/******************************************************************************
 *
 * Module Name: evgpeinit - System GPE initialization and update
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2025, 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 "acevents.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_EVENTS
        ACPI_MODULE_NAME    ("evgpeinit")

#if (!ACPI_REDUCED_HARDWARE) /* Entire module */

/*
 * Note: History of _PRW support in ACPICA
 *
 * Originally (2000 - 2010), the GPE initialization code performed a walk of
 * the entire namespace to execute the _PRW methods and detect all GPEs
 * capable of waking the system.
 *
 * As of 10/2010, the _PRW method execution has been removed since it is
 * actually unnecessary. The host OS must in fact execute all _PRW methods
 * in order to identify the device/power-resource dependencies. We now put
 * the onus on the host OS to identify the wake GPEs as part of this process
 * and to inform ACPICA of these GPEs via the AcpiSetupGpeForWake interface. This
 * not only reduces the complexity of the ACPICA initialization code, but in
 * some cases (on systems with very large namespaces) it should reduce the
 * kernel boot time as well.
 */

/*******************************************************************************
 *
 * 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);


    ACPI_DEBUG_PRINT_RAW ((ACPI_DB_INIT,
        "Initializing General Purpose Events (GPEs):\n"));

    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.Address,
            AcpiGbl_FADT.XGpe0Block.SpaceId,
            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.Address,
                AcpiGbl_FADT.XGpe1Block.SpaceId,
                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.
             */
        }
    }

    /* 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"));
        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.
 *
 ******************************************************************************/

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;


    /*
     * Find any _Lxx/_Exx GPE methods that have just been loaded.
     *
     * Any GPEs that correspond to new _Lxx/_Exx methods 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.OwnerId = TableOwnerId;
    WalkInfo.ExecuteByOwnerId = 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)
    {
        ACPI_INFO (("Enabled %u new GPEs", WalkInfo.Count));
    }

    (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.
 *
 ******************************************************************************/

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_STATUS             Status;
    UINT32                  GpeNumber;
    UINT8                   TempGpeNumber;
    char                    Name[ACPI_NAMESEG_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_NAMESEG_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
     */
    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 */

    Status = AcpiUtAsciiToHexByte (&Name[2], &TempGpeNumber);
    if (ACPI_FAILURE (Status))
    {
        /* 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 */

    GpeNumber = (UINT32) TempGpeNumber;
    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 ((ACPI_GPE_DISPATCH_TYPE (GpeEventInfo->Flags) ==
            ACPI_GPE_DISPATCH_HANDLER) ||
        (ACPI_GPE_DISPATCH_TYPE (GpeEventInfo->Flags) ==
            ACPI_GPE_DISPATCH_RAW_HANDLER))
    {
        /* If there is already a handler, ignore this GPE method */

        return_ACPI_STATUS (AE_OK);
    }

    if (ACPI_GPE_DISPATCH_TYPE (GpeEventInfo->Flags) ==
        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);
    }

    /* Disable the GPE in case it's been enabled already. */

    (void) AcpiHwLowSetGpe (GpeEventInfo, ACPI_GPE_DISABLE);

    /*
     * Add the GPE information from above to the GpeEventInfo block for
     * use during dispatch of this GPE.
     */
    GpeEventInfo->Flags &= ~(ACPI_GPE_DISPATCH_MASK);
    GpeEventInfo->Flags |= (UINT8) (Type | ACPI_GPE_DISPATCH_METHOD);
    GpeEventInfo->Dispatch.MethodNode = MethodNode;
    WalkInfo->Count++;

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

#endif /* !ACPI_REDUCED_HARDWARE */
