linux-kernel - [RFC][PATCH 3/9] cpuidle: Move IRQ state validation

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Message-ID: <20220519213421.748352112@infradead.org>
Date:   Thu, 19 May 2022 23:27:53 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     frederic@...nel.org, paulmck@...nel.org, rjw@...ysocki.net,
        x86@...nel.org
Cc:     linux-kernel@...r.kernel.org, peterz@...radead.org,
        jpoimboe@...nel.org
Subject: [RFC][PATCH 3/9] cpuidle: Move IRQ state validation

Make cpuidle_enter_state() consistent with the s2idle variant and
verify ->enter() always returns with interrupts disabled.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 drivers/cpuidle/cpuidle.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -234,7 +234,11 @@ int cpuidle_enter_state(struct cpuidle_d
 	stop_critical_timings();
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
 		rcu_idle_enter();
+
 	entered_state = target_state->enter(dev, drv, index);
+	if (WARN_ON_ONCE(!irqs_disabled()))
+		raw_local_irq_disable();
+
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
 		rcu_idle_exit();
 	start_critical_timings();
@@ -246,12 +250,8 @@ int cpuidle_enter_state(struct cpuidle_d
 	/* The cpu is no longer idle or about to enter idle. */
 	sched_idle_set_state(NULL);
 
-	if (broadcast) {
-		if (WARN_ON_ONCE(!irqs_disabled()))
-			local_irq_disable();
-
+	if (broadcast)
 		tick_broadcast_exit();
-	}
 
 	if (!cpuidle_state_is_coupled(drv, index))
 		local_irq_enable();