powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL

In the SLB miss handler we may be returning to user or kernel. We need
to add a check early on and save the result in the cr4 register, and
then we bifurcate the return path based on that.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Nicholas Piggin 2018-01-10 03:07:15 +11:00 • committed by Michael Ellerman
commit c7305645eb