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/****************************************************************************** |
* |
* Module Name: nswalk - Functions for walking the ACPI namespace |
* |
*****************************************************************************/ |
|
/* |
* Copyright (C) 2000 - 2015, 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); |
} |
|
/* 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 peer node */ |
|
next_node = next_node->peer; |
} |
|
/* 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 |
* descending_callback - Called during tree descent |
* when an object of "Type" is found |
* ascending_callback - Called during tree ascent |
* when an object of "Type" is found |
* context - Passed to user function(s) above |
* 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 callback function is called whenever a node that matches |
* the type parameter is found. If the callback 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 callback function(s) 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 descending_callback, |
acpi_walk_callback ascending_callback, |
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; |
u8 node_previously_visited = FALSE; |
|
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 = acpi_ns_get_next_node(parent_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 && child_node) { |
status = AE_OK; |
|
/* 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); |
} |
} |
|
/* |
* Invoke the user function, either descending, ascending, |
* or both. |
*/ |
if (!node_previously_visited) { |
if (descending_callback) { |
status = |
descending_callback(child_node, |
level, context, |
return_value); |
} |
} else { |
if (ascending_callback) { |
status = |
ascending_callback(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 (!node_previously_visited && |
(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 = |
acpi_ns_get_next_node(parent_node, NULL); |
continue; |
} |
} |
|
/* No more children, re-visit this node */ |
|
if (!node_previously_visited) { |
node_previously_visited = TRUE; |
continue; |
} |
|
/* No more children, visit peers */ |
|
child_node = acpi_ns_get_next_node(parent_node, child_node); |
if (child_node) { |
node_previously_visited = FALSE; |
} |
|
/* No peers, re-visit parent */ |
|
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 = parent_node->parent; |
|
node_previously_visited = TRUE; |
} |
} |
|
/* Complete walk, not terminated by user function */ |
|
return_ACPI_STATUS(AE_OK); |
} |