[PATCH v5 02/10] powerpc/powernv/idle: Restore AMR/UAMOR/AMOR after idle

[Michael Ellerman]

Akshay Adiga <akshay.adiga at linux.vnet.ibm.com> writes:

> On Fri, Mar 08, 2019 at 12:16:11PM +1100, Michael Ellerman wrote:
>> In order to implement KUAP (Kernel Userspace Access Protection) on
>> Power9 we will be using the AMR, and therefore indirectly the
>> UAMOR/AMOR.
>> 
>> So save/restore these regs in the idle code.
>> 
>> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
>> ---
>> v5: Unchanged.
>> v4: New.
>> 
>>  arch/powerpc/kernel/idle_book3s.S | 27 +++++++++++++++++++++++----
>>  1 file changed, 23 insertions(+), 4 deletions(-)
>
> Opps.. i posted a comment on the v4. 
>
> It would be good if we can make AMOR/UAMOR/AMR save-restore
> code power9 only.

Yes that would be a good optimisation.

If you can send an incremental patch against this one I'll squash it in.
If not I'll try and get it done at some point before merging.

cheers