From 493c1822825f00025d6754ec0632990a27edc6f8 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <frederic@kernel.org>
Date: Wed, 8 Jun 2022 16:40:27 +0200
Subject: context_tracking: Take NMI eqs entrypoints over RCU

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

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>
---
 kernel/context_tracking.c | 10 ++++++++++
 kernel/entry/common.c     |  4 ++--
 kernel/extable.c          |  4 ++--
 kernel/trace/trace.c      |  2 +-
 4 files changed, 15 insertions(+), 5 deletions(-)

(limited to 'kernel')

diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 72bd71a02c44..b8a731f20778 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -55,6 +55,16 @@ void ct_irq_exit_irqson(void)
 {
 	rcu_irq_exit_irqson();
 }
+
+noinstr void ct_nmi_enter(void)
+{
+	rcu_nmi_enter();
+}
+
+noinstr void ct_nmi_exit(void)
+{
+	rcu_nmi_exit();
+}
 #endif /* #ifdef CONFIG_CONTEXT_TRACKING_IDLE */
 
 #ifdef CONFIG_CONTEXT_TRACKING_USER
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index 667ba5d581ff..063068a9ea9b 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -449,7 +449,7 @@ irqentry_state_t noinstr irqentry_nmi_enter(struct pt_regs *regs)
 	__nmi_enter();
 	lockdep_hardirqs_off(CALLER_ADDR0);
 	lockdep_hardirq_enter();
-	rcu_nmi_enter();
+	ct_nmi_enter();
 
 	instrumentation_begin();
 	trace_hardirqs_off_finish();
@@ -469,7 +469,7 @@ void noinstr irqentry_nmi_exit(struct pt_regs *regs, irqentry_state_t irq_state)
 	}
 	instrumentation_end();
 
-	rcu_nmi_exit();
+	ct_nmi_exit();
 	lockdep_hardirq_exit();
 	if (irq_state.lockdep)
 		lockdep_hardirqs_on(CALLER_ADDR0);
diff --git a/kernel/extable.c b/kernel/extable.c
index bda5e9761541..71f482581cab 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -114,7 +114,7 @@ int kernel_text_address(unsigned long addr)
 
 	/* Treat this like an NMI as it can happen anywhere */
 	if (no_rcu)
-		rcu_nmi_enter();
+		ct_nmi_enter();
 
 	if (is_module_text_address(addr))
 		goto out;
@@ -127,7 +127,7 @@ int kernel_text_address(unsigned long addr)
 	ret = 0;
 out:
 	if (no_rcu)
-		rcu_nmi_exit();
+		ct_nmi_exit();
 
 	return ret;
 }
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index fe78a6818126..5fc7f17f5ec7 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3105,7 +3105,7 @@ void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
 	}
 
 	/*
-	 * When an NMI triggers, RCU is enabled via rcu_nmi_enter(),
+	 * When an NMI triggers, RCU is enabled via ct_nmi_enter(),
 	 * but if the above rcu_is_watching() failed, then the NMI
 	 * triggered someplace critical, and ct_irq_enter() should
 	 * not be called from NMI.
-- 
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