rcu/context_tracking: Move dynticks counter to context tracking

In order to prepare for merging RCU dynticks counter into the context
tracking state, move the rcu_data's dynticks field to the context
tracking structure. It will later be mixed within the context tracking
state itself.

[ paulmck: Move enum ctx_state into global scope. ]

Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>

1 files changed, 38 insertions, 7 deletions

diff --git a/include/linux/context_tracking_state.h b/include/linux/context_tracking_state.h
index 9c16a8b2c194..5a8da2787287 100644
--- a/include/linux/context_tracking_state.h
+++ b/include/linux/context_tracking_state.h
@@ -6,7 +6,15 @@
 #include <linux/static_key.h>
 #include <linux/context_tracking_irq.h>
 
+enum ctx_state {
+	CONTEXT_DISABLED = -1,	/* returned by ct_state() if unknown */
+	CONTEXT_KERNEL = 0,
+	CONTEXT_USER,
+	CONTEXT_GUEST,
+};
+
 struct context_tracking {
+#ifdef CONFIG_CONTEXT_TRACKING_USER
 	/*
 	 * When active is false, probes are unset in order
 	 * to minimize overhead: TIF flags are cleared
@@ -15,17 +23,40 @@ struct context_tracking {
 	 */
 	bool active;
 	int recursion;
-	enum ctx_state {
-		CONTEXT_DISABLED = -1,	/* returned by ct_state() if unknown */
-		CONTEXT_KERNEL = 0,
-		CONTEXT_USER,
-		CONTEXT_GUEST,
-	} state;
+	enum ctx_state state;
+#endif
+#ifdef CONFIG_CONTEXT_TRACKING_IDLE
+	atomic_t dynticks;		/* Even value for idle, else odd. */
+#endif
 };
 
+#ifdef CONFIG_CONTEXT_TRACKING
+DECLARE_PER_CPU(struct context_tracking, context_tracking);
+#endif
+
+#ifdef CONFIG_CONTEXT_TRACKING_IDLE
+static __always_inline int ct_dynticks(void)
+{
+	return atomic_read(this_cpu_ptr(&context_tracking.dynticks));
+}
+
+static __always_inline int ct_dynticks_cpu(int cpu)
+{
+	struct context_tracking *ct = per_cpu_ptr(&context_tracking, cpu);
+
+	return atomic_read(&ct->dynticks);
+}
+
+static __always_inline int ct_dynticks_cpu_acquire(int cpu)
+{
+	struct context_tracking *ct = per_cpu_ptr(&context_tracking, cpu);
+
+	return atomic_read_acquire(&ct->dynticks);
+}
+#endif /* #ifdef CONFIG_CONTEXT_TRACKING_IDLE */
+
 #ifdef CONFIG_CONTEXT_TRACKING_USER
 extern struct static_key_false context_tracking_key;
-DECLARE_PER_CPU(struct context_tracking, context_tracking);
 
 static __always_inline bool context_tracking_enabled(void)
 {