From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755833Ab1EKU7v (ORCPT ); Wed, 11 May 2011 16:59:51 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:35498 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755438Ab1EKU7t (ORCPT ); Wed, 11 May 2011 16:59:49 -0400 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, patches@linaro.org, "Paul E. McKenney" , "Paul E. McKenney" Subject: [PATCH tip/core/rcu 2/3] atomic: add atomic_or() Date: Wed, 11 May 2011 13:59:36 -0700 Message-Id: <1305147577-1812-2-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.3.2 In-Reply-To: <20110511205915.GA1731@linux.vnet.ibm.com> References: <20110511205915.GA1731@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul E. McKenney An atomic_or() function is needed by TREE_RCU to avoid deadlock, so add a generic version. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- include/linux/atomic.h | 13 +++++++++++++ 1 files changed, 13 insertions(+), 0 deletions(-) diff --git a/include/linux/atomic.h b/include/linux/atomic.h index 96c038e..ee456c7 100644 --- a/include/linux/atomic.h +++ b/include/linux/atomic.h @@ -34,4 +34,17 @@ static inline int atomic_inc_not_zero_hint(atomic_t *v, int hint) } #endif +#ifndef CONFIG_ARCH_HAS_ATOMIC_OR +static inline void atomic_or(int i, atomic_t *v) +{ + int old; + int new; + + do { + old = atomic_read(v); + new = old | i; + } while (atomic_cmpxchg(v, old, new) != old); +} +#endif /* #ifndef CONFIG_ARCH_HAS_ATOMIC_OR */ + #endif /* _LINUX_ATOMIC_H */ -- 1.7.3.2