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

 *

 * Module Name: evgpeinit - System GPE initialization and update

 *

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

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

 *

 * 1. Copyright Notice

 *

 * Some or all of this work - Copyright (c) 1999 - 2010, 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.

 *

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

#include "acpi.h"

#include "accommon.h"

#include "acevents.h"

#include "acnamesp.h"

#include "acinterp.h"

#define _COMPONENT          ACPI_EVENTS

        ACPI_MODULE_NAME    ("evgpeinit")

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

 *

 * FUNCTION:    AcpiEvGpeInitialize

 *

 * PARAMETERS:  None

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Initialize the GPE data structures and the FADT GPE 0/1 blocks

 *

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

ACPI_STATUS

AcpiEvGpeInitialize (

    void)

{

    UINT32                  RegisterCount0 = 0;

    UINT32                  RegisterCount1 = 0;

    UINT32                  GpeNumberMax = 0;

    ACPI_STATUS             Status;

    ACPI_FUNCTION_TRACE (EvGpeInitialize);

    Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);

    if (ACPI_FAILURE (Status))

    {

        return_ACPI_STATUS (Status);

    }

    /*

     * Initialize the GPE Block(s) defined in the FADT

     *

     * Why the GPE register block lengths are divided by 2:  From the ACPI

     * Spec, section "General-Purpose Event Registers", we have:

     *

     * "Each register block contains two registers of equal length

     *  GPEx_STS and GPEx_EN (where x is 0 or 1). The length of the

     *  GPE0_STS and GPE0_EN registers is equal to half the GPE0_LEN

     *  The length of the GPE1_STS and GPE1_EN registers is equal to

     *  half the GPE1_LEN. If a generic register block is not supported

     *  then its respective block pointer and block length values in the

     *  FADT table contain zeros. The GPE0_LEN and GPE1_LEN do not need

     *  to be the same size."

     */

    /*

     * Determine the maximum GPE number for this machine.

     *

     * Note: both GPE0 and GPE1 are optional, and either can exist without

     * the other.

     *

     * If EITHER the register length OR the block address are zero, then that

     * particular block is not supported.

     */

    if (AcpiGbl_FADT.Gpe0BlockLength &&

        AcpiGbl_FADT.XGpe0Block.Address)

    {

        /* GPE block 0 exists (has both length and address > 0) */

        RegisterCount0 = (UINT16) (AcpiGbl_FADT.Gpe0BlockLength / 2);

        GpeNumberMax = (RegisterCount0 * ACPI_GPE_REGISTER_WIDTH) - 1;

        /* Install GPE Block 0 */

        Status = AcpiEvCreateGpeBlock (AcpiGbl_FadtGpeDevice,

                    &AcpiGbl_FADT.XGpe0Block, RegisterCount0, 0,

                    AcpiGbl_FADT.SciInterrupt, &AcpiGbl_GpeFadtBlocks[0]);

        if (ACPI_FAILURE (Status))

        {

            ACPI_EXCEPTION ((AE_INFO, Status,

                "Could not create GPE Block 0"));

        }

    }

    if (AcpiGbl_FADT.Gpe1BlockLength &&

        AcpiGbl_FADT.XGpe1Block.Address)

    {

        /* GPE block 1 exists (has both length and address > 0) */

        RegisterCount1 = (UINT16) (AcpiGbl_FADT.Gpe1BlockLength / 2);

        /* Check for GPE0/GPE1 overlap (if both banks exist) */

        if ((RegisterCount0) &&

            (GpeNumberMax >= AcpiGbl_FADT.Gpe1Base))

        {

            ACPI_ERROR ((AE_INFO,

                "GPE0 block (GPE 0 to %u) overlaps the GPE1 block "

                "(GPE %u to %u) - Ignoring GPE1",

                GpeNumberMax, AcpiGbl_FADT.Gpe1Base,

                AcpiGbl_FADT.Gpe1Base +

                ((RegisterCount1 * ACPI_GPE_REGISTER_WIDTH) - 1)));

            /* Ignore GPE1 block by setting the register count to zero */

            RegisterCount1 = 0;

        }

        else

        {

            /* Install GPE Block 1 */

            Status = AcpiEvCreateGpeBlock (AcpiGbl_FadtGpeDevice,

                        &AcpiGbl_FADT.XGpe1Block, RegisterCount1,

                        AcpiGbl_FADT.Gpe1Base,

                        AcpiGbl_FADT.SciInterrupt, &AcpiGbl_GpeFadtBlocks[1]);

            if (ACPI_FAILURE (Status))

            {

                ACPI_EXCEPTION ((AE_INFO, Status,

                    "Could not create GPE Block 1"));

            }

            /*

             * GPE0 and GPE1 do not have to be contiguous in the GPE number

             * space. However, GPE0 always starts at GPE number zero.

