 * we won't be searching the parent tree.
	 */
	if (!parent_node) {
		ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "[%4.4s] has no parent\n",
				  ACPI_CAST_PTR(char, &target_name)));
		return_ACPI_STATUS(AE_NOT_FOUND);
	}

	if (acpi_ns_local(type)) {
		ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
				  "[%4.4s] type [%s] must be local to this scope (no parent search)\n",
				  ACPI_CAST_PTR(char, &target_name),
				  acpi_ut_get_type_name(type)));
		return_ACPI_STATUS(AE_NOT_FOUND);
	}

	/* Search the parent tree */

	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
			  "Searching parent [%4.4s] for [%4.4s]\n",
			  acpi_ut_get_node_name(parent_node),
			  ACPI_CAST_PTR(char, &target_name)));

	/*
	 * Search parents until target is found or we have backed up to the root
	 */
	while (parent_node) {
		/*
		 * Search parent scope.  Use TYPE_ANY because we don't care about the
		 * object type at this point, we only care about the existence of
		 * the actual name we are searching for.  Typechecking comes later.
		 */
		status = acpi_ns_search_node(target_name, parent_node,
					     ACPI_TYPE_ANY, return_node);
		if (ACPI_SUCCESS(status)) {
			return_ACPI_STATUS(status);
		}

		/*
		 * Not found here, go up another level
		 * (until we reach the root)
		 */
		parent_node = acpi_ns_get_parent_node(parent_node);
	}

	/* Not found in parent tree */

	return_ACPI_STATUS(AE_NOT_FOUND);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_search_and_enter
 *
 * PARAMETERS:  target_name         - Ascii ACPI name to search for (4 chars)
 *              walk_state          - Current state of the walk
 *              Node                - Starting node where search will begin
 *              interpreter_mode    - Add names only in ACPI_MODE_LOAD_PASS_x.
 *                                    Otherwise,search only.
 *              Type                - Object type to match
 *              Flags               - Flags describing the search restrictions
 *              return_node         - Where the Node is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Search for a name segment in a single namespace level,
 *              optionally adding it if it is not found.  If the passed
 *              Type is not Any and the type previously stored in the
 *              entry was Any (i.e. unknown), update the stored type.
 *
 *              In ACPI_IMODE_EXECUTE, search only.
 *              In other modes, search and add if not found.
 *
 ******************************************************************************/

acpi_status
acpi_ns_search_and_enter(u32 target_name,
			 struct acpi_walk_state *walk_state,
			 struct acpi_namespace_node *node,
			 acpi_interpreter_mode interpreter_mode,
			 acpi_object_type type,
			 u32 flags, struct acpi_namespace_node **return_node)
{
	acpi_status status;
	struct acpi_namespace_node *new_node;

	ACPI_FUNCTION_TRACE("ns_search_and_enter");

	/* Parameter validation */

	if (!node || !target_name || !return_node) {
		ACPI_ERROR((AE_INFO,
			    "Null param: Node %p Name %X return_node %p",
			    node, target_name, return_node));
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/* Name must consist of printable characters */

	if (!acpi_ut_valid_acpi_name(target_name)) {
		ACPI_ERROR((AE_INFO, "Bad character in ACPI Name: %X",
			    target_name));
		return_ACPI_STATUS(AE_BAD_CHARACTER);
	}

	/* Try to find the name in the namespace level specified by the caller */

	*return_node = ACPI_ENTRY_NOT_FOUND;
	status = acpi_ns_search_node(target_name, node, type, return_node);
	if (status != AE_NOT_FOUND) {
		/*
		 * If we found it AND the request specifies that a find is an error,
		 * return the error
		 */
		if ((status == AE_OK) && (flags & ACPI_NS_ERROR_IF_FOUND)) {
			status = AE_ALREADY_EXISTS;
		}

		/*
		 * Either found it or there was an error
		 * -- finished either way
		 */
		return_ACPI_STATUS(status);
	}

