1 files changed, 28 insertions, 0 deletions

diff --git a/include/asm-sparc64/backoff.h b/include/asm-sparc64/backoff.h
new file mode 100644
index 000000000000..0e32f8b62fd2
--- /dev/null
+++ b/include/asm-sparc64/backoff.h
@@ -0,0 +1,28 @@
+#ifndef _SPARC64_BACKOFF_H
+#define _SPARC64_BACKOFF_H
+
+#define BACKOFF_LIMIT   (4 * 1024)
+
+#ifdef CONFIG_SMP
+
+#define BACKOFF_SETUP(reg)      \
+        mov     1, reg
+
+#define BACKOFF_SPIN(reg, tmp, label)   \
+        mov     reg, tmp; \
+88:     brnz,pt tmp, 88b; \
+         sub    tmp, 1, tmp; \
+        cmp     reg, BACKOFF_LIMIT; \
+        bg,pn   %xcc, label; \
+         nop; \
+        ba,pt   %xcc, label; \
+         sllx   reg, 1, reg;
+
+#else
+
+#define BACKOFF_SETUP(reg)
+#define BACKOFF_SPIN(reg, tmp, label)
+
+#endif
+
+#endif /* _SPARC64_BACKOFF_H */