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

 *

 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing

 *

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

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

 *

 * 1. Copyright Notice

 *

 * Some or all of this work - Copyright (c) 1999 - 2011, 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.

 *

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

#define __DSMETHOD_C__

#include "acpi.h"

#include "accommon.h"

#include "acdispat.h"

#include "acinterp.h"

#include "acnamesp.h"

#include "acdisasm.h"

#define _COMPONENT          ACPI_DISPATCHER

        ACPI_MODULE_NAME    ("dsmethod")

/* Local prototypes */

static ACPI_STATUS

AcpiDsCreateMethodMutex (

    ACPI_OPERAND_OBJECT     *MethodDesc);

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

 *

 * FUNCTION:    AcpiDsMethodError

 *

 * PARAMETERS:  Status          - Execution status

 *              WalkState       - Current state

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Called on method error. Invoke the global exception handler if

 *              present, dump the method data if the disassembler is configured

 *

 *              Note: Allows the exception handler to change the status code

 *

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

ACPI_STATUS

AcpiDsMethodError (

    ACPI_STATUS             Status,

    ACPI_WALK_STATE         *WalkState)

{

    ACPI_FUNCTION_ENTRY ();

    /* Ignore AE_OK and control exception codes */

    if (ACPI_SUCCESS (Status) ||

        (Status & AE_CODE_CONTROL))

    {

        return (Status);

    }

    /* Invoke the global exception handler */

    if (AcpiGbl_ExceptionHandler)

    {

        /* Exit the interpreter, allow handler to execute methods */

        AcpiExExitInterpreter ();

        /*

         * Handler can map the exception code to anything it wants, including

         * AE_OK, in which case the executing method will not be aborted.

         */

        Status = AcpiGbl_ExceptionHandler (Status,

                    WalkState->MethodNode ?

                        WalkState->MethodNode->Name.Integer : 0,

                    WalkState->Opcode, WalkState->AmlOffset, NULL);

        AcpiExEnterInterpreter ();

    }

    AcpiDsClearImplicitReturn (WalkState);

#ifdef ACPI_DISASSEMBLER

    if (ACPI_FAILURE (Status))

    {

        /* Display method locals/args if disassembler is present */

        AcpiDmDumpMethodInfo (Status, WalkState, WalkState->Op);

    }

#endif

    return (Status);

}

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

 *

 * FUNCTION:    AcpiDsCreateMethodMutex

 *

 * PARAMETERS:  ObjDesc             - The method object

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Create a mutex object for a serialized control method

 *

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

static ACPI_STATUS

AcpiDsCreateMethodMutex (

    ACPI_OPERAND_OBJECT     *MethodDesc)

{

    ACPI_OPERAND_OBJECT     *MutexDesc;

    ACPI_STATUS             Status;

    ACPI_FUNCTION_TRACE (DsCreateMethodMutex);

    /* Create the new mutex object */

    MutexDesc = AcpiUtCreateInternalObject (ACPI_TYPE_MUTEX);

    if (!MutexDesc)

    {

        return_ACPI_STATUS (AE_NO_MEMORY);

    }

    /* Create the actual OS Mutex */

    Status = AcpiOsCreateMutex (&MutexDesc->Mutex.OsMutex);

    if (ACPI_FAILURE (Status))

    {

        return_ACPI_STATUS (Status);

    }

    MutexDesc->Mutex.SyncLevel = MethodDesc->Method.SyncLevel;

    MethodDesc->Method.Mutex = MutexDesc;

    return_ACPI_STATUS (AE_OK);

}

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

 *

 * FUNCTION:    AcpiDsBeginMethodExecution

 *

 * PARAMETERS:  MethodNode          - Node of the method

 *              ObjDesc             - The method object

 *              WalkState           - current state, NULL if not yet executing

 *                                    a method.

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,

 *              increments the thread count, and waits at the method semaphore

 *              for clearance to execute.