             */

            GpeNumberMax = AcpiGbl_FADT.Gpe1Base +

                            ((RegisterCount1 * ACPI_GPE_REGISTER_WIDTH) - 1);

        }

    }

    /* Exit if there are no GPE registers */

    if ((RegisterCount0 + RegisterCount1) == 0)

    {

        /* GPEs are not required by ACPI, this is OK */

        ACPI_DEBUG_PRINT ((ACPI_DB_INIT,

            "There are no GPE blocks defined in the FADT\n"));

        Status = AE_OK;

        goto Cleanup;

    }

    /* Check for Max GPE number out-of-range */

    if (GpeNumberMax > ACPI_GPE_MAX)

    {

        ACPI_ERROR ((AE_INFO,

            "Maximum GPE number from FADT is too large: 0x%X",

            GpeNumberMax));

        Status = AE_BAD_VALUE;

        goto Cleanup;

    }

Cleanup:

    (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);

    return_ACPI_STATUS (AE_OK);

}

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

 *

 * FUNCTION:    AcpiEvUpdateGpes

 *

 * PARAMETERS:  TableOwnerId        - ID of the newly-loaded ACPI table

 *

 * RETURN:      None

 *

 * DESCRIPTION: Check for new GPE methods (_Lxx/_Exx) made available as a

 *              result of a Load() or LoadTable() operation. If new GPE

 *              methods have been installed, register the new methods and

 *              enable and runtime GPEs that are associated with them. Also,

 *              run any newly loaded _PRW methods in order to discover any

 *              new CAN_WAKE GPEs.

 *

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

void

AcpiEvUpdateGpes (

    ACPI_OWNER_ID           TableOwnerId)

{

    ACPI_GPE_XRUPT_INFO     *GpeXruptInfo;

    ACPI_GPE_BLOCK_INFO     *GpeBlock;

    ACPI_GPE_WALK_INFO      WalkInfo;

    ACPI_STATUS             Status = AE_OK;

    UINT32                  NewWakeGpeCount = 0;

    /* We will examine only _PRW/_Lxx/_Exx methods owned by this table */

    WalkInfo.OwnerId = TableOwnerId;

    WalkInfo.ExecuteByOwnerId = TRUE;

    WalkInfo.Count = 0;

    if (AcpiGbl_LeaveWakeGpesDisabled)

    {

        /*

         * 1) Run any newly-loaded _PRW methods to find any GPEs that

         * can now be marked as CAN_WAKE GPEs. Note: We must run the

         * _PRW methods before we process the _Lxx/_Exx methods because

         * we will enable all runtime GPEs associated with the new

         * _Lxx/_Exx methods at the time we process those methods.

         *

         * Unlock interpreter so that we can run the _PRW methods.

         */

        WalkInfo.GpeBlock = NULL;

        WalkInfo.GpeDevice = NULL;

        AcpiExExitInterpreter ();

        Status = AcpiNsWalkNamespace (ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,

                    ACPI_UINT32_MAX, ACPI_NS_WALK_NO_UNLOCK,

                    AcpiEvMatchPrwAndGpe, NULL, &WalkInfo, NULL);

        if (ACPI_FAILURE (Status))

        {

            ACPI_EXCEPTION ((AE_INFO, Status,

                "While executing _PRW methods"));

        }

        AcpiExEnterInterpreter ();

        NewWakeGpeCount = WalkInfo.Count;

    }

    /*

     * 2) Find any _Lxx/_Exx GPE methods that have just been loaded.

     *

     * Any GPEs that correspond to new _Lxx/_Exx methods and are not

     * marked as CAN_WAKE are immediately enabled.

     *

     * Examine the namespace underneath each GpeDevice within the

     * GpeBlock lists.

