[PATCH v2] arm64: do not set dma masks that device connection can't handle

[Nikita Yushchenko]

>> What issue "IOMMU doesn't solve"?
>>
>> Issue I'm trying to address is - inconsistency within swiotlb
>> dma_map_ops, where (1) any wide mask is silently accepted, but (2) then
>> mask is used to decide if bounce buffers are needed or not. This
>> inconsistency causes NVMe+R-Car cobmo not working (and breaking memory
>> instead).
> 
> The fundamental underlying problem is the "any wide mask is silently
> accepted" part, and that applies equally to IOMMU ops as well.

Is just posted version better?

It should cover iommu case as well.

Nikita