diff --git a/kernel/up.c b/kernel/up.c
new file mode 100644
index 0000000..ce62cc9
--- /dev/null
+++ b/kernel/up.c
@@ -0,0 +1,18 @@
+/*
+ * Uniprocessor-only support functions.  The counterpart to kernel/smp.c
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/smp.h>
+
+int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
+				int wait)
+{
+	WARN_ON(cpuid != 0);
+	local_irq_disable();
+	(func)(info);
+	local_irq_enable();
+	return 0;
+}
+EXPORT_SYMBOL(smp_call_function_single);