Re: [PATCH v3 2/2] powerpc/shared: Use static key to detect shared processor

2019-12-05 Thread Phil Auld 
On Thu, Dec 05, 2019 at 02:02:18PM +0530 Srikar Dronamraju wrote:
> With the static key shared processor available, is_shared_processor()
> can return without having to query the lppaca structure.
> 
> Cc: Parth Shah 
> Cc: Ihor Pasichnyk 
> Cc: Juri Lelli 
> Cc: Phil Auld 
> Cc: Waiman Long 
> Signed-off-by: Srikar Dronamraju 
> ---
> Changelog v1 (https://patchwork.ozlabs.org/patch/1204192/) ->v2:
> Now that we no more refer to lppaca, remove the comment.
> 
> Changelog v2->v3:
> Code is now under CONFIG_PPC_SPLPAR as it depends on CONFIG_PPC_PSERIES.
> This was suggested by Waiman Long.
> 
>  arch/powerpc/include/asm/spinlock.h | 9 ++---
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/spinlock.h 
> b/arch/powerpc/include/asm/spinlock.h
> index de817c25deff..e83d57f27566 100644
> --- a/arch/powerpc/include/asm/spinlock.h
> +++ b/arch/powerpc/include/asm/spinlock.h
> @@ -111,13 +111,8 @@ static inline void splpar_rw_yield(arch_rwlock_t *lock) 
> {};
>  
>  static inline bool is_shared_processor(void)
>  {
> -/*
> - * LPPACA is only available on Pseries so guard anything LPPACA related to
> - * allow other platforms (which include this common header) to compile.
> - */
> -#ifdef CONFIG_PPC_PSERIES
> - return (IS_ENABLED(CONFIG_PPC_SPLPAR) &&
> - lppaca_shared_proc(local_paca->lppaca_ptr));
> +#ifdef CONFIG_PPC_SPLPAR
> + return static_branch_unlikely(_processor);
>  #else
>   return false;
>  #endif
> -- 
> 2.18.1
> 

Fwiw,

Acked-by: Phil Auld 
--

Re: [PATCH v3 2/2] powerpc/shared: Use static key to detect shared processor

2019-12-05 Thread Waiman Long 
On 12/5/19 3:32 AM, Srikar Dronamraju wrote:
> With the static key shared processor available, is_shared_processor()
> can return without having to query the lppaca structure.
>
> Cc: Parth Shah 
> Cc: Ihor Pasichnyk 
> Cc: Juri Lelli 
> Cc: Phil Auld 
> Cc: Waiman Long 
> Signed-off-by: Srikar Dronamraju 
> ---
> Changelog v1 (https://patchwork.ozlabs.org/patch/1204192/) ->v2:
> Now that we no more refer to lppaca, remove the comment.
>
> Changelog v2->v3:
> Code is now under CONFIG_PPC_SPLPAR as it depends on CONFIG_PPC_PSERIES.
> This was suggested by Waiman Long.
>
>  arch/powerpc/include/asm/spinlock.h | 9 ++---
>  1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/spinlock.h 
> b/arch/powerpc/include/asm/spinlock.h
> index de817c25deff..e83d57f27566 100644
> --- a/arch/powerpc/include/asm/spinlock.h
> +++ b/arch/powerpc/include/asm/spinlock.h
> @@ -111,13 +111,8 @@ static inline void splpar_rw_yield(arch_rwlock_t *lock) 
> {};
>  
>  static inline bool is_shared_processor(void)
>  {
> -/*
> - * LPPACA is only available on Pseries so guard anything LPPACA related to
> - * allow other platforms (which include this common header) to compile.
> - */
> -#ifdef CONFIG_PPC_PSERIES
> - return (IS_ENABLED(CONFIG_PPC_SPLPAR) &&
> - lppaca_shared_proc(local_paca->lppaca_ptr));
> +#ifdef CONFIG_PPC_SPLPAR
> + return static_branch_unlikely(_processor);
>  #else
>   return false;
>  #endif

Acked-by: Waiman Long