[Intel-gfx] [PATCH] drm/i915: stop using swiotlb

[Christoph Hellwig]

On Fri, Jul 22, 2022 at 10:45:54AM +0100, Tvrtko Ursulin wrote:
>> -	unsigned int size = swiotlb_max_segment();
>> -
>> -	if (size == 0)
>> -		size = UINT_MAX;
>
> On a more detailed look, there was a CI failure which makes me think this 
> cap might need to stay. Because max sg segment is unsigned int. So I wonder 
> if sg contstruction overflows without it.
>
> If this quick analysis is right, you could leave i915_sg_segment_size 
> helper and cap the return from dma_max_mapping_size to UINT_MAX in it.

As dma_max_mapping_size retuns a size_t it would be good to make
all variables using it a size_t as well.  In places where that gets
lower to an unsigned int your probably want this cap.