From patchwork Thu Aug 9 12:46:00 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: 1300451 Return-Path: X-Original-To: patchwork-linux-acpi@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 CFA7DE00F0 for ; Thu, 9 Aug 2012 12:46:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932467Ab2HIMqg (ORCPT ); Thu, 9 Aug 2012 08:46:36 -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 S932548Ab2HIMqf (ORCPT ); Thu, 9 Aug 2012 08:46:35 -0400 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP; 09 Aug 2012 05:46:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.77,739,1336374000"; d="scan'208";a="177969517" Received: from dr3-desktop.iind.intel.com ([10.223.107.36]) by orsmga001.jf.intel.com with ESMTP; 09 Aug 2012 05:46:31 -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 08/13] Thermal: Introduce fair_share thermal governor Date: Thu, 9 Aug 2012 18:16:00 +0530 Message-Id: <1344516365-7230-9-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-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org This patch introduces a simple 'weight' based governor named fair_share governor. Whenever the thermal framework gets notified of the trip point violation, this governor (if configured), throttles the cooling devices associated with a thermal zone. This mapping between a thermal zone and a cooling device and the effectiveness of cooling are provided in the platform layer. Signed-off-by: Durgadoss R --- drivers/thermal/Kconfig | 6 ++ drivers/thermal/Makefile | 3 +- drivers/thermal/fair_share.c | 128 ++++++++++++++++++++++++++++++++++++++++++ include/linux/thermal.h | 9 +++ 4 files changed, 145 insertions(+), 1 deletion(-) create mode 100644 drivers/thermal/fair_share.c diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index 3ab2bd5..f5110c0 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -27,3 +27,9 @@ config SPEAR_THERMAL help Enable this to plug the SPEAr thermal sensor driver into the Linux thermal framework + +config FAIR_SHARE + bool "Fair-share thermal governor" + depends on THERMAL + help + Enable this to manage platform thermals using fair-share governor. diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile index a9fff0b..4ffe1a8 100644 --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -3,4 +3,5 @@ # obj-$(CONFIG_THERMAL) += thermal_sys.o -obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o \ No newline at end of file +obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o +obj-$(CONFIG_FAIR_SHARE) += fair_share.o diff --git a/drivers/thermal/fair_share.c b/drivers/thermal/fair_share.c new file mode 100644 index 0000000..b8c8d45 --- /dev/null +++ b/drivers/thermal/fair_share.c @@ -0,0 +1,128 @@ +/* + * fair_share.c - A simple weight based Thermal 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 + +/** + * 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); +} + +static void thermal_cdev_update(struct thermal_cooling_device *cdev) +{ + struct thermal_instance *instance; + unsigned long target = 0; + + 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 > target) + target = instance->target; + } + + mutex_unlock(&cdev->lock); + + cdev->ops->set_cur_state(cdev, target); +} + +/** + * 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 + */ +void fair_share_throttle(struct thermal_zone_device *tz, int trip) +{ + 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) + return; + + tzp = tz->tzp; + + for (i = 0; i < tzp->num_cdevs; i++) { + cdev = get_cdev_by_name(tzp->cdevs_name[i]); + if (!cdev) + continue; + + instance = get_thermal_instance(tz, cdev, trip); + if (!instance) + continue; + + instance->target = get_target_state(tz, cdev, + tzp->weights[i], cur_trip_level); + + thermal_cdev_update(cdev); + } +} +EXPORT_SYMBOL(fair_share_throttle); + +MODULE_AUTHOR("Durgadoss R"); +MODULE_DESCRIPTION("A simple weight based thermal throttling governor"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 1d49f05..4e2dc2c 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -257,6 +257,15 @@ struct thermal_instance *get_thermal_instance(struct thermal_zone_device *, */ extern int (*get_platform_thermal_params)(struct thermal_zone_device *); +#ifdef CONFIG_FAIR_SHARE +extern void fair_share_throttle(struct thermal_zone_device *tz, int trip); +#else +static inline void fair_share_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