freebsd/sys/contrib/dev/acpica/evgpeblk.c

/******************************************************************************
 *
 * Module Name: evgpeblk - GPE block creation and initialization.
 *              $Revision: 23 $
 *
 *****************************************************************************/

/******************************************************************************
 *
 * 1. Copyright Notice
 *
 * Some or all of this work - Copyright (c) 1999 - 2003, 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 "acevents.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_EVENTS
        ACPI_MODULE_NAME    ("evgpeblk")


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvValidGpeEvent
 *
 * PARAMETERS:  GpeEventInfo - Info for this GPE
 *
 * RETURN:      TRUE if the GpeEvent is valid
 *
 * DESCRIPTION: Validate a GPE event.  DO NOT CALL FROM INTERRUPT LEVEL.
 *              Should be called only when the GPE lists are semaphore locked
 *              and not subject to change.
 *
 ******************************************************************************/

BOOLEAN
AcpiEvValidGpeEvent (
    ACPI_GPE_EVENT_INFO     *GpeEventInfo)
{
    ACPI_GPE_XRUPT_INFO     *GpeXruptBlock;
    ACPI_GPE_BLOCK_INFO     *GpeBlock;


    ACPI_FUNCTION_ENTRY ();


    /* No need for spin lock since we are not changing any list elements */

    /* Walk the GPE interrupt levels */

    GpeXruptBlock = AcpiGbl_GpeXruptListHead;
    while (GpeXruptBlock)
    {
        GpeBlock = GpeXruptBlock->GpeBlockListHead;

        /* Walk the GPE blocks on this interrupt level */

        while (GpeBlock)
        {
            if ((&GpeBlock->EventInfo[0] <= GpeEventInfo) &&
                (&GpeBlock->EventInfo[((ACPI_SIZE) GpeBlock->RegisterCount) * 8] > GpeEventInfo))
            {
                return (TRUE);
            }

            GpeBlock = GpeBlock->Next;
        }

        GpeXruptBlock = GpeXruptBlock->Next;
    }

    return (FALSE);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvWalkGpeList
 *
 * PARAMETERS:  GpeWalkCallback     - Routine called for each GPE block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Walk the GPE lists.
 *              FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 *
 ******************************************************************************/

ACPI_STATUS
AcpiEvWalkGpeList (
    ACPI_GPE_CALLBACK       GpeWalkCallback)
{
    ACPI_GPE_BLOCK_INFO     *GpeBlock;
    ACPI_GPE_XRUPT_INFO     *GpeXruptInfo;
    ACPI_STATUS             Status = AE_OK;


    ACPI_FUNCTION_TRACE ("EvWalkGpeList");


    AcpiOsAcquireLock (AcpiGbl_GpeLock, ACPI_ISR);

    /* 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)
        {
            /* One callback per GPE block */

            Status = GpeWalkCallback (GpeXruptInfo, GpeBlock);
            if (ACPI_FAILURE (Status))
            {
                goto UnlockAndExit;
            }

            GpeBlock = GpeBlock->Next;
        }

        GpeXruptInfo = GpeXruptInfo->Next;
    }

UnlockAndExit:
    AcpiOsReleaseLock (AcpiGbl_GpeLock, ACPI_ISR);
    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvSaveMethodInfo
 *
 * 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
 *
 *              The name of each GPE control method is of the form:
 *                  "_Lnn" or "_Enn"
 *                  Where:
 *                      L      - means that the GPE is level triggered
 *                      E      - means that the GPE is edge triggered
 *                      nn     - is the GPE number [in HEX]
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiEvSaveMethodInfo (
    ACPI_HANDLE             ObjHandle,
    UINT32                  Level,
    void                    *ObjDesc,
    void                    **ReturnValue)
{
    ACPI_GPE_BLOCK_INFO     *GpeBlock = (void *) ObjDesc;
    ACPI_GPE_EVENT_INFO     *GpeEventInfo;
    UINT32                  GpeNumber;
    char                    Name[ACPI_NAME_SIZE + 1];
    UINT8                   Type;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE ("EvSaveMethodInfo");


    /* Extract the name from the object and convert to a string */

    ACPI_MOVE_32_TO_32 (Name,
                        &((ACPI_NAMESPACE_NODE *) ObjHandle)->Name.Integer);
    Name[ACPI_NAME_SIZE] = 0;

