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From:   "Rafael J. Wysocki" <rjw@rjwysocki.net>
To:     Linux PM <linux-pm@vger.kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Linux ACPI <linux-acpi@vger.kernel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        Zhang Rui <rui.zhang@intel.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Lukasz Luba <lukasz.luba@arm.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>
Subject: [PATCH v1 06/13] thermal: gov_fair_share: Rearrange get_trip_level()
Date:   Thu, 21 Sep 2023 19:54:02 +0200
Message-ID: <1882755.CQOukoFCf9@kreacher>
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Make get_trip_level() access the thermal zone's trip table directly
instead of using __thermal_zone_get_trip() which adds overhead related
to the unnecessary bounds checking and copying the trip point data.

Also rearrange the code in it to make it somewhat easier to follow.

The general functionality is not expected to be changed.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/thermal/gov_fair_share.c |   22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

Index: linux-pm/drivers/thermal/gov_fair_share.c
===================================================================
--- linux-pm.orig/drivers/thermal/gov_fair_share.c
+++ linux-pm/drivers/thermal/gov_fair_share.c
@@ -21,23 +21,21 @@
  */
 static int get_trip_level(struct thermal_zone_device *tz)
 {
-	struct thermal_trip trip;
-	int count;
+	const struct thermal_trip *trip = tz->trips;
+	int i;
 
-	for (count = 0; count < tz->num_trips; count++) {
-		__thermal_zone_get_trip(tz, count, &trip);
-		if (tz->temperature < trip.temperature)
+	if (tz->temperature < trip->temperature)
+		return 0;
+
+	for (i = 0; i < tz->num_trips - 1; i++) {
+		trip++;
+		if (tz->temperature < trip->temperature)
 			break;
 	}
 
-	/*
-	 * count > 0 only if temperature is greater than first trip
-	 * point, in which case, trip_point = count - 1
-	 */
-	if (count > 0)
-		trace_thermal_zone_trip(tz, count - 1, trip.type);
+	trace_thermal_zone_trip(tz, i, tz->trips[i].type);
 
-	return count;
+	return i;
 }
 
 static long get_target_state(struct thermal_zone_device *tz,