acpica/namespace/nseval.c

/*******************************************************************************
 *
 * Module Name: nseval - Object evaluation, includes control method execution
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2011, 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 MERCHANTIBILITY 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.
 */

#define __NSEVAL_C__

#include "acpi.h"
#include "accommon.h"
#include "acparser.h"
#include "acinterp.h"
#include "acnamesp.h"


#define _COMPONENT          ACPI_NAMESPACE
        ACPI_MODULE_NAME    ("nseval")

/* Local prototypes */

static void
AcpiNsExecModuleCode (
    ACPI_OPERAND_OBJECT     *MethodObj,
    ACPI_EVALUATE_INFO      *Info);


/*******************************************************************************
 *
 * FUNCTION:    AcpiNsEvaluate
 *
 * PARAMETERS:  Info            - Evaluation info block, contains:
 *                  PrefixNode      - Prefix or Method/Object Node to execute
 *                  Pathname        - Name of method to execute, If NULL, the
 *                                    Node is the object to execute
 *                  Parameters      - List of parameters to pass to the method,
 *                                    terminated by NULL. Params itself may be
 *                                    NULL if no parameters are being passed.
 *                  ReturnObject    - Where to put method's return value (if
 *                                    any). If NULL, no value is returned.
 *                  ParameterType   - Type of Parameter list
 *                  ReturnObject    - Where to put method's return value (if
 *                                    any). If NULL, no value is returned.
 *                  Flags           - ACPI_IGNORE_RETURN_VALUE to delete return
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute a control method or return the current value of an
 *              ACPI namespace object.
 *
 * MUTEX:       Locks interpreter
 *
 ******************************************************************************/

ACPI_STATUS
AcpiNsEvaluate (
    ACPI_EVALUATE_INFO      *Info)
{
    ACPI_STATUS             Status;
    ACPI_NAMESPACE_NODE     *Node;


    ACPI_FUNCTION_TRACE (NsEvaluate);


    if (!Info)
    {
        return_ACPI_STATUS (AE_BAD_PARAMETER);
    }

    /* Initialize the return value to an invalid object */

    Info->ReturnObject = NULL;
    Info->ParamCount = 0;

    /*
     * Get the actual namespace node for the target object. Handles these cases:
     *
     * 1) Null node, Pathname (absolute path)
     * 2) Node, Pathname (path relative to Node)
     * 3) Node, Null Pathname
     */
    Status = AcpiNsGetNode (Info->PrefixNode, Info->Pathname,
                ACPI_NS_NO_UPSEARCH, &Info->ResolvedNode);
    if (ACPI_FAILURE (Status))
    {
        return_ACPI_STATUS (Status);
    }

    /*
     * For a method alias, we must grab the actual method node so that proper
     * scoping context will be established before execution.
     */
    if (AcpiNsGetType (Info->ResolvedNode) == ACPI_TYPE_LOCAL_METHOD_ALIAS)
    {
        Info->ResolvedNode =
            ACPI_CAST_PTR (ACPI_NAMESPACE_NODE, Info->ResolvedNode->Object);
    }

    ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "%s [%p] Value %p\n", Info->Pathname,
        Info->ResolvedNode, AcpiNsGetAttachedObject (Info->ResolvedNode)));

    Node = Info->ResolvedNode;

    /*
     * Two major cases here:
     *
     * 1) The object is a control method -- execute it
     * 2) The object is not a method -- just return it's current value
     */
    if (AcpiNsGetType (Info->ResolvedNode) == ACPI_TYPE_METHOD)
    {
        /*
         * 1) Object is a control method - execute it
         */

        /* Verify that there is a method object associated with this node */

        Info->ObjDesc = AcpiNsGetAttachedObject (Info->ResolvedNode);
        if (!Info->ObjDesc)
        {
            ACPI_ERROR ((AE_INFO, "Control method has no attached sub-object"));
            return_ACPI_STATUS (AE_NULL_OBJECT);
        }

        /* Count the number of arguments being passed to the method */

        if (Info->Parameters)
        {
            while (Info->Parameters[Info->ParamCount])
            {
                if (Info->ParamCount > ACPI_METHOD_MAX_ARG)
                {
                    return_ACPI_STATUS (AE_LIMIT);
                }
                Info->ParamCount++;
            }
        }

        ACPI_DUMP_PATHNAME (Info->ResolvedNode, "ACPI: Execute Method",
            ACPI_LV_INFO, _COMPONENT);

        ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
            "Method at AML address %p Length %X\n",
            Info->ObjDesc->Method.AmlStart + 1,
            Info->ObjDesc->Method.AmlLength - 1));

        /*
         * Any namespace deletion must acquire both the namespace and
         * interpreter locks to ensure that no thread is using the portion of
         * the namespace that is being deleted.
         *
         * Execute the method via the interpreter. The interpreter is locked
         * here before calling into the AML parser
         */
        AcpiExEnterInterpreter ();
        Status = AcpiPsExecuteMethod (Info);
        AcpiExExitInterpreter ();
    }
    else
    {
        /*
         * 2) Object is not a method, return its current value
         *
         * Disallow certain object types. For these, "evaluation" is undefined.
         */
        switch (Info->ResolvedNode->Type)
        {
        case ACPI_TYPE_DEVICE:
        case ACPI_TYPE_EVENT:
        case ACPI_TYPE_MUTEX:
        case ACPI_TYPE_REGION:
        case ACPI_TYPE_THERMAL:
        case ACPI_TYPE_LOCAL_SCOPE:

            ACPI_ERROR ((AE_INFO,
                "[%4.4s] Evaluation of object type [%s] is not supported",
                Info->ResolvedNode->Name.Ascii,
                AcpiUtGetTypeName (Info->ResolvedNode->Type)));

            return_ACPI_STATUS (AE_TYPE);

        default:
            break;
        }

        /*
         * Objects require additional resolution steps (e.g., the Node may be
         * a field that must be read, etc.) -- we can't just grab the object
         * out of the node.
         *
         * Use ResolveNodeToValue() to get the associated value.
         *
         * NOTE: we can get away with passing in NULL for a walk state because
         * ResolvedNode is guaranteed to not be a reference to either a method
         * local or a method argument (because this interface is never called
         * from a running method.)
         *
         * Even though we do not directly invoke the interpreter for object
         * resolution, we must lock it because we could access an opregion.
         * The opregion access code assumes that the interpreter is locked.
         */
        AcpiExEnterInterpreter ();

        /* Function has a strange interface */

        Status = AcpiExResolveNodeToValue (&Info->ResolvedNode, NULL);
        AcpiExExitInterpreter ();

        /*
         * If AcpiExResolveNodeToValue() succeeded, the return value was placed
         * in ResolvedNode.
         */
        if (ACPI_SUCCESS (Status))
        {
            Status = AE_CTRL_RETURN_VALUE;
            Info->ReturnObject =
                ACPI_CAST_PTR (ACPI_OPERAND_OBJECT, Info->ResolvedNode);

            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "Returning object %p [%s]\n",
                Info->ReturnObject,
                AcpiUtGetObjectTypeName (Info->ReturnObject)));
        }
    }

    /*
     * Check input argument count against the ASL-defined count for a method.
     * Also check predefined names: argument count and return value against
     * the ACPI specification. Some incorrect return value types are repaired.
     */
    (void) AcpiNsCheckPredefinedNames (Node, Info->ParamCount,
                Status, &Info->ReturnObject);

    /* Check if there is a return value that must be dealt with */

    if (Status == AE_CTRL_RETURN_VALUE)
    {
        /* If caller does not want the return value, delete it */

        if (Info->Flags & ACPI_IGNORE_RETURN_VALUE)
        {
            AcpiUtRemoveReference (Info->ReturnObject);
            Info->ReturnObject = NULL;
        }

        /* Map AE_CTRL_RETURN_VALUE to AE_OK, we are done with it */

        Status = AE_OK;
    }

    ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
        "*** Completed evaluation of object %s ***\n", Info->Pathname));

    /*
     * Namespace was unlocked by the handling AcpiNs* function, so we
     * just return
     */
    return_ACPI_STATUS (Status);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiNsExecModuleCodeList
 *
 * PARAMETERS:  None
 *
 * RETURN:      None. Exceptions during method execution are ignored, since
 *              we cannot abort a table load.
 *
 * DESCRIPTION: Execute all elements of the global module-level code list.
 *              Each element is executed as a single control method.
 *
 ******************************************************************************/

void
AcpiNsExecModuleCodeList (
    void)
{
    ACPI_OPERAND_OBJECT     *Prev;
    ACPI_OPERAND_OBJECT     *Next;
    ACPI_EVALUATE_INFO      *Info;
    UINT32                  MethodCount = 0;