     */

    Status = AcpiUtAcquireMutex (ACPI_MTX_EVENTS);

    if (ACPI_FAILURE (Status))

    {

        return;

    }

    WalkInfo.Count = 0;

    WalkInfo.EnableThisGpe = TRUE;

    /* Walk the interrupt level descriptor list */

    GpeXruptInfo = AcpiGbl_GpeXruptListHead;

    while (GpeXruptInfo)

    {

        /* Walk all Gpe Blocks attached to this interrupt level */

        GpeBlock = GpeXruptInfo->GpeBlockListHead;

        while (GpeBlock)

        {

            WalkInfo.GpeBlock = GpeBlock;

            WalkInfo.GpeDevice = GpeBlock->Node;

            Status = AcpiNsWalkNamespace (ACPI_TYPE_METHOD,

                        WalkInfo.GpeDevice, ACPI_UINT32_MAX,

                        ACPI_NS_WALK_NO_UNLOCK, AcpiEvMatchGpeMethod,

                        NULL, &WalkInfo, NULL);

            if (ACPI_FAILURE (Status))

            {

                ACPI_EXCEPTION ((AE_INFO, Status,

                    "While decoding _Lxx/_Exx methods"));

            }

            GpeBlock = GpeBlock->Next;

        }

        GpeXruptInfo = GpeXruptInfo->Next;

    }

    if (WalkInfo.Count || NewWakeGpeCount)

    {

        ACPI_INFO ((AE_INFO,

            "Enabled %u new runtime GPEs, added %u new wakeup GPEs",

            WalkInfo.Count, NewWakeGpeCount));

    }

    (void) AcpiUtReleaseMutex (ACPI_MTX_EVENTS);

    return;

}

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

 *

 * FUNCTION:    AcpiEvMatchGpeMethod

 *

 * PARAMETERS:  Callback from WalkNamespace

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Called from AcpiWalkNamespace. Expects each object to be a

 *              control method under the _GPE portion of the namespace.

 *              Extract the name and GPE type from the object, saving this

 *              information for quick lookup during GPE dispatch. Allows a

 *              per-OwnerId evaluation if ExecuteByOwnerId is TRUE in the

 *              WalkInfo parameter block.

 *

 *              The name of each GPE control method is of the form:

 *              "_Lxx" or "_Exx", where:

 *                  L      - means that the GPE is level triggered

 *                  E      - means that the GPE is edge triggered

 *                  xx     - is the GPE number [in HEX]

 *

 * If WalkInfo->ExecuteByOwnerId is TRUE, we only execute examine GPE methods

 *    with that owner.

 * If WalkInfo->EnableThisGpe is TRUE, the GPE that is referred to by a GPE

 *    method is immediately enabled (Used for Load/LoadTable operators)

 *

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

ACPI_STATUS

AcpiEvMatchGpeMethod (

    ACPI_HANDLE             ObjHandle,

    UINT32                  Level,

    void                    *Context,

    void                    **ReturnValue)

{

    ACPI_NAMESPACE_NODE     *MethodNode = ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, ObjHandle);

    ACPI_GPE_WALK_INFO      *WalkInfo = ACPI_CAST_PTR (ACPI_GPE_WALK_INFO, Context);

    ACPI_GPE_EVENT_INFO     *GpeEventInfo;

    ACPI_NAMESPACE_NODE     *GpeDevice;

    ACPI_STATUS             Status;

    UINT32                  GpeNumber;

    char                    Name[ACPI_NAME_SIZE + 1];

    UINT8                   Type;

    ACPI_FUNCTION_TRACE (EvMatchGpeMethod);

    /* Check if requested OwnerId matches this OwnerId */

    if ((WalkInfo->ExecuteByOwnerId) &&

        (MethodNode->OwnerId != WalkInfo->OwnerId))

    {

        return_ACPI_STATUS (AE_OK);

    }

    /*

     * Match and decode the _Lxx and _Exx GPE method names

     *

     * 1) Extract the method name and null terminate it

     */

    ACPI_MOVE_32_TO_32 (Name, &MethodNode->Name.Integer);

    Name[ACPI_NAME_SIZE] = 0;

    /* 2) Name must begin with an underscore */

    if (Name[0] != '_')

    {

        return_ACPI_STATUS (AE_OK); /* Ignore this method */

    }

    /*

     * 3) Edge/Level determination is based on the 2nd character

     *    of the method name

     *

     * NOTE: Default GPE type is RUNTIME only. Later, if a _PRW object is

     * found that points to this GPE, the ACPI_GPE_CAN_WAKE flag is set.

