dist/events/evregion.c

/******************************************************************************
 *
 * Module Name: evregion - Operation Region support
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2021, 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"
#include "acinterp.h"

#define _COMPONENT          ACPI_EVENTS
        ACPI_MODULE_NAME    ("evregion")


extern UINT8        AcpiGbl_DefaultAddressSpaces[];

/* Local prototypes */

static void
AcpiEvExecuteOrphanRegMethod (
    ACPI_NAMESPACE_NODE     *DeviceNode,
    ACPI_ADR_SPACE_TYPE     SpaceId);


static ACPI_STATUS
AcpiEvRegRun (
    ACPI_HANDLE             ObjHandle,
    UINT32                  Level,
    void                    *Context,
    void                    **ReturnValue);


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvInitializeOpRegions
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute _REG methods for all Operation Regions that have
 *              an installed default region handler.
 *
 ******************************************************************************/

ACPI_STATUS
AcpiEvInitializeOpRegions (
    void)
{
    ACPI_STATUS             Status;
    UINT32                  i;


    ACPI_FUNCTION_TRACE (EvInitializeOpRegions);


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

    /* Run the _REG methods for OpRegions in each default address space */

    for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++)
    {
        /*
         * Make sure the installed handler is the DEFAULT handler. If not the
         * default, the _REG methods will have already been run (when the
         * handler was installed)
         */
        if (AcpiEvHasDefaultHandler (AcpiGbl_RootNode,
               AcpiGbl_DefaultAddressSpaces[i]))
        {
            AcpiEvExecuteRegMethods (AcpiGbl_RootNode,
                AcpiGbl_DefaultAddressSpaces[i], ACPI_REG_CONNECT);
        }
    }

    (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvAddressSpaceDispatch
 *
 * PARAMETERS:  RegionObj           - Internal region object
 *              FieldObj            - Corresponding field. Can be NULL.
 *              Function            - Read or Write operation
 *              RegionOffset        - Where in the region to read or write
 *              BitWidth            - Field width in bits (8, 16, 32, or 64)
 *              Value               - Pointer to in or out value, must be
 *                                    a full 64-bit integer
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Dispatch an address space or operation region access to
 *              a previously installed handler.
 *
 * NOTE: During early initialization, we always install the default region
 * handlers for Memory, I/O and PCI_Config. This ensures that these operation
 * region address spaces are always available as per the ACPI specification.
 * This is especially needed in order to support the execution of
 * module-level AML code during loading of the ACPI tables.
 *
 ******************************************************************************/

ACPI_STATUS
AcpiEvAddressSpaceDispatch (
    ACPI_OPERAND_OBJECT     *RegionObj,
    ACPI_OPERAND_OBJECT     *FieldObj,
    UINT32                  Function,
    UINT32                  RegionOffset,
    UINT32                  BitWidth,
    UINT64                  *Value)
{
    ACPI_STATUS             Status;
    ACPI_ADR_SPACE_HANDLER  Handler;
    ACPI_ADR_SPACE_SETUP    RegionSetup;
    ACPI_OPERAND_OBJECT     *HandlerDesc;
    ACPI_OPERAND_OBJECT     *RegionObj2;
    void                    *RegionContext = NULL;
    ACPI_CONNECTION_INFO    *Context;
    ACPI_MUTEX              ContextMutex;
    BOOLEAN                 ContextLocked;
    ACPI_PHYSICAL_ADDRESS   Address;


    ACPI_FUNCTION_TRACE (EvAddressSpaceDispatch);


    RegionObj2 = AcpiNsGetSecondaryObject (RegionObj);
    if (!RegionObj2)
    {
        return_ACPI_STATUS (AE_NOT_EXIST);
    }

