[Xen-devel] [PATCH v4 3/7] [RFC] arm/arm64: introduce is_dma_coherent

[Stefano Stabellini]

On Mon, 27 Oct 2014, David Vrabel wrote:
> On 25/10/14 17:15, Stefano Stabellini wrote:
> > On Sat, 25 Oct 2014, Ian Campbell wrote:
> >> On Sat, 2014-10-25 at 14:29 +0100, Stefano Stabellini wrote:
> >>>  
> >>> Your suggestions and looking more at the code gave me another idea, that
> >>> I think is clean and at the same time suitable for 3.18.
> >>> What do you think of the following? It is simple, self-contained and
> >>> doesn't need a new flag in struct device.
> >>
> >> of_dma_is_coherent looks to be quite expensive though (walks up the
> >> Device Tree doing strcmps on each property of each node until it finds
> >> the one it is looking for.
> > 
> > It takes spin_locks too!
> > Too bad, I think I'll have to ditch it. In that case I'l try the new
> > flag in struct device approach.
> 
> If you're having to make changes to struct device, this is looking like
> a series for 3.19 (not 3.18).

After looking more into it, I went for adding the flag to dev_archdata
under arm and arm64. Let's see what the maintainers say.