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

[Logan Gunthorpe]

On 2021-05-03 12:28 p.m., Christoph Hellwig wrote:
> On Tue, Apr 27, 2021 at 08:01:13PM -0300, Jason Gunthorpe wrote:
>> 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.
> 
> We already have a mapping function that can return errors:
> dma_map_sgtable.
> 
> I think it might make more sense to piggy back on that, as the sg_table
> abstraction is pretty useful basically everywhere that we deal with
> scatterlists anyway.

Oh, I didn't even realize that existed. I'll use dma_map_sgtable() for v2.

Thanks,

Logan