[PATCH 4/4] ARM: keystone: Use dma-ranges for dma_pfn_offset configuration

Arnd Bergmann arnd at arndb.de
Tue Feb 25 03:35:05 EST 2014

On Monday 24 February 2014 16:38:00 Santosh Shilimkar wrote:
> > I also wonder if this shouldn't be in ARM architecture wide code
> > rather than platform code. Unfortunately it can't be in drivers/base
> > since the offset is stored in an ARM specific location.
> > 
> Notifier callback is in mach code mainly because platform's might have to
> do custom things here. Like setting up the coherent masters,
> populating the dma_pfn_offset or populating custom dma_ops etc.
> As such the in these callbacks is not much and I see only
> couple of machines using it.

Yes, but since "dma-ranges" is a standard property, I think we should
provide a generic implementation so other platforms don't have to
copy one. Most platforms today are never cache-coherent and have
a trivial mapping, so they don't need this function, but I suppose
the case you have is getting more popular. I think shmobile is in
exactly the same position with their new r-car parts for instance.


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