    /* Ensure that there is a handler associated with this region */

    HandlerDesc = RegionObj->Region.Handler;
    if (!HandlerDesc)
    {
        ACPI_ERROR ((AE_INFO,
            "No handler for Region [%4.4s] (%p) [%s]",
            AcpiUtGetNodeName (RegionObj->Region.Node),
            RegionObj, AcpiUtGetRegionName (RegionObj->Region.SpaceId)));

        return_ACPI_STATUS (AE_NOT_EXIST);
    }

    Context = HandlerDesc->AddressSpace.Context;
    ContextMutex = HandlerDesc->AddressSpace.ContextMutex;
    ContextLocked = FALSE;

    /*
     * It may be the case that the region has never been initialized.
     * Some types of regions require special init code
     */
    if (!(RegionObj->Region.Flags & AOPOBJ_SETUP_COMPLETE))
    {
        /* This region has not been initialized yet, do it */

        RegionSetup = HandlerDesc->AddressSpace.Setup;
        if (!RegionSetup)
        {
            /* No initialization routine, exit with error */

            ACPI_ERROR ((AE_INFO,
                "No init routine for region(%p) [%s]",
                RegionObj, AcpiUtGetRegionName (RegionObj->Region.SpaceId)));
            return_ACPI_STATUS (AE_NOT_EXIST);
        }

	if (RegionObj->Region.SpaceId == ACPI_ADR_SPACE_PLATFORM_COMM)
	{
	    ACPI_PCC_INFO *Ctx = HandlerDesc->AddressSpace.Context;

	    Ctx->InternalBuffer = FieldObj->Field.InternalPccBuffer;
	    Ctx->Length = (UINT16) RegionObj->Region.Length;
	    Ctx->SubspaceId = (UINT8) RegionObj->Region.Address;
	}

        /*
         * We must exit the interpreter because the region setup will
         * potentially execute control methods (for example, the _REG method
         * for this region)
         */
        AcpiExExitInterpreter ();

        Status = RegionSetup (RegionObj, ACPI_REGION_ACTIVATE,
            Context, &RegionContext);

        /* Re-enter the interpreter */

        AcpiExEnterInterpreter ();

        /* Check for failure of the Region Setup */

        if (ACPI_FAILURE (Status))
        {
            ACPI_EXCEPTION ((AE_INFO, Status,
                "During region initialization: [%s]",
                AcpiUtGetRegionName (RegionObj->Region.SpaceId)));
            return_ACPI_STATUS (Status);
        }

        /* Region initialization may have been completed by RegionSetup */

        if (!(RegionObj->Region.Flags & AOPOBJ_SETUP_COMPLETE))
        {
            RegionObj->Region.Flags |= AOPOBJ_SETUP_COMPLETE;

            /*
             * Save the returned context for use in all accesses to
             * the handler for this particular region
             */
            if (!(RegionObj2->Extra.RegionContext))
            {
                RegionObj2->Extra.RegionContext = RegionContext;
            }
        }
    }

    /* We have everything we need, we can invoke the address space handler */

    Handler = HandlerDesc->AddressSpace.Handler;
    Address = (RegionObj->Region.Address + RegionOffset);

    ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
        "Handler %p (@%p) Address %8.8X%8.8X [%s]\n",
        &RegionObj->Region.Handler->AddressSpace, Handler,
        ACPI_FORMAT_UINT64 (Address),
        AcpiUtGetRegionName (RegionObj->Region.SpaceId)));

    if (!(HandlerDesc->AddressSpace.HandlerFlags &
        ACPI_ADDR_HANDLER_DEFAULT_INSTALLED))
    {
        /*
         * For handlers other than the default (supplied) handlers, we must
         * exit the interpreter because the handler *might* block -- we don't
         * know what it will do, so we can't hold the lock on the interpreter.
         */
        AcpiExExitInterpreter();
    }

    /*
     * Special handling for GenericSerialBus and GeneralPurposeIo:
     * There are three extra parameters that must be passed to the
     * handler via the context:
     *   1) Connection buffer, a resource template from Connection() op
     *   2) Length of the above buffer
     *   3) Actual access length from the AccessAs() op
     *
     * Since we pass these extra parameters via the context, which is
     * shared between threads, we must lock the context to avoid these
     * parameters being changed from another thread before the handler
     * has completed running.
     *
     * In addition, for GeneralPurposeIo, the Address and BitWidth fields
     * are defined as follows:
     *   1) Address is the pin number index of the field (bit offset from
     *      the previous Connection)
     *   2) BitWidth is the actual bit length of the field (number of pins)
     */
    if ((RegionObj->Region.SpaceId == ACPI_ADR_SPACE_GSBUS ||
         RegionObj->Region.SpaceId == ACPI_ADR_SPACE_GPIO) &&
        Context &&
        FieldObj)
    {

