linux-kernel - [RFC PATCH for 6.13 v1 02/20] thermal: core: Rearrange PM notification code

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Message-ID: <4940614.GXAFRqVoOG@rjwysocki.net>
Date: Sat, 14 Sep 2024 12:27:17 +0200
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Linux PM <linux-pm@...r.kernel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
 Daniel Lezcano <daniel.lezcano@...aro.org>,
 Lukasz Luba <lukasz.luba@....com>, Zhang Rui <rui.zhang@...el.com>
Subject:
 [RFC PATCH for 6.13 v1 02/20] thermal: core: Rearrange PM notification code

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Move the code run for each thermal zone by the thermal PM notify
handler to separate functions and use the thermal zone guard to
implement locking in them.

This will help to make some subsequent changes look somewhat more
straightforward, among other things.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/thermal/thermal_core.c |   84 ++++++++++++++++++++---------------------
 1 file changed, 42 insertions(+), 42 deletions(-)

Index: linux-pm/drivers/thermal/thermal_core.c
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_core.c
+++ linux-pm/drivers/thermal/thermal_core.c
@@ -1662,6 +1662,44 @@ static void thermal_zone_device_resume(s
 	tz->resuming = false;
 }
 
+static void thermal_zone_pm_prepare(struct thermal_zone_device *tz)
+{
+	guard(thermal_zone)(tz);
+
+	if (tz->resuming) {
+		/*
+		 * thermal_zone_device_resume() queued up for this zone has not
+		 * acquired the lock yet, so release it to let the function run
+		 * and wait util it has done the work.
+		 */
+		mutex_unlock(&tz->lock);
+
+		wait_for_completion(&tz->resume);
+
+		mutex_lock(&tz->lock);
+	}
+
+	tz->suspended = true;
+}
+
+static void thermal_zone_pm_complete(struct thermal_zone_device *tz)
+{
+	guard(thermal_zone)(tz);
+
+	cancel_delayed_work(&tz->poll_queue);
+
+	reinit_completion(&tz->resume);
+	tz->resuming = true;
+
+	/*
+	 * Replace the work function with the resume one, which will restore the
+	 * original work function and schedule the polling work if needed.
+	 */
+	INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_resume);
+	/* Queue up the work without a delay. */
+	mod_delayed_work(system_freezable_power_efficient_wq, &tz->poll_queue, 0);
+}
+
 static int thermal_pm_notify(struct notifier_block *nb,
 			     unsigned long mode, void *_unused)
 {
@@ -1673,27 +1711,8 @@ static int thermal_pm_notify(struct noti
 	case PM_SUSPEND_PREPARE:
 		mutex_lock(&thermal_list_lock);
 
-		list_for_each_entry(tz, &thermal_tz_list, node) {
-			mutex_lock(&tz->lock);
-
-			if (tz->resuming) {
-				/*
-				 * thermal_zone_device_resume() queued up for
-				 * this zone has not acquired the lock yet, so
-				 * release it to let the function run and wait
-				 * util it has done the work.
-				 */
-				mutex_unlock(&tz->lock);
-
-				wait_for_completion(&tz->resume);
-
-				mutex_lock(&tz->lock);
-			}
-
-			tz->suspended = true;
-
-			mutex_unlock(&tz->lock);
-		}
+		list_for_each_entry(tz, &thermal_tz_list, node)
+			thermal_zone_pm_prepare(tz);
 
 		mutex_unlock(&thermal_list_lock);
 		break;
@@ -1702,27 +1721,8 @@ static int thermal_pm_notify(struct noti
 	case PM_POST_SUSPEND:
 		mutex_lock(&thermal_list_lock);
 
-		list_for_each_entry(tz, &thermal_tz_list, node) {
-			mutex_lock(&tz->lock);
-
-			cancel_delayed_work(&tz->poll_queue);
-
-			reinit_completion(&tz->resume);
-			tz->resuming = true;
-
-			/*
-			 * Replace the work function with the resume one, which
-			 * will restore the original work function and schedule
-			 * the polling work if needed.
-			 */
-			INIT_DELAYED_WORK(&tz->poll_queue,
-					  thermal_zone_device_resume);
-			/* Queue up the work without a delay. */
-			mod_delayed_work(system_freezable_power_efficient_wq,
-					 &tz->poll_queue, 0);
-
-			mutex_unlock(&tz->lock);
-		}
+		list_for_each_entry(tz, &thermal_tz_list, node)
+			thermal_zone_pm_complete(tz);
 
 		mutex_unlock(&thermal_list_lock);
 		break;