__iommu_queue_command_sync
ret = __iommu_queue_command_sync(iommu, cmd, sync);
ret = __iommu_queue_command_sync(iommu, &cmd, false);
ret = __iommu_queue_command_sync(iommu, &cmd, true);
ret = __iommu_queue_command_sync(iommu, &cmd, false);