/******************************************************************************
*
* Module Name: nswalk - Functions for walking the ACPI namespace
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2022, 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 MERCHANTABILITY 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.h"
#include "accommon.h"
#include "acnamesp.h"
#define _COMPONENT ACPI_NAMESPACE
ACPI_MODULE_NAME ("nswalk")
/*******************************************************************************
*
* FUNCTION: AcpiNsGetNextNode
*
* PARAMETERS: ParentNode - Parent node whose children we are
* getting
* ChildNode - Previous child that was found.
* The NEXT child will be returned
*
* RETURN: 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.
*
******************************************************************************/
ACPI_NAMESPACE_NODE *
AcpiNsGetNextNode (
ACPI_NAMESPACE_NODE *ParentNode,
ACPI_NAMESPACE_NODE *ChildNode)
{
ACPI_FUNCTION_ENTRY ();
if (!ChildNode)
{
/* It's really the parent's _scope_ that we want */
return (ParentNode->Child);
}
/* Otherwise just return the next peer */
return (ChildNode->Peer);
}
/*******************************************************************************
*
* FUNCTION: AcpiNsGetNextNodeTyped
*
* PARAMETERS: Type - Type of node to be searched for
* ParentNode - Parent node whose children we are
* getting
* ChildNode - Previous child that was found.
* The NEXT child will be returned
*
* RETURN: 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.
*
******************************************************************************/
ACPI_NAMESPACE_NODE *
AcpiNsGetNextNodeTyped (
ACPI_OBJECT_TYPE Type,
ACPI_NAMESPACE_NODE *ParentNode,
ACPI_NAMESPACE_NODE *ChildNode)
{
ACPI_NAMESPACE_NODE *NextNode = NULL;
ACPI_FUNCTION_ENTRY ();
NextNode = AcpiNsGetNextNode (ParentNode, ChildNode);
/* If any type is OK, we are done */
if (Type == ACPI_TYPE_ANY)
{
/* NextNode is NULL if we are at the end-of-list */
return (NextNode);
}
/* Must search for the node -- but within this scope only */
while (NextNode)
{
/* If type matches, we are done */
if (NextNode->Type == Type)
{
return (NextNode);
}
/* Otherwise, move on to the next peer node */
NextNode = NextNode->Peer;
}
/* Not found */
return (NULL);
}
/*******************************************************************************
*
* FUNCTION: AcpiNsWalkNamespace
*
* PARAMETERS: Type - ACPI_OBJECT_TYPE to search for
* StartNode - Handle in namespace where search begins
* MaxDepth - Depth to which search is to reach
* Flags - Whether to unlock the NS before invoking
* the callback routine
* DescendingCallback - Called during tree descent
* when an object of "Type" is found
* AscendingCallback - Called during tree ascent
* when an object of "Type" is found
* Context - Passed to user function(s) above
* ReturnValue - from the UserFunction 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 StartHandle.
* 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
AcpiNsWalkNamespace (
ACPI_OBJECT_TYPE Type,
ACPI_HANDLE StartNode,
UINT32 MaxDepth,
UINT32 Flags,
ACPI_WALK_CALLBACK DescendingCallback,
ACPI_WALK_CALLBACK AscendingCallback,
void *Context,
void **ReturnValue)
{
ACPI_STATUS Status;
ACPI_STATUS MutexStatus;
ACPI_NAMESPACE_NODE *ChildNode;
ACPI_NAMESPACE_NODE *ParentNode;
ACPI_OBJECT_TYPE ChildType;
UINT32 Level;
BOOLEAN NodePreviouslyVisited = FALSE;
ACPI_FUNCTION_TRACE (NsWalkNamespace);
/* Special case for the namespace Root Node */
if (StartNode == ACPI_ROOT_OBJECT)
{
StartNode = AcpiGbl_RootNode;
if (!StartNode)
{
return_ACPI_STATUS (AE_NO_NAMESPACE);
}
}
/* Null child means "get first node" */
ParentNode = StartNode;
ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
ChildType = 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 (StartEntry)
*/
while (Level > 0 && ChildNode)
{
Status = AE_OK;
/* Found next child, get the type if we are not searching for ANY */
if (Type != ACPI_TYPE_ANY)
{
ChildType = ChildNode->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 ((ChildNode->Flags & ANOBJ_TEMPORARY) &&
!(Flags & ACPI_NS_WALK_TEMP_NODES))
{
Status = AE_CTRL_DEPTH;
}
/* Type must match requested type */
else if (ChildType == Type)
{
/*
* Found a matching node, invoke the user callback function.
* Unlock the namespace if flag is set.
*/
if (Flags & ACPI_NS_WALK_UNLOCK)
{
MutexStatus = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE (MutexStatus))
{
return_ACPI_STATUS (MutexStatus);
}
}
/*
* Invoke the user function, either descending, ascending,
* or both.
*/
if (!NodePreviouslyVisited)
{
if (DescendingCallback)
{
Status = DescendingCallback (ChildNode, Level,
Context, ReturnValue);
}
}
else
{
if (AscendingCallback)
{
Status = AscendingCallback (ChildNode, Level,
Context, ReturnValue);
}
}
if (Flags & ACPI_NS_WALK_UNLOCK)
{
MutexStatus = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE (MutexStatus))
{
return_ACPI_STATUS (MutexStatus);
}
}
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 (!NodePreviouslyVisited &&
(Level < MaxDepth) &&
(Status != AE_CTRL_DEPTH))
{
if (ChildNode->Child)
{
/* There is at least one child of this node, visit it */
Level++;
ParentNode = ChildNode;
ChildNode = AcpiNsGetNextNode (ParentNode, NULL);
continue;
}
}
/* No more children, re-visit this node */
if (!NodePreviouslyVisited)
{
NodePreviouslyVisited = TRUE;
continue;
}
/* No more children, visit peers */
ChildNode = AcpiNsGetNextNode (ParentNode, ChildNode);
if (ChildNode)
{
NodePreviouslyVisited = FALSE;
}
/* No peers, re-visit parent */
else
{
/*
* No more children of this node (AcpiNsGetNextNode failed), go
* back upwards in the namespace tree to the node's parent.
*/
Level--;
ChildNode = ParentNode;
ParentNode = ParentNode->Parent;
NodePreviouslyVisited = TRUE;
}
}
/* Complete walk, not terminated by user function */
return_ACPI_STATUS (AE_OK);
}