     */

    switch (Name[1])

    {

    case 'L':

        Type = ACPI_GPE_LEVEL_TRIGGERED;

        break;

    case 'E':

        Type = ACPI_GPE_EDGE_TRIGGERED;

        break;

    default:

        /* Unknown method type, just ignore it */

        ACPI_DEBUG_PRINT ((ACPI_DB_LOAD,

            "Ignoring unknown GPE method type: %s "

            "(name not of form _Lxx or _Exx)", Name));

        return_ACPI_STATUS (AE_OK);

    }

    /* 4) The last two characters of the name are the hex GPE Number */

    GpeNumber = ACPI_STRTOUL (&Name[2], NULL, 16);

    if (GpeNumber == ACPI_UINT32_MAX)

    {

        /* Conversion failed; invalid method, just ignore it */

        ACPI_DEBUG_PRINT ((ACPI_DB_LOAD,

            "Could not extract GPE number from name: %s "

            "(name is not of form _Lxx or _Exx)", Name));

        return_ACPI_STATUS (AE_OK);

    }

    /* Ensure that we have a valid GPE number for this GPE block */

    GpeEventInfo = AcpiEvLowGetGpeInfo (GpeNumber, WalkInfo->GpeBlock);

    if (!GpeEventInfo)

    {

        /*

         * This GpeNumber is not valid for this GPE block, just ignore it.

         * However, it may be valid for a different GPE block, since GPE0

         * and GPE1 methods both appear under \_GPE.

         */

        return_ACPI_STATUS (AE_OK);

    }

    if ((GpeEventInfo->Flags & ACPI_GPE_DISPATCH_MASK) ==

            ACPI_GPE_DISPATCH_HANDLER)

    {

        /* If there is already a handler, ignore this GPE method */

        return_ACPI_STATUS (AE_OK);

    }

    if ((GpeEventInfo->Flags & ACPI_GPE_DISPATCH_MASK) ==

            ACPI_GPE_DISPATCH_METHOD)

    {

        /*

         * If there is already a method, ignore this method. But check

         * for a type mismatch (if both the _Lxx AND _Exx exist)

         */

        if (Type != (GpeEventInfo->Flags & ACPI_GPE_XRUPT_TYPE_MASK))

        {

            ACPI_ERROR ((AE_INFO,

                "For GPE 0x%.2X, found both _L%2.2X and _E%2.2X methods",

                GpeNumber, GpeNumber, GpeNumber));

        }

        return_ACPI_STATUS (AE_OK);

    }

    /*

     * Add the GPE information from above to the GpeEventInfo block for

     * use during dispatch of this GPE.

     */

    GpeEventInfo->Flags |= (UINT8) (Type | ACPI_GPE_DISPATCH_METHOD);

    GpeEventInfo->Dispatch.MethodNode = MethodNode;

    /*

     * Enable this GPE if requested. This only happens when during the

     * execution of a Load or LoadTable operator. We have found a new

     * GPE method and want to immediately enable the GPE if it is a

     * runtime GPE.

     */

    if (WalkInfo->EnableThisGpe)

    {

        /* Ignore GPEs that can wake the system */

        if (!(GpeEventInfo->Flags & ACPI_GPE_CAN_WAKE) ||

            !AcpiGbl_LeaveWakeGpesDisabled)

        {

            WalkInfo->Count++;

            GpeDevice = WalkInfo->GpeDevice;

            if (GpeDevice == AcpiGbl_FadtGpeDevice)

            {

                GpeDevice = NULL;

            }

            Status = AcpiEnableGpe (GpeDevice, GpeNumber,

                        ACPI_GPE_TYPE_RUNTIME);

            if (ACPI_FAILURE (Status))

            {

                ACPI_EXCEPTION ((AE_INFO, Status,

                    "Could not enable GPE 0x%02X", GpeNumber));

            }

        }

    }

    ACPI_DEBUG_PRINT ((ACPI_DB_LOAD,

        "Registered GPE method %s as GPE number 0x%.2X\n",

        Name, GpeNumber));

    return_ACPI_STATUS (AE_OK);

}

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

 *

 * FUNCTION:    AcpiEvMatchPrwAndGpe

 *

 * PARAMETERS:  Callback from WalkNamespace

 *

 * RETURN:      Status. NOTE: We ignore errors so that the _PRW walk is

 *              not aborted on a single _PRW failure.

 *

 * DESCRIPTION: Called from AcpiWalkNamespace. Expects each object to be a

 *              Device. Run the _PRW method. If present, extract the GPE

 *              number and mark the GPE as a CAN_WAKE GPE. Allows a

 *              per-OwnerId execution if ExecuteByOwnerId is TRUE in the

 *              WalkInfo parameter block.

 *

 * If WalkInfo->ExecuteByOwnerId is TRUE, we only execute _PRWs with that

 *    owner.

 * If WalkInfo->GpeDevice is NULL, we execute every _PRW found. Otherwise,

 *    we only execute _PRWs that refer to the input GpeDevice.