    /*
     * Edge/Level determination is based on the 2nd character 
     * of the method name
     */
    switch (Name[1])
    {
    case 'L':
        Type = ACPI_EVENT_LEVEL_TRIGGERED;
        break;

    case 'E':
        Type = ACPI_EVENT_EDGE_TRIGGERED;
        break;

    default:
        /* Unknown method type, just ignore it! */

        ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
            "Unknown GPE method type: %s (name not of form _Lnn or _Enn)\n",
            Name));
        return_ACPI_STATUS (AE_OK);
    }

    /* Convert the last two characters of the name to the 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_ERROR,
            "Could not extract GPE number from name: %s (name is not of form _Lnn or _Enn)\n",
            Name));
        return_ACPI_STATUS (AE_OK);
    }

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

    if ((GpeNumber < GpeBlock->BlockBaseNumber) ||
        (GpeNumber >= (GpeBlock->BlockBaseNumber + (GpeBlock->RegisterCount * 8))))
    {
        /*
         * 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);
    }

    /*
     * Now we can add this information to the GpeEventInfo block
     * for use during dispatch of this GPE.
     */
    GpeEventInfo = &GpeBlock->EventInfo[GpeNumber - GpeBlock->BlockBaseNumber];

    GpeEventInfo->Flags      = Type;
    GpeEventInfo->MethodNode = (ACPI_NAMESPACE_NODE *) ObjHandle;

    /* Enable the GPE (SCIs should be disabled at this point) */

    Status = AcpiHwEnableGpe (GpeEventInfo);
    if (ACPI_FAILURE (Status))
    {
        return_ACPI_STATUS (Status);
    }

    ACPI_DEBUG_PRINT ((ACPI_DB_LOAD,
        "Registered GPE method %s as GPE number 0x%.2X\n",
        Name, GpeNumber));
    return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvGetGpeXruptBlock
 *
 * PARAMETERS:  InterruptLevel      - Interrupt for a GPE block
 *
 * RETURN:      A GPE interrupt block
 *
 * DESCRIPTION: Get or Create a GPE interrupt block.  There is one interrupt
 *              block per unique interrupt level used for GPEs.
 *              Should be called only when the GPE lists are semaphore locked
 *              and not subject to change.
 *
 ******************************************************************************/

static ACPI_GPE_XRUPT_INFO *
AcpiEvGetGpeXruptBlock (
    UINT32                  InterruptLevel)
{
    ACPI_GPE_XRUPT_INFO     *NextGpeXrupt;
    ACPI_GPE_XRUPT_INFO     *GpeXrupt;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE ("EvGetGpeXruptBlock");


    /* No need for spin lock since we are not changing any list elements here */

    NextGpeXrupt = AcpiGbl_GpeXruptListHead;
    while (NextGpeXrupt)
    {
        if (NextGpeXrupt->InterruptLevel == InterruptLevel)
        {
            return_PTR (NextGpeXrupt);
        }

        NextGpeXrupt = NextGpeXrupt->Next;
    }

    /* Not found, must allocate a new xrupt descriptor */

    GpeXrupt = ACPI_MEM_CALLOCATE (sizeof (ACPI_GPE_XRUPT_INFO));
    if (!GpeXrupt)
    {
        return_PTR (NULL);
    }

    GpeXrupt->InterruptLevel = InterruptLevel;

    /* Install new interrupt descriptor with spin lock */

    AcpiOsAcquireLock (AcpiGbl_GpeLock, ACPI_NOT_ISR);
    if (AcpiGbl_GpeXruptListHead)
    {
        NextGpeXrupt = AcpiGbl_GpeXruptListHead;
        while (NextGpeXrupt->Next)
        {
            NextGpeXrupt = NextGpeXrupt->Next;
        }

        NextGpeXrupt->Next = GpeXrupt;
        GpeXrupt->Previous = NextGpeXrupt;
    }
    else
    {
        AcpiGbl_GpeXruptListHead = GpeXrupt;
    }
    AcpiOsReleaseLock (AcpiGbl_GpeLock, ACPI_NOT_ISR);

