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Commit 1c8db713 authored by Paul Mundt's avatar Paul Mundt
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sh: Fix up smp_mb__xxx() memory barriers for SH-4A SMP. 



In the past these were simply wrapping to barrier() which was sufficient
on SH SMP platforms predating SH-4A. Unfortunately due to ll/sc semantics
an explicit synco is needed in these cases, which is sorted for us by
just switching these over to smp_mb(). smp_mb() also has the benefit of
being wrapped to barrier() in the UP and non-SH4A cases, so old behaviour
is maintained for those parts.

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 15dfdddb

arch/sh/include/asm/atomic.h

+4 −5
Original line number Diff line number Diff line
@@ -78,11 +78,10 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u) 
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))

#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)



/* Atomic operations are already serializing on SH */

#define smp_mb__before_atomic_dec()	barrier()

#define smp_mb__after_atomic_dec()	barrier()

#define smp_mb__before_atomic_inc()	barrier()

#define smp_mb__after_atomic_inc()	barrier()

#define smp_mb__before_atomic_dec()	smp_mb()

#define smp_mb__after_atomic_dec()	smp_mb()

#define smp_mb__before_atomic_inc()	smp_mb()

#define smp_mb__after_atomic_inc()	smp_mb()



#include <asm-generic/atomic-long.h>

#include <asm-generic/atomic64.h>

arch/sh/include/asm/bitops.h

+2 −2
Original line number Diff line number Diff line
@@ -26,8 +26,8 @@ 
/*

 * clear_bit() doesn't provide any barrier for the compiler.

 */

#define smp_mb__before_clear_bit()	barrier()

#define smp_mb__after_clear_bit()	barrier()

#define smp_mb__before_clear_bit()	smp_mb()

#define smp_mb__after_clear_bit()	smp_mb()



#ifdef CONFIG_SUPERH32

static inline unsigned long ffz(unsigned long word)