[PATCH v5 08/13] firmware: arm_sdei: Remove while loop in sdei_event_register()

From: Gavin Shan <gshan@redhat.com>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, Jonathan.Cameron@huawei.com,
	james.morse@arm.com, mark.rutland@arm.com,
	catalin.marinas@arm.com, will@kernel.org, shan.gavin@gmail.com
Subject: [PATCH v5 08/13] firmware: arm_sdei: Remove while loop in sdei_event_register()
Date: Tue, 22 Sep 2020 23:04:18 +1000	[thread overview]
Message-ID: <20200922130423.10173-9-gshan@redhat.com> (raw)
In-Reply-To: <20200922130423.10173-1-gshan@redhat.com>

This removes the unnecessary while loop in sdei_event_register()
because of the following two reasons. This shouldn't cause any
functional changes.

   * The while loop is executed for once, meaning it's not needed
     in theory.
   * With the while loop removed, the nested statements can be
     avoid to make the code a bit cleaner.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/firmware/arm_sdei.c | 52 ++++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 27 deletions(-)

diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
index 4caeef3e1e0b..6595bd66aa73 100644
--- a/drivers/firmware/arm_sdei.c
+++ b/drivers/firmware/arm_sdei.c
@@ -590,36 +590,34 @@ int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg)
 	WARN_ON(in_nmi());
 
 	mutex_lock(&sdei_events_lock);
-	do {
-		if (sdei_event_find(event_num)) {
-			pr_warn("Event %u already registered\n", event_num);
-			err = -EBUSY;
-			break;
-		}
+	if (sdei_event_find(event_num)) {
+		pr_warn("Event %u already registered\n", event_num);
+		err = -EBUSY;
+		goto unlock;
+	}
 
-		event = sdei_event_create(event_num, cb, arg);
-		if (IS_ERR(event)) {
-			err = PTR_ERR(event);
-			pr_warn("Failed to create event %u: %d\n", event_num,
-				err);
-			break;
-		}
+	event = sdei_event_create(event_num, cb, arg);
+	if (IS_ERR(event)) {
+		err = PTR_ERR(event);
+		pr_warn("Failed to create event %u: %d\n", event_num, err);
+		goto unlock;
+	}
 
-		cpus_read_lock();
-		err = _sdei_event_register(event);
-		if (err) {
-			sdei_event_destroy(event);
-			pr_warn("Failed to register event %u: %d\n", event_num,
-				err);
-		} else {
-			spin_lock(&sdei_list_lock);
-			event->reregister = true;
-			spin_unlock(&sdei_list_lock);
-		}
-		cpus_read_unlock();
-	} while (0);
-	mutex_unlock(&sdei_events_lock);
+	cpus_read_lock();
+	err = _sdei_event_register(event);
+	if (err) {
+		sdei_event_destroy(event);
+		pr_warn("Failed to register event %u: %d\n", event_num, err);
+		goto cpu_unlock;
+	}
 
+	spin_lock(&sdei_list_lock);
+	event->reregister = true;
+	spin_unlock(&sdei_list_lock);
+cpu_unlock:
+	cpus_read_unlock();
+unlock:
+	mutex_unlock(&sdei_events_lock);
 	return err;
 }
 
-- 
2.23.0

