[PATCH 06/14] powerpc/rtas: Load rtas entry MSR explicitly

[Laurent Dufour]

On 08/03/2022, 14:50:39, Nicholas Piggin wrote:
> Rather than adjust the current MSR value to find the rtas entry
> MSR on 64-bit, load the explicit value we want as 32-bit does.
> 
> This prevents some facilities (e.g., VEC and VSX) from being left
> enabled which doesn't seem to cause a problem but it's more
> consistent to always use the same MSR and minimise facilities
> enabled.
> 
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>

Reviewed-by: Laurent Dufour <ldufour at linux.ibm.com>

> ---
>  arch/powerpc/kernel/rtas_entry.S | 9 +--------
>  1 file changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/rtas_entry.S b/arch/powerpc/kernel/rtas_entry.S
> index 7b93687b9a10..08eb731f08b8 100644
> --- a/arch/powerpc/kernel/rtas_entry.S
> +++ b/arch/powerpc/kernel/rtas_entry.S
> @@ -99,14 +99,7 @@ _GLOBAL(enter_rtas)
>  	clrldi	r4,r4,2			/* convert to realmode address */
>  	mtlr	r4
>  
> -	li	r0,0
> -	ori	r0,r0,MSR_EE|MSR_SE|MSR_BE|MSR_RI
> -	andc	r0,r6,r0
> -
> -	li	r9,1
> -	rldicr	r9,r9,MSR_SF_LG,(63-MSR_SF_LG)
> -	ori	r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP|MSR_RI|MSR_LE
> -	andc	r6,r0,r9
> +	LOAD_REG_IMMEDIATE(r6, MSR_ME)
>  
>  __enter_rtas:
>  	LOAD_REG_ADDR(r4, rtas)