From patchwork Thu Jul 7 07:15:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Luba X-Patchwork-Id: 588415 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48F99CCA479 for ; Thu, 7 Jul 2022 07:16:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234533AbiGGHQO (ORCPT ); Thu, 7 Jul 2022 03:16:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230004AbiGGHQN (ORCPT ); Thu, 7 Jul 2022 03:16:13 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 077F02FFCD; Thu, 7 Jul 2022 00:16:13 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 21360113E; Thu, 7 Jul 2022 00:16:13 -0700 (PDT) Received: from e123648.arm.com (unknown [10.57.11.194]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DFAC73F70D; Thu, 7 Jul 2022 00:16:09 -0700 (PDT) From: Lukasz Luba To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Cc: daniel.lezcano@linaro.org, amitk@kernel.org, rui.zhang@intel.com, lukasz.luba@arm.com, viresh.kumar@linaro.org, rafael@kernel.org, dietmar.eggemann@arm.com, nm@ti.com, sboyd@kernel.org, sudeep.holla@arm.com, cristian.marussi@arm.com, matthias.bgg@gmail.com, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 2/4] Documentation: EM: Switch to micro-Watts scale Date: Thu, 7 Jul 2022 08:15:53 +0100 Message-Id: <20220707071555.10085-3-lukasz.luba@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220707071555.10085-1-lukasz.luba@arm.com> References: <20220707071555.10085-1-lukasz.luba@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The EM now uses the micro-Watts scale for the power values. Update related documentation to reflect that fact. Fix also a problematic sentence in the doc "to:" which triggers test scripts complaining about wrong email address. Reviewed-by: Daniel Lezcano Signed-off-by: Lukasz Luba --- Documentation/power/energy-model.rst | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/Documentation/power/energy-model.rst b/Documentation/power/energy-model.rst index feb257b7f350..ef341be2882b 100644 --- a/Documentation/power/energy-model.rst +++ b/Documentation/power/energy-model.rst @@ -20,20 +20,20 @@ possible source of information on its own, the EM framework intervenes as an abstraction layer which standardizes the format of power cost tables in the kernel, hence enabling to avoid redundant work. -The power values might be expressed in milli-Watts or in an 'abstract scale'. +The power values might be expressed in micro-Watts or in an 'abstract scale'. Multiple subsystems might use the EM and it is up to the system integrator to check that the requirements for the power value scale types are met. An example can be found in the Energy-Aware Scheduler documentation Documentation/scheduler/sched-energy.rst. For some subsystems like thermal or powercap power values expressed in an 'abstract scale' might cause issues. These subsystems are more interested in estimation of power used in the past, -thus the real milli-Watts might be needed. An example of these requirements can +thus the real micro-Watts might be needed. An example of these requirements can be found in the Intelligent Power Allocation in Documentation/driver-api/thermal/power_allocator.rst. Kernel subsystems might implement automatic detection to check whether EM registered devices have inconsistent scale (based on EM internal flag). Important thing to keep in mind is that when the power values are expressed in -an 'abstract scale' deriving real energy in milli-Joules would not be possible. +an 'abstract scale' deriving real energy in micro-Joules would not be possible. The figure below depicts an example of drivers (Arm-specific here, but the approach is applicable to any architecture) providing power costs to the EM @@ -98,7 +98,7 @@ Drivers are expected to register performance domains into the EM framework by calling the following API:: int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, - struct em_data_callback *cb, cpumask_t *cpus, bool milliwatts); + struct em_data_callback *cb, cpumask_t *cpus, bool microwatts); Drivers must provide a callback function returning tuples for each performance state. The callback function provided by the driver is free @@ -106,10 +106,10 @@ to fetch data from any relevant location (DT, firmware, ...), and by any mean deemed necessary. Only for CPU devices, drivers must specify the CPUs of the performance domains using cpumask. For other devices than CPUs the last argument must be set to NULL. -The last argument 'milliwatts' is important to set with correct value. Kernel +The last argument 'microwatts' is important to set with correct value. Kernel subsystems which use EM might rely on this flag to check if