[PATCH] rcu: add declarations of undeclared items

[Ben Dooks <ben.dooks@codethink.co.uk>]

The rcu_state, rcu_rnp_online_cpus and rcu_dynticks_curr_cpu_in_eqs
do not have declarations in a header. Add these to remove the
following sparse warnings:

kernel/rcu/tree.c:87:18: warning: symbol 'rcu_state' was not declared. Should it be static?
kernel/rcu/tree.c:191:15: warning: symbol 'rcu_rnp_online_cpus' was not declared. Should it be static?
kernel/rcu/tree.c:297:6: warning: symbol 'rcu_dynticks_curr_cpu_in_eqs' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
---
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 kernel/rcu/tree.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index c612f306fe89..1f88351b9014 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -352,6 +352,8 @@ struct rcu_state {
 						/*  GP pre-initialization. */
 };
 
+extern struct rcu_state rcu_state;
+
 /* Values for rcu_state structure's gp_flags field. */
 #define RCU_GP_FLAG_INIT 0x1	/* Need grace-period initialization. */
 #define RCU_GP_FLAG_FQS  0x2	/* Need grace-period quiescent-state forcing. */
@@ -472,3 +474,7 @@ static void rcu_iw_handler(struct irq_work *iwp);
 static void check_cpu_stall(struct rcu_data *rdp);
 static void rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp,
 				     const unsigned long gpssdelay);
+
+extern unsigned long rcu_rnp_online_cpus(struct rcu_node *rnp);
+extern bool rcu_dynticks_curr_cpu_in_eqs(void);
+
-- 
2.23.0