From patchwork Wed May 11 09:35:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chanwoo Choi X-Patchwork-Id: 574180 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 E7D86C433EF for ; Wed, 11 May 2022 09:36:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233055AbiEKJgc (ORCPT ); Wed, 11 May 2022 05:36:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241994AbiEKJgP (ORCPT ); Wed, 11 May 2022 05:36:15 -0400 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F37BCB2C; Wed, 11 May 2022 02:36:08 -0700 (PDT) Received: by mail-pj1-x102c.google.com with SMTP id x88so1731344pjj.1; Wed, 11 May 2022 02:36:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=8PuIpOa+OutSQzZeqQOjh/jYrd4MSz5o8F1cQrrAL5A=; b=gAThPUxtKtOjsFnGb5dcyojLgqf8+WVJeRq+kXM+0WjWqpC72BNkwtVYFf/2LwTW45 AnjfExAJJk2D18oGhiERiqBQIzWCEIwoU2EEcFYxavqltXp04NLEFJ5ud/6DFjr7grF1 LViVRvfRQZoSXgSnUfxkMBpgXNn6rB9+dtbLPJIGk0kAJ9MOGXOx2UDpE07Ev4VYVNPz vB8fjWbyQhVYdJqJU2xPsC6Z82VieWREPlOPeory90yyzapDTzByNKwGKz+Xg+xdXbd2 FRQnfXuFd8TgVqrQ3tNBloCN+k2rueZwV4skr7CTPndnnbz9lnxMXU0qM+vlbJMPg12k hvpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=8PuIpOa+OutSQzZeqQOjh/jYrd4MSz5o8F1cQrrAL5A=; b=kSgYDL1aHU5FgkVL3CvhAEUjlARQpLt/OnRKdREorqfZ5pPmbK22r6XY7AMuOTv2FD 7KqbSWFTkXY8K/GhciyvzxeUZv6wC29Gdnb5gVzjLsz6jQA45aDxdIcbVhXJzQxsAEb/ SkSQBFNGZsDfkXGoBsz8XbO5kG0QFkqaEL+8ShFyrk8YphvKc4TGnfsz+FQeTdRjKz5k UobbI1te3LZyluRm+bxX8qPGNhtc9c1dleKvvwBdQ5E1owWGQLmhYiPvIWyuSizc7obw diL1DzwW4WJlL6ZqRkAQxeSEMBseh+IMvUBpEV22IS8Skq+2+FsCrhcTtblb1ZPhv4GT DbEA== X-Gm-Message-State: AOAM531zUrp5H42w4iTQL7zcGDq1K/M8TNTYVL3yQfxWbOaKCUuM76H9 hBZtySg6xZk13p+NVnx0CwjOBCHxe9OGfQ== X-Google-Smtp-Source: ABdhPJzB7BSKYA6U13uQzNNBXDVvPkxsQTWmIQAh0JyTjrUZjxWppMS35L9N1YQCrN8KvcY/F4JvzA== X-Received: by 2002:a17:90b:4c43:b0:1dc:d759:76f2 with SMTP id np3-20020a17090b4c4300b001dcd75976f2mr4489739pjb.191.1652261768169; Wed, 11 May 2022 02:36:08 -0700 (PDT) Received: from localhost.localdomain ([14.32.163.5]) by smtp.gmail.com with ESMTPSA id p14-20020a17090a428e00b001dcf8960a13sm3492640pjg.40.2022.05.11.02.36.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 May 2022 02:36:07 -0700 (PDT) From: Chanwoo Choi X-Google-Original-From: Chanwoo Choi To: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: johnson.wang@mediatek.com, mka@chromium.org, wenst@chromium.org, jia-wei.chang@mediatek.com, andrew-sh.cheng@mediatek.com, hsinyi@chromium.org, saravanak@google.com, cw00.choi@samsung.com, myungjoo.ham@samsung.com, kyungmin.park@samsung.com, Saravana Kannan , Sibi Sankar Subject: [PATCH v4 2/4] PM / devfreq: Add cpu based scaling support to passive governor Date: Wed, 11 May 2022 18:35:52 +0900 Message-Id: <20220511093554.17535-3-cw00.choi@samsung.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220511093554.17535-1-cw00.choi@samsung.com> References: <20220511093554.17535-1-cw00.choi@samsung.