use generic DMA mapping code in powerpc V4

[Christoph Hellwig]

On Thu, Jan 31, 2019 at 01:48:26PM +0100, Christian Zigotzky wrote:
> Hi Christoph,
>
> I compiled kernels for the X5000 and X1000 from your branch 'powerpc-dma.6' 
> today.
>
> Gitweb: 
> http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/powerpc-dma.6
>
> git clone git://git.infradead.org/users/hch/misc.git -b powerpc-dma.6 a
>
> The X1000 and X5000 boot but unfortunately the P.A. Semi Ethernet doesn't 
> work.

Oh.  Can you try with just the next one and then two patches applied
over the working setup?  That is first:

http://git.infradead.org/users/hch/misc.git/commitdiff/b50f42f0fe12965ead395c76bcb6a14f00cdf65b

then also with:

http://git.infradead.org/users/hch/misc.git/commitdiff/21fe52470a483afbb1726741118abef8602dde4d