diff --git a/[refs] b/[refs]
index 6ac40a622990..8ded69bad656 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 44d06ba72990893eb5506516b25ccaf3a757ffc0
+refs/heads/master: 643d3c139b0a5289d7f0ba19fdcb24be6d7e768f
diff --git a/trunk/arch/powerpc/boot/devtree.c b/trunk/arch/powerpc/boot/devtree.c
index c9951550ed2c..ae8b886f5a1d 100644
--- a/trunk/arch/powerpc/boot/devtree.c
+++ b/trunk/arch/powerpc/boot/devtree.c
@@ -74,6 +74,8 @@ void dt_fixup_cpu_clocks(u32 cpu, u32 tb, u32 bus)
 		if (bus > 0)
 			setprop_val(devp, "bus-frequency", bus);
 	}
+
+	timebase_period_ns = 1000000000 / tb;
 }
 
 void dt_fixup_clock(const char *path, u32 freq)
diff --git a/trunk/arch/powerpc/boot/ops.h b/trunk/arch/powerpc/boot/ops.h
index 86077066cd7c..aebd6edc9a90 100644
--- a/trunk/arch/powerpc/boot/ops.h
+++ b/trunk/arch/powerpc/boot/ops.h
@@ -191,4 +191,6 @@ static inline void exit(void)
 	static char _bss_stack[size]; \
 	void *_platform_stack_top = _bss_stack + sizeof(_bss_stack);
 
+extern unsigned long timebase_period_ns;
+
 #endif /* _PPC_BOOT_OPS_H_ */