linux-kernel - [PATCH 15/24] Input: ps2mult - use guard notation when acquiring spinlock

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Message-ID: <20240905041732.2034348-16-dmitry.torokhov@gmail.com>
Date: Wed,  4 Sep 2024 21:17:20 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: linux-input@...r.kernel.org
Cc: Pali Rohár <pali@...nel.org>,
	Helge Deller <deller@....de>,
	"K. Y. Srinivasan" <kys@...rosoft.com>,
	Wei Liu <wei.liu@...nel.org>,
	Dexuan Cui <decui@...rosoft.com>,
	Samuel Holland <samuel@...lland.org>,
	Lyude Paul <thatslyude@...il.com>,
	Michal Simek <michal.simek@....com>,
	Hans de Goede <hdegoede@...hat.com>,
	linux-kernel@...r.kernel.org,
	linux-hyperv@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-sunxi@...ts.linux.dev
Subject: [PATCH 15/24] Input: ps2mult - use guard notation when acquiring spinlock

Using guard notation makes the code more compact and error handling
more robust by ensuring that locks are released in all code paths
when control leaves critical section.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---
 drivers/input/serio/ps2mult.c | 25 +++++++------------------
 1 file changed, 7 insertions(+), 18 deletions(-)

diff --git a/drivers/input/serio/ps2mult.c b/drivers/input/serio/ps2mult.c
index 937ecdea491d..b96cee52fc52 100644
--- a/drivers/input/serio/ps2mult.c
+++ b/drivers/input/serio/ps2mult.c
@@ -76,9 +76,8 @@ static int ps2mult_serio_write(struct serio *serio, unsigned char data)
 	struct ps2mult *psm = serio_get_drvdata(mx_port);
 	struct ps2mult_port *port = serio->port_data;
 	bool need_escape;
-	unsigned long flags;
 
-	spin_lock_irqsave(&psm->lock, flags);
+	guard(spinlock_irqsave)(&psm->lock);
 
 	if (psm->out_port != port)
 		ps2mult_select_port(psm, port);
@@ -93,8 +92,6 @@ static int ps2mult_serio_write(struct serio *serio, unsigned char data)
 
 	serio_write(mx_port, data);
 
-	spin_unlock_irqrestore(&psm->lock, flags);
-
 	return 0;
 }
 
@@ -102,11 +99,10 @@ static int ps2mult_serio_start(struct serio *serio)
 {
 	struct ps2mult *psm = serio_get_drvdata(serio->parent);
 	struct ps2mult_port *port = serio->port_data;
-	unsigned long flags;
 
-	spin_lock_irqsave(&psm->lock, flags);
+	guard(spinlock_irqsave)(&psm->lock);
+
 	port->registered = true;
-	spin_unlock_irqrestore(&psm->lock, flags);
 
 	return 0;
 }
@@ -115,11 +111,10 @@ static void ps2mult_serio_stop(struct serio *serio)
 {
 	struct ps2mult *psm = serio_get_drvdata(serio->parent);
 	struct ps2mult_port *port = serio->port_data;
-	unsigned long flags;
 
-	spin_lock_irqsave(&psm->lock, flags);
+	guard(spinlock_irqsave)(&psm->lock);
+
 	port->registered = false;
-	spin_unlock_irqrestore(&psm->lock, flags);
 }
 
 static int ps2mult_create_port(struct ps2mult *psm, int i)
@@ -148,16 +143,12 @@ static int ps2mult_create_port(struct ps2mult *psm, int i)
 
 static void ps2mult_reset(struct ps2mult *psm)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&psm->lock, flags);
+	guard(spinlock_irqsave)(&psm->lock);
 
 	serio_write(psm->mx_serio, PS2MULT_SESSION_END);
 	serio_write(psm->mx_serio, PS2MULT_SESSION_START);
 
 	ps2mult_select_port(psm, &psm->ports[PS2MULT_KBD_PORT]);
-
-	spin_unlock_irqrestore(&psm->lock, flags);
 }
 
 static int ps2mult_connect(struct serio *serio, struct serio_driver *drv)
@@ -234,11 +225,10 @@ static irqreturn_t ps2mult_interrupt(struct serio *serio,
 {
 	struct ps2mult *psm = serio_get_drvdata(serio);
 	struct ps2mult_port *in_port;
-	unsigned long flags;
 
 	dev_dbg(&serio->dev, "Received %02x flags %02x\n", data, dfl);
 
-	spin_lock_irqsave(&psm->lock, flags);
+	guard(spinlock_irqsave)(&psm->lock);
 
 	if (psm->escape) {
 		psm->escape = false;
@@ -285,7 +275,6 @@ static irqreturn_t ps2mult_interrupt(struct serio *serio,
 	}
 
  out:
-	spin_unlock_irqrestore(&psm->lock, flags);
 	return IRQ_HANDLED;
 }
 
-- 
2.46.0.469.g59c65b2a67-goog