3.13.11.7 -stable review patch.  If anyone has any objections, please let me 
know.

------------------

From: Christian Borntraeger <[email protected]>

commit 36e7fdaa1a04fcf65b864232e1af56a51c7814d6 upstream.

commit 4badad352a6bb202ec68afa7a574c0bb961e5ebc (locking/mutex: Disable
optimistic spinning on some architectures) fenced spinning for
architectures without proper cmpxchg.
There is no need to disable mutex spinning on s390, though:
The instructions CS,CSG and friends provide the proper guarantees.
(We dont implement cmpxchg with locks).

Signed-off-by: Christian Borntraeger <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
---
 arch/s390/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index c8d8283..8993c96 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -93,6 +93,7 @@ config S390
        select ARCH_INLINE_WRITE_UNLOCK_IRQ
        select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
        select ARCH_SAVE_PAGE_KEYS if HIBERNATION
+       select ARCH_SUPPORTS_ATOMIC_RMW
        select ARCH_USE_CMPXCHG_LOCKREF
        select ARCH_WANT_IPC_PARSE_VERSION
        select BUILDTIME_EXTABLE_SORT
-- 
1.9.1

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