RE: [PATCH v8 1/3] iommu/arm-smmu: add NVIDIA implementation for dual ARM MMU-500 usage

[Krishna Reddy]

>OK, well I see what you are saying, but if we intended to support all 3 for Tegra194, then we should ensure all 3 are initialised correctly.

The driver intend to support up to 3 instances. It doesn't really mandate that all three instances be present in same DT node.
Each mmio aperture in "reg" property is an instance here. reg = <inst0_base, size>, <inst1_base, size>, <inst2_base, size>;
The reg can have all three or less and driver just configures based on reg and it works fine.

>It would be better to query the number of SMMUs populated in device-tree and then ensure that all are initialised correctly.

Getting the IORESOURCE_MEM is the way to count the instances driver need to support.  
In a way, It is already querying through IORESOURCE_MEM here. 


-KR