Re: libata+SGIO: is .dma_boundary respected?

[Mark Lord <liml@rtr.ca>]

Jens Axboe wrote:
> On Tue, Mar 21 2006, Mark Lord wrote:
>> Jens Axboe wrote:
..
>>> It would be much nicer if the iommu actually had some more knowledge,
>>> ideally the same requirements that the block layer is faced with. No
>>> driver should have to check the mapped sg list.
>> Yup.  Absolutely.  So long as they continue to never *add* new sg entries
>> (only doing merges instead), then I believe they just need to know the
>> device's .dma_boundary parameter.  We could pass this to them as an extra
>> parameters, or perhaps embed it into the sg_list data structure somehow.
> 
> You want max size as well, so boundary and max size should be enough.

Oh, now there's a thought.  How do we specify "max segment size" today?
I'll need to make sure that sata_mv still does that (64KB), even though
it doesn't care about crossing 64KB boundaries.

Thanks