[PATCH v2 06/12] ARM: mcpm: change max clusters to 4

[Dave Martin]

On Tue, Apr 08, 2014 at 04:00:46PM +0800, Haojian Zhuang wrote:
> In order to support 4 clusters with 4 Cortex A15 Cores in each cluster,
> enlarge maximum clusters from 2 to 4 in MCPM.

CC Nico on mcpm patches please.  I'm happy to be CC'd as well.

> 
> Signed-off-by: Haojian Zhuang <haojian.zhuang at linaro.org>
> ---
>  arch/arm/include/asm/mcpm.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/include/asm/mcpm.h b/arch/arm/include/asm/mcpm.h
> index 608516e..68f82cf 100644
> --- a/arch/arm/include/asm/mcpm.h
> +++ b/arch/arm/include/asm/mcpm.h
> @@ -20,7 +20,7 @@
>   * to consider dynamic allocation.
>   */
>  #define MAX_CPUS_PER_CLUSTER	4
> -#define MAX_NR_CLUSTERS		2
> +#define MAX_NR_CLUSTERS		4

Because of the need for alignment to the biggest cacheline size in the
system, the MCPM low-level locking structures consume a non-trivial
amount of memory.

Therefore, I'm not keen on the idea of simply increasing this #define
every time a platform appears with a larger number of clusters.
If hip04 is not built into the kernel, this just wastes memory.

I'll leave it to Nico to decide whether we can increase the #define
to 4 or whether this needs a proper fix now.  Ideally, we would have
a way of choosing the maximum value required by the set of boards built
into the kernel, or switch to dynamic allocation.

Cheers
---Dave