/*******************************************************************************
 *
 * Module Name: utstate - state object support procedures
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2016, 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.
 */

#include "acpi.h"
#include "accommon.h"

#define _COMPONENT          ACPI_UTILITIES
        ACPI_MODULE_NAME    ("utstate")


/*******************************************************************************
 *
 * FUNCTION:    AcpiUtPushGenericState
 *
 * PARAMETERS:  ListHead            - Head of the state stack
 *              State               - State object to push
 *
 * RETURN:      None
 *
 * DESCRIPTION: Push a state object onto a state stack
 *
 ******************************************************************************/

void
AcpiUtPushGenericState (
    ACPI_GENERIC_STATE      **ListHead,
    ACPI_GENERIC_STATE      *State)
{
    ACPI_FUNCTION_ENTRY ();


    /* Push the state object onto the front of the list (stack) */

    State->Common.Next = *ListHead;
    *ListHead = State;
    return;
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiUtPopGenericState
 *
 * PARAMETERS:  ListHead            - Head of the state stack
 *
 * RETURN:      The popped state object
 *
 * DESCRIPTION: Pop a state object from a state stack
 *
 ******************************************************************************/

ACPI_GENERIC_STATE *
AcpiUtPopGenericState (
    ACPI_GENERIC_STATE      **ListHead)
{
    ACPI_GENERIC_STATE      *State;


    ACPI_FUNCTION_ENTRY ();


    /* Remove the state object at the head of the list (stack) */

    State = *ListHead;
    if (State)
    {
        /* Update the list head */

        *ListHead = State->Common.Next;
    }

    return (State);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiUtCreateGenericState
 *
 * PARAMETERS:  None
 *
 * RETURN:      The new state object. NULL on failure.
 *
 * DESCRIPTION: Create a generic state object. Attempt to obtain one from
 *              the global state cache;  If none available, create a new one.
 *
 ******************************************************************************/

ACPI_GENERIC_STATE *
AcpiUtCreateGenericState (
    void)
{
    ACPI_GENERIC_STATE      *State;


    ACPI_FUNCTION_ENTRY ();


    State = AcpiOsAcquireObject (AcpiGbl_StateCache);
    if (State)
    {
        /* Initialize */
        State->Common.DescriptorType = ACPI_DESC_TYPE_STATE;
    }

    return (State);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiUtCreateThreadState
 *
 * PARAMETERS:  None
 *
 * RETURN:      New Thread State. NULL on failure
 *
 * DESCRIPTION: Create a "Thread State" - a flavor of the generic state used
 *              to track per-thread info during method execution
 *
 ******************************************************************************/

ACPI_THREAD_STATE *
AcpiUtCreateThreadState (
    void)
{
    ACPI_GENERIC_STATE      *State;


    ACPI_FUNCTION_ENTRY ();


    /* Create the generic state object */

    State = AcpiUtCreateGenericState ();
    if (!State)
    {
        return (NULL);
    }

    /* Init fields specific to the update struct */

    State->Common.DescriptorType = ACPI_DESC_TYPE_STATE_THREAD;
    State->Thread.ThreadId = AcpiOsGetThreadId ();

    /* Check for invalid thread ID - zero is very bad, it will break things */

    if (!State->Thread.ThreadId)
    {
        ACPI_ERROR ((AE_INFO, "Invalid zero ID from AcpiOsGetThreadId"));
        State->Thread.ThreadId = (ACPI_THREAD_ID) 1;
    }

    return ((ACPI_THREAD_STATE *) State);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiUtCreateUpdateState
 *
 * PARAMETERS:  Object          - Initial Object to be installed in the state
 *              Action          - Update action to be performed
 *
 * RETURN:      New state object, null on failure
 *
 * DESCRIPTION: Create an "Update State" - a flavor of the generic state used
 *              to update reference counts and delete complex objects such
 *              as packages.
 *
 ******************************************************************************/

ACPI_GENERIC_STATE *
AcpiUtCreateUpdateState (
    ACPI_OPERAND_OBJECT     *Object,
    UINT16                  Action)
{
    ACPI_GENERIC_STATE      *State;


    ACPI_FUNCTION_ENTRY ();


    /* Create the generic state object */

    State = AcpiUtCreateGenericState ();
    if (!State)
    {
        return (NULL);
    }

    /* Init fields specific to the update struct */

    State->Common.DescriptorType = ACPI_DESC_TYPE_STATE_UPDATE;
    State->Update.Object = Object;
    State->Update.Value = Action;
    return (State);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiUtCreatePkgState
 *
 * PARAMETERS:  Object          - Initial Object to be installed in the state
 *              Action          - Update action to be performed
 *
 * RETURN:      New state object, null on failure
 *
 * DESCRIPTION: Create a "Package State"
 *
 ******************************************************************************/

ACPI_GENERIC_STATE *
AcpiUtCreatePkgState (
    void                    *InternalObject,
    void                    *ExternalObject,
    UINT16                  Index)
{
    ACPI_GENERIC_STATE      *State;


    ACPI_FUNCTION_ENTRY ();


    /* Create the generic state object */

    State = AcpiUtCreateGenericState ();
    if (!State)
    {
        return (NULL);
    }

    /* Init fields specific to the update struct */

    State->Common.DescriptorType = ACPI_DESC_TYPE_STATE_PACKAGE;
    State->Pkg.SourceObject = (ACPI_OPERAND_OBJECT *) InternalObject;
    State->Pkg.DestObject = ExternalObject;
    State->Pkg.Index= Index;
    State->Pkg.NumPackages = 1;

    return (State);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiUtCreateControlState
 *
 * PARAMETERS:  None
 *
 * RETURN:      New state object, null on failure
 *
 * DESCRIPTION: Create a "Control State" - a flavor of the generic state used
 *              to support nested IF/WHILE constructs in the AML.
 *
 ******************************************************************************/

ACPI_GENERIC_STATE *
AcpiUtCreateControlState (
    void)
{
    ACPI_GENERIC_STATE      *State;


    ACPI_FUNCTION_ENTRY ();


    /* Create the generic state object */

    State = AcpiUtCreateGenericState ();
    if (!State)
    {
        return (NULL);
    }

    /* Init fields specific to the control struct */

    State->Common.DescriptorType = ACPI_DESC_TYPE_STATE_CONTROL;
    State->Common.State = ACPI_CONTROL_CONDITIONAL_EXECUTING;

    return (State);
}


/*******************************************************************************
 *
 * FUNCTION:    AcpiUtDeleteGenericState
 *
 * PARAMETERS:  State               - The state object to be deleted
 *
 * RETURN:      None
 *
 * DESCRIPTION: Release a state object to the state cache. NULL state objects
 *              are ignored.
 *
 ******************************************************************************/

void
AcpiUtDeleteGenericState (
    ACPI_GENERIC_STATE      *State)
{
    ACPI_FUNCTION_ENTRY ();


    /* Ignore null state */

    if (State)
    {
        (void) AcpiOsReleaseObject (AcpiGbl_StateCache, State);
    }

    return;
}