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Diffstat (limited to 'drivers/acpi/namespace/nswalk.c')
| -rw-r--r-- | drivers/acpi/namespace/nswalk.c | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/drivers/acpi/namespace/nswalk.c b/drivers/acpi/namespace/nswalk.c new file mode 100644 index 000000000000..4de2444df300 --- /dev/null +++ b/drivers/acpi/namespace/nswalk.c @@ -0,0 +1,289 @@ +/****************************************************************************** + * + * Module Name: nswalk - Functions for walking the ACPI namespace + * + *****************************************************************************/ + +/* + * Copyright (C) 2000 - 2005, 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 ("nswalk") + + +/******************************************************************************* + * + * FUNCTION: acpi_ns_get_next_node + * + * 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 ( + 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 (); + + + if (!child_node) { + /* It's really the parent's _scope_ that we want */ + + if (parent_node->child) { + next_node = parent_node->child; + } + } + + else { + /* Start search at the NEXT node */ + + next_node = acpi_ns_get_next_valid_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 + * unlock_before_callback- 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, + u8 unlock_before_callback, + 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 (ACPI_TYPE_ANY, parent_node, child_node); + if (child_node) { + /* + * Found node, Get the type if we are not + * searching for ANY + */ + if (type != ACPI_TYPE_ANY) { + child_type = child_node->type; + } + + if (child_type == type) { + /* + * Found a matching node, invoke the user + * callback function + */ + if (unlock_before_callback) { + 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 (unlock_before_callback) { + 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 (acpi_ns_get_next_node (ACPI_TYPE_ANY, child_node, NULL)) { + /* + * There is at least one child of this + * node, visit the onde + */ + 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); +} + + |