 *

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

ACPI_STATUS

AcpiDsBeginMethodExecution (

    ACPI_NAMESPACE_NODE     *MethodNode,

    ACPI_OPERAND_OBJECT     *ObjDesc,

    ACPI_WALK_STATE         *WalkState)

{

    ACPI_STATUS             Status = AE_OK;

    ACPI_FUNCTION_TRACE_PTR (DsBeginMethodExecution, MethodNode);

    if (!MethodNode)

    {

        return_ACPI_STATUS (AE_NULL_ENTRY);

    }

    /* Prevent wraparound of thread count */

    if (ObjDesc->Method.ThreadCount == ACPI_UINT8_MAX)

    {

        ACPI_ERROR ((AE_INFO,

            "Method reached maximum reentrancy limit (255)"));

        return_ACPI_STATUS (AE_AML_METHOD_LIMIT);

    }

    /*

     * If this method is serialized, we need to acquire the method mutex.

     */

    if (ObjDesc->Method.InfoFlags & ACPI_METHOD_SERIALIZED)

    {

        /*

         * Create a mutex for the method if it is defined to be Serialized

         * and a mutex has not already been created. We defer the mutex creation

         * until a method is actually executed, to minimize the object count

         */

        if (!ObjDesc->Method.Mutex)

        {

            Status = AcpiDsCreateMethodMutex (ObjDesc);

            if (ACPI_FAILURE (Status))

            {

                return_ACPI_STATUS (Status);

            }

        }

        /*

         * The CurrentSyncLevel (per-thread) must be less than or equal to

         * the sync level of the method. This mechanism provides some

         * deadlock prevention

         *

         * Top-level method invocation has no walk state at this point

         */

        if (WalkState &&

            (WalkState->Thread->CurrentSyncLevel > ObjDesc->Method.Mutex->Mutex.SyncLevel))

        {

            ACPI_ERROR ((AE_INFO,

                "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%u)",

                AcpiUtGetNodeName (MethodNode),

                WalkState->Thread->CurrentSyncLevel));

            return_ACPI_STATUS (AE_AML_MUTEX_ORDER);

        }

        /*

         * Obtain the method mutex if necessary. Do not acquire mutex for a

         * recursive call.

         */

        if (!WalkState ||

            !ObjDesc->Method.Mutex->Mutex.ThreadId ||

            (WalkState->Thread->ThreadId != ObjDesc->Method.Mutex->Mutex.ThreadId))

        {

            /*

             * Acquire the method mutex. This releases the interpreter if we

             * block (and reacquires it before it returns)

             */

            Status = AcpiExSystemWaitMutex (ObjDesc->Method.Mutex->Mutex.OsMutex,

                        ACPI_WAIT_FOREVER);

            if (ACPI_FAILURE (Status))

            {

                return_ACPI_STATUS (Status);

            }

            /* Update the mutex and walk info and save the original SyncLevel */

            if (WalkState)

            {

                ObjDesc->Method.Mutex->Mutex.OriginalSyncLevel =

                    WalkState->Thread->CurrentSyncLevel;

                ObjDesc->Method.Mutex->Mutex.ThreadId = WalkState->Thread->ThreadId;

                WalkState->Thread->CurrentSyncLevel = ObjDesc->Method.SyncLevel;

            }

            else

            {

                ObjDesc->Method.Mutex->Mutex.OriginalSyncLevel =

                    ObjDesc->Method.Mutex->Mutex.SyncLevel;

            }

        }

        /* Always increase acquisition depth */

        ObjDesc->Method.Mutex->Mutex.AcquisitionDepth++;

    }

    /*

     * Allocate an Owner ID for this method, only if this is the first thread

     * to begin concurrent execution. We only need one OwnerId, even if the

     * method is invoked recursively.

