From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C3A7C432C0 for ; Mon, 2 Dec 2019 20:28:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4BB1A2464D for ; Mon, 2 Dec 2019 20:28:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="pGQTyEz/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727656AbfLBU2a (ORCPT ); Mon, 2 Dec 2019 15:28:30 -0500 Received: from mail-wm1-f67.google.com ([209.85.128.67]:35942 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727570AbfLBU22 (ORCPT ); Mon, 2 Dec 2019 15:28:28 -0500 Received: by mail-wm1-f67.google.com with SMTP id p17so1002104wma.1 for ; Mon, 02 Dec 2019 12:28:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=u/XZ42o6JQslkvFLamrbPFromrVRymGRCu4l6TNmPmg=; b=pGQTyEz/WQXCR/cwDW7ONwNyFbW6HCc+KC79LjdPfzjNmKUSN5a4+MHU1LX6Civ0DU 21ifRchJpfzbXEnYeCx9bSxrblZiHumJsLpY3BoLvcVc+UHKSnF0uNzy16oquvCz3nbP essePBwi0aPKXATDfFQ+JlA2V9RJdw56YqEijJP3ODPHdJcG7NT5QsbYH9mlZbCDBiOs A+hbtTPGttJrLeHiMJ1lvqQyawFOaJ7bSDz3i43BVpLb1IBO+RmihJU5Miw526yxsqRf Rz7TkYykH5cNaUhFVGuljaYoWWDKerCshEla/Lshj7ppFs1zQcAgy/NCk0lBKRrPaiRe gIPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=u/XZ42o6JQslkvFLamrbPFromrVRymGRCu4l6TNmPmg=; b=RS/XuctfOY1Q87y/NwxQCUtggJJeEE0RzXaxu0d4Jp4o9hGB4n1fUnb02U1/5HuiB7 4COzxzevCr1Qlp6Ilbt5u81gY+448RiRMAgV1ry0dxTAl/4rRUCjSwwTNVbSxosmV+Zt /KWUZdR20iROPectfO6LXmYcW4f7HbFoJUIWSYMUKtf4oHr5lvCOG1AyfWS7kLrS8jvh EgoHHCqZUjRYwObkCNRzBzSzZH334l5Z4xpywQk/Oi1763ygZioq9vXnjEfOKdLq9P++ S68TBc8MMNNxt/tV1N+cDZMdPo4qCbauR/O483GQamYgDlXri6hK90AqFYMtiHcOmgwf bRbQ== X-Gm-Message-State: APjAAAVRg5guzVcpYH0+8d/TvmaBFCjy6t8QvzoqBy88Qyy8G2cpRKeh iOG2Lk8J1/NKIRNrn6LJwrtxS+d2vaI= X-Google-Smtp-Source: APXvYqxeSsq8blCOIo6XfjDZlp/5lNEDlCxNIVrH1yAtH8sbFPZO4Q3bm0vun8Kg+WV2dLC+rMcK4w== X-Received: by 2002:a1c:f70a:: with SMTP id v10mr28607034wmh.159.1575318505049; Mon, 02 Dec 2019 12:28:25 -0800 (PST) Received: from localhost.localdomain ([2a01:e34:ed2f:f020:8196:cbcc:fb2c:4975]) by smtp.gmail.com with ESMTPSA id k20sm556456wmj.10.2019.12.02.12.28.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Dec 2019 12:28:24 -0800 (PST) From: Daniel Lezcano To: viresh.kumar@linaro.org, rui.zhang@intel.com Cc: rjw@rjwysocki.net, edubezval@gmail.com, linux-pm@vger.kernel.org, amit.kucheria@linaro.org, linux-kernel@vger.kernel.org Subject: [PATCH V2 3/4] thermal/drivers/cpu_cooling: Introduce the cpu idle cooling driver Date: Mon, 2 Dec 2019 21:28:14 +0100 Message-Id: <20191202202815.22731-3-daniel.lezcano@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191202202815.22731-1-daniel.lezcano@linaro.org> References: <20191202202815.22731-1-daniel.lezcano@linaro.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The cpu idle cooling device offers a new method to cool down a CPU by injecting idle cycles at runtime. It has some similarities with the intel power clamp driver but it is actually designed to be more generic and relying on the idle injection powercap framework. The idle injection cycle is fixed while the running cycle is variable. That allows to have control on the device reactivity for the user experience. An idle state powering down the CPU or the cluster will allow to drop the static leakage, thus restoring the heat capacity of the SoC. It can be set with a trip point between the hot and the critical points, giving the opportunity to prevent a hard reset of the system when the cpufreq cooling fails to cool down the CPU. With more sophisticated boards having a per core sensor, the idle cooling device allows to cool down a single core without throttling the compute capacity of several cpus belonging to the same clock line, so it could be used in collaboration with the cpufreq cooling device. Signed-off-by: Daniel Lezcano --- V2: - Remove idle_duration_us field and use idle_inject API instead (Viresh Kumar) - Fixed function definition wheh CPU_IDLE_COOLING is not set - Inverted the initialization in the init function (Viresh Kumar) --- drivers/thermal/Kconfig | 7 + drivers/thermal/Makefile | 1 + drivers/thermal/cpuidle_cooling.c | 233 ++++++++++++++++++++++++++++++ include/linux/cpu_cooling.h | 22 +++ 4 files changed, 263 insertions(+) create mode 100644 drivers/thermal/cpuidle_cooling.c diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index 4e3ee036938b..4ee9953ba5ce 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -169,6 +169,13 @@ config CPU_FREQ_THERMAL This will be useful for platforms using the generic thermal interface and not the ACPI interface. +config CPU_IDLE_THERMAL + bool "CPU idle cooling device" + depends on IDLE_INJECT + help + This implements the CPU cooling mechanism through + idle injection. This will throttle the CPU by injecting + idle cycle. endif config CLOCK_THERMAL diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile index d3b01cc96981..9c8aa2d4bd28 100644 --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -20,6 +20,7 @@ thermal_sys-$(CONFIG_THERMAL_GOV_POWER_ALLOCATOR) += power_allocator.o # cpufreq cooling thermal_sys-$(CONFIG_CPU_FREQ_THERMAL) += cpu_cooling.o +thermal_sys-$(CONFIG_CPU_IDLE_THERMAL) += cpuidle_cooling.o # clock cooling thermal_sys-$(CONFIG_CLOCK_THERMAL) += clock_cooling.o diff --git a/drivers/thermal/cpuidle_cooling.c b/drivers/thermal/cpuidle_cooling.c new file mode 100644 index 000000000000..6e586ad446d6 --- /dev/null +++ b/drivers/thermal/cpuidle_cooling.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Linaro Limited. + * + * Author: Daniel Lezcano + * + */ +#include +#include +#include +#include +#include +#include +#include + +/** + * struct cpuidle_cooling_device - data for the idle cooling device + * @ii_dev: an atomic to keep track of the last task exiting the idle cycle + * @state: an normalized integer giving the state of the cooling device + */ +struct cpuidle_cooling_device { + struct idle_inject_device *ii_dev; + unsigned long state; +}; + +static DEFINE_IDA(cpuidle_ida); + +/** + * cpuidle_cooling_runtime - Running time computation + * @idle_duration_us: the idle cooling device + * @state: a percentile based number + * + * The running duration is computed from the idle injection duration + * which is fixed. If we reach 100% of idle injection ratio, that + * means the running duration is zero. If we have a 50% ratio + * injection, that means we have equal duration for idle and for + * running duration. + * + * The formula is deduced as the following: + * + * running = idle x ((100 / ratio) - 1) + * + * For precision purpose for integer math, we use the following: + * + * running = (idle x 100) / ratio - idle + * + * For example, if we have an injected duration of 50%, then we end up + * with 10ms of idle injection and 10ms of running duration. + * + * Returns an unsigned int for an usec based runtime duration. + */ +static unsigned int cpuidle_cooling_runtime(unsigned int idle_duration_us, + unsigned long state) +{ + if (!state) + return 0; + + return ((idle_duration_us * 100) / state) - idle_duration_us; +} + +/** + * cpuidle_cooling_get_max_state - Get the maximum state + * @cdev : the thermal cooling device + * @state : a pointer to the state variable to be filled + * + * The function always gives 100 as the injection ratio is percentile + * based for consistency accros different platforms. + * + * The function can not fail, it always returns zero. + */ +static int cpuidle_cooling_get_max_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + /* + * Depending on the configuration or the hardware, the running + * cycle and the idle cycle could be different. We want unify + * that to an 0..100 interval, so the set state interface will + * be the same whatever the platform is. + * + * The state 100% will make the cluster 100% ... idle. A 0% + * injection ratio means no idle injection at all and 50% + * means for 10ms of idle injection, we have 10ms of running + * time. + */ + *state = 100; + + return 0; +} + +/** + * cpuidle_cooling_get_cur_state - Get the current cooling state + * @cdev: the thermal cooling device + * @state: a pointer to the state + * + * The function just copy the state value from the private thermal + * cooling device structure, the mapping is 1 <-> 1. + * + * The function can not fail, it always returns zero. + */ +static int cpuidle_cooling_get_cur_state(struct thermal_cooling_device *cdev, + unsigned long *state) +{ + struct cpuidle_cooling_device *idle_cdev = cdev->devdata; + + *state = idle_cdev->state; + + return 0; +} + +/** + * cpuidle_cooling_set_cur_state - Set the current cooling state + * @cdev: the thermal cooling device + * @state: the target state + * + * The function checks first if we are initiating the mitigation which + * in