[PATCH 05/16] dma-mapping: Introduce dma_map_sg_p2pdma()

[Jason Gunthorpe]

On Tue, Apr 27, 2021 at 04:55:45PM -0600, Logan Gunthorpe wrote:

> > Also, I see only 8 users of this function. How about just fix them all
> > to support negative returns and use this as the p2p API instead of
> > adding new API?
> 
> Well there might be 8 users of dma_map_sg_attrs() but there are a very
> large number of dma_map_sg(). Seems odd to me to single out the first as
> requiring these changes, but leave the latter.

At a high level I'm OK with it. dma_map_sg_attrs() is the extra
extended version of dma_map_sg(), it already has a different
signature, a different return code is not out of the question.

dma_map_sg() is just the simple easy to use interface that can't do
advanced stuff.

> I'm not that opposed to this. But it will make this series a fair bit
> longer to change the 8 map_sg_attrs() usages.

Yes, but the result seems much nicer to not grow the DMA API further.

Jason