Re: [PATCH] arch/powerpc: provide zero_bytemask() for big-endian

[Michael Ellerman <mpe@ellerman.id.au>]

On Wed, 2015-10-07 at 10:46 -0400, Chris Metcalf wrote:
> For some reason, only the little-endian flavor of
> powerpc provided the zero_bytemask() implementation.

Because previously it was optional unless DCACHE_WORD_ACCESS was enabled.

> Reported-by: Michal Sojka <sojkam1@fel.cvut.cz>
> Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
> ---
>  arch/powerpc/include/asm/word-at-a-time.h | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/word-at-a-time.h b/arch/powerpc/include/asm/word-at-a-time.h
> index 5b3a903adae6..e4396a7d0f7c 100644
> --- a/arch/powerpc/include/asm/word-at-a-time.h
> +++ b/arch/powerpc/include/asm/word-at-a-time.h
> @@ -40,6 +40,11 @@ static inline bool has_zero(unsigned long val, unsigned long *data, const struct
>  	return (val + c->high_bits) & ~rhs;
>  }
>  
> +static inline unsigned long zero_bytemask(unsigned long mask)
> +{
> +	return ~1ul << __fls(mask);
> +}
> +
>  #else
>  
>  #ifdef CONFIG_64BIT


This looks right, and I tested it too so have an ack if you want it:

Acked-by: Michael Ellerman <mpe@ellerman.id.au>


If you can CC linuxppc-dev@lists.ozlabs.org in future on powerpc patches I'll
notice them quicker, I know I was CC'ed on this but because it also went to
LKML it got put in my lkml folder.

cheers