[RFC] switch m68k to use the generic remapping DMA allocator

[Christoph Hellwig]

On Mon, Jun 17, 2019 at 08:53:55PM +0200, Geert Uytterhoeven wrote:
> Hi Christoph,
> 
> On Fri, Jun 14, 2019 at 12:21 PM Christoph Hellwig <hch at lst.de> wrote:
> > can you take a look at the (untested) patches below?  They convert m68k
> > to use the generic remapping DMA allocator, which is also used by
> > arm64 and csky.
> 
> Thanks. But what does this buy us?

A common dma mapping code base with everyone, including supporting
DMA allocations from atomic context, which the documentation and
API assume are there, but which don't work on m68k.

> bloat-o-meter says:
> 
> add/remove: 75/0 grow/shrink: 11/6 up/down: 4122/-82 (4040)

What do these values stand for?  The code should grow a little as
we now need to include the the pool allocator for the above API
fix.