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

 *

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

 *

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

/*

 * Copyright (C) 2000 - 2007, 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>

#include <acpi/acevents.h>

#define _COMPONENT          ACPI_EXECUTER

ACPI_MODULE_NAME("exmutex")

/* Local prototypes */

static void

acpi_ex_link_mutex(union acpi_operand_object *obj_desc,

                   struct acpi_thread_state *thread);

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

 *

 * FUNCTION:    acpi_ex_unlink_mutex

 *

 * PARAMETERS:  obj_desc            - The mutex to be unlinked

 *

 * RETURN:      None

 *

 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" 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;

        }

        /* Doubly linked list */

        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

 *              Thread          - Current executing thread object

 *

 * RETURN:      None

 *

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

 *

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

static 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           - Timeout integer

 *              obj_desc            - Mutex object

 *              walk_state          - Current method execution state

 *

 * 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_ERROR((AE_INFO,

                            "Cannot acquire Mutex [%4.4s], null thread info",

                            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_ERROR((AE_INFO,

                            "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",

                            acpi_ut_get_node_name(obj_desc->mutex.node),

                            walk_state->thread->current_sync_level));

                return_ACPI_STATUS(AE_AML_MUTEX_ORDER);

        }

        /* Support for multiple acquires by the owning thread */

        if (obj_desc->mutex.owner_thread) {

                if (obj_desc->mutex.owner_thread->thread_id ==

                    walk_state->thread->thread_id) {

                        /*

                         * 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. Special case for Global Lock */

        if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {

                status =

                    acpi_ev_acquire_global_lock((u16) time_desc->integer.value);

        } else {

                status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,

                                                   (u16) time_desc->integer.

                                                   value);

        }

        if (ACPI_FAILURE(status)) {

                /* Includes failure from a timeout on time_desc */

                return_ACPI_STATUS(status);

        }

        /* Have the mutex: update mutex and walk info and save the sync_level */

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

        obj_desc->mutex.acquisition_depth = 1;

        obj_desc->mutex.original_sync_level =

            walk_state->thread->current_sync_level;

        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

 *              walk_state          - Current method execution state

 *

 * 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 = AE_OK;

        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_ERROR((AE_INFO,

                            "Cannot release Mutex [%4.4s], not acquired",

                            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_ERROR((AE_INFO,

                            "Cannot release Mutex [%4.4s], null thread info",

                            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.os_mutex != acpi_gbl_global_lock_mutex)) {

                ACPI_ERROR((AE_INFO,

                            "Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",

                            (unsigned long)walk_state->thread->thread_id,

                            acpi_ut_get_node_name(obj_desc->mutex.node),

                            (unsigned long)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_ERROR((AE_INFO,

                            "Cannot release Mutex [%4.4s], incorrect SyncLevel",

                            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, special case for Global Lock */

        if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {

                status = acpi_ev_release_global_lock();

        } else {

                acpi_os_release_mutex(obj_desc->mutex.os_mutex);

        }

        /* Update the mutex and restore sync_level */

        obj_desc->mutex.owner_thread = NULL;

        walk_state->thread->current_sync_level =

            obj_desc->mutex.original_sync_level;

        return_ACPI_STATUS(status);

}

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

 *

 * FUNCTION:    acpi_ex_release_all_mutexes

 *

 * PARAMETERS:  Thread          - Current executing thread object

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Release all mutexes held by this thread

 *

 * NOTE: This function is called as the thread is exiting the interpreter.

 * Mutexes are not released when an individual control method is exited, but

 * only when the parent thread actually exits the interpreter. This allows one

 * method to acquire a mutex, and a different method to release it, as long as

 * this is performed underneath a single parent control method.

 *

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

void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)

{

        union acpi_operand_object *next = thread->acquired_mutex_list;

        union acpi_operand_object *obj_desc;

        ACPI_FUNCTION_ENTRY();

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

        while (next) {

                obj_desc = next;

                next = obj_desc->mutex.next;

                obj_desc->mutex.prev = NULL;

                obj_desc->mutex.next = NULL;

                obj_desc->mutex.acquisition_depth = 0;

                /* Release the mutex, special case for Global Lock */

                if (obj_desc->mutex.os_mutex == acpi_gbl_global_lock_mutex) {

                        /* Ignore errors */

                        (void)acpi_ev_release_global_lock();

                } else {

                        acpi_os_release_mutex(obj_desc->mutex.os_mutex);

                }

                /* Mark mutex unowned */

                obj_desc->mutex.owner_thread = NULL;

                /* Update Thread sync_level (Last mutex is the important one) */

                thread->current_sync_level =

                    obj_desc->mutex.original_sync_level;

        }

}