tree bcff78fc62495872b5c46266f089ec9c048c637e
parent 5e35ee249e26e36cae641bee8d212fba0e1bb6e6
author Oliver O'Halloran <oohall@gmail.com> 1499330803 +1000
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1501193280 -0700

powerpc/asm: Mark cr0 as clobbered in mftb()

commit 2400fd822f467cb4c886c879d8ad99feac9cf319 upstream.

The workaround for the CELL timebase bug does not correctly mark cr0 as
being clobbered. This means GCC doesn't know that the asm block changes cr0 and
might leave the result of an unrelated comparison in cr0 across the block, which
we then trash, leading to basically random behaviour.

Fixes: 859deea949c3 ("[POWERPC] Cell timebase bug workaround")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Tweak change log and flag for stable]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>