/*******************************************************************************
*
* FUNCTION: acpi_acquire_global_lock
*
* PARAMETERS: Timeout - How long the caller is willing to wait
* Handle - Where the handle to the lock is returned
* (if acquired)
*
* RETURN: Status
*
* DESCRIPTION: Acquire the ACPI Global Lock
*
* Note: Allows callers with the same thread ID to acquire the global lock
* multiple times. In other words, externally, the behavior of the global lock
* is identical to an AML mutex. On the first acquire, a new handle is
* returned. On any subsequent calls to acquire by the same thread, the same
* handle is returned.
*
******************************************************************************/
acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
{
acpi_status status;
if (!handle) {
return (AE_BAD_PARAMETER);
}
/* Must lock interpreter to prevent race conditions */
acpi_ex_enter_interpreter();
status = acpi_ex_acquire_mutex_object(timeout,
acpi_gbl_global_lock_mutex,
acpi_os_get_thread_id());
if (ACPI_SUCCESS(status)) {
/* Return the global lock handle (updated in acpi_ev_acquire_global_lock) */
*handle = acpi_gbl_global_lock_handle;
}
acpi_ex_exit_interpreter();
return (status);
}
acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
{
acpi_status status;
if (!handle) {
return (AE_BAD_PARAMETER);
}
acpi_ex_enter_interpreter();
status = acpi_ex_acquire_mutex_object(timeout,
acpi_gbl_global_lock_mutex,
acpi_os_get_thread_id());
if (ACPI_SUCCESS(status)) {
*handle = acpi_gbl_global_lock_handle;
}
acpi_ex_exit_interpreter();
return (status);
}
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);
}
/* 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 level 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);
}
status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value,
obj_desc,
walk_state->thread->thread_id);
if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {
/* Save Thread object, original/current sync levels */
obj_desc->mutex.owner_thread = walk_state->thread;
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(status);
}