x86: unify x86_32 and x86_64 play_dead into one function

Add the new play_dead into smpboot.c, as it fits more cleanly in there
alongside other CONFIG_HOTPLUG functions.

Separate out the common code into its own function.
Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/process_32.c

@@ -72,38 +72,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
 	return ((unsigned long *)tsk->thread.sp)[3];
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
-#include <asm/nmi.h>
-
-/* We don't actually take CPU down, just spin without interrupts. */
-void native_play_dead(void)
-{
-	int cpu = raw_smp_processor_id();
-
-	idle_task_exit();
-
-	reset_lazy_tlbstate();
-
-	irq_ctx_exit(cpu);
-
-	mb();
-	/* Ack it */
-	__get_cpu_var(cpu_state) = CPU_DEAD;
-
-	/*
-	 * With physical CPU hotplug, we should halt the cpu
-	 */
-	local_irq_disable();
-	/* mask all interrupts, flush any and all caches, and halt */
-	wbinvd_halt();
-}
-#else
-void native_play_dead(void)
-{
-	BUG();
-}
-#endif /* CONFIG_HOTPLUG_CPU */
-
 /*
  * The idle thread. There's no useful work to be
  * done, so just try to conserve power and have a

arch/x86/kernel/process_64.c

@@ -85,29 +85,6 @@ void exit_idle(void)
 	__exit_idle();
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
-DECLARE_PER_CPU(int, cpu_state);
-
-#include <asm/nmi.h>
-/* We halt the CPU with physical CPU hotplug */
-void native_play_dead(void)
-{
-	idle_task_exit();
-	mb();
-	/* Ack it */
-	__get_cpu_var(cpu_state) = CPU_DEAD;
-
-	local_irq_disable();
-	/* mask all interrupts, flush any and all caches, and halt */
-	wbinvd_halt();
-}
-#else
-void native_play_dead(void)
-{
-	BUG();
-}
-#endif /* CONFIG_HOTPLUG_CPU */
-
 /*
  * The idle thread. There's no useful work to be
  * done, so just try to conserve power and have a

arch/x86/kernel/smpboot.c

@@ -1402,6 +1402,29 @@ void native_cpu_die(unsigned int cpu)
 	}
 	printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 }
+
+void play_dead_common(void)
+{
+	idle_task_exit();
+	reset_lazy_tlbstate();
+	irq_ctx_exit(raw_smp_processor_id());
+
+	mb();
+	/* Ack it */
+	__get_cpu_var(cpu_state) = CPU_DEAD;
+
+	/*
+	 * With physical CPU hotplug, we should halt the cpu
+	 */
+	local_irq_disable();
+}
+
+void native_play_dead(void)
+{
+	play_dead_common();
+	wbinvd_halt();
+}
+
 #else /* ... !CONFIG_HOTPLUG_CPU */
 int native_cpu_disable(void)
 {
@@ -1413,4 +1436,10 @@ void native_cpu_die(unsigned int cpu)
 	/* We said "no" in __cpu_disable */
 	BUG();
 }
+
+void native_play_dead(void)
+{
+	BUG();
+}
+
 #endif

include/asm-x86/smp.h

@@ -132,6 +132,7 @@ int native_cpu_up(unsigned int cpunum);
 int native_cpu_disable(void);
 void native_cpu_die(unsigned int cpu);
 void native_play_dead(void);
+void play_dead_common(void);
 
 void native_send_call_func_ipi(cpumask_t mask);
 void native_send_call_func_single_ipi(int cpu);