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Saravana Kannan Many CPU architectures have caches that can scale independent of the CPUs. Frequency scaling of the caches is necessary to make sure that the cache is not a performance bottleneck that leads to poor performance and power. The same idea applies for RAM/DDR. To achieve this, this patch adds support for cpu based scaling to the passive governor. This is accomplished by taking the current frequency of each CPU frequency domain and then adjust the frequency of the cache (or any devfreq device) based on the frequency of the CPUs. It listens to CPU frequency transition notifiers to keep itself up to date on the current CPU frequency. To decide the frequency of the device, the governor does one of the following: * Derives the optimal devfreq device opp from required-opps property of the parent cpu opp_table. * Scales the device frequency in proportion to the CPU frequency. So, if the CPUs are running at their max frequency, the device runs at its max frequency. If the CPUs are running at their min frequency, the device runs at its min frequency. It is interpolated for frequencies in between. Tested-by: Chen-Yu Tsai Tested-by: Johnson Wang Signed-off-by: Saravana Kannan [Sibi: Integrated cpu-freqmap governor into passive_governor] Signed-off-by: Sibi Sankar [Chanwoo: Fix conflict with latest code and cleanup code] Signed-off-by: Chanwoo Choi --- drivers/devfreq/governor.h | 22 +++ drivers/devfreq/governor_passive.c | 297 +++++++++++++++++++++++++++-- include/linux/devfreq.h | 17 +- 3 files changed, 322 insertions(+), 14 deletions(-) diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h index b0dbfee8bbf2..335c4a491254 100644 --- a/drivers/devfreq/governor.h +++ b/drivers/devfreq/governor.h @@ -47,6 +47,28 @@ #define DEVFREQ_GOV_ATTR_POLLING_INTERVAL BIT(0) #define DEVFREQ_GOV_ATTR_TIMER BIT(1) +/** + * struct devfreq_cpu_data - Hold the per-cpu data + * @dev: reference to cpu device. + * @first_cpu: the cpumask of the first cpu of a policy. + * @opp_table: reference to cpu opp table. + * @cur_freq: the current frequency of the cpu. + * @min_freq: the min frequency of the cpu. + * @max_freq: the max frequency of the cpu. + * + * This structure stores the required cpu_data of a cpu. + * This is auto-populated by the governor. + */ +struct devfreq_cpu_data { + struct device *dev; + unsigned int first_cpu; + + struct opp_table *opp_table; + unsigned int cur_freq; + unsigned int min_freq; + unsigned int max_freq; +}; + /** * struct devfreq_governor - Devfreq policy governor * @node: list node - contains registered devfreq governors diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c index fc09324a03e0..3fba05beaf24 100644 --- a/drivers/devfreq/governor_passive.c +++ b/drivers/devfreq/governor_passive.c @@ -8,11 +8,84 @@ */ #include +#include +#include +#include +#include #include #include #include "governor.h" -static int devfreq_passive_get_target_freq(struct devfreq *devfreq, +#define HZ_PER_KHZ 1000 + +static unsigned long get_target_freq_by_required_opp(struct device *p_dev, + struct opp_table *p_opp_table, + struct opp_table *opp_table, + unsigned long freq) +{ + struct dev_pm_opp *opp = NULL, *p_opp = NULL; + + if (!p_dev || !p_opp_table || !opp_table || !freq) + return 0; + + p_opp = devfreq_recommended_opp(p_dev, &freq, 0); + if (IS_ERR(p_opp)) + return 0; + + opp = dev_pm_opp_xlate_required_opp(p_opp_table, opp_table, p_opp); + dev_pm_opp_put(p_opp); + + if (IS_ERR(opp)) + return 0; + + freq = dev_pm_opp_get_freq(opp); + dev_pm_opp_put(opp); + + return freq; +} + +static int get_target_freq_with_cpufreq(struct devfreq *devfreq, + unsigned