     */

    if (!ObjDesc->Method.OwnerId)

    {

        Status = AcpiUtAllocateOwnerId (&ObjDesc->Method.OwnerId);

        if (ACPI_FAILURE (Status))

        {

            goto Cleanup;

        }

    }

    /*

     * Increment the method parse tree thread count since it has been

     * reentered one more time (even if it is the same thread)

     */

    ObjDesc->Method.ThreadCount++;

    AcpiMethodCount++;

    return_ACPI_STATUS (Status);

Cleanup:

    /* On error, must release the method mutex (if present) */

    if (ObjDesc->Method.Mutex)

    {

        AcpiOsReleaseMutex (ObjDesc->Method.Mutex->Mutex.OsMutex);

    }

    return_ACPI_STATUS (Status);

}

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

 *

 * FUNCTION:    AcpiDsCallControlMethod

 *

 * PARAMETERS:  Thread              - Info for this thread

 *              ThisWalkState       - Current walk state

 *              Op                  - Current Op to be walked

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Transfer execution to a called control method

 *

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

ACPI_STATUS

AcpiDsCallControlMethod (

    ACPI_THREAD_STATE       *Thread,

    ACPI_WALK_STATE         *ThisWalkState,

    ACPI_PARSE_OBJECT       *Op)

{

    ACPI_STATUS             Status;

    ACPI_NAMESPACE_NODE     *MethodNode;

    ACPI_WALK_STATE         *NextWalkState = NULL;

    ACPI_OPERAND_OBJECT     *ObjDesc;

    ACPI_EVALUATE_INFO      *Info;

    UINT32                  i;

    ACPI_FUNCTION_TRACE_PTR (DsCallControlMethod, ThisWalkState);

    ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Calling method %p, currentstate=%p\n",

        ThisWalkState->PrevOp, ThisWalkState));

    /*

     * Get the namespace entry for the control method we are about to call

     */

    MethodNode = ThisWalkState->MethodCallNode;

    if (!MethodNode)

    {

        return_ACPI_STATUS (AE_NULL_ENTRY);

    }

    ObjDesc = AcpiNsGetAttachedObject (MethodNode);

    if (!ObjDesc)

    {

        return_ACPI_STATUS (AE_NULL_OBJECT);

    }

    /* Init for new method, possibly wait on method mutex */

    Status = AcpiDsBeginMethodExecution (MethodNode, ObjDesc,

                ThisWalkState);

    if (ACPI_FAILURE (Status))

    {

        return_ACPI_STATUS (Status);

    }

    /* Begin method parse/execution. Create a new walk state */

    NextWalkState = AcpiDsCreateWalkState (ObjDesc->Method.OwnerId,

                        NULL, ObjDesc, Thread);

    if (!NextWalkState)

    {

        Status = AE_NO_MEMORY;

        goto Cleanup;

    }

    /*

     * The resolved arguments were put on the previous walk state's operand

     * stack. Operands on the previous walk state stack always

     * start at index 0. Also, null terminate the list of arguments

     */

    ThisWalkState->Operands [ThisWalkState->NumOperands] = NULL;

    /*

     * Allocate and initialize the evaluation information block

     * TBD: this is somewhat inefficient, should change interface to

     * DsInitAmlWalk. For now, keeps this struct off the CPU stack

     */

    Info = ACPI_ALLOCATE_ZEROED (sizeof (ACPI_EVALUATE_INFO));

    if (!Info)

    {

        return_ACPI_STATUS (AE_NO_MEMORY);

    }

    Info->Parameters = &ThisWalkState->Operands[0];

    Status = AcpiDsInitAmlWalk (NextWalkState, NULL, MethodNode,

                ObjDesc->Method.AmlStart, ObjDesc->Method.AmlLength,

                Info, ACPI_IMODE_EXECUTE);

    ACPI_FREE (Info);

    if (ACPI_FAILURE (Status))

    {

        goto Cleanup;

    }

    /*

     * Delete the operands on the previous walkstate operand stack

     * (they were copied to new objects)

     */

    for (i = 0; i < ObjDesc->Method.ParamCount; i++)

    {

        AcpiUtRemoveReference (ThisWalkState->Operands [i]);

        ThisWalkState->Operands [i] = NULL;

    }

    /* Clear the operand stack */

    ThisWalkState->NumOperands = 0;

    ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,

        "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",

        MethodNode->Name.Ascii, NextWalkState));

    /* Invoke an internal method if necessary */

    if (ObjDesc->Method.InfoFlags & ACPI_METHOD_INTERNAL_ONLY)