	/*
	 * The name was not found.  If we are NOT performing the first pass
	 * (name entry) of loading the namespace, search the parent tree (all the
	 * way to the root if necessary.) We don't want to perform the parent
	 * search when the namespace is actually being loaded.  We want to perform
	 * the search when namespace references are being resolved (load pass 2)
	 * and during the execution phase.
	 */
	if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) &&
	    (flags & ACPI_NS_SEARCH_PARENT)) {
		/*
		 * Not found at this level - search parent tree according to the
		 * ACPI specification
		 */
		status =
		    acpi_ns_search_parent_tree(target_name, node, type,
					       return_node);
		if (ACPI_SUCCESS(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * In execute mode, just search, never add names.  Exit now.
	 */
	if (interpreter_mode == ACPI_IMODE_EXECUTE) {
		ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
				  "%4.4s Not found in %p [Not adding]\n",
				  ACPI_CAST_PTR(char, &target_name), node));

		return_ACPI_STATUS(AE_NOT_FOUND);
	}

	/* Create the new named object */

	new_node = acpi_ns_create_node(target_name);
	if (!new_node) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	/* Install the new object into the parent's list of children */

	acpi_ns_install_node(walk_state, node, new_node, type);
	*return_node = new_node;

	return_ACPI_STATUS(AE_OK);
}
Commit	Line	Data
1da177e4 LT	1	/*******************************************************************************
	2	*
	3	* Module Name: nssearch - Namespace search
	4	*
	5	******************************************************************************/
	6
	7	/*
4a90c7e8	8	* Copyright (C) 2000 - 2006, R. Byron Moore
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 LT	44	#include <acpi/acpi.h>
	45	#include <acpi/acnamesp.h>
	46
1da177e4	47	#define _COMPONENT ACPI_NAMESPACE
4be44fcd	48	ACPI_MODULE_NAME("nssearch")
1da177e4	49
44f6c012	50	/* Local prototypes */
44f6c012	51	static acpi_status
4be44fcd LB	52	acpi_ns_search_parent_tree(u32 target_name,
	53	struct acpi_namespace_node *node,
	54	acpi_object_type type,
	55	struct acpi_namespace_node **return_node);
1da177e4 LT	56
	57	/*******************************************************************************
	58	*
	59	* FUNCTION: acpi_ns_search_node
	60	*
44f6c012 RM	61	* PARAMETERS: target_name - Ascii ACPI name to search for
	62	* Node - Starting node where search will begin
	63	* Type - Object type to match
	64	* return_node - Where the matched Named obj is returned
1da177e4 LT	65	*
	66	* RETURN: Status
	67	*
	68	* DESCRIPTION: Search a single level of the namespace. Performs a
	69	* simple search of the specified level, and does not add
	70	* entries or search parents.
	71	*
	72	*
	73	* Named object lists are built (and subsequently dumped) in the
	74	* order in which the names are encountered during the namespace load;
	75	*
	76	* All namespace searching is linear in this implementation, but
	77	* could be easily modified to support any improved search
	78	* algorithm. However, the linear search was chosen for simplicity
	79	* and because the trees are small and the other interpreter
	80	* execution overhead is relatively high.
	81	*
	82	******************************************************************************/
	83
	84	acpi_status
4be44fcd LB	85	acpi_ns_search_node(u32 target_name,
	86	struct acpi_namespace_node *node,
	87	acpi_object_type type,
	88	struct acpi_namespace_node **return_node)
1da177e4	89	{
