Re: [RFC/RFT PATCH 1/2] dma-contiguous: Simplify dma_*_from_contiguous() function calls

[Christoph Hellwig]

So while I really, really like this cleanup it turns out it isn't
actually safe for arm :(  arm remaps the CMA allocation in place
instead of using a new mapping, which can be done because they don't
share PMDs with the kernel.

So we'll probably need a __dma_alloc_from_contiguous version with
an additional bool fallback argument - everyone but arms uses
dma_alloc_from_contiguous as in your patch, just arm will get the
non-fallback one.

Sorry for not sorting this our earlier.