Re: cleanup the dma_pgprot handling
From: Christoph Hellwig
Date: Sat Aug 24 2019 - 18:35:00 EST
On Fri, Aug 23, 2019 at 09:58:04PM +0000, Paul Burton wrote:
> So I believe uncached & uncached accelerated are another case like that
> described above - they're 2 different CCAs but the same "access type",
> namely uncached.
>
> Section 4.9 then goes on to forbid mixing access types, but not CCAs.
>
> It would be nice if the precise mapping from CCA to access type was
> provided, but I don't see that anywhere. I can check with the
> architecture team to be sure, but to my knowledge we're fine to mix
> access via kseg1 (ie. uncached) & mappings with CCA=7 (uncached
> accelerated).
Ok. Looks like we can keep it then and I'll add a comment to the
code with the above reference.