sched/deadline: Unify dl_time_before() usage

Move dl_time_before() static definition in include/linux/sched/deadline.h
so that it can be used by different parties without being re-defined.

Reported-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441188096-23021-3-git-send-email-juri.lelli@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/sched/deadline.h

@@ -21,4 +21,9 @@ static inline int dl_task(struct task_struct *p)
 	return dl_prio(p->prio);
 }
 
+static inline bool dl_time_before(u64 a, u64 b)
+{
+	return (s64)(a - b) < 0;
+}
+
 #endif /* _SCHED_DEADLINE_H */

kernel/sched/cpudeadline.c

@@ -31,11 +31,6 @@ static inline int right_child(int i)
 	return (i << 1) + 2;
 }
 
-static inline int dl_time_before(u64 a, u64 b)
-{
-	return (s64)(a - b) < 0;
-}
-
 static void cpudl_exchange(struct cpudl *cp, int a, int b)
 {
 	int cpu_a = cp->elements[a].cpu, cpu_b = cp->elements[b].cpu;

kernel/sched/cpudeadline.h

@@ -2,6 +2,7 @@
 #define _LINUX_CPUDL_H
 
 #include <linux/sched.h>
+#include <linux/sched/deadline.h>
 
 #define IDX_INVALID     -1
 

kernel/sched/sched.h

@@ -118,11 +118,6 @@ static inline int task_has_dl_policy(struct task_struct *p)
 	return dl_policy(p->policy);
 }
 
-static inline bool dl_time_before(u64 a, u64 b)
-{
-	return (s64)(a - b) < 0;
-}
-
 /*
  * Tells if entity @a should preempt entity @b.
  */