powerpc/64s/hash: Use POWER6 SLBIA IH=1 variant in switch_slb
authorNicholas Piggin <npiggin@gmail.com>
Fri, 14 Sep 2018 15:30:49 +0000 (01:30 +1000)
committerMichael Ellerman <mpe@ellerman.id.au>
Wed, 19 Sep 2018 11:59:41 +0000 (21:59 +1000)
commit5141c182d75b4004c41ac2dc5af081b457b3e8cb
tree6ad0d69f47e7b6ac24dc98579a7e91cb12c8ac18
parent85376e2a17ec152e76f6a87fcb66332a68926218
powerpc/64s/hash: Use POWER6 SLBIA IH=1 variant in switch_slb

The SLBIA IH=1 hint will remove all non-zero SLBEs, but only
invalidate ERAT entries associated with a class value of 1, for
processors that support the hint (e.g., POWER6 and newer), which
Linux assigns to user addresses.

This prevents kernel ERAT entries from being invalidated when
context switchig (if the thread faulted in more than 8 user SLBEs).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/mm/slb.c