ACPI_STATUS
AcpiReleaseGlobalLock (
UINT32 Handle)
{
ACPI_STATUS Status;
if (!Handle || (Handle != AcpiGbl_GlobalLockHandle))
{
return (AE_NOT_ACQUIRED);
}
Status = AcpiExReleaseMutexObject (AcpiGbl_GlobalLockMutex);
return (Status);
}
ACPI_STATUS
AcpiExReleaseMutex (
ACPI_OPERAND_OBJECT *ObjDesc,
ACPI_WALK_STATE *WalkState)
{
ACPI_STATUS Status = AE_OK;
UINT8 PreviousSyncLevel;
ACPI_THREAD_STATE *OwnerThread;
ACPI_FUNCTION_TRACE (ExReleaseMutex);
if (!ObjDesc)
{
return_ACPI_STATUS (AE_BAD_PARAMETER);
}
OwnerThread = ObjDesc->Mutex.OwnerThread;
/* The mutex must have been previously acquired in order to release it */
if (!OwnerThread)
{
ACPI_ERROR ((AE_INFO,
"Cannot release Mutex [%4.4s], not acquired",
AcpiUtGetNodeName (ObjDesc->Mutex.Node)));
return_ACPI_STATUS (AE_AML_MUTEX_NOT_ACQUIRED);
}
/* Must have a valid thread ID */
if (!WalkState->Thread)
{
ACPI_ERROR ((AE_INFO,
"Cannot release Mutex [%4.4s], null thread info",
AcpiUtGetNodeName (ObjDesc->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 ((OwnerThread->ThreadId != WalkState->Thread->ThreadId) &&
(ObjDesc != AcpiGbl_GlobalLockMutex))
{
ACPI_ERROR ((AE_INFO,
"Thread %u cannot release Mutex [%4.4s] acquired by thread %u",
(UINT32) WalkState->Thread->ThreadId,
AcpiUtGetNodeName (ObjDesc->Mutex.Node),
(UINT32) OwnerThread->ThreadId));
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 (ObjDesc->Mutex.SyncLevel != OwnerThread->CurrentSyncLevel)
{
ACPI_ERROR ((AE_INFO,
"Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %u current %u",
AcpiUtGetNodeName (ObjDesc->Mutex.Node),
ObjDesc->Mutex.SyncLevel, WalkState->Thread->CurrentSyncLevel));
return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
}
/*
* Get the previous SyncLevel 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.
*/
PreviousSyncLevel =
OwnerThread->AcquiredMutexList->Mutex.OriginalSyncLevel;
Status = AcpiExReleaseMutexObject (ObjDesc);
if (ACPI_FAILURE (Status))
{
return_ACPI_STATUS (Status);
}
if (ObjDesc->Mutex.AcquisitionDepth == 0)
{
/* Restore the previous SyncLevel */
OwnerThread->CurrentSyncLevel = PreviousSyncLevel;
}
return_ACPI_STATUS (Status);
}