    /* Install new interrupt handler if not SCI_INT */

    if (InterruptLevel != AcpiGbl_FADT->SciInt)
    {
        Status = AcpiOsInstallInterruptHandler (InterruptLevel,
                    AcpiEvGpeXruptHandler, GpeXrupt);
        if (ACPI_FAILURE (Status))
        {
            ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
                "Could not install GPE interrupt handler at level 0x%X\n",
                InterruptLevel));
            return_PTR (NULL);
        }
    }

    return_PTR (GpeXrupt);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvDeleteGpeXrupt
 *
 * PARAMETERS:  GpeXrupt        - A GPE interrupt info block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Remove and free a GpeXrupt block.  Remove an associated
 *              interrupt handler if not the SCI interrupt.
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiEvDeleteGpeXrupt (
    ACPI_GPE_XRUPT_INFO     *GpeXrupt)
{
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE ("EvDeleteGpeXrupt");


    /* We never want to remove the SCI interrupt handler */

    if (GpeXrupt->InterruptLevel == AcpiGbl_FADT->SciInt)
    {
        GpeXrupt->GpeBlockListHead = NULL;
        return_ACPI_STATUS (AE_OK);
    }

    /* Disable this interrupt */

    Status = AcpiOsRemoveInterruptHandler (GpeXrupt->InterruptLevel,
                                    AcpiEvGpeXruptHandler);
    if (ACPI_FAILURE (Status))
    {
        return_ACPI_STATUS (Status);
    }

    /* Unlink the interrupt block with lock */

    AcpiOsAcquireLock (AcpiGbl_GpeLock, ACPI_NOT_ISR);
    if (GpeXrupt->Previous)
    {
        GpeXrupt->Previous->Next = GpeXrupt->Next;
    }

    if (GpeXrupt->Next)
    {
        GpeXrupt->Next->Previous = GpeXrupt->Previous;
    }
    AcpiOsReleaseLock (AcpiGbl_GpeLock, ACPI_NOT_ISR);

    /* Free the block */

    ACPI_MEM_FREE (GpeXrupt);
    return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvInstallGpeBlock
 *
 * PARAMETERS:  GpeBlock        - New GPE block
 *              InterruptLevel  - Level to be associated with this GPE block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install new GPE block with mutex support
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiEvInstallGpeBlock (
    ACPI_GPE_BLOCK_INFO     *GpeBlock,
    UINT32                  InterruptLevel)
{
    ACPI_GPE_BLOCK_INFO     *NextGpeBlock;
    ACPI_GPE_XRUPT_INFO     *GpeXruptBlock;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE ("EvInstallGpeBlock");


    Status = AcpiUtAcquireMutex (ACPI_MTX_EVENTS);
    if (ACPI_FAILURE (Status))
    {
        return_ACPI_STATUS (Status);
    }

    GpeXruptBlock = AcpiEvGetGpeXruptBlock (InterruptLevel);
    if (!GpeXruptBlock)
    {
        Status = AE_NO_MEMORY;
        goto UnlockAndExit;
    }

    /* Install the new block at the end of the list for this interrupt with lock */

    AcpiOsAcquireLock (AcpiGbl_GpeLock, ACPI_NOT_ISR);
    if (GpeXruptBlock->GpeBlockListHead)
    {
        NextGpeBlock = GpeXruptBlock->GpeBlockListHead;
        while (NextGpeBlock->Next)
        {
            NextGpeBlock = NextGpeBlock->Next;
        }

        NextGpeBlock->Next = GpeBlock;
        GpeBlock->Previous = NextGpeBlock;
    }
    else
    {
        GpeXruptBlock->GpeBlockListHead = GpeBlock;
    }

    GpeBlock->XruptBlock = GpeXruptBlock;
    AcpiOsReleaseLock (AcpiGbl_GpeLock, ACPI_NOT_ISR);

UnlockAndExit:
    Status = AcpiUtReleaseMutex (ACPI_MTX_EVENTS);
    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvDeleteGpeBlock
 *
 * PARAMETERS:  GpeBlock        - Existing GPE block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install new GPE block with mutex support
 *
 ******************************************************************************/

ACPI_STATUS
AcpiEvDeleteGpeBlock (
    ACPI_GPE_BLOCK_INFO     *GpeBlock)
{
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE ("EvInstallGpeBlock");


    Status = AcpiUtAcquireMutex (ACPI_MTX_EVENTS);
    if (ACPI_FAILURE (Status))
    {
        return_ACPI_STATUS (Status);
    }

    /* Disable all GPEs in this block */

    Status = AcpiHwDisableGpeBlock (GpeBlock->XruptBlock, GpeBlock);

    if (!GpeBlock->Previous && !GpeBlock->Next)
    {
        /* This is the last GpeBlock on this interrupt */

