On Mon, 8 Feb 2021, Christoph Hellwig wrote:

quoted

 Do you need to have this verified anyhow?  I only have a non-coherent 5Kc 
Malta though.

If you get a chance to test this logic, that would be great.

 I'll try to give it a hit in the next few days then.  Installed in my 
Malta I have a DEFPA, which is about as serious a DMA user as a piece of 
classic PCI hardware could be.  I need to debug the issue of another DEFPA 
not working with my POWER9 system, possibly due to an IOMMU handling bug 
(hopefully not broken host hardware), so I'll take the opportunity and do 
it all at once.

  Maciej