rcu: Re-arrange code to reduce #ifdef pain

Remove #ifdefs from kernel/rcupdate.c and
include/linux/rcupdate.h by moving code to
include/linux/rcutiny.h, include/linux/rcutree.h, and
kernel/rcutree.c.

Also remove some definitions that are no longer used.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1258908830885-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 111a652..c93eee5 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -35,12 +35,14 @@
 extern void rcu_sched_qs(int cpu);
 extern void rcu_bh_qs(int cpu);
 extern int rcu_needs_cpu(int cpu);
+extern void rcu_scheduler_starting(void);
 extern int rcu_expedited_torture_stats(char *page);
 
 #ifdef CONFIG_TREE_PREEMPT_RCU
 
 extern void __rcu_read_lock(void);
 extern void __rcu_read_unlock(void);
+extern void synchronize_rcu(void);
 extern void exit_rcu(void);
 
 #else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
@@ -55,7 +57,7 @@
 	preempt_enable();
 }
 
-#define __synchronize_sched() synchronize_rcu()
+#define synchronize_rcu synchronize_sched
 
 static inline void exit_rcu(void)
 {