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/******************************************************************************

 *

 * Module Name: nswalk - Functions for walking the ACPI namespace

 *

 *****************************************************************************/

/******************************************************************************

 *

 * 1. Copyright Notice

 *

 * Some or all of this work - Copyright (c) 1999 - 2011, Intel Corp.

 * All rights reserved.

 *

 * 2. License

 *

 * 2.1. This is your license from Intel Corp. under its intellectual property

 * rights.  You may have additional license terms from the party that provided

 * you this software, covering your right to use that party's intellectual

 * property rights.

 *

 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a

 * copy of the source code appearing in this file ("Covered Code") an

 * irrevocable, perpetual, worldwide license under Intel's copyrights in the

 * base code distributed originally by Intel ("Original Intel Code") to copy,

 * make derivatives, distribute, use and display any portion of the Covered

 * Code in any form, with the right to sublicense such rights; and

 *

 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent

 * license (with the right to sublicense), under only those claims of Intel

 * patents that are infringed by the Original Intel Code, to make, use, sell,

 * offer to sell, and import the Covered Code and derivative works thereof

 * solely to the minimum extent necessary to exercise the above copyright

 * license, and in no event shall the patent license extend to any additions

 * to or modifications of the Original Intel Code.  No other license or right

 * is granted directly or by implication, estoppel or otherwise;

 *

 * The above copyright and patent license is granted only if the following

 * conditions are met:

 *

 * 3. Conditions

 *

 * 3.1. Redistribution of Source with Rights to Further Distribute Source.

 * Redistribution of source code of any substantial portion of the Covered

 * Code or modification with rights to further distribute source must include

 * the above Copyright Notice, the above License, this list of Conditions,

 * and the following Disclaimer and Export Compliance provision.  In addition,

 * Licensee must cause all Covered Code to which Licensee contributes to

 * contain a file documenting the changes Licensee made to create that Covered

 * Code and the date of any change.  Licensee must include in that file the

 * documentation of any changes made by any predecessor Licensee.  Licensee

 * must include a prominent statement that the modification is derived,

 * directly or indirectly, from Original Intel Code.

 *

 * 3.2. Redistribution of Source with no Rights to Further Distribute Source.

 * Redistribution of source code of any substantial portion of the Covered

 * Code or modification without rights to further distribute source must

 * include the following Disclaimer and Export Compliance provision in the

 * documentation and/or other materials provided with distribution.  In

 * addition, Licensee may not authorize further sublicense of source of any

 * portion of the Covered Code, and must include terms to the effect that the

 * license from Licensee to its licensee is limited to the intellectual

 * property embodied in the software Licensee provides to its licensee, and

 * not to intellectual property embodied in modifications its licensee may

 * make.

 *

 * 3.3. Redistribution of Executable. Redistribution in executable form of any

 * substantial portion of the Covered Code or modification must reproduce the

 * above Copyright Notice, and the following Disclaimer and Export Compliance

 * provision in the documentation and/or other materials provided with the

 * distribution.

 *

 * 3.4. Intel retains all right, title, and interest in and to the Original

 * Intel Code.

 *

 * 3.5. Neither the name Intel nor any other trademark owned or controlled by

 * Intel shall be used in advertising or otherwise to promote the sale, use or

 * other dealings in products derived from or relating to the Covered Code

 * without prior written authorization from Intel.

 *

 * 4. Disclaimer and Export Compliance

 *

 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED

 * HERE.  ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE

 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT,  ASSISTANCE,

 * INSTALLATION, TRAINING OR OTHER SERVICES.  INTEL WILL NOT PROVIDE ANY

 * UPDATES, ENHANCEMENTS OR EXTENSIONS.  INTEL SPECIFICALLY DISCLAIMS ANY

 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A

 * PARTICULAR PURPOSE.

 *

 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES

 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR

 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,

 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY

 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL

 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.  THESE LIMITATIONS

 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY

 * LIMITED REMEDY.

 *

 * 4.3. Licensee shall not export, either directly or indirectly, any of this

 * software or system incorporating such software without first obtaining any

 * required license or other approval from the U. S. Department of Commerce or

 * any other agency or department of the United States Government.  In the

 * event Licensee exports any such software from the United States or

 * re-exports any such software from a foreign destination, Licensee shall

 * ensure that the distribution and export/re-export of the software is in

 * compliance with all laws, regulations, orders, or other restrictions of the

 * U.S. Export Administration Regulations. Licensee agrees that neither it nor

 * any of its subsidiaries will export/re-export any technical data, process,

 * software, or service, directly or indirectly, to any country for which the

 * United States government or any agency thereof requires an export license,

 * other governmental approval, or letter of assurance, without first obtaining

 * such license, approval or letter.

 *

 *****************************************************************************/

#define __NSWALK_C__

#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

 *              PreOrderVisit       - Called during tree pre-order visit

 *                                    when an object of "Type" is found

 *              PostOrderVisit      - Called during tree post-order visit

 *                                    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      PreOrderVisit,

    ACPI_WALK_CALLBACK      PostOrderVisit,

    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;

    }

    /* 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 pre-order or post-order

             * or both.

             */

            if (!NodePreviouslyVisited)

            {

                if (PreOrderVisit)

                {

                    Status = PreOrderVisit (ChildNode, Level,

                                Context, ReturnValue);

                }

            }

            else

            {

                if (PostOrderVisit)

                {

                    Status = PostOrderVisit (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);

}