sched/headers: Split hotplug CPU interfaces out of <linux/sched.h> into <linux/sched/hotplug.h>

Split the CPU hotplug scheduler APIs out of the common header.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/sched/hotplug.h

@@ -3,4 +3,24 @@
 
 #include <linux/sched.h>
 
+/*
+ * Scheduler interfaces for hotplug CPU support:
+ */
+
+extern int sched_cpu_starting(unsigned int cpu);
+extern int sched_cpu_activate(unsigned int cpu);
+extern int sched_cpu_deactivate(unsigned int cpu);
+
+#ifdef CONFIG_HOTPLUG_CPU
+extern int sched_cpu_dying(unsigned int cpu);
+#else
+# define sched_cpu_dying	NULL
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+extern void idle_task_exit(void);
+#else
+static inline void idle_task_exit(void) {}
+#endif
+
 #endif /* _LINUX_SCHED_HOTPLUG_H */