Re: [PATCH v2 22/32] s390: define __smp_xxx

From: Peter Zijlstra
Date: Mon Jan 04 2016 - 08:46:03 EST


On Thu, Dec 31, 2015 at 09:08:38PM +0200, Michael S. Tsirkin wrote:
> This defines __smp_xxx barriers for s390,
> for use by virtualization.
>
> Some smp_xxx barriers are removed as they are
> defined correctly by asm-generic/barriers.h
>
> Note: smp_mb, smp_rmb and smp_wmb are defined as full barriers
> unconditionally on this architecture.
>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> arch/s390/include/asm/barrier.h | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h
> index c358c31..fbd25b2 100644
> --- a/arch/s390/include/asm/barrier.h
> +++ b/arch/s390/include/asm/barrier.h
> @@ -26,18 +26,21 @@
> #define wmb() barrier()
> #define dma_rmb() mb()
> #define dma_wmb() mb()
> -#define smp_mb() mb()
> -#define smp_rmb() rmb()
> -#define smp_wmb() wmb()
> -
> -#define smp_store_release(p, v) \
> +#define __smp_mb() mb()
> +#define __smp_rmb() rmb()
> +#define __smp_wmb() wmb()
> +#define smp_mb() __smp_mb()
> +#define smp_rmb() __smp_rmb()
> +#define smp_wmb() __smp_wmb()

Why define the smp_*mb() primitives here? Would not the inclusion of
asm-generic/barrier.h do this?
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