4be44fcd	90	struct acpi_namespace_node *next_node;
1da177e4	91
4be44fcd	92	ACPI_FUNCTION_TRACE("ns_search_node");
1da177e4 LT	93
	94	#ifdef ACPI_DEBUG_OUTPUT
	95	if (ACPI_LV_NAMES & acpi_dbg_level) {
4be44fcd	96	char *scope_name;
1da177e4	97
4be44fcd	98	scope_name = acpi_ns_get_external_pathname(node);
1da177e4	99	if (scope_name) {
4be44fcd LB	100	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
4be44fcd LB	101	"Searching %s (%p) For [%4.4s] (%s)\n",
defba1d8 BM	102	scope_name, node, ACPI_CAST_PTR(char,
defba1d8 BM	103	&target_name),
4be44fcd	104	acpi_ut_get_type_name(type)));
1da177e4	105
4be44fcd	106	ACPI_MEM_FREE(scope_name);
1da177e4 LT	107	}
	108	}
	109	#endif
	110
	111	/*
	112	* Search for name at this namespace level, which is to say that we
	113	* must search for the name among the children of this object
	114	*/
	115	next_node = node->child;
	116	while (next_node) {
	117	/* Check for match against the name */
	118
	119	if (next_node->name.integer == target_name) {
	120	/* Resolve a control method alias if any */
	121
4be44fcd LB	122	if (acpi_ns_get_type(next_node) ==
	123	ACPI_TYPE_LOCAL_METHOD_ALIAS) {
	124	next_node =
	125	ACPI_CAST_PTR(struct acpi_namespace_node,
	126	next_node->object);
1da177e4 LT	127	}
	128
	129	/*
	130	* Found matching entry.
	131	*/
4be44fcd LB	132	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
4be44fcd LB	133	"Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",
defba1d8	134	ACPI_CAST_PTR(char, &target_name),
4be44fcd LB	135	acpi_ut_get_type_name(next_node->
	136	type),
	137	next_node,
	138	acpi_ut_get_node_name(node), node));
1da177e4 LT	139
1da177e4 LT	140	*return_node = next_node;
4be44fcd	141	return_ACPI_STATUS(AE_OK);
1da177e4 LT	142	}
	143
	144	/*
	145	* The last entry in the list points back to the parent,
	146	* so a flag is used to indicate the end-of-list
	147	*/
	148	if (next_node->flags & ANOBJ_END_OF_PEER_LIST) {
	149	/* Searched entire list, we are done */
	150
	151	break;
	152	}
	153
	154	/* Didn't match name, move on to the next peer object */
	155
	156	next_node = next_node->peer;
	157	}
	158
	159	/* Searched entire namespace level, not found */
	160
4be44fcd LB	161	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
4be44fcd LB	162	"Name [%4.4s] (%s) not found in search in scope [%4.4s] %p first child %p\n",
defba1d8 BM	163	ACPI_CAST_PTR(char, &target_name),
defba1d8 BM	164	acpi_ut_get_type_name(type),
4be44fcd	165	acpi_ut_get_node_name(node), node, node->child));
1da177e4	166
4be44fcd	167	return_ACPI_STATUS(AE_NOT_FOUND);
1da177e4 LT	168	}
1da177e4 LT	169
1da177e4 LT	170	/*******************************************************************************
	171	*
	172	* FUNCTION: acpi_ns_search_parent_tree
	173	*
44f6c012 RM	174	* PARAMETERS: target_name - Ascii ACPI name to search for
	175	* Node - Starting node where search will begin
	176	* Type - Object type to match
	177	* return_node - Where the matched Node is returned
1da177e4 LT	178	*
	179	* RETURN: Status
	180	*
	181	* DESCRIPTION: Called when a name has not been found in the current namespace
	182	* level. Before adding it or giving up, ACPI scope rules require
	183	* searching enclosing scopes in cases identified by acpi_ns_local().
	184	*
	185	* "A name is located by finding the matching name in the current
	186	* name space, and then in the parent name space. If the parent
	187	* name space does not contain the name, the search continues
	188	* recursively until either the name is found or the name space
	189	* does not have a parent (the root of the name space). This