 *

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

ACPI_STATUS

AcpiEvMatchPrwAndGpe (

    ACPI_HANDLE             ObjHandle,

    UINT32                  Level,

    void                    *Context,

    void                    **ReturnValue)

{

    ACPI_GPE_WALK_INFO      *WalkInfo = ACPI_CAST_PTR (ACPI_GPE_WALK_INFO, Context);

    ACPI_NAMESPACE_NODE     *GpeDevice;

    ACPI_GPE_BLOCK_INFO     *GpeBlock;

    ACPI_NAMESPACE_NODE     *TargetGpeDevice;

    ACPI_NAMESPACE_NODE     *PrwNode;

    ACPI_GPE_EVENT_INFO     *GpeEventInfo;

    ACPI_OPERAND_OBJECT     *PkgDesc;

    ACPI_OPERAND_OBJECT     *ObjDesc;

    UINT32                  GpeNumber;

    ACPI_STATUS             Status;

    ACPI_FUNCTION_TRACE (EvMatchPrwAndGpe);

    /* Check for a _PRW method under this device */

    Status = AcpiNsGetNode (ObjHandle, METHOD_NAME__PRW,

                ACPI_NS_NO_UPSEARCH, &PrwNode);

    if (ACPI_FAILURE (Status))

    {

        return_ACPI_STATUS (AE_OK);

    }

    /* Check if requested OwnerId matches this OwnerId */

    if ((WalkInfo->ExecuteByOwnerId) &&

        (PrwNode->OwnerId != WalkInfo->OwnerId))

    {

        return_ACPI_STATUS (AE_OK);

    }

    /* Execute the _PRW */

    Status = AcpiUtEvaluateObject (PrwNode, NULL,

                ACPI_BTYPE_PACKAGE, &PkgDesc);

    if (ACPI_FAILURE (Status))

    {

        return_ACPI_STATUS (AE_OK);

    }

    /* The returned _PRW package must have at least two elements */

    if (PkgDesc->Package.Count < 2)

    {

        goto Cleanup;

    }

    /* Extract pointers from the input context */

    GpeDevice = WalkInfo->GpeDevice;

    GpeBlock = WalkInfo->GpeBlock;

    /*

     * The _PRW object must return a package, we are only interested

     * in the first element

     */

    ObjDesc = PkgDesc->Package.Elements[0];

    if (ObjDesc->Common.Type == ACPI_TYPE_INTEGER)

    {

        /* Use FADT-defined GPE device (from definition of _PRW) */

        TargetGpeDevice = NULL;

        if (GpeDevice)

        {

            TargetGpeDevice = AcpiGbl_FadtGpeDevice;

        }

        /* Integer is the GPE number in the FADT described GPE blocks */

        GpeNumber = (UINT32) ObjDesc->Integer.Value;

    }

    else if (ObjDesc->Common.Type == ACPI_TYPE_PACKAGE)

    {

        /* Package contains a GPE reference and GPE number within a GPE block */

        if ((ObjDesc->Package.Count < 2) ||

            ((ObjDesc->Package.Elements[0])->Common.Type !=

                ACPI_TYPE_LOCAL_REFERENCE) ||

            ((ObjDesc->Package.Elements[1])->Common.Type !=

                ACPI_TYPE_INTEGER))

        {

            goto Cleanup;

        }

        /* Get GPE block reference and decode */

        TargetGpeDevice = ObjDesc->Package.Elements[0]->Reference.Node;

        GpeNumber = (UINT32) ObjDesc->Package.Elements[1]->Integer.Value;

    }

    else

    {

        /* Unknown type, just ignore it */

        goto Cleanup;

    }

    /* Get the GpeEventInfo for this GPE */

    if (GpeDevice)

    {

        /*

         * Is this GPE within this block?

         *

         * TRUE if and only if these conditions are true:

         *     1) The GPE devices match.

         *     2) The GPE index(number) is within the range of the Gpe Block

         *          associated with the GPE device.

         */

        if (GpeDevice != TargetGpeDevice)

        {

            goto Cleanup;

        }

        GpeEventInfo = AcpiEvLowGetGpeInfo (GpeNumber, GpeBlock);

    }

    else

    {

        /* GpeDevice is NULL, just match the TargetDevice and GpeNumber */

        GpeEventInfo = AcpiEvGetGpeEventInfo (TargetGpeDevice, GpeNumber);

    }

    if (GpeEventInfo)

    {

        if (!(GpeEventInfo->Flags & ACPI_GPE_CAN_WAKE))

        {

            /* This GPE can wake the system */

            GpeEventInfo->Flags |= ACPI_GPE_CAN_WAKE;

            WalkInfo->Count++;

        }

    }

Cleanup:

    AcpiUtRemoveReference (PkgDesc);

    return_ACPI_STATUS (AE_OK);

}