linux-stable.git/arch/arc/include/asm/bitops.h, branch linux-3.16.y Linux kernel stable tree ARC: add smp barriers around atomics per Documentation/atomic_ops.txt 2015-07-15T09:00:53+00:00 Vineet Gupta vgupta@synopsys.com 2014-11-20T10:12:09+00:00 2ef1fe7a71c72264feae4d0e47a7c7c941642103 commit 2576c28e3f623ed401db7e6197241865328620ef upstream. - arch_spin_lock/unlock were lacking the ACQUIRE/RELEASE barriers Since ARCv2 only provides load/load, store/store and all/all, we need the full barrier - LLOCK/SCOND based atomics, bitops, cmpxchg, which return modified values were lacking the explicit smp barriers. - Non LLOCK/SCOND varaints don't need the explicit barriers since that is implicity provided by the spin locks used to implement the critical section (the spin lock barriers in turn are also fixed in this commit as explained above Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> 
commit 2576c28e3f623ed401db7e6197241865328620ef upstream.

 - arch_spin_lock/unlock were lacking the ACQUIRE/RELEASE barriers
   Since ARCv2 only provides load/load, store/store and all/all, we need
   the full barrier

 - LLOCK/SCOND based atomics, bitops, cmpxchg, which return modified
   values were lacking the explicit smp barriers.

 - Non LLOCK/SCOND varaints don't need the explicit barriers since that
   is implicity provided by the spin locks used to implement the
   critical section (the spin lock barriers in turn are also fixed in
   this commit as explained above

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
arch,arc: Convert smp_mb__*() 2014-04-18T09:40:31+00:00 Peter Zijlstra peterz@infradead.org 2014-03-12T16:11:00+00:00 d594ffa94b7efdd8c6da5ee48aea8ae229809b55 The arc mb() implementation is a compiler barrier(), therefore it all doesn't matter one way or the other. Simply remove the existing definitions and use whatever is generated by the defaults. 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-ua48a59wri3ybz1rz8i7uvbr@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 
The arc mb() implementation is a compiler barrier(), therefore it all
doesn't matter one way or the other. Simply remove the existing
definitions and use whatever is generated by the defaults.

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-ua48a59wri3ybz1rz8i7uvbr@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
ARC: Atomic/bitops/cmpxchg/barriers 2013-02-11T14:30:30+00:00 Vineet Gupta vgupta@synopsys.com 2013-01-18T09:42:16+00:00 14e968bad788de922a755a84b92cb29f8c1342e4 This covers the UP / SMP (with no hardware assist for atomic r-m-w) as well as ARC700 LLOCK/SCOND insns based. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> 
This covers the UP / SMP (with no hardware assist for atomic r-m-w) as
well as ARC700 LLOCK/SCOND insns based.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>