/*******************************************************************************
*
* FUNCTION: acpi_release_global_lock
*
* PARAMETERS: Handle - Returned from acpi_acquire_global_lock
*
* RETURN: Status
*
* DESCRIPTION: Release the ACPI Global Lock. The handle must be valid.
*
******************************************************************************/
acpi_status acpi_release_global_lock(u32 handle)
{
acpi_status status;
if (!handle || (handle != acpi_gbl_global_lock_handle)) {
return (AE_NOT_ACQUIRED);
}
status = acpi_ex_release_mutex_object(acpi_gbl_global_lock_mutex);
return (status);
}
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);
}
/*
* 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 != 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);
}
/* 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 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], SyncLevel mismatch: mutex %d current %d",
acpi_ut_get_node_name(obj_desc->mutex.node),
obj_desc->mutex.sync_level,
walk_state->thread->current_sync_level));
return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
}
status = acpi_ex_release_mutex_object(obj_desc);
if (obj_desc->mutex.acquisition_depth == 0) {
/* Restore the original sync_level */
walk_state->thread->current_sync_level =
obj_desc->mutex.original_sync_level;
}
return_ACPI_STATUS(status);
}
acpi_status
acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
struct acpi_walk_state *walk_state)
{
acpi_status status = AE_OK;
u8 previous_sync_level;
struct acpi_thread_state *owner_thread;
ACPI_FUNCTION_TRACE(ex_release_mutex);
if (!obj_desc) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
owner_thread = obj_desc->mutex.owner_thread;
/* The mutex must have been previously acquired in order to release it */
if (!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);
}
/* Must have a valid thread. */
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 ((owner_thread->thread_id != walk_state->thread->thread_id) &&
(obj_desc != acpi_gbl_global_lock_mutex)) {
ACPI_ERROR((AE_INFO,
"Thread %u cannot release Mutex [%4.4s] acquired by thread %u",
(u32)walk_state->thread->thread_id,
acpi_ut_get_node_name(obj_desc->mutex.node),
(u32)owner_thread->thread_id));
return_ACPI_STATUS(AE_AML_NOT_OWNER);
}
/*
* The sync level of the mutex must be equal to the current sync level. In
* other words, the current level means that at least one mutex at that
* level is currently being held. Attempting to release a mutex of a
* different level can only mean that the mutex ordering rule is being
* violated. This behavior is clarified in ACPI 4.0 specification.
*/
if (obj_desc->mutex.sync_level != owner_thread->current_sync_level) {
ACPI_ERROR((AE_INFO,
"Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %u current %u",
acpi_ut_get_node_name(obj_desc->mutex.node),
obj_desc->mutex.sync_level,
walk_state->thread->current_sync_level));
return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
}
/*
* Get the previous sync_level from the head of the acquired mutex list.
* This handles the case where several mutexes at the same level have been
* acquired, but are not released in reverse order.
*/
previous_sync_level =
owner_thread->acquired_mutex_list->mutex.original_sync_level;
status = acpi_ex_release_mutex_object(obj_desc);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
if (obj_desc->mutex.acquisition_depth == 0) {
/* Restore the previous sync_level */
owner_thread->current_sync_level = previous_sync_level;
}
return_ACPI_STATUS(status);
}