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=unavailable 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 496C4C43603 for ; Thu, 19 Dec 2019 22:53:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13B0E24672 for ; Thu, 19 Dec 2019 22:53:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="UynOsnzI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727184AbfLSWxc (ORCPT ); Thu, 19 Dec 2019 17:53:32 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:35979 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726963AbfLSWx2 (ORCPT ); Thu, 19 Dec 2019 17:53:28 -0500 Received: by mail-wr1-f65.google.com with SMTP id z3so7618682wru.3 for ; Thu, 19 Dec 2019 14:53:25 -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=NESEgMCPpx7LsIUuhGkki9z39II2Nb7qI1us82kFX+c=; b=UynOsnzIPgir0ubSDp0xgFJjQxJNSuPbPNhPxuS+G37ssejX9PtwihJOsp7pMcfae/ 2ZzEOyNNq1xGj5ltgpszlbDhCTDIChTMj0TzdCH5dUHpcBEez0ilh8E8eI9Y+Zo22X2C 1DdAqHDJVokUxbPKP3vRHVoeZG7YMbGjhc9rPHrb8eifg1hTUeomPKiCGFW50ZgXqj1J 6y9e4uMExZC5O30abzB7yg4p6MLRgCW3q4fGGcTAIAhpifSbQCGhOoyZTEDqCPWxJzFX z5KBG/gyrJRP7MCW1cp37H2OXhbRP0yb11SHS8RXgAKcb+sNMAN589xWymdHUeEvFAK4 MC3A== 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=NESEgMCPpx7LsIUuhGkki9z39II2Nb7qI1us82kFX+c=; b=CxQGp7qZNcDeiySML4X6tnmN7nk87dWcP0xtVdFk5Fyuq/SW4lOLOOLZOk58Vn5gh6 hrZQbAsFPu98isiEMAHWz9gUaq7obfS7pE1OhBfN/RV80QwtHHdy8G1sW4J8G/VKJa7+ 2Nh0IJqnac3CPWVpfm1Y0k4fv3JsYYMfAZeomG0VM2Lifj8DHUMzvFyW3ca3NEj+0TBP Ay6ZKKRQNMl+u1fTl90vt7RsqNK96hYK1r0drn7vXZATQT5V7vdiTP2DPbvPry7jCXJN SM5mEXKvivCiVG8lXya/jVnmafwgfjqwuH3mzElaG4gsRcUDGwfgV6wkURRfPZ6Z6Urs 1RTQ== X-Gm-Message-State: APjAAAX3ao8ZhGwbxDJZ4RUKrfZVLBN6VK94g1WXnJiDp6n+Vwj7shiW IaYazliMyxqDoBA47sa+6Oce0w== X-Google-Smtp-Source: APXvYqxAk4oy7U/y/LEtpnEPzdzz8li0OAPChR8jTuYUBUlJ11yysvmaUHN93dNPL5tysblegqnXWw== X-Received: by 2002:adf:f606:: with SMTP id t6mr11385041wrp.85.1576796004832; Thu, 19 Dec 2019 14:53:24 -0800 (PST) Received: from localhost.localdomain ([2a01:e34:ed2f:f020:58d:4e9b:2833:86c3]) by smtp.gmail.com with ESMTPSA id p15sm7581930wma.40.2019.12.19.14.53.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Dec 2019 14:53:24 -0800 (PST) From: Daniel Lezcano To: daniel.lezcano@linaro.org, rui.zhang@intel.com Cc: rjw@rjwysocki.net, linux-pm@vger.kernel.org, viresh.kumar@linaro.org, amit.kucheria@linaro.org, linux-kernel@vger.kernel.org, martin.kepplinger@puri.sm Subject: [PATCH V6 2/3] thermal/drivers/cpu_cooling: Introduce the cpu idle cooling driver Date: Thu, 19 Dec 2019 23:53:16 +0100 Message-Id: <20191219225317.17158-2-daniel.lezcano@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191219225317.17158-1-daniel.lezcano@linaro.org> References: <20191219225317.17158-1-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 duration is fixed while the running duration 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 Acked-by: Viresh Kumar --- V6: - Removed __init annotatations to prevent section mismatch - Converted register functions to return an integer instead of a pointer V5: - Fixed NULL pointer check from idle_inject_register - Fixed invalid zero value passed to idle_inject_set_duration V4: - Fixed typos in the kernel-doc and clarified the changelog (Amit Kucheria) V3: - Add missing parameter documentation (Viresh Kumar) - Fixed function description (Viresh Kumar) - Add entry in MAINTAINER file 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) --- MAINTAINERS | 3 + drivers/thermal/Kconfig | 7 + drivers/thermal/Makefile | 1 + drivers/thermal/cpuidle_cooling.c | 232 ++++++++++++++++++++++++++++++ include/linux/cpu_cooling.h | 18 +++ 5 files changed, 261 insertions(+) create mode 100644 drivers/thermal/cpuidle_cooling.c diff --git a/MAINTAINERS b/MAINTAINERS index bd5847e802de..d92e9eb14131 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -16330,12 +16330,15 @@ F: Documentation/devicetree/bindings/thermal/ THERMAL/CPU_COOLING M: Amit Daniel Kachhap +M: Daniel Lezcano M: Viresh Kumar M: Javi Merino L: linux-pm@vger.kernel.org S: Supported F: Documentation/driver-api/thermal/cpu-cooling-api.rst +F: Documentation/driver-api/thermal/cpu-idle-cooling.rst F: drivers/thermal/cpu_cooling.c +F: drivers/thermal/cpuidle_cooling.c F: include/linux/cpu_cooling.h THERMAL DRIVER FOR AMLOGIC SOCS diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index 702b33dcdb35..0d93c652014f 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -170,6 +170,13 @@ 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 3f3533c01aa3..6929e6fad1ac 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..0bb843246f59 --- /dev/null +++ b/drivers/thermal/cpuidle_cooling.c @@ -0,0 +1,232 @@ +// 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: a 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 follows: + * + * 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. + * + * Return: An unsigned int for a 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 returns 100 as the injection ratio. It is + * percentile based for consistency accross different platforms. + * + * Return: The function can not fail, it is always 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 to + * 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 copies the state value from the private thermal + * cooling device structure, the mapping is 1 <-> 1. + * + * Return: The function can not fail, it is always 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. + * + * Return: The function can not fail, it is always 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 + * @np: a node pointer to a device tree cooling device node + * + * This function is in charge of creating a cooling device per cpuidle + * driver and register it to thermal framework. + * + * Return: zero on success, or negative value corresponding to the + * error detected in the underlying subsystems. + */ +int 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 (!ii_dev) { + ret = -EINVAL; + goto out_id; + } + + idle_inject_set_duration(ii_dev, TICK_USEC, 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 0; + +out_unregister: + idle_inject_unregister(ii_dev); +out_id: + ida_simple_remove(&cpuidle_ida, id); +out_kfree: + kfree(idle_cdev); +out: + return 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. + * + * Return: zero on success, or negative value corresponding to the + * error detected in the underlying subsystems. + */ +int 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..65501d8f9778 100644 --- a/include/linux/cpu_cooling.h +++ b/include/linux/cpu_cooling.h @@ -60,4 +60,22 @@ of_cpufreq_cooling_register(struct cpufreq_policy *policy) } #endif /* CONFIG_CPU_FREQ_THERMAL */ +struct cpuidle_driver; + +#ifdef CONFIG_CPU_IDLE_THERMAL +int cpuidle_cooling_register(struct cpuidle_driver *drv); +int cpuidle_of_cooling_register(struct device_node *np, + struct cpuidle_driver *drv); +#else /* CONFIG_CPU_IDLE_THERMAL */ +static inline int cpuidle_cooling_register(struct cpuidle_driver *drv) +{ + return 0; +} +static inline int cpuidle_of_cooling_register(struct device_node *np, + struct cpuidle_driver *drv) +{ + return 0; +} +#endif /* CONFIG_CPU_IDLE_THERMAL */ + #endif /* __CPU_COOLING_H__ */ -- 2.17.1