Release 4.7 drivers/acpi/acpica/nswalk.c
  
  
/******************************************************************************
 *
 * Module Name: nswalk - Functions for walking the ACPI namespace
 *
 *****************************************************************************/
/*
 * Copyright (C) 2000 - 2016, 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);
}
Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| pre-git | pre-git | 20 | 46.51% | 2 | 25.00% | 
| robert moore | robert moore | 9 | 20.93% | 1 | 12.50% | 
| linus torvalds | linus torvalds | 6 | 13.95% | 2 | 25.00% | 
| lv zheng | lv zheng | 4 | 9.30% | 1 | 12.50% | 
| andy grover | andy grover | 4 | 9.30% | 2 | 25.00% | 
 | Total | 43 | 100.00% | 8 | 100.00% | 
/*******************************************************************************
 *
 * 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);
}
Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| pre-git | pre-git | 54 | 60.00% | 2 | 33.33% | 
| robert moore | robert moore | 31 | 34.44% | 1 | 16.67% | 
| alexey starikovskiy | alexey starikovskiy | 3 | 3.33% | 1 | 16.67% | 
| linus torvalds | linus torvalds | 1 | 1.11% | 1 | 16.67% | 
| andy grover | andy grover | 1 | 1.11% | 1 | 16.67% | 
 | Total | 90 | 100.00% | 6 | 100.00% | 
/*******************************************************************************
 *
 * 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);
}
Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| pre-git | pre-git | 195 | 47.79% | 2 | 10.53% | 
| lin ming | lin ming | 94 | 23.04% | 1 | 5.26% | 
| robert moore | robert moore | 50 | 12.25% | 7 | 36.84% | 
| andy grover | andy grover | 41 | 10.05% | 4 | 21.05% | 
| linus torvalds | linus torvalds | 24 | 5.88% | 3 | 15.79% | 
| alexey starikovskiy | alexey starikovskiy | 2 | 0.49% | 1 | 5.26% | 
| mika kukkonen | mika kukkonen | 2 | 0.49% | 1 | 5.26% | 
 | Total | 408 | 100.00% | 19 | 100.00% | 
Overall Contributors
 | Person | Tokens | Prop | Commits | CommitProp | 
| pre-git | pre-git | 279 | 49.56% | 2 | 8.00% | 
| robert moore | robert moore | 96 | 17.05% | 9 | 36.00% | 
| lin ming | lin ming | 94 | 16.70% | 1 | 4.00% | 
| andy grover | andy grover | 48 | 8.53% | 5 | 20.00% | 
| linus torvalds | linus torvalds | 32 | 5.68% | 3 | 12.00% | 
| alexey starikovskiy | alexey starikovskiy | 5 | 0.89% | 1 | 4.00% | 
| lv zheng | lv zheng | 4 | 0.71% | 1 | 4.00% | 
| mika kukkonen | mika kukkonen | 2 | 0.36% | 1 | 4.00% | 
| len brown | len brown | 2 | 0.36% | 1 | 4.00% | 
| patrick mochel | patrick mochel | 1 | 0.18% | 1 | 4.00% | 
 | Total | 563 | 100.00% | 25 | 100.00% | 
  
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