Re: [PATCH 09/10] xen: arm: weaken SMP barriers to inner shareable.

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

On Mon, 1 Jul 2013, Stefano Stabellini wrote:
> On Fri, 28 Jun 2013, Ian Campbell wrote:
> > Since all processors are in the inner-shareable domain and we map everything
> > that way this is sufficient.
> > 
> > The non-SMP barriers remain full system. Although in principal they could
> > become outer shareable barriers for some hardware this would require us to
> > know which class a given device is. Given the small number of device drivers
> > in Xen itself its probably not worth worrying over, although maybe someone
> > will benchmark at some point.
> > 
> > Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> 

same here

> >  xen/include/asm-arm/system.h |    6 +++---
> >  1 files changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/xen/include/asm-arm/system.h b/xen/include/asm-arm/system.h
> > index 68efba9..7c3e42d 100644
> > --- a/xen/include/asm-arm/system.h
> > +++ b/xen/include/asm-arm/system.h
> > @@ -20,9 +20,9 @@
> >  #define rmb()           dsb("sy")
> >  #define wmb()           dsb("sy")
> >  
> > -#define smp_mb()        dmb("sy")
> > -#define smp_rmb()       dmb("sy")
> > -#define smp_wmb()       dmb("sy")
> > +#define smp_mb()        dmb("ish")
> > +#define smp_rmb()       dmb("ish")
> > +#define smp_wmb()       dmb("ish")
> >  
> >  #define xchg(ptr,x) \
> >          ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
> > -- 
> > 1.7.2.5
> > 
>