    {

        Status = ObjDesc->Method.Dispatch.Implementation (NextWalkState);

        if (Status == AE_OK)

        {

            Status = AE_CTRL_TERMINATE;

        }

    }

    return_ACPI_STATUS (Status);

Cleanup:

    /* On error, we must terminate the method properly */

    AcpiDsTerminateControlMethod (ObjDesc, NextWalkState);

    if (NextWalkState)

    {

        AcpiDsDeleteWalkState (NextWalkState);

    }

    return_ACPI_STATUS (Status);

}

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

 *

 * FUNCTION:    AcpiDsRestartControlMethod

 *

 * PARAMETERS:  WalkState           - State for preempted method (caller)

 *              ReturnDesc          - Return value from the called method

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Restart a method that was preempted by another (nested) method

 *              invocation.  Handle the return value (if any) from the callee.

 *

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

ACPI_STATUS

AcpiDsRestartControlMethod (

    ACPI_WALK_STATE         *WalkState,

    ACPI_OPERAND_OBJECT     *ReturnDesc)

{

    ACPI_STATUS             Status;

    int                     SameAsImplicitReturn;

    ACPI_FUNCTION_TRACE_PTR (DsRestartControlMethod, WalkState);

    ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,

        "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",

        AcpiUtGetNodeName (WalkState->MethodNode),

        WalkState->MethodCallOp, ReturnDesc));

    ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,

        "    ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",

        WalkState->ReturnUsed,

        WalkState->Results, WalkState));

    /* Did the called method return a value? */

    if (ReturnDesc)

    {

        /* Is the implicit return object the same as the return desc? */

        SameAsImplicitReturn = (WalkState->ImplicitReturnObj == ReturnDesc);

        /* Are we actually going to use the return value? */

        if (WalkState->ReturnUsed)

        {

            /* Save the return value from the previous method */

            Status = AcpiDsResultPush (ReturnDesc, WalkState);

            if (ACPI_FAILURE (Status))

            {

                AcpiUtRemoveReference (ReturnDesc);

                return_ACPI_STATUS (Status);

            }

            /*

             * Save as THIS method's return value in case it is returned

             * immediately to yet another method

             */

            WalkState->ReturnDesc = ReturnDesc;

        }

        /*

         * The following code is the optional support for the so-called

         * "implicit return". Some AML code assumes that the last value of the

         * method is "implicitly" returned to the caller, in the absence of an

         * explicit return value.

         *

         * Just save the last result of the method as the return value.

         *

         * NOTE: this is optional because the ASL language does not actually

         * support this behavior.

         */

        else if (!AcpiDsDoImplicitReturn (ReturnDesc, WalkState, FALSE) ||

                 SameAsImplicitReturn)

        {

            /*

             * Delete the return value if it will not be used by the

             * calling method or remove one reference if the explicit return

             * is the same as the implicit return value.

             */

            AcpiUtRemoveReference (ReturnDesc);

        }

    }

    return_ACPI_STATUS (AE_OK);

}

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

 *

 * FUNCTION:    AcpiDsTerminateControlMethod

 *

 * PARAMETERS:  MethodDesc          - Method object

 *              WalkState           - State associated with the method

 *

 * RETURN:      None

 *

 * DESCRIPTION: Terminate a control method.  Delete everything that the method

 *              created, delete all locals and arguments, and delete the parse

 *              tree if requested.

 *

 * MUTEX:       Interpreter is locked

 *

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

void

AcpiDsTerminateControlMethod (

    ACPI_OPERAND_OBJECT     *MethodDesc,

    ACPI_WALK_STATE         *WalkState)

{

    ACPI_FUNCTION_TRACE_PTR (DsTerminateControlMethod, WalkState);

    /* MethodDesc is required, WalkState is optional */

    if (!MethodDesc)

    {

        return_VOID;

    }

    if (WalkState)

    {

        /* Delete all arguments and locals */

        AcpiDsMethodDataDeleteAll (WalkState);

        /*

         * If method is serialized, release the mutex and restore the

         * current sync level for this thread

         */

        if (MethodDesc->Method.Mutex)

