[PATCH 12/14] powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE]

[Nicholas Piggin]

Excerpts from Christophe Leroy's message of March 16, 2021 5:21 pm:
> 
> 
> Le 15/03/2021 à 23:04, Nicholas Piggin a écrit :
>> This extends the MSR[RI]=0 window a little further into the system
>> call in order to pair RI and EE enabling with a single mtmsrd.
> 
> Time ago, I proposed to delay that on PPC32 and Michael objected, see 
> https://patchwork.ozlabs.org/project/linuxppc-dev/patch/9f9dd859d571e324c7412ed9db9da8cfba678257.1548956511.git.christophe.leroy@c-s.fr/

Yeah, it is a concern. The speedup should be at least 5% I think on
64s (have not measured in isolation yet), so might be worth it.

We'll see.

Thanks,
Nick