Blackfin's atomic primitives do not imply a full barrier as whitnessed
from its SMP smp_mb__{before,after}_clear_bit() implementations.
However since !SMP smp_mb() reduces to barrier() remove everything and
rely on the asm-generic/barrier.h implentation.
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
arch/blackfin/include/asm/barrier.h | 3 +++
arch/blackfin/include/asm/bitops.h | 14 ++------------
2 files changed, 5 insertions(+), 12 deletions(-)
--- a/arch/blackfin/include/asm/barrier.h
+++ b/arch/blackfin/include/asm/barrier.h
@@ -27,6 +27,9 @@
#endif /* !CONFIG_SMP */
+#define smp_mb__before_atomic() barrier()
+#define smp_mb__after_atomic() barrier()
+
#include <asm-generic/barrier.h>
#endif /* _BLACKFIN_BARRIER_H */
--- a/arch/blackfin/include/asm/bitops.h
+++ b/arch/blackfin/include/asm/bitops.h
@@ -27,21 +27,17 @@
#include <asm-generic/bitops/ext2-atomic.h>
+#include <asm/barrier.h>
+
#ifndef CONFIG_SMP
#include <linux/irqflags.h>
-
/*
* clear_bit may not imply a memory barrier
*/
-#ifndef smp_mb__before_clear_bit
-#define smp_mb__before_clear_bit() smp_mb()
-#define smp_mb__after_clear_bit() smp_mb()
-#endif
#include <asm-generic/bitops/atomic.h>
#include <asm-generic/bitops/non-atomic.h>
#else
-#include <asm/barrier.h>
#include <asm/byteorder.h> /* swab32 */
#include <linux/linkage.h>
@@ -101,12 +97,6 @@ static inline int test_and_change_bit(in
return __raw_bit_test_toggle_asm(a, nr & 0x1f);
}
-/*
- * 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 test_bit __skip_test_bit
#include <asm-generic/bitops/non-atomic.h>
#undef test_bit
--
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