ANDROID: sched: Export few scheduler symbols for vendor modules

The following symbols are exported:

- cpu_scale: For arch_scale_cpu_capacity() API.

- update_rq_clock(): To refresh the rq->clock during task migrations.

- migrate_swap(): Brought of NUMA and exported. It is needed to
migrate tasks running on LITTLE and big CPUs.

Bug: 173468448
Change-Id: I72fb91c49abe365177acc3006ddd038cdb504188
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>

drivers/base/arch_topology.c

@@ -60,6 +60,7 @@ void topology_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq,
 }
 
 DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
+EXPORT_PER_CPU_SYMBOL_GPL(cpu_scale);
 
 void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity)
 {

kernel/sched/core.c

@@ -323,6 +323,7 @@ void update_rq_clock(struct rq *rq)
 	rq->clock += delta;
 	update_rq_clock_task(rq, delta);
 }
+EXPORT_SYMBOL_GPL(update_rq_clock);
 
 static inline void
 rq_csd_init(struct rq *rq, call_single_data_t *csd, smp_call_func_t func)
@@ -2015,7 +2016,6 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 }
 EXPORT_SYMBOL_GPL(set_task_cpu);
 
-#ifdef CONFIG_NUMA_BALANCING
 static void __migrate_swap_task(struct task_struct *p, int cpu)
 {
 	if (task_on_rq_queued(p)) {
@@ -2130,7 +2130,7 @@ int migrate_swap(struct task_struct *cur, struct task_struct *p,
 out:
 	return ret;
 }
-#endif /* CONFIG_NUMA_BALANCING */
+EXPORT_SYMBOL_GPL(migrate_swap);
 
 /*
  * wait_task_inactive - wait for a thread to unschedule.

kernel/sched/sched.h

@@ -1379,8 +1379,6 @@ enum numa_faults_stats {
 };
 extern void sched_setnuma(struct task_struct *p, int node);
 extern int migrate_task_to(struct task_struct *p, int cpu);
-extern int migrate_swap(struct task_struct *p, struct task_struct *t,
-			int cpu, int scpu);
 extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p);
 #else
 static inline void
@@ -1391,6 +1389,8 @@ init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
 
 #ifdef CONFIG_SMP
 
+extern int migrate_swap(struct task_struct *p, struct task_struct *t,
+			int cpu, int scpu);
 static inline void
 queue_balance_callback(struct rq *rq,
 		       struct callback_head *head,