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

 *

 * Module Name: exmutex - ASL Mutex Acquire/Release functions

 *

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

/*

 * Copyright (C) 2000 - 2004, R. Byron Moore

 * 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 <acpi/acinterp.h>

#define _COMPONENT          ACPI_EXECUTER

         ACPI_MODULE_NAME    ("exmutex")

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

 *

 * FUNCTION:    acpi_ex_unlink_mutex

 *

 * PARAMETERS:  *obj_desc           - The mutex to be unlinked

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Remove a mutex from the "acquired_mutex" list

 *

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

void

acpi_ex_unlink_mutex (

        union acpi_operand_object       *obj_desc)

{

        struct acpi_thread_state        *thread = obj_desc->mutex.owner_thread;

        if (!thread) {

                return;

        }

        if (obj_desc->mutex.next) {

                (obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;

        }

        if (obj_desc->mutex.prev) {

                (obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;

        }

        else {

                thread->acquired_mutex_list = obj_desc->mutex.next;

        }

}

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

 *

 * FUNCTION:    acpi_ex_link_mutex

 *

 * PARAMETERS:  *obj_desc           - The mutex to be linked

 *              *list_head          - head of the "acquired_mutex" list

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Add a mutex to the "acquired_mutex" list for this walk

 *

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

void

acpi_ex_link_mutex (

        union acpi_operand_object       *obj_desc,

        struct acpi_thread_state        *thread)

{

        union acpi_operand_object       *list_head;

        list_head = thread->acquired_mutex_list;

        /* This object will be the first object in the list */

        obj_desc->mutex.prev = NULL;

        obj_desc->mutex.next = list_head;

        /* Update old first object to point back to this object */

        if (list_head) {

                list_head->mutex.prev = obj_desc;

        }

        /* Update list head */

        thread->acquired_mutex_list = obj_desc;

}

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

 *

 * FUNCTION:    acpi_ex_acquire_mutex

 *

 * PARAMETERS:  *time_desc          - The 'time to delay' object descriptor

 *              *obj_desc           - The object descriptor for this op

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Acquire an AML mutex

 *

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

acpi_status

acpi_ex_acquire_mutex (

        union acpi_operand_object       *time_desc,

        union acpi_operand_object       *obj_desc,

        struct acpi_walk_state          *walk_state)

{

        acpi_status                     status;

        ACPI_FUNCTION_TRACE_PTR ("ex_acquire_mutex", obj_desc);

        if (!obj_desc) {

                return_ACPI_STATUS (AE_BAD_PARAMETER);

        }

        /* Sanity check -- we must have a valid thread ID */

        if (!walk_state->thread) {

                ACPI_REPORT_ERROR (("Cannot acquire Mutex [%4.4s], null thread info\n",

                                acpi_ut_get_node_name (obj_desc->mutex.node)));

                return_ACPI_STATUS (AE_AML_INTERNAL);

        }

        /*

         * Current Sync must be less than or equal to the sync level of the

         * mutex.  This mechanism provides some deadlock prevention

         */

        if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {

                ACPI_REPORT_ERROR (("Cannot acquire Mutex [%4.4s], incorrect sync_level\n",

                                acpi_ut_get_node_name (obj_desc->mutex.node)));

                return_ACPI_STATUS (AE_AML_MUTEX_ORDER);

        }

        /*

         * Support for multiple acquires by the owning thread

         */

        if (obj_desc->mutex.owner_thread) {

                /* Special case for Global Lock, allow all threads */

                if ((obj_desc->mutex.owner_thread->thread_id == walk_state->thread->thread_id) ||

                        (obj_desc->mutex.semaphore == acpi_gbl_global_lock_semaphore)) {

                        /*

                         * The mutex is already owned by this thread,

                         * just increment the acquisition depth

                         */

                        obj_desc->mutex.acquisition_depth++;

                        return_ACPI_STATUS (AE_OK);

                }

        }

        /* Acquire the mutex, wait if necessary */

        status = acpi_ex_system_acquire_mutex (time_desc, obj_desc);

        if (ACPI_FAILURE (status)) {

                /* Includes failure from a timeout on time_desc */

                return_ACPI_STATUS (status);

        }

        /* Have the mutex, update mutex and walk info */

        obj_desc->mutex.owner_thread    = walk_state->thread;

        obj_desc->mutex.acquisition_depth = 1;

        walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;

        /* Link the mutex to the current thread for force-unlock at method exit */

        acpi_ex_link_mutex (obj_desc, walk_state->thread);

        return_ACPI_STATUS (AE_OK);

}

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

 *

 * FUNCTION:    acpi_ex_release_mutex

 *

 * PARAMETERS:  *obj_desc           - The object descriptor for this op

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Release a previously acquired Mutex.

