On Fri, May 31, 2019 at 04:53:16PM +0000, Laurentiu Tudor wrote:

Unfortunately due to our hardware particularities we do not have alternatives. This is also the case for our next generation of ethernet drivers [1]. I'll let my colleagues that work on the ethernet drivers to comment more on this.

Then you need to enhance the DMA API to support your use case instead
of using an API only supported for two specific IOMMU implementations.

Remember in Linux you can should improve core code and not hack around
it in crappy ways making lots of assumptions in your drivers.