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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 CD67DC433FE for ; Tue, 8 Dec 2020 07:21:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E28123A79 for ; Tue, 8 Dec 2020 07:21:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726483AbgLHHVc (ORCPT ); Tue, 8 Dec 2020 02:21:32 -0500 Received: from foss.arm.com ([217.140.110.172]:43324 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726456AbgLHHVb (ORCPT ); Tue, 8 Dec 2020 02:21:31 -0500 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 EB0D130E; Mon, 7 Dec 2020 23:20:45 -0800 (PST) Received: from [10.57.34.152] (unknown [10.57.34.152]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9AB3B3F718; Mon, 7 Dec 2020 23:20:43 -0800 (PST) Subject: Re: [PATCH v4 3/4] scmi-cpufreq: get opp_shared_cpus from opp-v2 for EM To: Viresh Kumar Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, sudeep.holla@arm.com, rjw@rjwysocki.net, vireshk@kernel.org, robh+dt@kernel.org, sboyd@kernel.org, nm@ti.com, daniel.lezcano@linaro.org, morten.rasmussen@arm.com, chris.redpath@arm.com References: <20201202172356.10508-1-nicola.mazzucato@arm.com> <20201202172356.10508-4-nicola.mazzucato@arm.com> <20201208055053.kggxw26kxtnpneua@vireshk-i7> From: Nicola Mazzucato Message-ID: <0e4d3134-f9b2-31fa-b454-fb30265a80b5@arm.com> Date: Tue, 8 Dec 2020 07:22:52 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20201208055053.kggxw26kxtnpneua@vireshk-i7> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Viresh, thanks for looking into this. Please find below On 12/8/20 5:50 AM, Viresh Kumar wrote: > On 02-12-20, 17:23, Nicola Mazzucato wrote: >> By design, SCMI performance domains define the granularity of >> performance controls, they do not describe any underlying hardware >> dependencies (although they may match in many cases). >> >> It is therefore possible to have some platforms where hardware may have >> the ability to control CPU performance at different granularity and choose >> to describe fine-grained performance control through SCMI. >> >> In such situations, the energy model would be provided with inaccurate >> information based on controls, while it still needs to know the >> performance boundaries. >> >> To restore correct functionality, retrieve information of CPUs under the >> same v/f domain from operating-points-v2 in DT, and pass it on to EM. >> >> Signed-off-by: Nicola Mazzucato >> --- >> drivers/cpufreq/scmi-cpufreq.c | 51 +++++++++++++++++++++++----------- >> 1 file changed, 35 insertions(+), 16 deletions(-) >> >> diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c >> index 491a0a24fb1e..f505efcc62b1 100644 >> --- a/drivers/cpufreq/scmi-cpufreq.c >> +++ b/drivers/cpufreq/scmi-cpufreq.c >> @@ -127,6 +127,7 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy) >> struct cpufreq_frequency_table *freq_table; >> struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power); >> bool power_scale_mw; >> + cpumask_var_t opp_shared_cpus; >> >> cpu_dev = get_cpu_device(policy->cpu); >> if (!cpu_dev) { >> @@ -134,30 +135,45 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy) >> return -ENODEV; >> } >> >> - ret = handle->perf_ops->device_opps_add(handle, cpu_dev); >> - if (ret) { >> - dev_warn(cpu_dev, "failed to add opps to the device\n"); >> - return ret; >> - } >> + if (!zalloc_cpumask_var(&opp_shared_cpus, GFP_KERNEL)) >> + return -ENOMEM; >> >> ret = scmi_get_sharing_cpus(cpu_dev, policy->cpus); >> if (ret) { >> dev_warn(cpu_dev, "failed to get sharing cpumask\n"); >> - return ret; >> + goto out_free_cpumask; >> } >> >> - ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus); >> - if (ret) { >> - dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", >> - __func__, ret); >> - return ret; >> + /* >> + * The OPP 'sharing cpus' info may come from dt through an empty opp >> + * table and opp-shared. If found, it takes precedence over the SCMI >> + * domain IDs info. >> + */ >> + ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, opp_shared_cpus); >> + if (ret || !cpumask_weight(opp_shared_cpus)) { >> + /* >> + * Either opp-table is not set or no opp-shared was found, >> + * use the information from SCMI domain IDs. >> + */ >> + cpumask_copy(opp_shared_cpus, policy->cpus); >> } >> >> nr_opp = dev_pm_opp_get_opp_count(cpu_dev); >> if (nr_opp <= 0) { >> - dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n"); >> - ret = -EPROBE_DEFER; >> - goto out_free_opp; >> + ret = handle->perf_ops->device_opps_add(handle, cpu_dev); >> + if (ret) { >> + dev_warn(cpu_dev, "failed to add opps to the device\n"); >> + goto out_free_cpumask; >> + } >> + >> + ret = dev_pm_opp_set_sharing_cpus(cpu_dev, opp_shared_cpus); >> + if (ret) { >> + dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", >> + __func__, ret); >> + goto out_free_cpumask; >> + } >> + > > Why do we need to call above two after calling > dev_pm_opp_get_opp_count() ? Sorry, I am not sure to understand your question here. If there are no opps for a device we want to add them to it, otherwise no need as they would be duplicated. And we don't check the return value of > the below call anymore, moreover we have to call it twice now. This second get_opp_count is required such that we register em with the correct opp number after having added them. Without this the opp_count would not be correct. Hope I have answered your questions. > >> + nr_opp = dev_pm_opp_get_opp_count(cpu_dev); >> } >> >> priv = kzalloc(sizeof(*priv), GFP_KERNEL); >> @@ -191,15 +207,18 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy) >> handle->perf_ops->fast_switch_possible(handle, cpu_dev); >> >> power_scale_mw = handle->perf_ops->power_scale_mw_get(handle); >> - em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, policy->cpus, >> + em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, opp_shared_cpus, >> power_scale_mw); >> >> - return 0; >> + ret = 0; > > ret is already 0 here. true, nice spot, thanks > >> + goto out_free_cpumask; >> >> out_free_priv: >> kfree(priv); >> out_free_opp: >> dev_pm_opp_remove_all_dynamic(cpu_dev); >> +out_free_cpumask: >> + free_cpumask_var(opp_shared_cpus); >> >> return ret; >> } >> -- >> 2.27.0 >