From patchwork Thu Aug 9 12:46:01 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: durgadoss.r@intel.com X-Patchwork-Id: 1300461 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 775FDDFF7B for ; Thu, 9 Aug 2012 12:46:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932553Ab2HIMqj (ORCPT ); Thu, 9 Aug 2012 08:46:39 -0400 Received: from mga02.intel.com ([134.134.136.20]:14321 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932548Ab2HIMqi (ORCPT ); Thu, 9 Aug 2012 08:46:38 -0400 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP; 09 Aug 2012 05:46:37 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.77,739,1336374000"; d="scan'208";a="177969531" Received: from dr3-desktop.iind.intel.com ([10.223.107.36]) by orsmga001.jf.intel.com with ESMTP; 09 Aug 2012 05:46:34 -0700 From: Durgadoss R To: lenb@kernel.org, rui.zhang@intel.com, rjw@sisk.pl, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org Cc: eduardo.valentin@ti.com, amit.kachhap@linaro.org, wni@nvidia.com, Durgadoss R Subject: [PATCH 09/13] Thermal: Introduce a step_wise thermal governor Date: Thu, 9 Aug 2012 18:16:01 +0530 Message-Id: <1344516365-7230-10-git-send-email-durgadoss.r@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1344516365-7230-1-git-send-email-durgadoss.r@intel.com> References: <1344516365-7230-1-git-send-email-durgadoss.r@intel.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org This patch adds a simple step_wise governor to the generic thermal layer. This algorithm throttles the cooling devices in a linear fashion. If the 'trend' is heating, it throttles by one step. And if the thermal trend is cooling it de-throttles by one step. This actually moves the throttling logic from thermal_sys.c and puts inside step_wise.c, without any change. Signed-off-by: Durgadoss R --- drivers/thermal/Kconfig | 6 ++ drivers/thermal/Makefile | 1 + drivers/thermal/step_wise.c | 204 +++++++++++++++++++++++++++++++++++++++++++ include/linux/thermal.h | 9 ++ 4 files changed, 220 insertions(+) create mode 100644 drivers/thermal/step_wise.c diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index f5110c0..0401cdf 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -33,3 +33,9 @@ config FAIR_SHARE depends on THERMAL help Enable this to manage platform thermals using fair-share governor. + +config STEP_WISE + bool "Step_wise thermal governor" + depends on THERMAL + help + Enable this to manage platform thermals using a simple linear diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile index 4ffe1a8..c2c0ce0 100644 --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -5,3 +5,4 @@ obj-$(CONFIG_THERMAL) += thermal_sys.o obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o obj-$(CONFIG_FAIR_SHARE) += fair_share.o +obj-$(CONFIG_STEP_WISE) += step_wise.o diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c new file mode 100644 index 0000000..0456b38 --- /dev/null +++ b/drivers/thermal/step_wise.c @@ -0,0 +1,204 @@ +/* + * step_wise.c - A step-by-step Thermal throttling governor + * + * Copyright (C) 2012 Intel Corp + * Copyright (C) 2012 Durgadoss R + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * 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 +#include + +/* + * If the temperature is higher than a trip point, + * a. if the trend is THERMAL_TREND_RAISING, use higher cooling + * state for this trip point + * b. if the trend is THERMAL_TREND_DROPPING, use lower cooling + * state for this trip point + */ +static unsigned long get_target_state(struct thermal_instance *instance, + enum thermal_trend trend) +{ + struct thermal_cooling_device *cdev = instance->cdev; + unsigned long cur_state; + + cdev->ops->get_cur_state(cdev, &cur_state); + + if (trend == THERMAL_TREND_RAISING) { + cur_state = cur_state < instance->upper ? + (cur_state + 1) : instance->upper; + } else if (trend == THERMAL_TREND_DROPPING) { + cur_state = cur_state > instance->lower ? + (cur_state - 1) : instance->lower; + } + + return cur_state; +} + +static void update_passive_instance(struct thermal_zone_device *tz, + enum thermal_trip_type type, int value) +{ + /* + * If value is +1, activate a passive instance. + * If value is -1, deactivate a passive instance. + */ + if (type == THERMAL_TRIP_PASSIVE || type == THERMAL_TRIPS_NONE) + tz->passive += value; +} + +static void update_instance_for_throttle(struct