        {

            /* Acquisition Depth handles recursive calls */

            MethodDesc->Method.Mutex->Mutex.AcquisitionDepth--;

            if (!MethodDesc->Method.Mutex->Mutex.AcquisitionDepth)

            {

                WalkState->Thread->CurrentSyncLevel =

                    MethodDesc->Method.Mutex->Mutex.OriginalSyncLevel;

                AcpiOsReleaseMutex (MethodDesc->Method.Mutex->Mutex.OsMutex);

                MethodDesc->Method.Mutex->Mutex.ThreadId = 0;

            }

        }

        /*

         * Delete any namespace objects created anywhere within the

         * namespace by the execution of this method. Unless:

         * 1) This method is a module-level executable code method, in which

         *    case we want make the objects permanent.

         * 2) There are other threads executing the method, in which case we

         *    will wait until the last thread has completed.

         */

        if (!(MethodDesc->Method.InfoFlags & ACPI_METHOD_MODULE_LEVEL) &&

             (MethodDesc->Method.ThreadCount == 1))

        {

            /* Delete any direct children of (created by) this method */

            AcpiNsDeleteNamespaceSubtree (WalkState->MethodNode);

            /*

             * Delete any objects that were created by this method

             * elsewhere in the namespace (if any were created).

             * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the

             * deletion such that we don't have to perform an entire

             * namespace walk for every control method execution.

             */

            if (MethodDesc->Method.InfoFlags & ACPI_METHOD_MODIFIED_NAMESPACE)

            {

                AcpiNsDeleteNamespaceByOwner (MethodDesc->Method.OwnerId);

                MethodDesc->Method.InfoFlags &= ~ACPI_METHOD_MODIFIED_NAMESPACE;

            }

        }

    }

    /* Decrement the thread count on the method */

    if (MethodDesc->Method.ThreadCount)

    {

        MethodDesc->Method.ThreadCount--;

    }

    else

    {

        ACPI_ERROR ((AE_INFO,

            "Invalid zero thread count in method"));

    }

    /* Are there any other threads currently executing this method? */

    if (MethodDesc->Method.ThreadCount)

    {

        /*

         * Additional threads. Do not release the OwnerId in this case,

         * we immediately reuse it for the next thread executing this method

         */

        ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,

            "*** Completed execution of one thread, %u threads remaining\n",

            MethodDesc->Method.ThreadCount));

    }

    else

    {

        /* This is the only executing thread for this method */

        /*

         * Support to dynamically change a method from NotSerialized to

         * Serialized if it appears that the method is incorrectly written and

         * does not support multiple thread execution. The best example of this

         * is if such a method creates namespace objects and blocks. A second

         * thread will fail with an AE_ALREADY_EXISTS exception.

         *

         * This code is here because we must wait until the last thread exits

         * before marking the method as serialized.

         */

        if (MethodDesc->Method.InfoFlags & ACPI_METHOD_SERIALIZED_PENDING)

        {

            if (WalkState)

            {

                ACPI_INFO ((AE_INFO,

                    "Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",

                    WalkState->MethodNode->Name.Ascii));

            }

            /*

             * Method tried to create an object twice and was marked as

             * "pending serialized". The probable cause is that the method

             * cannot handle reentrancy.

             *

             * The method was created as NotSerialized, but it tried to create

             * a named object and then blocked, causing the second thread

             * entrance to begin and then fail. Workaround this problem by

             * marking the method permanently as Serialized when the last

             * thread exits here.

             */

            MethodDesc->Method.InfoFlags &= ~ACPI_METHOD_SERIALIZED_PENDING;

            MethodDesc->Method.InfoFlags |= ACPI_METHOD_SERIALIZED;

            MethodDesc->Method.SyncLevel = 0;

        }

        /* No more threads, we can free the OwnerId */

        if (!(MethodDesc->Method.InfoFlags & ACPI_METHOD_MODULE_LEVEL))

        {

            AcpiUtReleaseOwnerId (&MethodDesc->Method.OwnerId);

        }

    }

    return_VOID;

}