[PATCH 1/5 v2] dma-mapping: add generic dma_get_page_shift API

[Nishanth Aravamudan]

On 06.10.2015 [02:51:36 -0700], Christoph Hellwig wrote:
> Do we need a function here or can we just have a IOMMU_PAGE_SHIFT define
> with an #ifndef in common code?

On Power, since it's technically variable, we'd need a function. So are
you suggesting define'ing it to a function just on Power and leaving it
a constant elsewhere?

I noticed that sparc has a IOMMU_PAGE_SHIFT already, fwiw.

-Nish