all EM devices use the same scale. If there are different scales, these subsystems might decide -to: return warning/error, stop working or panic. +to return warning/error, stop working or panic. See Section 3. for an example of driver implementing this callback, or Section 2.4 for further documentation on this API @@ -137,7 +137,7 @@ The .get_cost() allows to provide the 'cost' values which reflect the efficiency of the CPUs. This would allow to provide EAS information which has different relation than what would be forced by the EM internal formulas calculating 'cost' values. To register an EM for such platform, the -driver must set the flag 'milliwatts' to 0, provide .get_power() callback +driver must set the flag 'microwatts' to 0, provide .get_power() callback and provide .get_cost() callback. The EM framework would handle such platform properly during registration. A flag EM_PERF_DOMAIN_ARTIFICIAL is set for such platform. Special care should be taken by other frameworks which are using EM From patchwork Thu Jul 7 07:15:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Luba X-Patchwork-Id: 588414 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F292EC43334 for ; Thu, 7 Jul 2022 07:16:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234435AbiGGHQW (ORCPT ); Thu, 7 Jul 2022 03:16:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234678AbiGGHQU (ORCPT ); Thu, 7 Jul 2022 03:16:20 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 619D62F675; Thu, 7 Jul 2022 00:16:19 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 85EB2106F; Thu, 7 Jul 2022 00:16:19 -0700 (PDT) Received: from e123648.arm.com (unknown [10.57.11.194]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 503463F70D; Thu, 7 Jul 2022 00:16:16 -0700 (PDT) From: Lukasz Luba To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Cc: daniel.lezcano@linaro.org, amitk@kernel.org, rui.zhang@intel.com, lukasz.luba@arm.com, viresh.kumar@linaro.org, rafael@kernel.org, dietmar.eggemann@arm.com, nm@ti.com, sboyd@kernel.org, sudeep.holla@arm.com, cristian.marussi@arm.com, matthias.bgg@gmail.com, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 4/4] cpufreq: scmi: Support the power scale in micro-Watts in SCMI v3.1 Date: Thu, 7 Jul 2022 08:15:55 +0100 Message-Id: <20220707071555.10085-5-lukasz.luba@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220707071555.10085-1-lukasz.luba@arm.com> References: <20220707071555.10085-1-lukasz.luba@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The SCMI v3.1 adds support for power values in micro-Watts. They are not always in milli-Watts anymore (ignoring the bogo-Watts). Thus, the power must be converted conditionally before sending to Energy Model. Add the logic which handles the needed checks and conversions. Acked-by: Sudeep Holla Signed-off-by: Lukasz Luba Acked-by: Viresh Kumar --- drivers/cpufreq/scmi-cpufreq.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c index bfd35583d653..513a071845c2 100644 --- a/drivers/cpufreq/scmi-cpufreq.c +++ b/drivers/cpufreq/scmi-cpufreq.c @@ -100,7 +100,7 @@ static int __maybe_unused scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power, unsigned long *KHz) { - bool power_scale_mw = perf_ops->power_scale_mw_get(ph); + enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph); unsigned long Hz; int ret, domain; @@ -114,8 +114,8 @@ scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power, if (ret) return ret; - /* Provide bigger resolution power to the Energy Model */ - if (power_scale_mw) + /* Convert the power to uW if it is mW (ignore bogoW) */ + if (power_scale == SCMI_POWER_MILLIWATTS) *power *= MICROWATT_PER_MILLIWATT; /* The EM framework specifies the frequency in KHz. */ @@ -255,8 +255,9 @@ static int scmi_cpufreq_exit(struct cpufreq_policy *policy) static void scmi_cpufreq_register_em(struct cpufreq_policy *policy) { struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power); - bool power_scale_mw = perf_ops->power_scale_mw_get(ph); + enum scmi_power_scale power_scale = perf_ops->power_scale_get(ph); struct scmi_data *priv = policy->driver_data; + bool em_power_scale = false; /* * This callback will be called for each policy, but we don't need to @@ -268,9 +269,13 @@ static void scmi_cpufreq_register_em(struct cpufreq_policy *policy) if (!priv->nr_opp) return; + if (power_scale == SCMI_POWER_MILLIWATTS + || power_scale == SCMI_POWER_MICROWATTS) + em_power_scale = true; + em_dev_register_perf_domain(get_cpu_device(policy->cpu), priv->nr_opp, &em_cb, priv->opp_shared_cpus, - power_scale_mw); + em_power_scale); } static struct cpufreq_driver scmi_cpufreq_driver = {