/*******************************************************************************
 *
 * 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/acpi.h>
#include "accommon.h"

#define _COMPONENT          ACPI_UTILITIES
ACPI_MODULE_NAME("utstate")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_push_generic_state
 *
 * PARAMETERS:  list_head           - Head of the state stack
 *              state               - State object to push
 *
 * RETURN:      None
 *
 * DESCRIPTION: Push a state object onto a state stack
 *
 ******************************************************************************/
void
acpi_ut_push_generic_state(union acpi_generic_state **list_head,
                           union acpi_generic_state *state)
{
        ACPI_FUNCTION_ENTRY();

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

        state->common.next = *list_head;
        *list_head = state;
        return;
}

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

union acpi_generic_state *acpi_ut_pop_generic_state(union acpi_generic_state
                                                    **list_head)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_ENTRY();

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

        state = *list_head;
        if (state) {

                /* Update the list head */

                *list_head = state->common.next;
        }

        return (state);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_generic_state
 *
 * 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.
 *
 ******************************************************************************/

union acpi_generic_state *acpi_ut_create_generic_state(void)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_ENTRY();

        state = acpi_os_acquire_object(acpi_gbl_state_cache);
        if (state) {

                /* Initialize */
                state->common.descriptor_type = ACPI_DESC_TYPE_STATE;
        }

        return (state);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_thread_state
 *
 * 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
 *
 ******************************************************************************/

struct acpi_thread_state *acpi_ut_create_thread_state(void)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_ENTRY();

        /* Create the generic state object */

        state = acpi_ut_create_generic_state();
        if (!state) {
                return (NULL);
        }

        /* Init fields specific to the update struct */

        state->common.descriptor_type = ACPI_DESC_TYPE_STATE_THREAD;
        state->thread.thread_id = acpi_os_get_thread_id();

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

        if (!state->thread.thread_id) {
                ACPI_ERROR((AE_INFO, "Invalid zero ID from AcpiOsGetThreadId"));
                state->thread.thread_id = (acpi_thread_id) 1;
        }

        return ((struct acpi_thread_state *)state);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_update_state
 *
 * 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.
 *
 ******************************************************************************/

union acpi_generic_state *acpi_ut_create_update_state(union acpi_operand_object
                                                      *object, u16 action)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_ENTRY();

        /* Create the generic state object */

        state = acpi_ut_create_generic_state();
        if (!state) {
                return (NULL);
        }

        /* Init fields specific to the update struct */

        state->common.descriptor_type = ACPI_DESC_TYPE_STATE_UPDATE;
        state->update.object = object;
        state->update.value = action;
        return (state);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_pkg_state
 *
 * 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"
 *
 ******************************************************************************/

union acpi_generic_state *acpi_ut_create_pkg_state(void *internal_object,
                                                   void *external_object,
                                                   u16 index)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_ENTRY();

        /* Create the generic state object */

        state = acpi_ut_create_generic_state();
        if (!state) {
                return (NULL);
        }

        /* Init fields specific to the update struct */

        state->common.descriptor_type = ACPI_DESC_TYPE_STATE_PACKAGE;
        state->pkg.source_object = (union acpi_operand_object *)internal_object;
        state->pkg.dest_object = external_object;
        state->pkg.index = index;
        state->pkg.num_packages = 1;

        return (state);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_create_control_state
 *
 * 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.
 *
 ******************************************************************************/

union acpi_generic_state *acpi_ut_create_control_state(void)
{
        union acpi_generic_state *state;

        ACPI_FUNCTION_ENTRY();

        /* Create the generic state object */

        state = acpi_ut_create_generic_state();
        if (!state) {
                return (NULL);
        }

        /* Init fields specific to the control struct */

        state->common.descriptor_type = ACPI_DESC_TYPE_STATE_CONTROL;
        state->common.state = ACPI_CONTROL_CONDITIONAL_EXECUTING;

        return (state);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_delete_generic_state
 *
 * 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 acpi_ut_delete_generic_state(union acpi_generic_state *state)
{
        ACPI_FUNCTION_ENTRY();

        /* Ignore null state */

        if (state) {
                (void)acpi_os_release_object(acpi_gbl_state_cache, state);
        }

        return;
}