MMU_IRQENABLE
iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
iommu_write_reg(obj, 0, MMU_IRQENABLE);