From: Frederic Weisbecker <frederic@kernel.org>
Date: Wed, 2 Dec 2020 11:57:32 +0000 (+0100)
Subject: irq: Call tick_irq_enter() inside HARDIRQ_OFFSET
X-Git-Tag: accepted/tizen/unified/20230118.172025~8173^2~31
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d14ce74f1fb376ccbbc0b05ded477ada51253729;p=platform%2Fkernel%2Flinux-rpi.git

irq: Call tick_irq_enter() inside HARDIRQ_OFFSET

Now that account_hardirq_enter() is called after HARDIRQ_OFFSET has
been incremented, there is nothing left that prevents us from also
moving tick_irq_enter() after HARDIRQ_OFFSET is incremented.

The desired outcome is to remove the nasty hack that prevents softirqs
from being raised through ksoftirqd instead of the hardirq bottom half.
Also tick_irq_enter() then becomes appropriately covered by lockdep.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201202115732.27827-6-frederic@kernel.org
---

diff --git a/kernel/softirq.c b/kernel/softirq.c
index b8f42b3..d5bfd5e 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -377,16 +377,12 @@ restart:
  */
 void irq_enter_rcu(void)
 {
-	if (is_idle_task(current) && !in_interrupt()) {
-		/*
-		 * Prevent raise_softirq from needlessly waking up ksoftirqd
-		 * here, as softirq will be serviced on return from interrupt.
-		 */
-		local_bh_disable();
+	__irq_enter_raw();
+
+	if (is_idle_task(current) && (irq_count() == HARDIRQ_OFFSET))
 		tick_irq_enter();
-		_local_bh_enable();
-	}
-	__irq_enter();
+
+	account_hardirq_enter(current);
 }
 
 /**