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Date: Tue, 10 Oct 2017 10:54:14 +0100
From: Mark Rutland <mark.rutland@arm.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH 13/13] rcutorture: formal: prepare for ACCESS_ONCE()
 removal
Message-ID: <20171010095413.GE27659@leverpostej>
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On Mon, Oct 09, 2017 at 12:51:12PM -0700, Paul E. McKenney wrote:
> On Mon, Oct 09, 2017 at 07:28:50PM +0100, Mark Rutland wrote:
> > diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h
> > index 6687acc..ee4e4f8 100644
> > --- a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h
> > +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h
> > @@ -34,8 +34,9 @@
> >  #define rs_smp_mb() do {} while (0)
> >  #endif
> > 
> > -#define ACCESS_ONCE(x) (*(volatile typeof(x) *) &(x))
> > -#define READ_ONCE(x) ACCESS_ONCE(x)
> > -#define WRITE_ONCE(x, val) (ACCESS_ONCE(x) = (val))
> > +#define __ACCESS_ONCE(x) (*(volatile typeof(x) *) &(x))
> > +#define ACCESS_ONCE(x) __ACCESS_ONCE(x)
> > +#define READ_ONCE(x) __ACCESS_ONCE(x)
> > +#define WRITE_ONCE(x, val) (__ACCESS_ONCE(x) = (val))
> 
> How about something like the following?
> 
> #define READ_ONCE(x) (*(volatile typeof(x) *) &(x))
> #define WRITE_ONCE(x) ((*(volatile typeof(x) *) &(x)) = (val))

Sure; folded in and pushed out. :)

I've assumed that the ACCESS_ONCE() definition needs to be kept until
that's ripped out treewide. Please shout if that's not the case!

Thanks,
Mark.