	190	* indicates that the name is not found" (From ACPI Specification,
	191	* section 5.3)
	192	*
	193	******************************************************************************/
	194
	195	static acpi_status
4be44fcd LB	196	acpi_ns_search_parent_tree(u32 target_name,
	197	struct acpi_namespace_node *node,
	198	acpi_object_type type,
	199	struct acpi_namespace_node **return_node)
1da177e4	200	{
4be44fcd LB	201	acpi_status status;
4be44fcd LB	202	struct acpi_namespace_node *parent_node;
1da177e4	203
4be44fcd	204	ACPI_FUNCTION_TRACE("ns_search_parent_tree");
1da177e4	205
4be44fcd	206	parent_node = acpi_ns_get_parent_node(node);
1da177e4 LT	207
	208	/*
	209	* If there is no parent (i.e., we are at the root) or type is "local",
	210	* we won't be searching the parent tree.
	211	*/
	212	if (!parent_node) {
4be44fcd	213	ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "[%4.4s] has no parent\n",
defba1d8	214	ACPI_CAST_PTR(char, &target_name)));
4be44fcd	215	return_ACPI_STATUS(AE_NOT_FOUND);
1da177e4 LT	216	}
1da177e4 LT	217
4be44fcd LB	218	if (acpi_ns_local(type)) {
	219	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
	220	"[%4.4s] type [%s] must be local to this scope (no parent search)\n",
defba1d8	221	ACPI_CAST_PTR(char, &target_name),
4be44fcd LB	222	acpi_ut_get_type_name(type)));
4be44fcd LB	223	return_ACPI_STATUS(AE_NOT_FOUND);
1da177e4 LT	224	}
	225
	226	/* Search the parent tree */
	227
4be44fcd LB	228	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
	229	"Searching parent [%4.4s] for [%4.4s]\n",
	230	acpi_ut_get_node_name(parent_node),
defba1d8	231	ACPI_CAST_PTR(char, &target_name)));
1da177e4 LT	232
	233	/*
	234	* Search parents until target is found or we have backed up to the root
	235	*/
	236	while (parent_node) {
	237	/*
	238	* Search parent scope. Use TYPE_ANY because we don't care about the
	239	* object type at this point, we only care about the existence of
	240	* the actual name we are searching for. Typechecking comes later.
	241	*/
4be44fcd LB	242	status = acpi_ns_search_node(target_name, parent_node,
	243	ACPI_TYPE_ANY, return_node);
	244	if (ACPI_SUCCESS(status)) {
	245	return_ACPI_STATUS(status);
1da177e4 LT	246	}
	247
	248	/*
	249	* Not found here, go up another level
	250	* (until we reach the root)
	251	*/
4be44fcd	252	parent_node = acpi_ns_get_parent_node(parent_node);
1da177e4 LT	253	}
	254
	255	/* Not found in parent tree */
	256
4be44fcd	257	return_ACPI_STATUS(AE_NOT_FOUND);
1da177e4 LT	258	}
1da177e4 LT	259
1da177e4 LT	260	/*******************************************************************************
	261	*
	262	* FUNCTION: acpi_ns_search_and_enter
	263	*
	264	* PARAMETERS: target_name - Ascii ACPI name to search for (4 chars)
	265	* walk_state - Current state of the walk
44f6c012	266	* Node - Starting node where search will begin
1da177e4 LT	267	* interpreter_mode - Add names only in ACPI_MODE_LOAD_PASS_x.
	268	* Otherwise,search only.
	269	* Type - Object type to match
	270	* Flags - Flags describing the search restrictions
44f6c012	271	* return_node - Where the Node is returned
1da177e4 LT	272	*
	273	* RETURN: Status
	274	*
	275	* DESCRIPTION: Search for a name segment in a single namespace level,
	276	* optionally adding it if it is not found. If the passed
	277	* Type is not Any and the type previously stored in the
	278	* entry was Any (i.e. unknown), update the stored type.
	279	*
	280	* In ACPI_IMODE_EXECUTE, search only.
	281	* In other modes, search and add if not found.
	282	*
