context_tracking: Take IRQ eqs entrypoints over RCU

The RCU dynticks counter is going to be merged into the context tracking
subsystem. Prepare with moving the IRQ extended quiescent states
entrypoints to context tracking. For now those are dumb redirection to
existing RCU calls.

[ paulmck: Apply Stephen Rothwell feedback from -next. ]
[ paulmck: Apply Nathan Chancellor feedback. ]

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>

5 files changed, 28 insertions, 9 deletions

diff --git a/include/linux/context_tracking_irq.h b/include/linux/context_tracking_irq.h
new file mode 100644
index 000000000000..62f62bbd1a50
--- /dev/null
+++ b/include/linux/context_tracking_irq.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_CONTEXT_TRACKING_IRQ_H
+#define _LINUX_CONTEXT_TRACKING_IRQ_H
+
+#ifdef CONFIG_CONTEXT_TRACKING_IDLE
+void ct_irq_enter(void);
+void ct_irq_exit(void);
+void ct_irq_enter_irqson(void);
+void ct_irq_exit_irqson(void);
+#else
+static inline void ct_irq_enter(void) { }
+static inline void ct_irq_exit(void) { }
+static inline void ct_irq_enter_irqson(void) { }
+static inline void ct_irq_exit_irqson(void) { }
+#endif
+
+#endif
diff --git a/include/linux/context_tracking_state.h b/include/linux/context_tracking_state.h
index 2b46afe105a9..9c16a8b2c194 100644
--- a/include/linux/context_tracking_state.h
+++ b/include/linux/context_tracking_state.h
@@ -4,6 +4,7 @@
 
 #include <linux/percpu.h>
 #include <linux/static_key.h>
+#include <linux/context_tracking_irq.h>
 
 struct context_tracking {
 	/*
diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h
index c92ac75d6556..84a466b176cf 100644
--- a/include/linux/entry-common.h
+++ b/include/linux/entry-common.h
@@ -357,7 +357,7 @@ void irqentry_exit_to_user_mode(struct pt_regs *regs);
 /**
  * struct irqentry_state - Opaque object for exception state storage
  * @exit_rcu: Used exclusively in the irqentry_*() calls; signals whether the
- *            exit path has to invoke rcu_irq_exit().
+ *            exit path has to invoke ct_irq_exit().
  * @lockdep: Used exclusively in the irqentry_nmi_*() calls; ensures that
  *           lockdep state is restored correctly on exit from nmi.
  *
@@ -395,12 +395,12 @@ typedef struct irqentry_state {
  *
  * For kernel mode entries RCU handling is done conditional. If RCU is
  * watching then the only RCU requirement is to check whether the tick has
- * to be restarted. If RCU is not watching then rcu_irq_enter() has to be
- * invoked on entry and rcu_irq_exit() on exit.
+ * to be restarted. If RCU is not watching then ct_irq_enter() has to be
+ * invoked on entry and ct_irq_exit() on exit.
  *
- * Avoiding the rcu_irq_enter/exit() calls is an optimization but also
+ * Avoiding the ct_irq_enter/exit() calls is an optimization but also
  * solves the problem of kernel mode pagefaults which can schedule, which
- * is not possible after invoking rcu_irq_enter() without undoing it.
+ * is not possible after invoking ct_irq_enter() without undoing it.
  *
  * For user mode entries irqentry_enter_from_user_mode() is invoked to
  * establish the proper context for NOHZ_FULL. Otherwise scheduling on exit
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 6ebe754501c3..f1562d91c67d 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -29,6 +29,7 @@
 #include <linux/lockdep.h>
 #include <asm/processor.h>
 #include <linux/cpumask.h>
+#include <linux/context_tracking_irq.h>
 
 #define ULONG_CMP_GE(a, b)	(ULONG_MAX / 2 >= (a) - (b))
 #define ULONG_CMP_LT(a, b)	(ULONG_MAX / 2 < (a) - (b))
@@ -143,9 +144,9 @@ static inline void rcu_nocb_flush_deferred_wakeup(void) { }
  */
 #define RCU_NONIDLE(a) \
 	do { \
-		rcu_irq_enter_irqson(); \
+		ct_irq_enter_irqson(); \
 		do { a; } while (0); \
-		rcu_irq_exit_irqson(); \
+		ct_irq_exit_irqson(); \
 	} while (0)
 
 /*
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 28031b15f878..55717a2eda08 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -200,13 +200,13 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
 		 */							\
 		if (rcuidle) {						\
 			__idx = srcu_read_lock_notrace(&tracepoint_srcu);\
-			rcu_irq_enter_irqson();				\
+			ct_irq_enter_irqson();				\
 		}							\
 									\
 		__DO_TRACE_CALL(name, TP_ARGS(args));			\
 									\
 		if (rcuidle) {						\
-			rcu_irq_exit_irqson();				\
+			ct_irq_exit_irqson();				\
 			srcu_read_unlock_notrace(&tracepoint_srcu, __idx);\
 		}							\
 									\