iommu_go_to_state
ret = iommu_go_to_state(IOMMU_ACPI_FINISHED);
ret = iommu_go_to_state(IOMMU_ENABLED);
ret = iommu_go_to_state(IOMMU_INITIALIZED);
ret = iommu_go_to_state(IOMMU_IVRS_DETECTED);