On Thursday 18 December 2014 10:33:31 Jorge Ramirez-Ortiz wrote:

Hi,

I need some some pointers on how to write a IOMMU driver on arm64 for a new SoC. The iommu interface is currently not being provided in dma-mappings.c (the DMA API is SWIOTLB-based)

what is the alternative?

Please see the linux-arm-kernel mailing list archives, there is a lot of ongoing work for this. Will Deacon has posted a first series to instantiate the iommu at probe time, and there also a series for exynos building on top of that. There are probably also SMMU patches doing the same, but I don't recall seeing them on the list now.

Arnd