thermal_zone_device *tz, + int trip, enum thermal_trip_type trip_type, + enum thermal_trend trend) +{ + struct thermal_instance *instance; + + list_for_each_entry(instance, &tz->thermal_instances, tz_node) { + if (instance->trip != trip) + continue; + + instance->target = get_target_state(instance, trend); + + /* Activate a passive thermal instance */ + if (instance->target == THERMAL_NO_TARGET) + update_passive_instance(tz, trip_type, 1); + + instance->cdev->updated = false; /* cdev needs update */ + } +} + +static void update_instance_for_dethrottle(struct thermal_zone_device *tz, + int trip, enum thermal_trip_type trip_type) +{ + struct thermal_instance *instance; + struct thermal_cooling_device *cdev; + unsigned long cur_state; + + list_for_each_entry(instance, &tz->thermal_instances, tz_node) { + if (instance->trip != trip || + instance->target == THERMAL_NO_TARGET) + continue; + + cdev = instance->cdev; + cdev->ops->get_cur_state(cdev, &cur_state); + + instance->target = cur_state > instance->lower ? + (cur_state - 1) : THERMAL_NO_TARGET; + + /* Deactivate a passive thermal instance */ + if (instance->target == THERMAL_NO_TARGET) + update_passive_instance(tz, trip_type, -1); + + cdev->updated = false; /* cdev needs update */ + } +} + +static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip) +{ + long trip_temp; + enum thermal_trip_type trip_type; + enum thermal_trend trend; + + if (trip == THERMAL_TRIPS_NONE) { + trip_temp = tz->forced_passive; + trip_type = THERMAL_TRIPS_NONE; + } else { + tz->ops->get_trip_temp(tz, trip, &trip_temp); + tz->ops->get_trip_type(tz, trip, &trip_type); + } + + trend = get_tz_trend(tz, trip); + + mutex_lock(&tz->lock); + + if (tz->temperature >= trip_temp) + update_instance_for_throttle(tz, trip, trip_type, trend); + else + update_instance_for_dethrottle(tz, trip, trip_type); + + mutex_unlock(&tz->lock); +} + +/** + * thermal_cdev_update - Updates the throttle state for the given cdev + * @cdev - cooling device, for which the throttle state is to be set + * + * This function loops through all the instances for the given cdev, + * to find out the maximum throttle state; and sets the cur_state of + * the cdev to that value. + */ +static void thermal_cdev_update(struct thermal_cooling_device *cdev) +{ + struct thermal_instance *instance; + unsigned long target = 0; + + /* cdev is already updated */ + if (cdev->updated) + return; + + mutex_lock(&cdev->lock); + + /* Make sure cdev enters the deepest cooling state */ + list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { + if (instance->target == THERMAL_NO_TARGET) + continue; + if (instance->target > target) + target = instance->target; + } + + mutex_unlock(&cdev->lock); + + cdev->ops->set_cur_state(cdev, target); + cdev->updated = true; +} + +/** + * step_wise_throttle - throttles devices asscciated with the given zone + * @tz - thermal_zone_device + * @trip - the trip point + * @trip_type - type of the trip point + * + * Throttling Logic: This uses the trend of the thermal zone to throttle. + * If the thermal zone is 'heating up' this throttles all the cooling + * devices associated with the zone and its particular trip point, by one + * step. If the zone is 'cooling down' it brings back the performance of + * the devices by one step. + */ +void step_wise_throttle(struct thermal_zone_device *tz, int trip) +{ + struct thermal_instance *instance; + + thermal_zone_trip_update(tz, trip); + + if (tz->forced_passive) + thermal_zone_trip_update(tz, THERMAL_TRIPS_NONE); + + mutex_lock(&tz->lock); + + list_for_each_entry(instance, &tz->thermal_instances, tz_node) + thermal_cdev_update(instance->cdev); + + mutex_unlock(&tz->lock); +} +EXPORT_SYMBOL(step_wise_throttle); + +MODULE_AUTHOR("Durgadoss R"); +MODULE_DESCRIPTION("A step-by-step thermal throttling governor"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 4e2dc2c..60d2743 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -266,6 +266,15 @@ static inline void fair_share_throttle(struct thermal_zone_device *tz, int trip) } #endif +#ifdef CONFIG_STEP_WISE +extern void step_wise_throttle(struct thermal_zone_device *tz, int trip); +#else +static inline void step_wise_throttle(struct thermal_zone_device *tz, int trip) +{ + return; +} +#endif + #ifdef CONFIG_NET extern int thermal_generate_netlink_event(u32 orig, enum events event); #else