[OpenRISC] [PATCH] openrisc: define mb() as its mandatory

[Peter Zijlstra <peterz@infradead.org>]

On Sun, Apr 08, 2018 at 09:07:29AM +0900, Stafford Horne wrote:
> On Sat, Apr 07, 2018 at 11:09:05AM +0200, Peter Zijlstra wrote:
> > On Sat, Apr 07, 2018 at 05:58:49AM +0900, Stafford Horne wrote:
> > > Following Peter Z's patch ("asm-generic: Disallow no-op mb() for SMP
> > > systems") which makes mb() mandatory for SMP architectures we define it
> > > as l.msync.  On OpenRISC this will flush the current cores write buffer
> > > and trigger remote cores to invalidate their caches of the written
> > > memory.
> > > 
> > > Signed-off-by: Stafford Horne <shorne@gmail.com>
> > > Link: https://lkml.org/lkml/2018/1/31/254
> > > Cc: Peter Zijlstra <peterz@infradead.org>
> > > Cc: Will Deacon <will.deacon@arm.com>
> > > ---
> > > 
> > > Notes:
> > >   - Sorry, its been a while since we discussed this patch is the parent to this 
> > >     still going in Peter?
> > 
> > Oops.. yes it should. It seems I also lost track of it. Thanks for the
> > reminder!
> 
> No Problem,
> 
> If you think this patch makes sense I can just put it into my OpenRISC queue for
> 4.17.  I dont see any reason to wait for yours. Any thoughts?

I'm fine with you taking the patch, but I just saw the build robot found
two failure cases: PARISC and 32-bit SPARC. I send patches for both, if
their respective maintainers agree you could do the lot.