[PATCH] powernv: Clear SPRN_PSSCR when a POWER9 CPU comes online

[Michael Neuling]

On Tue, 2016-11-22 at 23:36 +0530, Gautham R. Shenoy wrote:
> From: "Gautham R. Shenoy" <ego at linux.vnet.ibm.com>
> 
> Ensure that PSSCR is set to a safe value corresponding to no
> state-loss each time a POWER9 CPU comes online.
> 
> Signed-off-by: Gautham R. Shenoy <ego at linux.vnet.ibm.com>

Tested here on my configuration... FWIW

Acked-By: Michael Neuling <mikey at neuling.org>

> ---
>  arch/powerpc/kernel/cpu_setup_power.S | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/powerpc/kernel/cpu_setup_power.S
> b/arch/powerpc/kernel/cpu_setup_power.S
> index 52ff3f0..37ad045 100644
> --- a/arch/powerpc/kernel/cpu_setup_power.S
> +++ b/arch/powerpc/kernel/cpu_setup_power.S
> @@ -96,6 +96,7 @@ _GLOBAL(__setup_cpu_power9)
>  	mtlr	r11
>  	beqlr
>  	li	r0,0
> +	mtspr	SPRN_PSSCR,r0
>  	mtspr	SPRN_LPID,r0
>  	mfspr	r3,SPRN_LPCR
>  	ori	r3, r3, LPCR_PECEDH
> @@ -116,6 +117,7 @@ _GLOBAL(__restore_cpu_power9)
>  	mtlr	r11
>  	beqlr
>  	li	r0,0
> +	mtspr	SPRN_PSSCR,r0
>  	mtspr	SPRN_LPID,r0
>  	mfspr   r3,SPRN_LPCR
>  	ori	r3, r3, LPCR_PECEDH