/******************************************************************************
*
* Module Name: exmutex - ASL Mutex Acquire/Release functions
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2006, 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")
/* 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 "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;
}
/* 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 "acquired_mutex" 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], incorrect sync_level",
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 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;
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.semaphore != acpi_gbl_global_lock_semaphore)) {
ACPI_ERROR((AE_INFO,
"Thread %X cannot release Mutex [%4.4s] acquired by thread %X",
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_ERROR((AE_INFO,
"Cannot release Mutex [%4.4s], incorrect sync_level",
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, restore sync_level before acquire */
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
*
******************************************************************************/
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;
/* Update Thread sync_level (Last mutex is the important one) */
thread->current_sync_level = this->mutex.original_sync_level;
}
}
