acpi_status
acpi_ex_acquire_mutex (
acpi_operand_object *time_desc,
acpi_operand_object *obj_desc,
acpi_walk_state *walk_state)
{
acpi_status status;
FUNCTION_TRACE_PTR ("Ex_acquire_mutex", obj_desc);
if (!obj_desc) {
return_ACPI_STATUS (AE_BAD_PARAMETER);
}
/*
* Current Sync must be less than or equal to the sync level of the
* mutex. This mechanism provides some deadlock prevention
*/
if (walk_state->current_sync_level > obj_desc->mutex.sync_level) {
return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
}
/*
* If the mutex is already owned by this thread,
* just increment the acquisition depth
*/
if (obj_desc->mutex.owner == walk_state) {
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 = walk_state;
obj_desc->mutex.acquisition_depth = 1;
walk_state->current_sync_level = obj_desc->mutex.sync_level;
/* Link the mutex to the walk state for force-unlock at method exit */
acpi_ex_link_mutex (obj_desc, (acpi_operand_object *)
&(walk_state->walk_list->acquired_mutex_list));
return_ACPI_STATUS (AE_OK);
}
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) {
/* Special case for Global Lock, allow all threads */
if ((obj_desc->mutex.owner_thread->thread_id ==
walk_state->thread->thread_id) ||
(obj_desc->mutex.os_mutex == ACPI_GLOBAL_LOCK)) {
/*
* 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);
}