        Status = AcpiOsAcquireMutex (ContextMutex, ACPI_WAIT_FOREVER);
        if (ACPI_FAILURE (Status))
        {
            goto ReEnterInterpreter;
        }

        ContextLocked = TRUE;

        /* Get the Connection (ResourceTemplate) buffer */

        Context->Connection = FieldObj->Field.ResourceBuffer;
        Context->Length = FieldObj->Field.ResourceLength;
        Context->AccessLength = FieldObj->Field.AccessLength;

        if (RegionObj->Region.SpaceId == ACPI_ADR_SPACE_GPIO)
        {
            Address = FieldObj->Field.PinNumberIndex;
            BitWidth = FieldObj->Field.BitLength;
        }
    }

    /* Call the handler */

    Status = Handler (Function, Address, BitWidth, Value, Context,
        RegionObj2->Extra.RegionContext);

    if (ContextLocked)
    {
        AcpiOsReleaseMutex (ContextMutex);
    }

    if (ACPI_FAILURE (Status))
    {
        ACPI_EXCEPTION ((AE_INFO, Status, "Returned by Handler for [%s]",
            AcpiUtGetRegionName (RegionObj->Region.SpaceId)));

        /*
         * Special case for an EC timeout. These are seen so frequently
         * that an additional error message is helpful
         */
        if ((RegionObj->Region.SpaceId == ACPI_ADR_SPACE_EC) &&
            (Status == AE_TIME))
        {
            ACPI_ERROR ((AE_INFO,
                "Timeout from EC hardware or EC device driver"));
        }
    }

ReEnterInterpreter:
    if (!(HandlerDesc->AddressSpace.HandlerFlags &
        ACPI_ADDR_HANDLER_DEFAULT_INSTALLED))
    {
        /*
         * We just returned from a non-default handler, we must re-enter the
         * interpreter
         */
        AcpiExEnterInterpreter ();
    }

    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvDetachRegion
 *
 * PARAMETERS:  RegionObj           - Region Object
 *              AcpiNsIsLocked      - Namespace Region Already Locked?
 *
 * RETURN:      None
 *
 * DESCRIPTION: Break the association between the handler and the region
 *              this is a two way association.
 *
 ******************************************************************************/

void
AcpiEvDetachRegion (
    ACPI_OPERAND_OBJECT     *RegionObj,
    BOOLEAN                 AcpiNsIsLocked)
{
    ACPI_OPERAND_OBJECT     *HandlerObj;
    ACPI_OPERAND_OBJECT     *ObjDesc;
    ACPI_OPERAND_OBJECT     *StartDesc;
    ACPI_OPERAND_OBJECT     **LastObjPtr;
    ACPI_ADR_SPACE_SETUP    RegionSetup;
    void                    **RegionContext;
    ACPI_OPERAND_OBJECT     *RegionObj2;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE (EvDetachRegion);


    RegionObj2 = AcpiNsGetSecondaryObject (RegionObj);
    if (!RegionObj2)
    {
        return_VOID;
    }
    RegionContext = &RegionObj2->Extra.RegionContext;

    /* Get the address handler from the region object */

    HandlerObj = RegionObj->Region.Handler;
    if (!HandlerObj)
    {
        /* This region has no handler, all done */

        return_VOID;
    }

    /* Find this region in the handler's list */

    ObjDesc = HandlerObj->AddressSpace.RegionList;
    StartDesc = ObjDesc;
    LastObjPtr = &HandlerObj->AddressSpace.RegionList;

    while (ObjDesc)
    {
        /* Is this the correct Region? */

        if (ObjDesc == RegionObj)
        {
            ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
                "Removing Region %p from address handler %p\n",
                RegionObj, HandlerObj));

            /* This is it, remove it from the handler's list */

            *LastObjPtr = ObjDesc->Region.Next;
            ObjDesc->Region.Next = NULL;        /* Must clear field */

            if (AcpiNsIsLocked)
            {
                Status = AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
                if (ACPI_FAILURE (Status))
                {
                    return_VOID;
                }
            }

            /* Now stop region accesses by executing the _REG method */

            Status = AcpiEvExecuteRegMethod (RegionObj, ACPI_REG_DISCONNECT);
            if (ACPI_FAILURE (Status))
            {
                ACPI_EXCEPTION ((AE_INFO, Status, "from region _REG, [%s]",
                    AcpiUtGetRegionName (RegionObj->Region.SpaceId)));
            }

            if (AcpiNsIsLocked)
            {
                Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
                if (ACPI_FAILURE (Status))
                {
                    return_VOID;
                }
            }

            /*
             * If the region has been activated, call the setup handler with
             * the deactivate notification
             */
            if (RegionObj->Region.Flags & AOPOBJ_SETUP_COMPLETE)
            {
                RegionSetup = HandlerObj->AddressSpace.Setup;
                Status = RegionSetup (RegionObj, ACPI_REGION_DEACTIVATE,
                    HandlerObj->AddressSpace.Context, RegionContext);

                /*
                 * RegionContext should have been released by the deactivate
                 * operation. We don't need access to it anymore here.
                 */
                if (RegionContext)
                {
                    *RegionContext = NULL;
                }

                /* Init routine may fail, Just ignore errors */

                if (ACPI_FAILURE (Status))
                {
                    ACPI_EXCEPTION ((AE_INFO, Status,
                        "from region handler - deactivate, [%s]",
                        AcpiUtGetRegionName (RegionObj->Region.SpaceId)));
                }

                RegionObj->Region.Flags &= ~(AOPOBJ_SETUP_COMPLETE);
            }

            /*
             * Remove handler reference in the region
             *
             * NOTE: this doesn't mean that the region goes away, the region
             * is just inaccessible as indicated to the _REG method
             *
             * If the region is on the handler's list, this must be the
             * region's handler
             */
            RegionObj->Region.Handler = NULL;
            AcpiUtRemoveReference (HandlerObj);

            return_VOID;
        }

        /* Walk the linked list of handlers */

        LastObjPtr = &ObjDesc->Region.Next;
        ObjDesc = ObjDesc->Region.Next;

        /* Prevent infinite loop if list is corrupted */

        if (ObjDesc == StartDesc)
        {
            ACPI_ERROR ((AE_INFO,
                "Circular handler list in region object %p",
                RegionObj));
            return_VOID;
        }
    }

    /* If we get here, the region was not in the handler's region list */

    ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
        "Cannot remove region %p from address handler %p\n",
        RegionObj, HandlerObj));

    return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvAttachRegion
 *
 * PARAMETERS:  HandlerObj          - Handler Object
 *              RegionObj           - Region Object
 *              AcpiNsIsLocked      - Namespace Region Already Locked?
 *
 * RETURN:      None
 *
 * DESCRIPTION: Create the association between the handler and the region
 *              this is a two way association.
 *
 ******************************************************************************/

ACPI_STATUS
AcpiEvAttachRegion (
    ACPI_OPERAND_OBJECT     *HandlerObj,
    ACPI_OPERAND_OBJECT     *RegionObj,
    BOOLEAN                 AcpiNsIsLocked)
{

    ACPI_FUNCTION_TRACE (EvAttachRegion);


    /* Install the region's handler */

    if (RegionObj->Region.Handler)
    {
        return_ACPI_STATUS (AE_ALREADY_EXISTS);
    }

    ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
        "Adding Region [%4.4s] %p to address handler %p [%s]\n",
        AcpiUtGetNodeName (RegionObj->Region.Node),
        RegionObj, HandlerObj,
        AcpiUtGetRegionName (RegionObj->Region.SpaceId)));

    /* Link this region to the front of the handler's list */

    RegionObj->Region.Next = HandlerObj->AddressSpace.RegionList;
    HandlerObj->AddressSpace.RegionList = RegionObj;
    RegionObj->Region.Handler = HandlerObj;
    AcpiUtAddReference (HandlerObj);

    return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvExecuteRegMethod
 *
 * PARAMETERS:  RegionObj           - Region object
 *              Function            - Passed to _REG: On (1) or Off (0)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute _REG method for a region
 *
 ******************************************************************************/

ACPI_STATUS
AcpiEvExecuteRegMethod (
    ACPI_OPERAND_OBJECT     *RegionObj,
    UINT32                  Function)
{
    ACPI_EVALUATE_INFO      *Info;
    ACPI_OPERAND_OBJECT     *Args[3];
    ACPI_OPERAND_OBJECT     *RegionObj2;
    const ACPI_NAME         *RegNamePtr = ACPI_ALIGNED_STR_UNION (ACPI_NAME, METHOD_NAME__REG);
    ACPI_NAMESPACE_NODE     *MethodNode;
    ACPI_NAMESPACE_NODE     *Node;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE (EvExecuteRegMethod);


    if (!AcpiGbl_NamespaceInitialized ||
        RegionObj->Region.Handler == NULL)
    {
        return_ACPI_STATUS (AE_OK);
    }

    RegionObj2 = AcpiNsGetSecondaryObject (RegionObj);
    if (!RegionObj2)
    {
        return_ACPI_STATUS (AE_NOT_EXIST);
    }

    /*
     * Find any "_REG" method associated with this region definition.
     * The method should always be updated as this function may be
     * invoked after a namespace change.
     */
    Node = RegionObj->Region.Node->Parent;
    Status = AcpiNsSearchOneScope (
        *RegNamePtr, Node, ACPI_TYPE_METHOD, &MethodNode);
    if (ACPI_SUCCESS (Status))
    {
        /*
         * The _REG method is optional and there can be only one per
         * region definition. This will be executed when the handler is
         * attached or removed.
         */
        RegionObj2->Extra.Method_REG = MethodNode;
    }
    if (RegionObj2->Extra.Method_REG == NULL)
    {
        return_ACPI_STATUS (AE_OK);
    }

    /* _REG(DISCONNECT) should be paired with _REG(CONNECT) */

    if ((Function == ACPI_REG_CONNECT &&
        RegionObj->Common.Flags & AOPOBJ_REG_CONNECTED) ||
        (Function == ACPI_REG_DISCONNECT &&
         !(RegionObj->Common.Flags & AOPOBJ_REG_CONNECTED)))
    {
        return_ACPI_STATUS (AE_OK);
    }

    /* Allocate and initialize the evaluation information block */

    Info = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_EVALUATE_INFO));
    if (!Info)
    {
        return_ACPI_STATUS (AE_NO_MEMORY);
    }

    Info->PrefixNode = RegionObj2->Extra.Method_REG;
    Info->RelativePathname = NULL;
    Info->Parameters = Args;
    Info->Flags = ACPI_IGNORE_RETURN_VALUE;

    /*
     * The _REG method has two arguments:
     *
     * Arg0 - Integer:
     *  Operation region space ID Same value as RegionObj->Region.SpaceId
     *
     * Arg1 - Integer:
     *  connection status 1 for connecting the handler, 0 for disconnecting
     *  the handler (Passed as a parameter)
     */
    Args[0] = AcpiUtCreateIntegerObject ((UINT64) RegionObj->Region.SpaceId);
    if (!Args[0])
    {
        Status = AE_NO_MEMORY;
        goto Cleanup1;
    }

    Args[1] = AcpiUtCreateIntegerObject ((UINT64) Function);
    if (!Args[1])
    {
        Status = AE_NO_MEMORY;
        goto Cleanup2;
    }

