Hello all, For pcie RC's iommu, (this iommu translates address for each PCI device dma masters when they access memory or io in the system), we can set "iommus" specifier in the device tree node for the PCIe RC. The "iommus" property generally tells for a bus master devices which iommu device's master interface it is connected to. (iommu device sits between the interconnect and the dma master device). For PCIe RC case, we can use RID(requester ID) from the PCIe device in the iommu processing so that the PCIe devices can use their own address translation table in the iommu. I briefly saw 'of_iommu_configure_dev_id' and 'of_map_id' functions and guessed even if the hardware connects the RID from the PCIe to the iommu device, if I set 'iommu-map-mask' value to zero, the software sets the iommu translation table so that the actual RID is not used in the processing. But I'm not sure if my guess is correct. Can any one tell me what the case is? Thank you. Chan Kim