nssearch.c

acpi tools for linux include acpiexec and acpixtract

/*******************************************************************************
 *
 * Module Name: nssearch - Namespace search
 *              $Revision: 1.122 $
 *
 ******************************************************************************/

/******************************************************************************
 *
 * 1. Copyright Notice
 *
 * Some or all of this work - Copyright (c) 1999 - 2008, 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 __NSSEARCH_C__

#include "acpi.h"
#include "acnamesp.h"


#define _COMPONENT          ACPI_NAMESPACE
        ACPI_MODULE_NAME    ("nssearch")

/* Local prototypes */

static ACPI_STATUS
AcpiNsSearchParentTree (
    UINT32                  TargetName,
    ACPI_NAMESPACE_NODE     *Node,
    ACPI_OBJECT_TYPE        Type,
    ACPI_NAMESPACE_NODE     **ReturnNode);


/*******************************************************************************
 *
 * FUNCTION:    AcpiNsSearchOneScope
 *
 * PARAMETERS:  TargetName      - Ascii ACPI name to search for
 *              ParentNode      - Starting node where search will begin
 *              Type            - Object type to match
 *              ReturnNode      - Where the matched Named obj is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Search a single level of the namespace. Performs a
 *              simple search of the specified level, and does not add
 *              entries or search parents.
 *
 *
 *      Named object lists are built (and subsequently dumped) in the
 *      order in which the names are encountered during the namespace load;
 *
 *      All namespace searching is linear in this implementation, but
 *      could be easily modified to support any improved search
 *      algorithm. However, the linear search was chosen for simplicity
 *      and because the trees are small and the other interpreter
 *      execution overhead is relatively high.
 *
 *      Note: CPU execution analysis has shown that the AML interpreter spends
 *      a very small percentage of its time searching the namespace. Therefore,
 *      the linear search seems to be sufficient, as there would seem to be
 *      little value in improving the search.
 *
 ******************************************************************************/

ACPI_STATUS
AcpiNsSearchOneScope (
    UINT32                  TargetName,
    ACPI_NAMESPACE_NODE     *ParentNode,
    ACPI_OBJECT_TYPE        Type,
    ACPI_NAMESPACE_NODE     **ReturnNode)
{
    ACPI_NAMESPACE_NODE     *Node;


    ACPI_FUNCTION_TRACE (NsSearchOneScope);


#ifdef ACPI_DEBUG_OUTPUT
    if (ACPI_LV_NAMES & AcpiDbgLevel)
    {
        char                *ScopeName;

        ScopeName = AcpiNsGetExternalPathname (ParentNode);
        if (ScopeName)
        {
            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
                "Searching %s (%p) For [%4.4s] (%s)\n",
                ScopeName, ParentNode, ACPI_CAST_PTR (char, &TargetName),
                AcpiUtGetTypeName (Type)));

            ACPI_FREE (ScopeName);
        }
    }
#endif

    /*
     * Search for name at this namespace level, which is to say that we
     * must search for the name among the children of this object
     */
    Node = ParentNode->Child;
    while (Node)
    {
        /* Check for match against the name */

        if (Node->Name.Integer == TargetName)
        {
            /* Resolve a control method alias if any */

            if (AcpiNsGetType (Node) == ACPI_TYPE_LOCAL_METHOD_ALIAS)
            {
                Node = ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, Node->Object);
            }

            /* Found matching entry */

            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
                "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",
                ACPI_CAST_PTR (char, &TargetName),
                AcpiUtGetTypeName (Node->Type),
                Node, AcpiUtGetNodeName (ParentNode), ParentNode));

            *ReturnNode = Node;
            return_ACPI_STATUS (AE_OK);
        }

        /*
         * The last entry in the list points back to the parent,
         * so a flag is used to indicate the end-of-list
         */
        if (Node->Flags & ANOBJ_END_OF_PEER_LIST)
        {
            /* Searched entire list, we are done */

            break;
        }

        /* Didn't match name, move on to the next peer object */

        Node = Node->Peer;
    }

    /* Searched entire namespace level, not found */

    ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
        "Name [%4.4s] (%s) not found in search in scope [%4.4s] %p first child %p\n",
        ACPI_CAST_PTR (char, &TargetName), AcpiUtGetTypeName (Type),
        AcpiUtGetNodeName (ParentNode), ParentNode, ParentNode->Child));

    return_ACPI_STATUS (AE_NOT_FOUND);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiNsSearchParentTree