From 0015d9a2a72745308ef9728a746ff7b1e82138bc Mon Sep 17 00:00:00 2001
From: Amit Kucheria <amit.kucheria@linaro.org>
Date: Mon, 11 May 2020 17:55:01 +0530
Subject: thermal/governors: Prefix all source files with gov_

Bang-bang governor source file is prefixed with gov_. Do the same for
other governors for consistency so they're easy to find in the sources.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/b9a85d3204712f14e320504948c12712dc0b291b.1589199124.git.amit.kucheria@linaro.org
---
 drivers/thermal/gov_fair_share.c | 120 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 drivers/thermal/gov_fair_share.c

(limited to 'drivers/thermal/gov_fair_share.c')

diff --git a/drivers/thermal/gov_fair_share.c b/drivers/thermal/gov_fair_share.c
new file mode 100644
index 000000000000..aaa07180ab48
--- /dev/null
+++ b/drivers/thermal/gov_fair_share.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  fair_share.c - A simple weight based Thermal governor
+ *
+ *  Copyright (C) 2012 Intel Corp
+ *  Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.com>
+ *
+ *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/thermal.h>
+#include <trace/events/thermal.h>
+
+#include "thermal_core.h"
+
+/**
+ * get_trip_level: - obtains the current trip level for a zone
+ * @tz:		thermal zone device
+ */
+static int get_trip_level(struct thermal_zone_device *tz)
+{
+	int count = 0;
+	int trip_temp;
+	enum thermal_trip_type trip_type;
+
+	if (tz->trips == 0 || !tz->ops->get_trip_temp)
+		return 0;
+
+	for (count = 0; count < tz->trips; count++) {
+		tz->ops->get_trip_temp(tz, count, &trip_temp);
+		if (tz->temperature < trip_temp)
+			break;
+	}
+
+	/*
+	 * count > 0 only if temperature is greater than first trip
+	 * point, in which case, trip_point = count - 1
+	 */
+	if (count > 0) {
+		tz->ops->get_trip_type(tz, count - 1, &trip_type);
+		trace_thermal_zone_trip(tz, count - 1, trip_type);
+	}
+
+	return count;
+}
+
+static long get_target_state(struct thermal_zone_device *tz,
+		struct thermal_cooling_device *cdev, int percentage, int level)
+{
+	unsigned long max_state;
+
+	cdev->ops->get_max_state(cdev, &max_state);
+
+	return (long)(percentage * level * max_state) / (100 * tz->trips);
+}
+
+/**
+ * fair_share_throttle - throttles devices associated with the given zone
+ * @tz: thermal_zone_device
+ * @trip: trip point index
+ *
+ * Throttling Logic: This uses three parameters to calculate the new
+ * throttle state of the cooling devices associated with the given zone.
+ *
+ * Parameters used for Throttling:
+ * P1. max_state: Maximum throttle state exposed by the cooling device.
+ * P2. percentage[i]/100:
+ *	How 'effective' the 'i'th device is, in cooling the given zone.
+ * P3. cur_trip_level/max_no_of_trips:
+ *	This describes the extent to which the devices should be throttled.
+ *	We do not want to throttle too much when we trip a lower temperature,
+ *	whereas the throttling is at full swing if we trip critical levels.
+ *	(Heavily assumes the trip points are in ascending order)
+ * new_state of cooling device = P3 * P2 * P1
+ */
+static int fair_share_throttle(struct thermal_zone_device *tz, int trip)
+{
+	struct thermal_instance *instance;
+	int total_weight = 0;
+	int total_instance = 0;
+	int cur_trip_level = get_trip_level(tz);
+
+	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
+		if (instance->trip != trip)
+			continue;
+
+		total_weight += instance->weight;
+		total_instance++;
+	}
+
+	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
+		int percentage;
+		struct thermal_cooling_device *cdev = instance->cdev;
+
+		if (instance->trip != trip)
+			continue;
+
+		if (!total_weight)
+			percentage = 100 / total_instance;
+		else
+			percentage = (instance->weight * 100) / total_weight;
+
+		instance->target = get_target_state(tz, cdev, percentage,
+						    cur_trip_level);
+
+		mutex_lock(&instance->cdev->lock);
+		instance->cdev->updated = false;
+		mutex_unlock(&instance->cdev->lock);
+		thermal_cdev_update(cdev);
+	}
+	return 0;
+}
+
+static struct thermal_governor thermal_gov_fair_share = {
+	.name		= "fair_share",
+	.throttle	= fair_share_throttle,
+};
+THERMAL_GOVERNOR_DECLARE(thermal_gov_fair_share);
-- 
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