        Status = AcpiEvDeleteGpeXrupt (GpeBlock->XruptBlock);
        if (ACPI_FAILURE (Status))
        {
            goto UnlockAndExit;
        }
    }
    else
    {
        /* Remove the block on this interrupt with lock */

        AcpiOsAcquireLock (AcpiGbl_GpeLock, ACPI_NOT_ISR);
        if (GpeBlock->Previous)
        {
            GpeBlock->Previous->Next = GpeBlock->Next;
        }
        else
        {
            GpeBlock->XruptBlock->GpeBlockListHead = GpeBlock->Next;
        }

        if (GpeBlock->Next)
        {
            GpeBlock->Next->Previous = GpeBlock->Previous;
        }
        AcpiOsReleaseLock (AcpiGbl_GpeLock, ACPI_NOT_ISR);
    }

    /* Free the GpeBlock */

    ACPI_MEM_FREE (GpeBlock->RegisterInfo);
    ACPI_MEM_FREE (GpeBlock->EventInfo);
    ACPI_MEM_FREE (GpeBlock);

UnlockAndExit:
    Status = AcpiUtReleaseMutex (ACPI_MTX_EVENTS);
    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvCreateGpeInfoBlocks
 *
 * PARAMETERS:  GpeBlock    - New GPE block
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Create the RegisterInfo and EventInfo blocks for this GPE block
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiEvCreateGpeInfoBlocks (
    ACPI_GPE_BLOCK_INFO     *GpeBlock)
{
    ACPI_GPE_REGISTER_INFO  *GpeRegisterInfo = NULL;
    ACPI_GPE_EVENT_INFO     *GpeEventInfo = NULL;
    ACPI_GPE_EVENT_INFO     *ThisEvent;
    ACPI_GPE_REGISTER_INFO  *ThisRegister;
    ACPI_NATIVE_UINT        i;
    ACPI_NATIVE_UINT        j;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE ("EvCreateGpeInfoBlocks");


    /* Allocate the GPE register information block */

    GpeRegisterInfo = ACPI_MEM_CALLOCATE (
                                (ACPI_SIZE) GpeBlock->RegisterCount *
                                sizeof (ACPI_GPE_REGISTER_INFO));
    if (!GpeRegisterInfo)
    {
        ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
            "Could not allocate the GpeRegisterInfo table\n"));
        return_ACPI_STATUS (AE_NO_MEMORY);
    }

    /*
     * Allocate the GPE EventInfo block.  There are eight distinct GPEs
     * per register.  Initialization to zeros is sufficient.
     */
    GpeEventInfo = ACPI_MEM_CALLOCATE (
                        ((ACPI_SIZE) GpeBlock->RegisterCount * ACPI_GPE_REGISTER_WIDTH) *
                        sizeof (ACPI_GPE_EVENT_INFO));
    if (!GpeEventInfo)
    {
        ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not allocate the GpeEventInfo table\n"));
        Status = AE_NO_MEMORY;
        goto ErrorExit;
    }

    /* Save the new Info arrays in the GPE block */

    GpeBlock->RegisterInfo = GpeRegisterInfo;
    GpeBlock->EventInfo    = GpeEventInfo;

    /*
     * Initialize the GPE Register and Event structures.  A goal of these
     * tables is to hide the fact that there are two separate GPE register sets
     * in a given gpe hardware block, the status registers occupy the first half,
     * and the enable registers occupy the second half.
     */
    ThisRegister = GpeRegisterInfo;
    ThisEvent    = GpeEventInfo;

    for (i = 0; i < GpeBlock->RegisterCount; i++)
    {
        /* Init the RegisterInfo for this GPE register (8 GPEs) */

        ThisRegister->BaseGpeNumber = (UINT8) (GpeBlock->BlockBaseNumber +
                                                 (i * ACPI_GPE_REGISTER_WIDTH));

        ACPI_STORE_ADDRESS (ThisRegister->StatusAddress.Address,
                                (ACPI_GET_ADDRESS (GpeBlock->BlockAddress.Address)
                                + i));

        ACPI_STORE_ADDRESS (ThisRegister->EnableAddress.Address,
                                (ACPI_GET_ADDRESS (GpeBlock->BlockAddress.Address)
                                + i
                                + GpeBlock->RegisterCount));

