diff --git a/include/linux/cpu.h b/include/linux/cpu.h
new file mode 100644
index 0000000..fe0298e
--- /dev/null
+++ b/include/linux/cpu.h
@@ -0,0 +1,83 @@
+/*
+ * include/linux/cpu.h - generic cpu definition
+ *
+ * This is mainly for topological representation. We define the 
+ * basic 'struct cpu' here, which can be embedded in per-arch 
+ * definitions of processors.
+ *
+ * Basic handling of the devices is done in drivers/base/cpu.c
+ * and system devices are handled in drivers/base/sys.c. 
+ *
+ * CPUs are exported via driverfs in the class/cpu/devices/
+ * directory. 
+ *
+ * Per-cpu interfaces can be implemented using a struct device_interface. 
+ * See the following for how to do this: 
+ * - drivers/base/intf.c 
+ * - Documentation/driver-model/interface.txt
+ */
+#ifndef _LINUX_CPU_H_
+#define _LINUX_CPU_H_
+
+#include <linux/sysdev.h>
+#include <linux/node.h>
+#include <linux/compiler.h>
+#include <linux/cpumask.h>
+#include <asm/semaphore.h>
+
+struct cpu {
+	int node_id;		/* The node which contains the CPU */
+	int no_control;		/* Should the sysfs control file be created? */
+	struct sys_device sysdev;
+};
+
+extern int register_cpu(struct cpu *, int, struct node *);
+#ifdef CONFIG_HOTPLUG_CPU
+extern void unregister_cpu(struct cpu *, struct node *);
+#endif
+struct notifier_block;
+
+#ifdef CONFIG_SMP
+/* Need to know about CPUs going up/down? */
+extern int register_cpu_notifier(struct notifier_block *nb);
+extern void unregister_cpu_notifier(struct notifier_block *nb);
+
+int cpu_up(unsigned int cpu);
+
+#else
+
+static inline int register_cpu_notifier(struct notifier_block *nb)
+{
+	return 0;
+}
+static inline void unregister_cpu_notifier(struct notifier_block *nb)
+{
+}
+
+#endif /* CONFIG_SMP */
+extern struct sysdev_class cpu_sysdev_class;
+
+#ifdef CONFIG_HOTPLUG_CPU
+/* Stop CPUs going up and down. */
+extern struct semaphore cpucontrol;
+#define lock_cpu_hotplug()	down(&cpucontrol)
+#define unlock_cpu_hotplug()	up(&cpucontrol)
+#define lock_cpu_hotplug_interruptible() down_interruptible(&cpucontrol)
+#define hotcpu_notifier(fn, pri) {				\
+	static struct notifier_block fn##_nb =			\
+		{ .notifier_call = fn, .priority = pri };	\
+	register_cpu_notifier(&fn##_nb);			\
+}
+int cpu_down(unsigned int cpu);
+#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
+#else
+#define lock_cpu_hotplug()	do { } while (0)
+#define unlock_cpu_hotplug()	do { } while (0)
+#define lock_cpu_hotplug_interruptible() 0
+#define hotcpu_notifier(fn, pri)
+
+/* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
+static inline int cpu_is_offline(int cpu) { return 0; }
+#endif
+
+#endif /* _LINUX_CPU_H_ */