linux-kernel - [patch 42/46] genirq/manage: Rework prepare_percpu

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Message-ID: <20250313155916.727004678@linutronix.de>
Date: Thu, 13 Mar 2025 17:00:55 +0100 (CET)
From: Thomas Gleixner <tglx@...utronix.de>
To: LKML <linux-kernel@...r.kernel.org>
Cc: Peter Zijlstra <peterz@...radead.org>,
 Jiri Slaby <jirislaby@...nel.org>
Subject: [patch 42/46] genirq/manage: Rework prepare_percpu_nmi()

Use the new guards to get and lock the interrupt descriptor and tidy up the
code.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 kernel/irq/manage.c |   31 +++++++++----------------------
 1 file changed, 9 insertions(+), 22 deletions(-)

--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -2605,32 +2605,19 @@ int request_percpu_nmi(unsigned int irq,
  */
 int prepare_percpu_nmi(unsigned int irq)
 {
-	unsigned long flags;
-	struct irq_desc *desc;
-	int ret = 0;
+	int ret = -EINVAL;
 
 	WARN_ON(preemptible());
 
-	desc = irq_get_desc_lock(irq, &flags,
-				 IRQ_GET_DESC_CHECK_PERCPU);
-	if (!desc)
-		return -EINVAL;
-
-	if (WARN(!irq_is_nmi(desc),
-		 KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n",
-		 irq)) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	ret = irq_nmi_setup(desc);
-	if (ret) {
-		pr_err("Failed to setup NMI delivery: irq %u\n", irq);
-		goto out;
+	scoped_irqdesc_get_and_lock(irq, IRQ_GET_DESC_CHECK_PERCPU) {
+		if (WARN(!irq_is_nmi(scoped_irqdesc),
+			 "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n", irq))
+			return -EINVAL;
+
+		ret = irq_nmi_setup(scoped_irqdesc);
+		if (ret)
+			pr_err("Failed to setup NMI delivery: irq %u\n", irq);
 	}
-
-out:
-	irq_put_desc_unlock(desc, flags);
 	return ret;
 }