        ThisRegister->StatusAddress.AddressSpaceId    = GpeBlock->BlockAddress.AddressSpaceId;
        ThisRegister->EnableAddress.AddressSpaceId    = GpeBlock->BlockAddress.AddressSpaceId;
        ThisRegister->StatusAddress.RegisterBitWidth  = ACPI_GPE_REGISTER_WIDTH;
        ThisRegister->EnableAddress.RegisterBitWidth  = ACPI_GPE_REGISTER_WIDTH;
        ThisRegister->StatusAddress.RegisterBitOffset = ACPI_GPE_REGISTER_WIDTH;
        ThisRegister->EnableAddress.RegisterBitOffset = ACPI_GPE_REGISTER_WIDTH;

        /* Init the EventInfo for each GPE within this register */

        for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++)
        {
            ThisEvent->BitMask = AcpiGbl_DecodeTo8bit[j];
            ThisEvent->RegisterInfo = ThisRegister;
            ThisEvent++;
        }

        /*
         * Clear the status/enable registers.  Note that status registers
         * are cleared by writing a '1', while enable registers are cleared
         * by writing a '0'.
         */
        Status = AcpiHwLowLevelWrite (ACPI_GPE_REGISTER_WIDTH, 0x00,
                    &ThisRegister->EnableAddress);
        if (ACPI_FAILURE (Status))
        {
            goto ErrorExit;
        }

        Status = AcpiHwLowLevelWrite (ACPI_GPE_REGISTER_WIDTH, 0xFF,
                    &ThisRegister->StatusAddress);
        if (ACPI_FAILURE (Status))
        {
            goto ErrorExit;
        }

        ThisRegister++;
    }

    return_ACPI_STATUS (AE_OK);


ErrorExit:
    if (GpeRegisterInfo)
    {
        ACPI_MEM_FREE (GpeRegisterInfo);
    }
    if (GpeEventInfo)
    {
        ACPI_MEM_FREE (GpeEventInfo);
    }

    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvCreateGpeBlock
 *
 * PARAMETERS:  GpeDevice           - Handle to the parent GPE block
 *              GpeBlockAddress     - Address and SpaceID
 *              RegisterCount       - Number of GPE register pairs in the block
 *              GpeBlockBaseNumber  - Starting GPE number for the block
 *              InterruptLevel      - H/W interrupt for the block
 *              ReturnGpeBlock      - Where the new block descriptor is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Create and Install a block of GPE registers
 *
 ******************************************************************************/

ACPI_STATUS
AcpiEvCreateGpeBlock (
    ACPI_NAMESPACE_NODE     *GpeDevice,
    ACPI_GENERIC_ADDRESS    *GpeBlockAddress,
    UINT32                  RegisterCount,
    UINT8                   GpeBlockBaseNumber,
    UINT32                  InterruptLevel,
    ACPI_GPE_BLOCK_INFO     **ReturnGpeBlock)
{
    ACPI_GPE_BLOCK_INFO     *GpeBlock;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE ("EvCreateGpeBlock");


    if (!RegisterCount)
    {
        return_ACPI_STATUS (AE_OK);
    }

    /* Allocate a new GPE block */

    GpeBlock = ACPI_MEM_CALLOCATE (sizeof (ACPI_GPE_BLOCK_INFO));
    if (!GpeBlock)
    {
        return_ACPI_STATUS (AE_NO_MEMORY);
    }

    /* Initialize the new GPE block */

    GpeBlock->RegisterCount   = RegisterCount;
    GpeBlock->BlockBaseNumber = GpeBlockBaseNumber;

    ACPI_MEMCPY (&GpeBlock->BlockAddress, GpeBlockAddress, sizeof (ACPI_GENERIC_ADDRESS));

    /* Create the RegisterInfo and EventInfo sub-structures */

    Status = AcpiEvCreateGpeInfoBlocks (GpeBlock);
    if (ACPI_FAILURE (Status))
    {
        ACPI_MEM_FREE (GpeBlock);
        return_ACPI_STATUS (Status);
    }

    /* Install the new block in the global list(s) */

    Status = AcpiEvInstallGpeBlock (GpeBlock, InterruptLevel);
    if (ACPI_FAILURE (Status))
    {
        ACPI_MEM_FREE (GpeBlock);
        return_ACPI_STATUS (Status);
    }