turn wakes up all the idle injection tasks belonging to the idle + * cooling device. In any case, it updates the internal state for the + * cooling device. + * + * The function can not fail, it always returns zero. + */ +static int cpuidle_cooling_set_cur_state(struct thermal_cooling_device *cdev, + unsigned long state) +{ + struct cpuidle_cooling_device *idle_cdev = cdev->devdata; + struct idle_inject_device *ii_dev = idle_cdev->ii_dev; + unsigned long current_state = idle_cdev->state; + unsigned int runtime_us, idle_duration_us; + + idle_cdev->state = state; + + idle_inject_get_duration(ii_dev, &runtime_us, &idle_duration_us); + + runtime_us = cpuidle_cooling_runtime(idle_duration_us, state); + + idle_inject_set_duration(ii_dev, runtime_us, idle_duration_us); + + if (current_state == 0 && state > 0) { + idle_inject_start(ii_dev); + } else if (current_state > 0 && !state) { + idle_inject_stop(ii_dev); + } + + return 0; +} + +/** + * cpuidle_cooling_ops - thermal cooling device ops + */ +static struct thermal_cooling_device_ops cpuidle_cooling_ops = { + .get_max_state = cpuidle_cooling_get_max_state, + .get_cur_state = cpuidle_cooling_get_cur_state, + .set_cur_state = cpuidle_cooling_set_cur_state, +}; + +/** + * cpuidle_of_cooling_register - Idle cooling device initialization function + * @drv: a cpuidle driver structure pointer + * + * This function is in charge of creating a cooling device per cpuidle + * driver and register it to thermal framework. + * + * Returns a valid pointer to a thermal cooling device, a PTR_ERR + * corresponding to the error detected in the underlying subsystems. + */ +struct thermal_cooling_device * +__init cpuidle_of_cooling_register(struct device_node *np, + struct cpuidle_driver *drv) +{ + struct idle_inject_device *ii_dev; + struct cpuidle_cooling_device *idle_cdev; + struct thermal_cooling_device *cdev; + char dev_name[THERMAL_NAME_LENGTH]; + int id, ret; + + idle_cdev = kzalloc(sizeof(*idle_cdev), GFP_KERNEL); + if (!idle_cdev) { + ret = -ENOMEM; + goto out; + } + + id = ida_simple_get(&cpuidle_ida, 0, 0, GFP_KERNEL); + if (id < 0) { + ret = id; + goto out_kfree; + } + + ii_dev = idle_inject_register(drv->cpumask); + if (IS_ERR(ii_dev)) { + ret = PTR_ERR(ii_dev); + goto out_id; + } + + idle_inject_set_duration(ii_dev, 0, TICK_USEC); + + idle_cdev->ii_dev = ii_dev; + + snprintf(dev_name, sizeof(dev_name), "thermal-idle-%d", id); + + cdev = thermal_of_cooling_device_register(np, dev_name, idle_cdev, + &cpuidle_cooling_ops); + if (IS_ERR(cdev)) { + ret = PTR_ERR(cdev); + goto out_unregister; + } + + return cdev; + +out_unregister: + idle_inject_unregister(ii_dev); +out_id: + ida_simple_remove(&cpuidle_ida, id); +out_kfree: + kfree(idle_cdev); +out: + return ERR_PTR(ret); +} + +/** + * cpuidle_cooling_register - Idle cooling device initialization function + * @drv: a cpuidle driver structure pointer + * + * This function is in charge of creating a cooling device per cpuidle + * driver and register it to thermal framework. + * + * Returns a valid pointer to a thermal cooling device, a PTR_ERR + * corresponding to the error detected in the underlying subsystems. + */ +struct thermal_cooling_device * +__init cpuidle_cooling_register(struct cpuidle_driver *drv) +{ + return cpuidle_of_cooling_register(NULL, drv); +} diff --git a/include/linux/cpu_cooling.h b/include/linux/cpu_cooling.h index 3cdd85f987d7..da0970183d1f 100644 --- a/include/linux/cpu_cooling.h +++ b/include/linux/cpu_cooling.h @@ -60,4 +60,26 @@ of_cpufreq_cooling_register(struct cpufreq_policy *policy) } #endif /* CONFIG_CPU_FREQ_THERMAL */ +struct cpuidle_driver; + +#ifdef CONFIG_CPU_IDLE_THERMAL +extern struct thermal_cooling_device * +__init cpuidle_cooling_register(struct cpuidle_driver *drv); +extern struct thermal_cooling_device * +__init cpuidle_of_cooling_register(struct device_node *np, + struct cpuidle_driver *drv); +#else /* CONFIG_CPU_IDLE_THERMAL */ +static inline struct thermal_cooling_device * +__init cpuidle_cooling_register(struct cpuidle_driver *drv) +{ + return ERR_PTR(-EINVAL); +} +static inline struct thermal_cooling_device * +__init cpuidle_of_cooling_register(struct device_node *np, + struct cpuidle_driver *drv) +{ + return ERR_PTR(-EINVAL); +} +#endif /* CONFIG_CPU_IDLE_THERMAL */ + #endif /* __CPU_COOLING_H__ */ -- 2.17.1