[PATCH 3/6] MIPS: Octeon: qspinlock: Flush write buffer

[Alexander A Sverdlin]

From: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>

Flushing the write buffer brings aroung 10% performace on the tight
uncontended spinlock loops on Octeon. Refer to commit 500c2e1fdbcc
("MIPS: Optimize spinlocks.").

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>
---
 arch/mips/include/asm/spinlock.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/mips/include/asm/spinlock.h b/arch/mips/include/asm/spinlock.h
index 8a88eb2..0a707f3 100644
--- a/arch/mips/include/asm/spinlock.h
+++ b/arch/mips/include/asm/spinlock.h
@@ -24,6 +24,9 @@ static inline void queued_spin_unlock(struct qspinlock *lock)
 	/* This could be optimised with ARCH_HAS_MMIOWB */
 	mmiowb();
 	smp_store_release(&lock->locked, 0);
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+	nudge_writes();
+#endif
 }
 
 #include <asm/qspinlock.h>
-- 
2.10.2