    /* Dump info about this GPE block */

    ACPI_DEBUG_PRINT ((ACPI_DB_INIT, "GPE %02d to %02d [%4.4s] %d regs at %8.8X%8.8X on int %d\n",
        GpeBlock->BlockBaseNumber,
        (UINT32) (GpeBlock->BlockBaseNumber +
                ((GpeBlock->RegisterCount * ACPI_GPE_REGISTER_WIDTH) -1)),
        GpeDevice->Name.Ascii,
        GpeBlock->RegisterCount,
        ACPI_HIDWORD (ACPI_GET_ADDRESS (GpeBlock->BlockAddress.Address)),
        ACPI_LODWORD (ACPI_GET_ADDRESS (GpeBlock->BlockAddress.Address)),
        InterruptLevel));

    /* Find all GPE methods (_Lxx, _Exx) for this block */

    Status = AcpiNsWalkNamespace (ACPI_TYPE_METHOD, GpeDevice,
                                ACPI_UINT32_MAX, ACPI_NS_WALK_NO_UNLOCK, AcpiEvSaveMethodInfo,
                                GpeBlock, NULL);

    /* Return the new block */

    if (ReturnGpeBlock)
    {
        (*ReturnGpeBlock) = GpeBlock;
    }

    return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvGpeInitialize
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Initialize the GPE data structures
 *
 ******************************************************************************/

ACPI_STATUS
AcpiEvGpeInitialize (void)
{
    UINT32                  RegisterCount0 = 0;
    UINT32                  RegisterCount1 = 0;
    UINT32                  GpeNumberMax = 0;
    ACPI_HANDLE             GpeDevice;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE ("EvGpeInitialize");


    /* Get a handle to the predefined _GPE object */

    Status = AcpiGetHandle (NULL, "\\_GPE", &GpeDevice);
    if (ACPI_FAILURE (Status))
    {
        return_ACPI_STATUS (Status);
    }

    /*
     * Initialize the GPE Blocks 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->Gpe0BlkLen &&
        ACPI_GET_ADDRESS (AcpiGbl_FADT->XGpe0Blk.Address))
    {
        /* GPE block 0 exists (has both length and address > 0) */

        RegisterCount0 = (UINT16) (AcpiGbl_FADT->Gpe0BlkLen / 2);

        GpeNumberMax = (RegisterCount0 * ACPI_GPE_REGISTER_WIDTH) - 1;

        /* Install GPE Block 0 */

        Status = AcpiEvCreateGpeBlock (GpeDevice, &AcpiGbl_FADT->XGpe0Blk,
                    RegisterCount0, 0, AcpiGbl_FADT->SciInt, &AcpiGbl_GpeFadtBlocks[0]);
        if (ACPI_FAILURE (Status))
        {
            ACPI_REPORT_ERROR ((
                "Could not create GPE Block 0, %s\n",
                AcpiFormatException (Status)));
        }
    }

    if (AcpiGbl_FADT->Gpe1BlkLen &&
        ACPI_GET_ADDRESS (AcpiGbl_FADT->XGpe1Blk.Address))
    {
        /* GPE block 1 exists (has both length and address > 0) */

        RegisterCount1 = (UINT16) (AcpiGbl_FADT->Gpe1BlkLen / 2);

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

        if ((RegisterCount0) &&
            (GpeNumberMax >= AcpiGbl_FADT->Gpe1Base))
        {
            ACPI_REPORT_ERROR ((
                "GPE0 block (GPE 0 to %d) overlaps the GPE1 block (GPE %d to %d) - Ignoring GPE1\n",
                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 (GpeDevice, &AcpiGbl_FADT->XGpe1Blk,
                        RegisterCount1, AcpiGbl_FADT->Gpe1Base,
                        AcpiGbl_FADT->SciInt, &AcpiGbl_GpeFadtBlocks[1]);
            if (ACPI_FAILURE (Status))
            {
                ACPI_REPORT_ERROR ((
                    "Could not create GPE Block 1, %s\n",
                    AcpiFormatException (Status)));
            }

            /*
             * 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_REPORT_INFO (("There are no GPE blocks defined in the FADT\n"));
        return_ACPI_STATUS (AE_OK);
    }

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

    if (GpeNumberMax > ACPI_GPE_MAX)
    {
        ACPI_REPORT_ERROR (("Maximum GPE number from FADT is too large: 0x%X\n",
            GpeNumberMax));
        return_ACPI_STATUS (AE_BAD_VALUE);
    }

    return_ACPI_STATUS (AE_OK);
}