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Diffstat (limited to 'arch/sparc/include/asm/backoff.h')
-rw-r--r--arch/sparc/include/asm/backoff.h31
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/backoff.h b/arch/sparc/include/asm/backoff.h
new file mode 100644
index 00000000000..fa1fdf67e35
--- /dev/null
+++ b/arch/sparc/include/asm/backoff.h
@@ -0,0 +1,31 @@
+#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; \
+ set BACKOFF_LIMIT, tmp; \
+ cmp reg, tmp; \
+ bg,pn %xcc, label; \
+ nop; \
+ ba,pt %xcc, label; \
+ sllx reg, 1, reg;
+
+#else
+
+#define BACKOFF_SETUP(reg)
+#define BACKOFF_SPIN(reg, tmp, label) \
+ ba,pt %xcc, label; \
+ nop;
+
+#endif
+
+#endif /* _SPARC64_BACKOFF_H */