diff --git a/kernel/up.c b/kernel/up.c
index 630d72b..509403e 100644
--- a/kernel/up.c
+++ b/kernel/up.c
@@ -22,6 +22,17 @@
 }
 EXPORT_SYMBOL(smp_call_function_single);
 
+void __smp_call_function_single(int cpu, struct call_single_data *csd,
+				int wait)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	csd->func(csd->info);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(__smp_call_function_single);
+
 int on_each_cpu(smp_call_func_t func, void *info, int wait)
 {
 	unsigned long flags;