    Args[2] = NULL; /* Terminate list */

    /* Execute the method, no return value */

    ACPI_DEBUG_EXEC (
        AcpiUtDisplayInitPathname (ACPI_TYPE_METHOD, Info->PrefixNode, NULL));

    Status = AcpiNsEvaluate (Info);
    AcpiUtRemoveReference (Args[1]);

    if (ACPI_FAILURE (Status))
    {
        goto Cleanup2;
    }

    if (Function == ACPI_REG_CONNECT)
    {
        RegionObj->Common.Flags |= AOPOBJ_REG_CONNECTED;
    }
    else
    {
        RegionObj->Common.Flags &= ~AOPOBJ_REG_CONNECTED;
    }

Cleanup2:
    AcpiUtRemoveReference (Args[0]);

Cleanup1:
    ACPI_FREE (Info);
    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvExecuteRegMethods
 *
 * PARAMETERS:  Node            - Namespace node for the device
 *              SpaceId         - The address space ID
 *              Function        - Passed to _REG: On (1) or Off (0)
 *
 * RETURN:      None
 *
 * DESCRIPTION: Run all _REG methods for the input Space ID;
 *              Note: assumes namespace is locked, or system init time.
 *
 ******************************************************************************/

void
AcpiEvExecuteRegMethods (
    ACPI_NAMESPACE_NODE     *Node,
    ACPI_ADR_SPACE_TYPE     SpaceId,
    UINT32                  Function)
{
    ACPI_REG_WALK_INFO      Info;


    ACPI_FUNCTION_TRACE (EvExecuteRegMethods);

    /*
     * These address spaces do not need a call to _REG, since the ACPI
     * specification defines them as: "must always be accessible". Since
     * they never change state (never become unavailable), no need to ever
     * call _REG on them. Also, a DataTable is not a "real" address space,
     * so do not call _REG. September 2018.
     */
    if ((SpaceId == ACPI_ADR_SPACE_SYSTEM_MEMORY) ||
        (SpaceId == ACPI_ADR_SPACE_SYSTEM_IO) ||
        (SpaceId == ACPI_ADR_SPACE_DATA_TABLE))
    {
        return_VOID;
    }

    Info.SpaceId = SpaceId;
    Info.Function = Function;
    Info.RegRunCount = 0;

    ACPI_DEBUG_PRINT_RAW ((ACPI_DB_NAMES,
        "    Running _REG methods for SpaceId %s\n",
        AcpiUtGetRegionName (Info.SpaceId)));

    /*
     * Run all _REG methods for all Operation Regions for this space ID. This
     * is a separate walk in order to handle any interdependencies between
     * regions and _REG methods. (i.e. handlers must be installed for all
     * regions of this Space ID before we can run any _REG methods)
     */
    (void) AcpiNsWalkNamespace (ACPI_TYPE_ANY, Node, ACPI_UINT32_MAX,
        ACPI_NS_WALK_UNLOCK, AcpiEvRegRun, NULL, &Info, NULL);

    /*
     * Special case for EC and GPIO: handle "orphan" _REG methods with
     * no region.
     */
    if (SpaceId == ACPI_ADR_SPACE_EC || SpaceId == ACPI_ADR_SPACE_GPIO)
    {
        AcpiEvExecuteOrphanRegMethod (Node, SpaceId);
    }

    ACPI_DEBUG_PRINT_RAW ((ACPI_DB_NAMES,
        "    Executed %u _REG methods for SpaceId %s\n",
        Info.RegRunCount, AcpiUtGetRegionName (Info.SpaceId)));

    return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvRegRun
 *
 * PARAMETERS:  WalkNamespace callback
 *
 * DESCRIPTION: Run _REG method for region objects of the requested spaceID
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiEvRegRun (
    ACPI_HANDLE             ObjHandle,
    UINT32                  Level,
    void                    *Context,
    void                    **ReturnValue)
{
    ACPI_OPERAND_OBJECT     *ObjDesc;
    ACPI_NAMESPACE_NODE     *Node;
    ACPI_STATUS             Status;
    ACPI_REG_WALK_INFO      *Info;


    Info = ACPI_CAST_PTR (ACPI_REG_WALK_INFO, Context);

    /* Convert and validate the device handle */

    Node = AcpiNsValidateHandle (ObjHandle);
    if (!Node)
    {
        return (AE_BAD_PARAMETER);
    }

    /*
     * We only care about regions and objects that are allowed to have
     * address space handlers
     */
    if ((Node->Type != ACPI_TYPE_REGION) &&
        (Node != AcpiGbl_RootNode))
    {
        return (AE_OK);
    }

    /* Check for an existing internal object */

    ObjDesc = AcpiNsGetAttachedObject (Node);
    if (!ObjDesc)
    {
        /* No object, just exit */

        return (AE_OK);
    }

    /* Object is a Region */

    if (ObjDesc->Region.SpaceId != Info->SpaceId)
    {
        /* This region is for a different address space, just ignore it */

        return (AE_OK);
    }

    Info->RegRunCount++;
    Status = AcpiEvExecuteRegMethod (ObjDesc, Info->Function);
    return (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvExecuteOrphanRegMethod
 *
 * PARAMETERS:  DeviceNode          - Namespace node for an ACPI device
 *              SpaceId             - The address space ID
 *
 * RETURN:      None
 *
 * DESCRIPTION: Execute an "orphan" _REG method that appears under an ACPI
 *              device. This is a _REG method that has no corresponding region
 *              within the device's scope. ACPI tables depending on these
 *              "orphan" _REG methods have been seen for both EC and GPIO
 *              Operation Regions. Presumably the Windows ACPI implementation
 *              always calls the _REG method independent of the presence of
 *              an actual Operation Region with the correct address space ID.
 *
 *  MUTEX:      Assumes the namespace is locked
 *
 ******************************************************************************/

static void
AcpiEvExecuteOrphanRegMethod (
    ACPI_NAMESPACE_NODE     *DeviceNode,
    ACPI_ADR_SPACE_TYPE     SpaceId)
{
    ACPI_HANDLE             RegMethod;
    ACPI_NAMESPACE_NODE     *NextNode;
    ACPI_STATUS             Status;
    ACPI_OBJECT_LIST        Args;
    ACPI_OBJECT             Objects[2];


    ACPI_FUNCTION_TRACE (EvExecuteOrphanRegMethod);


    if (!DeviceNode)
    {
        return_VOID;
    }

    /* Namespace is currently locked, must release */

    (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);

    /* Get a handle to a _REG method immediately under the EC device */

    Status = AcpiGetHandle (DeviceNode, METHOD_NAME__REG, &RegMethod);
    if (ACPI_FAILURE (Status))
    {
        goto Exit; /* There is no _REG method present */
    }

    /*
     * Execute the _REG method only if there is no Operation Region in
     * this scope with the Embedded Controller space ID. Otherwise, it
     * will already have been executed. Note, this allows for Regions
     * with other space IDs to be present; but the code below will then
     * execute the _REG method with the EmbeddedControl SpaceID argument.
     */
    NextNode = AcpiNsGetNextNode (DeviceNode, NULL);
    while (NextNode)
    {
        if ((NextNode->Type == ACPI_TYPE_REGION) &&
            (NextNode->Object) &&
            (NextNode->Object->Region.SpaceId == SpaceId))
        {
            goto Exit; /* Do not execute the _REG */
        }

        NextNode = AcpiNsGetNextNode (DeviceNode, NextNode);
    }

    /* Evaluate the _REG(SpaceId,Connect) method */

    Args.Count = 2;
    Args.Pointer = Objects;
    Objects[0].Type = ACPI_TYPE_INTEGER;
    Objects[0].Integer.Value = SpaceId;
    Objects[1].Type = ACPI_TYPE_INTEGER;
    Objects[1].Integer.Value = ACPI_REG_CONNECT;

    (void) AcpiEvaluateObject (RegMethod, NULL, &Args, NULL);

Exit:
    /* We ignore all errors from above, don't care */

    (void) AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
    return_VOID;
}