sched: Make cookie functions static

Make cookie functions static as these are no longer invoked directly
by other code.

No functional change intended.
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210922085735.52812-1-zhangshaokun@hisilicon.com

kernel/sched/core_sched.c

@@ -11,7 +11,7 @@ struct sched_core_cookie {
 	refcount_t refcnt;
 };
 
-unsigned long sched_core_alloc_cookie(void)
+static unsigned long sched_core_alloc_cookie(void)
 {
 	struct sched_core_cookie *ck = kmalloc(sizeof(*ck), GFP_KERNEL);
 	if (!ck)
@@ -23,7 +23,7 @@ unsigned long sched_core_alloc_cookie(void)
 	return (unsigned long)ck;
 }
 
-void sched_core_put_cookie(unsigned long cookie)
+static void sched_core_put_cookie(unsigned long cookie)
 {
 	struct sched_core_cookie *ptr = (void *)cookie;
 
@@ -33,7 +33,7 @@ void sched_core_put_cookie(unsigned long cookie)
 	}
 }
 
-unsigned long sched_core_get_cookie(unsigned long cookie)
+static unsigned long sched_core_get_cookie(unsigned long cookie)
 {
 	struct sched_core_cookie *ptr = (void *)cookie;
 
@@ -53,7 +53,8 @@ unsigned long sched_core_get_cookie(unsigned long cookie)
  *
  * Returns: the old cookie
  */
-unsigned long sched_core_update_cookie(struct task_struct *p, unsigned long cookie)
+static unsigned long sched_core_update_cookie(struct task_struct *p,
+					      unsigned long cookie)
 {
 	unsigned long old_cookie;
 	struct rq_flags rf;

kernel/sched/sched.h

@@ -1258,11 +1258,6 @@ extern void sched_core_dequeue(struct rq *rq, struct task_struct *p);
 extern void sched_core_get(void);
 extern void sched_core_put(void);
 
-extern unsigned long sched_core_alloc_cookie(void);
-extern void sched_core_put_cookie(unsigned long cookie);
-extern unsigned long sched_core_get_cookie(unsigned long cookie);
-extern unsigned long sched_core_update_cookie(struct task_struct *p, unsigned long cookie);
-
 #else /* !CONFIG_SCHED_CORE */
 
 static inline bool sched_core_enabled(struct rq *rq)