powerpc: Add POWER8 features to CPU_FTRS_POSSIBLE/ALWAYS

We have been a bit slack about updating the CPU_FTRS_POSSIBLE and
CPU_FTRS_ALWAYS masks. When we added POWER8, and also POWER8E we forgot
to update the ALWAYS mask. And when we added POWER8_DD1 we forgot to
update both the POSSIBLE and ALWAYS masks.

Luckily this hasn't caused any actual bugs AFAICS. Failing to update the
ALWAYS mask just forgoes a potential optimisation opportunity. Failing
to update the POSSIBLE mask for POWER8_DD1 is also OK because it only
removes a bit rather than adding any.

Regardless they should all be in both masks so as to avoid any future
bugs when the set of ALWAYS/POSSIBLE bits changes, or the masks
themselves change.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/cputable.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

On Wed, 2014-08-06 at 15:42 +1000, Michael Ellerman wrote:
> We have been a bit slack about updating the CPU_FTRS_POSSIBLE and
> CPU_FTRS_ALWAYS masks. When we added POWER8, and also POWER8E we forgot
> to update the ALWAYS mask. And when we added POWER8_DD1 we forgot to
> update both the POSSIBLE and ALWAYS masks.
> 
> Luckily this hasn't caused any actual bugs AFAICS. Failing to update the
> ALWAYS mask just forgoes a potential optimisation opportunity. Failing
> to update the POSSIBLE mask for POWER8_DD1 is also OK because it only
> removes a bit rather than adding any.
> 
> Regardless they should all be in both masks so as to avoid any future
> bugs when the set of ALWAYS/POSSIBLE bits changes, or the masks
> themselves change.
> 
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

CCing Joel but FWIW

Acked-by: Michael Neuling <mikey@neuling.org>

> ---
>  arch/powerpc/include/asm/cputable.h | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
> index af5598688daf..d696eeb2def0 100644
> --- a/arch/powerpc/include/asm/cputable.h
> +++ b/arch/powerpc/include/asm/cputable.h
> @@ -458,7 +458,8 @@ extern const char *powerpc_base_platform;
>  #define CPU_FTRS_POSSIBLE	\
>  	    (CPU_FTRS_POWER4 | CPU_FTRS_PPC970 | CPU_FTRS_POWER5 | \
>  	     CPU_FTRS_POWER6 | CPU_FTRS_POWER7 | CPU_FTRS_POWER8E | \
> -	     CPU_FTRS_POWER8 | CPU_FTRS_CELL | CPU_FTRS_PA6T | CPU_FTR_VSX)
> +	     CPU_FTRS_POWER8 | CPU_FTRS_POWER8_DD1 | CPU_FTRS_CELL | \
> +	     CPU_FTRS_PA6T | CPU_FTR_VSX)
>  #endif
>  #else
>  enum {
> @@ -508,7 +509,8 @@ enum {
>  #define CPU_FTRS_ALWAYS		\
>  	    (CPU_FTRS_POWER4 & CPU_FTRS_PPC970 & CPU_FTRS_POWER5 & \
>  	     CPU_FTRS_POWER6 & CPU_FTRS_POWER7 & CPU_FTRS_CELL & \
> -	     CPU_FTRS_PA6T & CPU_FTRS_POSSIBLE)
> +	     CPU_FTRS_PA6T & CPU_FTRS_POWER8 & CPU_FTRS_POWER8E & \
> +	     CPU_FTRS_POWER8_DD1 & CPU_FTRS_POSSIBLE)
>  #endif
>  #else
>  enum {

On Wed, Aug 6, 2014 at 3:12 PM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> We have been a bit slack about updating the CPU_FTRS_POSSIBLE and
> CPU_FTRS_ALWAYS masks. When we added POWER8, and also POWER8E we forgot
> to update the ALWAYS mask. And when we added POWER8_DD1 we forgot to
> update both the POSSIBLE and ALWAYS masks.
>
> Luckily this hasn't caused any actual bugs AFAICS. Failing to update the
> ALWAYS mask just forgoes a potential optimisation opportunity. Failing
> to update the POSSIBLE mask for POWER8_DD1 is also OK because it only
> removes a bit rather than adding any.
>
> Regardless they should all be in both masks so as to avoid any future
> bugs when the set of ALWAYS/POSSIBLE bits changes, or the masks
> themselves change.
>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Thanks for catching that.

Acked-by: Joel Stanley <joel@jms.id.au>