	283	******************************************************************************/
	284
	285	acpi_status
4be44fcd LB	286	acpi_ns_search_and_enter(u32 target_name,
	287	struct acpi_walk_state *walk_state,
	288	struct acpi_namespace_node *node,
	289	acpi_interpreter_mode interpreter_mode,
	290	acpi_object_type type,
	291	u32 flags, struct acpi_namespace_node **return_node)
1da177e4	292	{
4be44fcd LB	293	acpi_status status;
4be44fcd LB	294	struct acpi_namespace_node *new_node;
1da177e4	295
4be44fcd	296	ACPI_FUNCTION_TRACE("ns_search_and_enter");
1da177e4 LT	297
	298	/* Parameter validation */
	299
	300	if (!node \|\| !target_name \|\| !return_node) {
b8e4d893 BM	301	ACPI_ERROR((AE_INFO,
	302	"Null param: Node %p Name %X return_node %p",
	303	node, target_name, return_node));
4be44fcd	304	return_ACPI_STATUS(AE_BAD_PARAMETER);
1da177e4 LT	305	}
	306
	307	/* Name must consist of printable characters */
	308
4be44fcd	309	if (!acpi_ut_valid_acpi_name(target_name)) {
b8e4d893 BM	310	ACPI_ERROR((AE_INFO, "Bad character in ACPI Name: %X",
b8e4d893 BM	311	target_name));
4be44fcd	312	return_ACPI_STATUS(AE_BAD_CHARACTER);
1da177e4 LT	313	}
	314
	315	/* Try to find the name in the namespace level specified by the caller */
	316
	317	*return_node = ACPI_ENTRY_NOT_FOUND;
4be44fcd	318	status = acpi_ns_search_node(target_name, node, type, return_node);
1da177e4 LT	319	if (status != AE_NOT_FOUND) {
	320	/*
	321	* If we found it AND the request specifies that a find is an error,
	322	* return the error
	323	*/
4be44fcd	324	if ((status == AE_OK) && (flags & ACPI_NS_ERROR_IF_FOUND)) {
1da177e4 LT	325	status = AE_ALREADY_EXISTS;
	326	}
	327
	328	/*
	329	* Either found it or there was an error
	330	* -- finished either way
	331	*/
4be44fcd	332	return_ACPI_STATUS(status);
1da177e4 LT	333	}
	334
	335	/*
	336	* The name was not found. If we are NOT performing the first pass
	337	* (name entry) of loading the namespace, search the parent tree (all the
	338	* way to the root if necessary.) We don't want to perform the parent
	339	* search when the namespace is actually being loaded. We want to perform
	340	* the search when namespace references are being resolved (load pass 2)
	341	* and during the execution phase.
	342	*/
	343	if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) &&
4be44fcd	344	(flags & ACPI_NS_SEARCH_PARENT)) {
1da177e4 LT	345	/*
	346	* Not found at this level - search parent tree according to the
	347	* ACPI specification
	348	*/
4be44fcd LB	349	status =
	350	acpi_ns_search_parent_tree(target_name, node, type,
	351	return_node);
	352	if (ACPI_SUCCESS(status)) {
	353	return_ACPI_STATUS(status);
1da177e4 LT	354	}
	355	}
	356
	357	/*
	358	* In execute mode, just search, never add names. Exit now.
	359	*/
	360	if (interpreter_mode == ACPI_IMODE_EXECUTE) {
4be44fcd LB	361	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
4be44fcd LB	362	"%4.4s Not found in %p [Not adding]\n",
defba1d8	363	ACPI_CAST_PTR(char, &target_name), node));
1da177e4	364
4be44fcd	365	return_ACPI_STATUS(AE_NOT_FOUND);
1da177e4 LT	366	}
	367
	368	/* Create the new named object */
	369
4be44fcd	370	new_node = acpi_ns_create_node(target_name);
1da177e4	371	if (!new_node) {
4be44fcd	372	return_ACPI_STATUS(AE_NO_MEMORY);
1da177e4 LT	373	}
	374
	375	/* Install the new object into the parent's list of children */
	376
4be44fcd	377	acpi_ns_install_node(walk_state, node, new_node, type);
1da177e4 LT	378	*return_node = new_node;
1da177e4 LT	379
4be44fcd	380	return_ACPI_STATUS(AE_OK);
1da177e4	381	}