arch,s390: Convert smp_mb__*()
authorPeter Zijlstra <peterz@infradead.org>
Thu, 13 Mar 2014 18:00:35 +0000 (19:00 +0100)
committerIngo Molnar <mingo@kernel.org>
Fri, 18 Apr 2014 12:20:42 +0000 (14:20 +0200)
commit0e530747c69f1e191f101a925bb4051894e5c7b0
treedba0d885403109b8a5857bf59890dfe6b6cd077c
parentc645073f7e4f073e1ebcd0f0d91652c4468b8364
arch,s390: Convert smp_mb__*()

As per the existing implementation; implement the new one using
smp_mb().

AFAICT the s390 compare-and-swap does imply a barrier, however there
are some immediate ops that seem to be singly-copy atomic and do not
imply a barrier. One such is the "ni" op (which would be
and-immediate) which is used for the constant clear_bit
implementation. Therefore s390 needs full barriers for the
{before,after} atomic ops.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-kme5dz5hcobpnufnnkh1ech2@git.kernel.org
Cc: Chen Gang <gang.chen@asianux.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux390@de.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/s390/include/asm/atomic.h
arch/s390/include/asm/barrier.h