dsmethod.c

acpi tools for linux include acpiexec and acpixtract

/******************************************************************************
 *
 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
 *              $Revision: 1.140 $
 *
 *****************************************************************************/

/******************************************************************************
 *
 * 1. Copyright Notice
 *
 * Some or all of this work - Copyright (c) 1999 - 2008, 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 "amlcode.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.MethodFlags & AML_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 (%d)",
                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);