 *

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

acpi_status

acpi_ex_release_mutex (

        union acpi_operand_object       *obj_desc,

        struct acpi_walk_state          *walk_state)

{

        acpi_status                     status;

        ACPI_FUNCTION_TRACE ("ex_release_mutex");

        if (!obj_desc) {

                return_ACPI_STATUS (AE_BAD_PARAMETER);

        }

        /* The mutex must have been previously acquired in order to release it */

        if (!obj_desc->mutex.owner_thread) {

                ACPI_REPORT_ERROR (("Cannot release Mutex [%4.4s], not acquired\n",

                                acpi_ut_get_node_name (obj_desc->mutex.node)));

                return_ACPI_STATUS (AE_AML_MUTEX_NOT_ACQUIRED);

        }

        /* Sanity check -- we must have a valid thread ID */

        if (!walk_state->thread) {

                ACPI_REPORT_ERROR (("Cannot release Mutex [%4.4s], null thread info\n",

                                acpi_ut_get_node_name (obj_desc->mutex.node)));

                return_ACPI_STATUS (AE_AML_INTERNAL);

        }

        /*

         * The Mutex is owned, but this thread must be the owner.

         * Special case for Global Lock, any thread can release

         */

        if ((obj_desc->mutex.owner_thread->thread_id != walk_state->thread->thread_id) &&

                (obj_desc->mutex.semaphore != acpi_gbl_global_lock_semaphore)) {

                ACPI_REPORT_ERROR ((

                        "Thread %X cannot release Mutex [%4.4s] acquired by thread %X\n",

                        walk_state->thread->thread_id,

                        acpi_ut_get_node_name (obj_desc->mutex.node),

                        obj_desc->mutex.owner_thread->thread_id));

                return_ACPI_STATUS (AE_AML_NOT_OWNER);

        }

        /*

         * The sync level of the mutex must be less than or

         * equal to the current sync level

         */

        if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {

                ACPI_REPORT_ERROR (("Cannot release Mutex [%4.4s], incorrect sync_level\n",

                                acpi_ut_get_node_name (obj_desc->mutex.node)));

                return_ACPI_STATUS (AE_AML_MUTEX_ORDER);

        }

        /*

         * Match multiple Acquires with multiple Releases

         */

        obj_desc->mutex.acquisition_depth--;

        if (obj_desc->mutex.acquisition_depth != 0) {

                /* Just decrement the depth and return */

                return_ACPI_STATUS (AE_OK);

        }

        /* Unlink the mutex from the owner's list */

        acpi_ex_unlink_mutex (obj_desc);

        /* Release the mutex */

        status = acpi_ex_system_release_mutex (obj_desc);

        /* Update the mutex and walk state */

        obj_desc->mutex.owner_thread = NULL;

        walk_state->thread->current_sync_level = obj_desc->mutex.sync_level;

        return_ACPI_STATUS (status);

}

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

 *

 * FUNCTION:    acpi_ex_release_all_mutexes

 *

 * PARAMETERS:  *mutex_list           - Head of the mutex list

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Release all mutexes in the list

 *

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

void

acpi_ex_release_all_mutexes (

        struct acpi_thread_state        *thread)

{

        union acpi_operand_object       *next = thread->acquired_mutex_list;

        union acpi_operand_object       *this;

        acpi_status                     status;

        ACPI_FUNCTION_ENTRY ();

        /*

         * Traverse the list of owned mutexes, releasing each one.

         */

        while (next) {

                this = next;

                next = this->mutex.next;

                this->mutex.acquisition_depth = 1;

                this->mutex.prev             = NULL;

                this->mutex.next             = NULL;

                 /* Release the mutex */

                status = acpi_ex_system_release_mutex (this);

                if (ACPI_FAILURE (status)) {

                        continue;

                }

                /* Mark mutex unowned */

                this->mutex.owner_thread     = NULL;

        }

}