long *target_freq) +{ + struct devfreq_passive_data *p_data = + (struct devfreq_passive_data *)devfreq->data; + struct devfreq_cpu_data *parent_cpu_data; + unsigned long cpu, cpu_cur, cpu_min, cpu_max, cpu_percent; + unsigned long dev_min, dev_max; + unsigned long freq = 0; + + for_each_online_cpu(cpu) { + parent_cpu_data = p_data->parent_cpu_data[cpu]; + if (!parent_cpu_data || parent_cpu_data->first_cpu != cpu) + continue; + + /* Get target freq via required opps */ + cpu_cur = parent_cpu_data->cur_freq * HZ_PER_KHZ; + freq = get_target_freq_by_required_opp(parent_cpu_data->dev, + parent_cpu_data->opp_table, + devfreq->opp_table, cpu_cur); + if (freq) { + *target_freq = max(freq, *target_freq); + continue; + } + + /* Use interpolation if required opps is not available */ + devfreq_get_freq_range(devfreq, &dev_min, &dev_max); + + cpu_min = parent_cpu_data->min_freq; + cpu_max = parent_cpu_data->max_freq; + cpu_cur = parent_cpu_data->cur_freq; + + cpu_percent = ((cpu_cur - cpu_min) * 100) / (cpu_max - cpu_min); + freq = dev_min + mult_frac(dev_max - dev_min, cpu_percent, 100); + + *target_freq = max(freq, *target_freq); + } + + return 0; +} + +static int get_target_freq_with_devfreq(struct devfreq *devfreq, unsigned long *freq) { struct devfreq_passive_data *p_data @@ -99,6 +172,184 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq, return 0; } +static int devfreq_passive_get_target_freq(struct devfreq *devfreq, + unsigned long *freq) +{ + struct devfreq_passive_data *p_data = + (struct devfreq_passive_data *)devfreq->data; + int ret; + + if (!p_data) + return -EINVAL; + + /* + * If the devfreq device with passive governor has the specific method + * to determine the next frequency, should use the get_target_freq() + * of struct devfreq_passive_data. + */ + if (p_data->get_target_freq) + return p_data->get_target_freq(devfreq, freq); + + switch (p_data->parent_type) { + case DEVFREQ_PARENT_DEV: + ret = get_target_freq_with_devfreq(devfreq, freq); + break; + case CPUFREQ_PARENT_DEV: + ret = get_target_freq_with_cpufreq(devfreq, freq); + break; + default: + ret = -EINVAL; + dev_err(&devfreq->dev, "Invalid parent type\n"); + break; + } + + return ret; +} + +static int cpufreq_passive_notifier_call(struct notifier_block *nb, + unsigned long event, void *ptr) +{ + struct devfreq_passive_data *p_data = + container_of(nb, struct devfreq_passive_data, nb); + struct devfreq *devfreq = (struct devfreq *)p_data->this; + struct devfreq_cpu_data *parent_cpu_data; + struct cpufreq_freqs *freqs = ptr; + unsigned int cur_freq; + int ret; + + if (event != CPUFREQ_POSTCHANGE || !freqs || + !p_data->parent_cpu_data[freqs->policy->cpu]) + return 0; + + parent_cpu_data = p_data->parent_cpu_data[freqs->policy->cpu]; + if (parent_cpu_data->cur_freq == freqs->new) + return 0; + + cur_freq = parent_cpu_data->cur_freq; + parent_cpu_data->cur_freq = freqs->new; + + mutex_lock(&devfreq->lock); + ret = devfreq_update_target(devfreq, freqs->new); + mutex_unlock(&devfreq->lock); + if (ret) { + parent_cpu_data->cur_freq = cur_freq; + dev_err(&devfreq->dev, "failed to update the frequency.