Re: [PATCH] powernv: Properly mask POWER9 DD1 PVR for different chip types

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

Michael Neuling <mikey@neuling.org> writes:

> Bits 48:51 in the PVR for POWER9 represent different chip types (scale
> up vs out and 12 vs 24 core). Current chips have 0 here, but could be
> non-zero in the future.
>
> This changes the POWER9 DD1 mask to correctly ignore these bits 48:51.
>
> Signed-off-by: Michael Neuling <mikey@neuling.org>
> ---
>  arch/powerpc/kernel/cputable.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Presumably we should backport this?

cheers

> diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
> index 9b3e88b1a9..89dcd94237 100644
> --- a/arch/powerpc/kernel/cputable.c
> +++ b/arch/powerpc/kernel/cputable.c
> @@ -526,8 +526,8 @@ static struct cpu_spec __initdata cpu_specs[] = {
>  		.machine_check_early	= __machine_check_early_realmode_p8,
>  		.platform		= "power8",
>  	},
> -	{	/* Power9 DD1*/
> -		.pvr_mask		= 0xffffff00,
> +	{	/* Power9 DD1. Bits 48:51 represent chip type so mask these */
> +		.pvr_mask		= 0xffff0f00,
>  		.pvr_value		= 0x004e0100,
>  		.cpu_name		= "POWER9 (raw)",
>  		.cpu_features		= CPU_FTRS_POWER9_DD1,
> -- 
> 2.11.0