sparc64: Make lock backoff really a NOP on UP builds.
As noticed by Mikulas Patocka, the backoff macros don't
completely nop out for UP builds, we still get a
branch always and a delay slot nop.
Fix this by making the branch to the backoff spin loop
selective, then we can nop out the spin loop completely.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/include/asm/backoff.h b/arch/sparc/include/asm/backoff.h
index fa1fdf6..db3af0d 100644
--- a/arch/sparc/include/asm/backoff.h
+++ b/arch/sparc/include/asm/backoff.h
@@ -8,6 +8,9 @@
#define BACKOFF_SETUP(reg) \
mov 1, reg
+#define BACKOFF_LABEL(spin_label, continue_label) \
+ spin_label
+
#define BACKOFF_SPIN(reg, tmp, label) \
mov reg, tmp; \
88: brnz,pt tmp, 88b; \
@@ -22,9 +25,11 @@
#else
#define BACKOFF_SETUP(reg)
-#define BACKOFF_SPIN(reg, tmp, label) \
- ba,pt %xcc, label; \
- nop;
+
+#define BACKOFF_LABEL(spin_label, continue_label) \
+ continue_label
+
+#define BACKOFF_SPIN(reg, tmp, label)
#endif