dist/events/evhandler.c

/******************************************************************************
 *
 * Module Name: evhandler - Support for Address Space handlers
 *
 *****************************************************************************/

/*
 * 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    ("evhandler")


/* Local prototypes */

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


/* These are the address spaces that will get default handlers */

UINT8        AcpiGbl_DefaultAddressSpaces[ACPI_NUM_DEFAULT_SPACES] =
{
    ACPI_ADR_SPACE_SYSTEM_MEMORY,
    ACPI_ADR_SPACE_SYSTEM_IO,
    ACPI_ADR_SPACE_PCI_CONFIG,
    ACPI_ADR_SPACE_DATA_TABLE
};


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvInstallRegionHandlers
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Installs the core subsystem default address space handlers.
 *
 ******************************************************************************/

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


    ACPI_FUNCTION_TRACE (EvInstallRegionHandlers);


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

    /*
     * All address spaces (PCI Config, EC, SMBus) are scope dependent and
     * registration must occur for a specific device.
     *
     * In the case of the system memory and IO address spaces there is
     * currently no device associated with the address space. For these we
     * use the root.
     *
     * We install the default PCI config space handler at the root so that
     * this space is immediately available even though the we have not
     * enumerated all the PCI Root Buses yet. This is to conform to the ACPI
     * specification which states that the PCI config space must be always
     * available -- even though we are nowhere near ready to find the PCI root
     * buses at this point.
     *
     * NOTE: We ignore AE_ALREADY_EXISTS because this means that a handler
     * has already been installed (via AcpiInstallAddressSpaceHandler).
     * Similar for AE_SAME_HANDLER.
     */
    for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++)
    {
        Status = AcpiEvInstallSpaceHandler (AcpiGbl_RootNode,
            AcpiGbl_DefaultAddressSpaces[i],
            ACPI_DEFAULT_HANDLER, NULL, NULL);
        switch (Status)
        {
        case AE_OK:
        case AE_SAME_HANDLER:
        case AE_ALREADY_EXISTS:

            /* These exceptions are all OK */

            Status = AE_OK;
            break;

        default:

            goto UnlockAndExit;
        }
    }

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


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvHasDefaultHandler
 *
 * PARAMETERS:  Node                - Namespace node for the device
 *              SpaceId             - The address space ID
 *
 * RETURN:      TRUE if default handler is installed, FALSE otherwise
 *
 * DESCRIPTION: Check if the default handler is installed for the requested
 *              space ID.
 *
 ******************************************************************************/

BOOLEAN
AcpiEvHasDefaultHandler (
    ACPI_NAMESPACE_NODE     *Node,
    ACPI_ADR_SPACE_TYPE     SpaceId)
{
    ACPI_OPERAND_OBJECT     *ObjDesc;
    ACPI_OPERAND_OBJECT     *HandlerObj;


    /* Must have an existing internal object */

    ObjDesc = AcpiNsGetAttachedObject (Node);
    if (ObjDesc)
    {
        HandlerObj = ObjDesc->CommonNotify.Handler;

        /* Walk the linked list of handlers for this object */

        while (HandlerObj)
        {
            if (HandlerObj->AddressSpace.SpaceId == SpaceId)
            {
                if (HandlerObj->AddressSpace.HandlerFlags &
                    ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)
                {
                    return (TRUE);
                }
            }

            HandlerObj = HandlerObj->AddressSpace.Next;
        }
    }

    return (FALSE);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvInstallHandler
 *
 * PARAMETERS:  WalkNamespace callback
 *
 * DESCRIPTION: This routine installs an address handler into objects that are
 *              of type Region or Device.
 *
 *              If the Object is a Device, and the device has a handler of
 *              the same type then the search is terminated in that branch.
 *
 *              This is because the existing handler is closer in proximity
 *              to any more regions than the one we are trying to install.
 *
 ******************************************************************************/

static ACPI_STATUS
AcpiEvInstallHandler (
    ACPI_HANDLE             ObjHandle,
    UINT32                  Level,
    void                    *Context,
    void                    **ReturnValue)
{
    ACPI_OPERAND_OBJECT     *HandlerObj;
    ACPI_OPERAND_OBJECT     *NextHandlerObj;
    ACPI_OPERAND_OBJECT     *ObjDesc;
    ACPI_NAMESPACE_NODE     *Node;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_NAME (EvInstallHandler);


    HandlerObj = (ACPI_OPERAND_OBJECT  *) Context;

    /* Parameter validation */

    if (!HandlerObj)
    {
        return (AE_OK);
    }

    /* 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_DEVICE) &&
        (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);
    }

    /* Devices are handled different than regions */

    if (ObjDesc->Common.Type == ACPI_TYPE_DEVICE)
    {
        /* Check if this Device already has a handler for this address space */

        NextHandlerObj = AcpiEvFindRegionHandler (
            HandlerObj->AddressSpace.SpaceId, ObjDesc->CommonNotify.Handler);
        if (NextHandlerObj)
        {
            /* Found a handler, is it for the same address space? */

            ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
                "Found handler for region [%s] in device %p(%p) handler %p\n",
                AcpiUtGetRegionName (HandlerObj->AddressSpace.SpaceId),
                ObjDesc, NextHandlerObj, HandlerObj));

            /*
             * Since the object we found it on was a device, then it means
             * that someone has already installed a handler for the branch
             * of the namespace from this device on. Just bail out telling
             * the walk routine to not traverse this branch. This preserves
             * the scoping rule for handlers.
             */
            return (AE_CTRL_DEPTH);
        }

        /*
         * As long as the device didn't have a handler for this space we
         * don't care about it. We just ignore it and proceed.
         */
        return (AE_OK);
    }

    /* Object is a Region */

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

        return (AE_OK);
    }

    /*
     * Now we have a region and it is for the handler's address space type.
     *
     * First disconnect region for any previous handler (if any)
     */
    AcpiEvDetachRegion (ObjDesc, FALSE);

    /* Connect the region to the new handler */

    Status = AcpiEvAttachRegion (HandlerObj, ObjDesc, FALSE);
    return (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvFindRegionHandler
 *
 * PARAMETERS:  SpaceId         - The address space ID
 *              HandlerObj      - Head of the handler object list
 *
 * RETURN:      Matching handler object. NULL if space ID not matched
 *
 * DESCRIPTION: Search a handler object list for a match on the address
 *              space ID.
 *
 ******************************************************************************/

ACPI_OPERAND_OBJECT *
AcpiEvFindRegionHandler (
    ACPI_ADR_SPACE_TYPE     SpaceId,
    ACPI_OPERAND_OBJECT     *HandlerObj)
{

    /* Walk the handler list for this device */

    while (HandlerObj)
    {
        /* Same SpaceId indicates a handler is installed */

        if (HandlerObj->AddressSpace.SpaceId == SpaceId)
        {
            return (HandlerObj);
        }

        /* Next handler object */

        HandlerObj = HandlerObj->AddressSpace.Next;
    }

    return (NULL);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiEvInstallSpaceHandler
 *
 * PARAMETERS:  Node            - Namespace node for the device
 *              SpaceId         - The address space ID
 *              Handler         - Address of the handler
 *              Setup           - Address of the setup function
 *              Context         - Value passed to the handler on each access
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install a handler for all OpRegions of a given SpaceId.
 *              Assumes namespace is locked
 *
 ******************************************************************************/

ACPI_STATUS
AcpiEvInstallSpaceHandler (
    ACPI_NAMESPACE_NODE     *Node,
    ACPI_ADR_SPACE_TYPE     SpaceId,
    ACPI_ADR_SPACE_HANDLER  Handler,
    ACPI_ADR_SPACE_SETUP    Setup,
    void                    *Context)
{
    ACPI_OPERAND_OBJECT     *ObjDesc;
    ACPI_OPERAND_OBJECT     *HandlerObj;
    ACPI_STATUS             Status = AE_OK;
    ACPI_OBJECT_TYPE        Type;
    UINT8                   Flags = 0;


    ACPI_FUNCTION_TRACE (EvInstallSpaceHandler);


    /*
     * This registration is valid for only the types below and the root.
     * The root node is where the default handlers get installed.
     */
    if ((Node->Type != ACPI_TYPE_DEVICE)     &&
        (Node->Type != ACPI_TYPE_PROCESSOR)  &&
        (Node->Type != ACPI_TYPE_THERMAL)    &&
        (Node != AcpiGbl_RootNode))
    {
        Status = AE_BAD_PARAMETER;
        goto UnlockAndExit;
    }

    if (Handler == ACPI_DEFAULT_HANDLER)
    {
        Flags = ACPI_ADDR_HANDLER_DEFAULT_INSTALLED;

        switch (SpaceId)
        {
        case ACPI_ADR_SPACE_SYSTEM_MEMORY:

            Handler = AcpiExSystemMemorySpaceHandler;
            Setup   = AcpiEvSystemMemoryRegionSetup;
            break;

        case ACPI_ADR_SPACE_SYSTEM_IO:

            Handler = AcpiExSystemIoSpaceHandler;
            Setup   = AcpiEvIoSpaceRegionSetup;
            break;

        case ACPI_ADR_SPACE_PCI_CONFIG:

            Handler = AcpiExPciConfigSpaceHandler;
            Setup   = AcpiEvPciConfigRegionSetup;
            break;

        case ACPI_ADR_SPACE_CMOS:

            Handler = AcpiExCmosSpaceHandler;
            Setup   = AcpiEvCmosRegionSetup;
            break;

        case ACPI_ADR_SPACE_PCI_BAR_TARGET:

            Handler = AcpiExPciBarSpaceHandler;
            Setup   = AcpiEvPciBarRegionSetup;
            break;

        case ACPI_ADR_SPACE_DATA_TABLE:

            Handler = AcpiExDataTableSpaceHandler;
            Setup   = AcpiEvDataTableRegionSetup;
            break;

        default:

            Status = AE_BAD_PARAMETER;
            goto UnlockAndExit;
        }
    }

    /* If the caller hasn't specified a setup routine, use the default */

    if (!Setup)
    {
        Setup = AcpiEvDefaultRegionSetup;
    }

    /* Check for an existing internal object */

    ObjDesc = AcpiNsGetAttachedObject (Node);
    if (ObjDesc)
    {
        /*
         * The attached device object already exists. Now make sure
         * the handler is not already installed.
         */
        HandlerObj = AcpiEvFindRegionHandler (SpaceId,
            ObjDesc->CommonNotify.Handler);

        if (HandlerObj)
        {
            if (HandlerObj->AddressSpace.Handler == Handler)
            {
                /*
                 * It is (relatively) OK to attempt to install the SAME
                 * handler twice. This can easily happen with the
                 * PCI_Config space.
                 */
                Status = AE_SAME_HANDLER;
                goto UnlockAndExit;
            }
            else
            {
                /* A handler is already installed */

                Status = AE_ALREADY_EXISTS;
            }

            goto UnlockAndExit;
        }
    }
    else
    {
        ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
            "Creating object on Device %p while installing handler\n",
            Node));

        /* ObjDesc does not exist, create one */

        if (Node->Type == ACPI_TYPE_ANY)
        {
            Type = ACPI_TYPE_DEVICE;
        }
        else
        {
            Type = Node->Type;
        }

        ObjDesc = AcpiUtCreateInternalObject (Type);
        if (!ObjDesc)
        {
            Status = AE_NO_MEMORY;
            goto UnlockAndExit;
        }

        /* Init new descriptor */

        ObjDesc->Common.Type = (UINT8) Type;

        /* Attach the new object to the Node */

        Status = AcpiNsAttachObject (Node, ObjDesc, Type);

        /* Remove local reference to the object */

        AcpiUtRemoveReference (ObjDesc);

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

    ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
        "Installing address handler for region %s(%X) "
        "on Device %4.4s %p(%p)\n",
        AcpiUtGetRegionName (SpaceId), SpaceId,
        AcpiUtGetNodeName (Node), Node, ObjDesc));

    /*
     * Install the handler
     *
     * At this point there is no existing handler. Just allocate the object
     * for the handler and link it into the list.
     */
    HandlerObj = AcpiUtCreateInternalObject (ACPI_TYPE_LOCAL_ADDRESS_HANDLER);
    if (!HandlerObj)
    {
        Status = AE_NO_MEMORY;
        goto UnlockAndExit;
    }

    /* Init handler obj */

    Status = AcpiOsCreateMutex (&HandlerObj->AddressSpace.ContextMutex);
    if (ACPI_FAILURE (Status))
    {
        AcpiUtRemoveReference (HandlerObj);
        goto UnlockAndExit;
    }

    HandlerObj->AddressSpace.SpaceId = (UINT8) SpaceId;
    HandlerObj->AddressSpace.HandlerFlags = Flags;
    HandlerObj->AddressSpace.RegionList = NULL;
    HandlerObj->AddressSpace.Node = Node;
    HandlerObj->AddressSpace.Handler = Handler;
    HandlerObj->AddressSpace.Context = Context;
    HandlerObj->AddressSpace.Setup = Setup;

    /* Install at head of Device.AddressSpace list */

    HandlerObj->AddressSpace.Next = ObjDesc->CommonNotify.Handler;

    /*
     * The Device object is the first reference on the HandlerObj.
     * Each region that uses the handler adds a reference.
     */
    ObjDesc->CommonNotify.Handler = HandlerObj;

    /*
     * Walk the namespace finding all of the regions this handler will
     * manage.
     *
     * Start at the device and search the branch toward the leaf nodes
     * until either the leaf is encountered or a device is detected that
     * has an address handler of the same type.
     *
     * In either case, back up and search down the remainder of the branch
     */
    Status = AcpiNsWalkNamespace (ACPI_TYPE_ANY, Node,
        ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
        AcpiEvInstallHandler, NULL, HandlerObj, NULL);

UnlockAndExit:
    return_ACPI_STATUS (Status);
}