Thermal: Introduce fair_share thermal governor (4ccc5743) · Commits · 戴 / test

drivers/thermal/Kconfig

+6 −0

Original line number	Diff line number	Diff line
		@@ -55,3 +55,9 @@ config EXYNOS_THERMAL
		help
		If you say yes here you get support for TMU (Thermal Managment
		Unit) on SAMSUNG EXYNOS series of SoC.

		config FAIR_SHARE
		bool "Fair-share thermal governor"
		depends on THERMAL
		help
		Enable this to manage platform thermals using fair-share governor.

drivers/thermal/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -7,3 +7,4 @@ obj-$(CONFIG_CPU_THERMAL) += cpu_cooling.o
		obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o
		obj-$(CONFIG_RCAR_THERMAL) += rcar_thermal.o
		obj-$(CONFIG_EXYNOS_THERMAL) += exynos_thermal.o
		obj-$(CONFIG_FAIR_SHARE) += fair_share.o

drivers/thermal/fair_share.c

0 → 100644

+133 −0

Original line number	Diff line number	Diff line
		/*
		* fair_share.c - A simple weight based Thermal governor
		*
		* Copyright (C) 2012 Intel Corp
		* Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.com>
		*
		* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; version 2 of the License.
		*
		* This program is distributed in the hope that it will be useful, but
		* WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
		* General Public License for more details.
		*
		* You should have received a copy of the GNU General Public License along
		* with this program; if not, write to the Free Software Foundation, Inc.,
		* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
		*
		* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		*/

		#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

		#include <linux/module.h>
		#include <linux/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;
		unsigned long trip_temp;

		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;
		}
		return count;
		}

		static long get_target_state(struct thermal_zone_device *tz,
		struct thermal_cooling_device *cdev, int weight, int level)
		{
		unsigned long max_state;

		cdev->ops->get_max_state(cdev, &max_state);

		return (long)(weight * level * max_state) / (100 * tz->trips);
		}

		/**
		* fair_share_throttle - throttles devices asscciated with the given zone
		* @tz - thermal_zone_device
		*
		* 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. weight[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
		*/
		int fair_share_throttle(struct thermal_zone_device *tz, int trip)
		{
		const struct thermal_zone_params *tzp;
		struct thermal_cooling_device *cdev;
		struct thermal_instance *instance;
		int i;
		int cur_trip_level = get_trip_level(tz);

		if (!tz->tzp \|\| !tz->tzp->tbp)
		return -EINVAL;

		tzp = tz->tzp;

		for (i = 0; i < tzp->num_tbps; i++) {
		if (!tzp->tbp[i].cdev)
		continue;

		cdev = tzp->tbp[i].cdev;
		instance = get_thermal_instance(tz, cdev, trip);
		if (!instance)
		continue;

		instance->target = get_target_state(tz, cdev,
		tzp->tbp[i].weight, cur_trip_level);

		instance->cdev->updated = false;
		thermal_cdev_update(cdev);
		}
		return 0;
		}

		struct thermal_governor thermal_gov_fair_share = {
		.name = "fair_share",
		.throttle = fair_share_throttle,
		.owner = THIS_MODULE,
		};

		static int __init thermal_gov_fair_share_init(void)
		{
		return thermal_register_governor(&thermal_gov_fair_share);
		}

		static void __exit thermal_gov_fair_share_exit(void)
		{
		thermal_unregister_governor(&thermal_gov_fair_share);
		}

		/* This should load after thermal framework */
		fs_initcall(thermal_gov_fair_share_init);
		module_exit(thermal_gov_fair_share_exit);

		MODULE_AUTHOR("Durgadoss R");
		MODULE_DESCRIPTION("A simple weight based thermal throttling governor");
		MODULE_LICENSE("GPL");

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