alpha: fix bitops

Documentation/atomic_ops.txt defines these primitives must contain a memory
barrier both before and after their memory operation.  This is consistent with
the atomic ops implementation on alpha.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/asm-alpha/bitops.h b/include/asm-alpha/bitops.h
index ca667d121898..f1bbe6cf0e84 100644
--- a/include/asm-alpha/bitops.h
+++ b/include/asm-alpha/bitops.h
@@ -117,6 +117,9 @@ test_and_set_bit(unsigned long nr, volatile void *addr)
         int *m = ((int *) addr) + (nr >> 5);
 
         __asm__ __volatile__(
+#ifdef CONFIG_SMP
+        "       mb\n"
+#endif
         "1:     ldl_l %0,%4\n"
         "       and %0,%3,%2\n"
         "       bne %2,2f\n"
@@ -158,6 +161,9 @@ test_and_clear_bit(unsigned long nr, volatile void * addr)
         int *m = ((int *) addr) + (nr >> 5);
 
         __asm__ __volatile__(
+#ifdef CONFIG_SMP
+        "       mb\n"
+#endif
         "1:     ldl_l %0,%4\n"
         "       and %0,%3,%2\n"
         "       beq %2,2f\n"
@@ -199,6 +205,9 @@ test_and_change_bit(unsigned long nr, volatile void * addr)
         int *m = ((int *) addr) + (nr >> 5);
 
         __asm__ __volatile__(
+#ifdef CONFIG_SMP
+        "       mb\n"
+#endif
         "1:     ldl_l %0,%4\n"
         "       and %0,%3,%2\n"
         "       xor %0,%3,%0\n"