\n"); + return ret; + } + + return 0; +} + +static int cpufreq_passive_unregister_notifier(struct devfreq *devfreq) +{ + struct devfreq_passive_data *p_data + = (struct devfreq_passive_data *)devfreq->data; + struct devfreq_cpu_data *parent_cpu_data; + int cpu, ret; + + if (p_data->nb.notifier_call) { + ret = cpufreq_unregister_notifier(&p_data->nb, + CPUFREQ_TRANSITION_NOTIFIER); + if (ret < 0) + return ret; + } + + for_each_possible_cpu(cpu) { + parent_cpu_data = p_data->parent_cpu_data[cpu]; + if (!parent_cpu_data) + continue; + + if (parent_cpu_data->opp_table) + dev_pm_opp_put_opp_table(parent_cpu_data->opp_table); + kfree(parent_cpu_data); + } + + return 0; +} + +static int cpufreq_passive_register_notifier(struct devfreq *devfreq) +{ + struct devfreq_passive_data *p_data + = (struct devfreq_passive_data *)devfreq->data; + struct device *dev = devfreq->dev.parent; + struct opp_table *opp_table = NULL; + struct devfreq_cpu_data *parent_cpu_data; + struct cpufreq_policy *policy; + struct device *cpu_dev; + unsigned int cpu; + int ret; + + if (!p_data->this) + p_data->this = devfreq; + + p_data->nb.notifier_call = cpufreq_passive_notifier_call; + ret = cpufreq_register_notifier(&p_data->nb, CPUFREQ_TRANSITION_NOTIFIER); + if (ret) { + dev_err(dev, "failed to register cpufreq notifier\n"); + p_data->nb.notifier_call = NULL; + goto err; + } + + for_each_possible_cpu(cpu) { + if (p_data->parent_cpu_data[cpu]) + continue; + + policy = cpufreq_cpu_get(cpu); + if (!policy) { + ret = -EPROBE_DEFER; + goto err; + } + + parent_cpu_data = kzalloc(sizeof(*parent_cpu_data), + GFP_KERNEL); + if (!parent_cpu_data) { + ret = -ENOMEM; + goto err_put_policy; + } + + cpu_dev = get_cpu_device(cpu); + if (!cpu_dev) { + dev_err(dev, "failed to get cpu device\n"); + ret = -ENODEV; + goto err_free_cpu_data; + } + + opp_table = dev_pm_opp_get_opp_table(cpu_dev); + if (IS_ERR(opp_table)) { + dev_err(dev, "failed to get opp_table of cpu%d\n", cpu); + ret = PTR_ERR(opp_table); + goto err_free_cpu_data; + } + + parent_cpu_data->dev = cpu_dev; + parent_cpu_data->opp_table = opp_table; + parent_cpu_data->first_cpu = cpumask_first(policy->related_cpus); + parent_cpu_data->cur_freq = policy->cur; + parent_cpu_data->min_freq = policy->cpuinfo.min_freq; + parent_cpu_data->max_freq = policy->cpuinfo.max_freq; + + p_data->parent_cpu_data[cpu] = parent_cpu_data; + cpufreq_cpu_put(policy); + } + + mutex_lock(&devfreq->lock); + ret = devfreq_update_target(devfreq, 0L); + mutex_unlock(&devfreq->lock); + if (ret) + dev_err(dev, "failed to update the frequency\n"); + + return ret; + +err_free_cpu_data: + kfree(parent_cpu_data); +err_put_policy: + cpufreq_cpu_put(policy); +err: + WARN_ON(cpufreq_passive_unregister_notifier(devfreq)); + + return ret; +} + static int devfreq_passive_notifier_call(struct notifier_block *nb, unsigned long event, void *ptr) { @@ -131,30 +382,52 @@ static int devfreq_passive_notifier_call(struct notifier_block *nb, return NOTIFY_DONE; } -static int devfreq_passive_event_handler(struct devfreq *devfreq, - unsigned int event, void *data) +static int devfreq_passive_unregister_notifier(struct devfreq *devfreq) +{ + struct devfreq_passive_data *p_data + = (struct devfreq_passive_data *)devfreq->data; + struct devfreq *parent = (struct devfreq *)p_data->parent; + struct notifier_block *nb = &p_data->nb; + + return devfreq_unregister_notifier(parent, nb, DEVFREQ_TRANSITION_NOTIFIER); +} + +static