1 files changed, 48 insertions, 0 deletions
diff --git a/include/asm-ppc64/delay.h b/include/asm-ppc64/delay.h
new file mode 100644
index 000000000000..05f198cf73d9
--- /dev/null
+++ b/include/asm-ppc64/delay.h
@@ -0,0 +1,48 @@
+#ifndef _PPC64_DELAY_H
+#define _PPC64_DELAY_H
+
+/*
+ * Copyright 1996, Paul Mackerras.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * PPC64 Support added by Dave Engebretsen, Todd Inglett, Mike Corrigan,
+ * Anton Blanchard.
+ */
+
+extern unsigned long tb_ticks_per_usec;
+
+/* define these here to prevent circular dependencies */ 
+#define __HMT_low()	asm volatile("or 1,1,1")
+#define __HMT_medium()	asm volatile("or 2,2,2")
+#define __barrier()	asm volatile("":::"memory")
+
+static inline unsigned long __get_tb(void)
+{
+	unsigned long rval;
+
+	asm volatile("mftb %0" : "=r" (rval));
+	return rval;
+}
+
+static inline void __delay(unsigned long loops)
+{
+	unsigned long start = __get_tb();
+
+	while((__get_tb()-start) < loops)
+		__HMT_low();
+	__HMT_medium();
+	__barrier();
+}
+
+static inline void udelay(unsigned long usecs)
+{
+	unsigned long loops = tb_ticks_per_usec * usecs;
+
+	__delay(loops);
+}
+
+#endif /* _PPC64_DELAY_H */