[PATCH] alpha: atomic dependency fix

My alpha build is exploding because asm/atomic.h now needs smb_mb(), which is
over in the (not included) system.h.

I fear what will happen if I include system.h into atomic.h, so let's put the
barriers into their own header file.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/include/asm-alpha/barrier.h b/include/asm-alpha/barrier.h
new file mode 100644
index 0000000..229c83f
--- /dev/null
+++ b/include/asm-alpha/barrier.h
@@ -0,0 +1,34 @@
+#ifndef __BARRIER_H
+#define __BARRIER_H
+
+#define mb() \
+__asm__ __volatile__("mb": : :"memory")
+
+#define rmb() \
+__asm__ __volatile__("mb": : :"memory")
+
+#define wmb() \
+__asm__ __volatile__("wmb": : :"memory")
+
+#define read_barrier_depends() \
+__asm__ __volatile__("mb": : :"memory")
+
+#ifdef CONFIG_SMP
+#define smp_mb()	mb()
+#define smp_rmb()	rmb()
+#define smp_wmb()	wmb()
+#define smp_read_barrier_depends()	read_barrier_depends()
+#else
+#define smp_mb()	barrier()
+#define smp_rmb()	barrier()
+#define smp_wmb()	barrier()
+#define smp_read_barrier_depends()	barrier()
+#endif
+
+#define set_mb(var, value) \
+do { var = value; mb(); } while (0)
+
+#define set_wmb(var, value) \
+do { var = value; wmb(); } while (0)
+
+#endif		/* __BARRIER_H */