[PATCH v8 1/3] iommu/arm-smmu: add NVIDIA implementation for dual ARM MMU-500 usage
vdumpa at nvidia.com
Tue Jun 30 13:16:09 EDT 2020
>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.
More information about the linux-arm-kernel