[RFC PATCH 1/2] dma-mapping: Clean up dma_set_*mask() hooks

[Christoph Hellwig]

On Wed, Jul 04, 2018 at 06:50:11PM +0100, Robin Murphy wrote:
> Arch-specific implementions for dma_set_{coherent_,}mask() currently
> rely on an inconsistent mix of arch-defined Kconfig symbols and macro
> overrides. Now that we have a nice centralised home for DMA API gubbins,
> let's consolidate these loose ends under consistent config options.
> 
> Signed-off-by: Robin Murphy <robin.murphy at arm.com>
> ---
> 
> Here's hoping the buildbot comes by to point out what I've inevitably
> missed, although I did check a cursory cross-compile of ppc64_defconfig
> to iron out the obvious howlers.

The patch looks sensible to me, although I was hoping to get rid of these
hooks in this or the next merge window as they are a horrible bad idea.

> The motivation here is that I'm looking at adding set_mask overrides
> for arm64, and having discovered a bit of a mess it seemed prudent to
> clean up before ingraining it any more.

What are you trying to do?  I really don't want to see more users of
the hooks as they are are a horribly bad idea.