+#ifdef CONFIG_HOTPLUG_CPU
+/* State of each CPU during hotplug phases */
+DEFINE_PER_CPU(int, cpu_state) = { 0 };
+
+int generic_cpu_disable(void)
+{
+ unsigned int cpu = smp_processor_id();
+
+ if (cpu == boot_cpuid)
+ return -EBUSY;
+
+ systemcfg->processorCount--;
+ cpu_clear(cpu, cpu_online_map);
+ fixup_irqs(cpu_online_map);
+ return 0;
+}
+
+int generic_cpu_enable(unsigned int cpu)
+{
+ /* Do the normal bootup if we haven't
+ * already bootstrapped. */
+ if (system_state != SYSTEM_RUNNING)
+ return -ENOSYS;
+
+ /* get the target out of it's holding state */
+ per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
+ smp_wmb();
+
+ while (!cpu_online(cpu))
+ cpu_relax();
+
+ fixup_irqs(cpu_online_map);
+ /* counter the irq disable in fixup_irqs */
+ local_irq_enable();
+ return 0;
+}
+
+void generic_cpu_die(unsigned int cpu)
+{
+ int i;
+
+ for (i = 0; i < 100; i++) {
+ smp_rmb();
+ if (per_cpu(cpu_state, cpu) == CPU_DEAD)
+ return;
+ msleep(100);
+ }
+ printk(KERN_ERR "CPU%d didn't die...\n", cpu);
+}
+
+void generic_mach_cpu_die(void)
+{
+ unsigned int cpu;
+
+ local_irq_disable();
+ cpu = smp_processor_id();
+ printk(KERN_DEBUG "CPU%d offline\n", cpu);
+ __get_cpu_var(cpu_state) = CPU_DEAD;
+ smp_wmb();
+ while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
+ cpu_relax();
+
+ flush_tlb_pending();
+ cpu_set(cpu, cpu_online_map);
+ local_irq_enable();
+}
+#endif
+
+static int __devinit cpu_enable(unsigned int cpu)
+{
+ if (smp_ops->cpu_enable)
+ return smp_ops->cpu_enable(cpu);
+
+ return -ENOSYS;
+}
+