Re: dma_declare_coherent_memory and SuperH

[Christoph Hellwig]

On Sat, Jun 26, 2021 at 05:36:08PM -0500, Rob Landley wrote:
> On 6/23/21 8:32 AM, Christoph Hellwig wrote:
> > Hi SuperH maintainers,
> > 
> > I have a vague recollection that you were planning on dropping support
> > for non-devicetree platforms, is that still the case?
> 
> We'd like to convert them, but have to rustle up test hardware for what _is_
> still available. (There was some motion towards this a year or so back, but it
> petered out because pandemic and everyone got distracted halfway through.)
> 
> (We should definitely START by converting the r2d board qemu emulates. :)
> 
> > The reason I'm asking is because all but one users of
> > dma_declare_coherent_memory are in the sh platform setup code, and
> > I'd really like to move towards killing this function off.
> 
> Understood. Is there an easy "convert to this" I could do to those callers?

Well, the replacement is to declare the device memory carveouts in the
Device Tree.