[RFC PATCH] ARM: cmpxchg: define __HAVE_ARCH_CMPXCHG for armv6 and later

[Yong Zhang]

On Thu, May 31, 2012 at 02:24:50AM +0100, Will Deacon wrote:
> Hello,
> 
> On Wed, May 30, 2012 at 08:51:26AM +0100, Yong Zhang wrote:
> > diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h
> > index 7eb18c1..a91b44e 100644
> > --- a/arch/arm/include/asm/cmpxchg.h
> > +++ b/arch/arm/include/asm/cmpxchg.h
> > @@ -127,6 +127,8 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
> >  
> >  #else	/* min ARCH >= ARMv6 */
> >  
> > +#define __HAVE_ARCH_CMPXCHG 1
> > +
> >  extern void __bad_cmpxchg(volatile void *ptr, int size);
> 
> As long as this only requires 4-byte cmpxchg support then I think this is
> fine. It looks like that's currently the case, so:

Yes and thanks for review.

Yong

> 
> Acked-by: Will Deacon <will.deacon at arm.com>
> 
> Will