Re: [RFCv3][PATCH 3/5] arm64: Implement ARCH_HAS_FORCE_CACHE

[Laura Abbott]

On 09/13/2016 02:19 AM, Will Deacon wrote:
> Hi Laura,
>
> On Mon, Sep 12, 2016 at 02:32:56PM -0700, Laura Abbott wrote:
> > arm64 may need to guarantee the caches are synced. Implement versions of
> > the kernel_force_cache API to allow this.
> >
> > Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx>
> > ---
> > v3: Switch to calling cache operations directly instead of relying on
> > DMA mapping.
> > ---
> >  arch/arm64/include/asm/cacheflush.h |  8 ++++++++
> >  arch/arm64/mm/cache.S               | 24 ++++++++++++++++++++----
> >  arch/arm64/mm/flush.c               | 11 +++++++++++
> >  3 files changed, 39 insertions(+), 4 deletions(-)
>
> I'm really hesitant to expose these cache routines as an API solely to
> support a driver sitting in staging/. I appreciate that there's a chicken
> and egg problem here, but we *really* don't want people using these routines
> in preference to the DMA API, and I fear that we'll simply grow a bunch
> more users of these things if we promote it as an API like you're proposing.
>
> Can the code not be contained under staging/, as part of ion?

I proposed that in V1 and it was suggested I make it a proper API

http://www.mail-archive.com/driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx/msg47654.html
http://www.mail-archive.com/driverdev-devel@xxxxxxxxxxxxxxxxxxxxxx/msg47672.html

> Will

Thanks,
Laura