From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 29 Apr 2025 06:55:41 +0000 (+0200)
Subject: genirq/manage: Rework can_request_irq()
X-Git-Tag: v6.16-rc1~189^2~19
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a1ceb831417b8e23bd041d3e7021e235fa845128;p=thirdparty%2Fkernel%2Flinux.git

genirq/manage: Rework can_request_irq()

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

Make the return value boolean to reflect it's meaning.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20250429065422.187250840@linutronix.de
---

diff --git a/include/linux/irq.h b/include/linux/irq.h
index dd5df1e2d032d..df93b238b8bf1 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -700,7 +700,7 @@ extern void note_interrupt(struct irq_desc *desc, irqreturn_t action_ret);
 extern int noirqdebug_setup(char *str);
 
 /* Checks whether the interrupt can be requested by request_irq(): */
-extern int can_request_irq(unsigned int irq, unsigned long irqflags);
+extern bool can_request_irq(unsigned int irq, unsigned long irqflags);
 
 /* Dummy irq-chip implementations: */
 extern struct irq_chip no_irq_chip;
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d1ff1e81d383d..b6f057a6b8ae4 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -888,22 +888,17 @@ EXPORT_SYMBOL(irq_set_irq_wake);
  * particular irq has been exclusively allocated or is available
  * for driver use.
  */
-int can_request_irq(unsigned int irq, unsigned long irqflags)
+bool can_request_irq(unsigned int irq, unsigned long irqflags)
 {
-	unsigned long flags;
-	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
-	int canrequest = 0;
-
-	if (!desc)
-		return 0;
+	scoped_irqdesc_get_and_lock(irq, IRQ_GET_DESC_CHECK_GLOBAL) {
+		struct irq_desc *desc = scoped_irqdesc;
 
-	if (irq_settings_can_request(desc)) {
-		if (!desc->action ||
-		    irqflags & desc->action->flags & IRQF_SHARED)
-			canrequest = 1;
+		if (irq_settings_can_request(desc)) {
+			if (!desc->action || irqflags & desc->action->flags & IRQF_SHARED)
+				return true;
+		}
 	}
-	irq_put_desc_unlock(desc, flags);
-	return canrequest;
+	return false;
 }
 
 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)