int devfreq_passive_register_notifier(struct devfreq *devfreq) { struct devfreq_passive_data *p_data = (struct devfreq_passive_data *)devfreq->data; struct devfreq *parent = (struct devfreq *)p_data->parent; struct notifier_block *nb = &p_data->nb; - int ret = 0; if (!parent) return -EPROBE_DEFER; + nb->notifier_call = devfreq_passive_notifier_call; + return devfreq_register_notifier(parent, nb, DEVFREQ_TRANSITION_NOTIFIER); +} + +static int devfreq_passive_event_handler(struct devfreq *devfreq, + unsigned int event, void *data) +{ + struct devfreq_passive_data *p_data + = (struct devfreq_passive_data *)devfreq->data; + int ret = -EINVAL; + + if (!p_data) + return -EINVAL; + switch (event) { case DEVFREQ_GOV_START: - if (!p_data->this) - p_data->this = devfreq; - - nb->notifier_call = devfreq_passive_notifier_call; - ret = devfreq_register_notifier(parent, nb, - DEVFREQ_TRANSITION_NOTIFIER); + if (p_data->parent_type == DEVFREQ_PARENT_DEV) + ret = devfreq_passive_register_notifier(devfreq); + else if (p_data->parent_type == CPUFREQ_PARENT_DEV) + ret = cpufreq_passive_register_notifier(devfreq); break; case DEVFREQ_GOV_STOP: - WARN_ON(devfreq_unregister_notifier(parent, nb, - DEVFREQ_TRANSITION_NOTIFIER)); + if (p_data->parent_type == DEVFREQ_PARENT_DEV) + WARN_ON(devfreq_passive_unregister_notifier(devfreq)); + else if (p_data->parent_type == CPUFREQ_PARENT_DEV) + WARN_ON(cpufreq_passive_unregister_notifier(devfreq)); break; default: break; diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 142474b4af96..b1e4a6f796ce 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -38,6 +38,7 @@ enum devfreq_timer { struct devfreq; struct devfreq_governor; +struct devfreq_cpu_data; struct thermal_cooling_device; /** @@ -288,6 +289,11 @@ struct devfreq_simple_ondemand_data { #endif #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) +enum devfreq_parent_dev_type { + DEVFREQ_PARENT_DEV, + CPUFREQ_PARENT_DEV, +}; + /** * struct devfreq_passive_data - ``void *data`` fed to struct devfreq * and devfreq_add_device @@ -299,8 +305,11 @@ struct devfreq_simple_ondemand_data { * using governors except for passive governor. * If the devfreq device has the specific method to decide * the next frequency, should use this callback. - * @this: the devfreq instance of own device. - * @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER list + * @parent_type: the parent type of the device. + * @this: the devfreq instance of own device. + * @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER or + * CPUFREQ_TRANSITION_NOTIFIER list. + * @parent_cpu_data: the state min/max/current frequency of all online cpu's. * * The devfreq_passive_data have to set the devfreq instance of parent * device with governors except for the passive governor. But, don't need to @@ -314,9 +323,13 @@ struct devfreq_passive_data { /* Optional callback to decide the next frequency of passvice device */ int (*get_target_freq)(struct devfreq *this, unsigned long *freq); + /* Should set the type of parent device */ + enum devfreq_parent_dev_type parent_type; + /* For passive governor's internal use. Don't need to set them */ struct devfreq *this; struct notifier_block nb; + struct devfreq_cpu_data *parent_cpu_data[NR_CPUS]; }; #endif