srcu: Export process_srcu()

Because process_srcu() will be used in DEFINE_SRCU(), which is a macro
that could be expanded pretty much anywhere, it can no longer be static.
Note that process_srcu() is still internal to srcu.h.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

include/linux/srcu.h

@@ -78,6 +78,8 @@ int init_srcu_struct(struct srcu_struct *sp);
 
 #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
 
+void process_srcu(struct work_struct *work);
+
 /**
  * call_srcu() - Queue a callback for invocation after an SRCU grace period
  * @sp: srcu_struct in queue the callback

kernel/srcu.c

@@ -94,9 +94,6 @@ static inline void rcu_batch_move(struct rcu_batch *to, struct rcu_batch *from)
 	}
 }
 
-/* single-thread state-machine */
-static void process_srcu(struct work_struct *work);
-
 static int init_srcu_struct_fields(struct srcu_struct *sp)
 {
 	sp->completed = 0;
@@ -639,7 +636,7 @@ static void srcu_reschedule(struct srcu_struct *sp)
 /*
  * This is the work-queue function that handles SRCU grace periods.
  */
-static void process_srcu(struct work_struct *work)
+void process_srcu(struct work_struct *work)
 {
 	struct srcu_struct *sp;
 
@@ -650,3 +647,4 @@ static void process_srcu(struct work_struct *work)
 	srcu_invoke_callbacks(sp);
 	srcu_reschedule(sp);
 }
+EXPORT_SYMBOL_GPL(process_srcu);