powerpc/perf: Avoid spurious PMU interrupts after idle
authorNicholas Piggin <npiggin@gmail.com>
Mon, 10 Jul 2017 06:19:38 +0000 (16:19 +1000)
committerMichael Ellerman <mpe@ellerman.id.au>
Tue, 18 Jul 2017 01:45:47 +0000 (11:45 +1000)
commit101dd590a7fa37954540cf3149a1c502c0acc524
tree0d25f21a5c4d5f3a3592de7e82249422065fed92
parenta70b487b07cf4201bc6702e7f646fa593b23009f
powerpc/perf: Avoid spurious PMU interrupts after idle

POWER9 DD2 can see spurious PMU interrupts after state-loss idle in
some conditions.

A solution is to save and reload MMCR0 over state-loss idle.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Tested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/kernel/idle_book3s.S