    ACPI_FUNCTION_TRACE (NsExecModuleCodeList);


    /* Exit now if the list is empty */

    Next = AcpiGbl_ModuleCodeList;
    if (!Next)
    {
        return_VOID;
    }

    /* Allocate the evaluation information block */

    Info = ACPI_ALLOCATE (sizeof (ACPI_EVALUATE_INFO));
    if (!Info)
    {
        return_VOID;
    }

    /* Walk the list, executing each "method" */

    while (Next)
    {
        Prev = Next;
        Next = Next->Method.Mutex;

        /* Clear the link field and execute the method */

        Prev->Method.Mutex = NULL;
        AcpiNsExecModuleCode (Prev, Info);
        MethodCount++;

        /* Delete the (temporary) method object */

        AcpiUtRemoveReference (Prev);
    }

    ACPI_INFO ((AE_INFO,
        "Executed %u blocks of module-level executable AML code",
        MethodCount));

    ACPI_FREE (Info);
    AcpiGbl_ModuleCodeList = NULL;
    return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiNsExecModuleCode
 *
 * PARAMETERS:  MethodObj           - Object container for the module-level code
 *              Info                - Info block for method evaluation
 *
 * RETURN:      None. Exceptions during method execution are ignored, since
 *              we cannot abort a table load.
 *
 * DESCRIPTION: Execute a control method containing a block of module-level
 *              executable AML code. The control method is temporarily
 *              installed to the root node, then evaluated.
 *
 ******************************************************************************/

static void
AcpiNsExecModuleCode (
    ACPI_OPERAND_OBJECT     *MethodObj,
    ACPI_EVALUATE_INFO      *Info)
{
    ACPI_OPERAND_OBJECT     *ParentObj;
    ACPI_NAMESPACE_NODE     *ParentNode;
    ACPI_OBJECT_TYPE        Type;
    ACPI_STATUS             Status;


    ACPI_FUNCTION_TRACE (NsExecModuleCode);


    /*
     * Get the parent node. We cheat by using the NextObject field
     * of the method object descriptor.
     */
    ParentNode = ACPI_CAST_PTR (ACPI_NAMESPACE_NODE,
                    MethodObj->Method.NextObject);
    Type = AcpiNsGetType (ParentNode);

    /*
     * Get the region handler and save it in the method object. We may need
     * this if an operation region declaration causes a _REG method to be run.
     *
     * We can't do this in AcpiPsLinkModuleCode because
     * AcpiGbl_RootNode->Object is NULL at PASS1.
     */
    if ((Type == ACPI_TYPE_DEVICE) && ParentNode->Object)
    {
        MethodObj->Method.Dispatch.Handler =
            ParentNode->Object->Device.Handler;
    }

    /* Must clear NextObject (AcpiNsAttachObject needs the field) */

    MethodObj->Method.NextObject = NULL;

    /* Initialize the evaluation information block */

    ACPI_MEMSET (Info, 0, sizeof (ACPI_EVALUATE_INFO));
    Info->PrefixNode = ParentNode;

    /*
     * Get the currently attached parent object. Add a reference, because the
     * ref count will be decreased when the method object is installed to
     * the parent node.
     */
    ParentObj = AcpiNsGetAttachedObject (ParentNode);
    if (ParentObj)
    {
        AcpiUtAddReference (ParentObj);
    }

    /* Install the method (module-level code) in the parent node */

    Status = AcpiNsAttachObject (ParentNode, MethodObj,
                ACPI_TYPE_METHOD);
    if (ACPI_FAILURE (Status))
    {
        goto Exit;
    }

    /* Execute the parent node as a control method */

    Status = AcpiNsEvaluate (Info);

    ACPI_DEBUG_PRINT ((ACPI_DB_INIT, "Executed module-level code at %p\n",
        MethodObj->Method.AmlStart));

    /* Delete a possible implicit return value (in slack mode) */

    if (Info->ReturnObject)
    {
        AcpiUtRemoveReference (Info->ReturnObject);
    }

    /* Detach the temporary method object */

    AcpiNsDetachObject (ParentNode);

    /* Restore the original parent object */

    if (ParentObj)
    {
        Status = AcpiNsAttachObject (ParentNode, ParentObj, Type);
    }
    else
    {
        ParentNode->Type = (UINT8) Type;
    }

Exit:
    if (ParentObj)
    {
        AcpiUtRemoveReference (ParentObj);
    }
    return_VOID;
}