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Message-ID: <f3c974bc-a306-c633-ad19-56e093d36296@quicinc.com>
Date: Thu, 14 Nov 2024 08:13:09 +0530
From: Sibi Sankar <quic_sibis@...cinc.com>
To: Vincent Guittot <vincent.guittot@...aro.org>
CC: <sudeep.holla@....com>, <cristian.marussi@....com>, <rafael@...nel.org>,
<viresh.kumar@...aro.org>, <morten.rasmussen@....com>,
<dietmar.eggemann@....com>, <lukasz.luba@....com>,
<pierre.gondois@....com>, <linux-arm-kernel@...ts.infradead.org>,
<linux-pm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<quic_mdtipton@...cinc.com>, <linux-arm-msm@...r.kernel.org>
Subject: Re: [PATCH V7 2/2] cpufreq: scmi: Register for limit change
notifications
On 11/3/24 20:42, Vincent Guittot wrote:
> On Thu, 31 Oct 2024 at 14:28, Sibi Sankar <quic_sibis@...cinc.com> wrote:
>>
>> Register for limit change notifications if supported and use the throttled
>> frequency from the notification to apply HW pressure.
>>
>> Signed-off-by: Sibi Sankar <quic_sibis@...cinc.com>
>> Tested-by: Mike Tipton <quic_mdtipton@...cinc.com>
>> Reviewed-by: Cristian Marussi <cristian.marussi@....com>
>> Reviewed-by: Lukasz Luba <lukasz.luba@....com>
>> ---
>>
>> v7:
>> * Add a new request instead of reusing the max_freq_req [Vincent]
>> * Use the non-devm versions of register/unregister of event notifier
>> since we have to remove them when the cpus get removed anyway.
>> * Add new patch to fix cleanup path on boost enablement failure.
>>
>> drivers/cpufreq/scmi-cpufreq.c | 51 ++++++++++++++++++++++++++++++++++
>> 1 file changed, 51 insertions(+)
>>
>> diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c
>> index 07d6f9a9b7c8..ff13f7d4b2c9 100644
>> --- a/drivers/cpufreq/scmi-cpufreq.c
>> +++ b/drivers/cpufreq/scmi-cpufreq.c
>> @@ -16,6 +16,7 @@
>> #include <linux/export.h>
>> #include <linux/module.h>
>> #include <linux/pm_opp.h>
>> +#include <linux/pm_qos.h>
>> #include <linux/slab.h>
>> #include <linux/scmi_protocol.h>
>> #include <linux/types.h>
>> @@ -25,7 +26,10 @@ struct scmi_data {
>> int domain_id;
>> int nr_opp;
>> struct device *cpu_dev;
>> + struct cpufreq_policy *policy;
>> cpumask_var_t opp_shared_cpus;
>> + struct notifier_block limit_notify_nb;
>> + struct freq_qos_request limits_freq_req;
>> };
>>
>> static struct scmi_protocol_handle *ph;
>> @@ -174,6 +178,25 @@ static struct freq_attr *scmi_cpufreq_hw_attr[] = {
>> NULL,
>> };
>>
>> +static int scmi_limit_notify_cb(struct notifier_block *nb, unsigned long event, void *data)
>> +{
>> + struct scmi_data *priv = container_of(nb, struct scmi_data, limit_notify_nb);
>> + struct scmi_perf_limits_report *limit_notify = data;
>> + struct cpufreq_policy *policy = priv->policy;
>> + unsigned int limit_freq_khz;
>> + int ret;
>> +
>> + limit_freq_khz = limit_notify->range_max_freq / HZ_PER_KHZ;
>> +
>> + policy->max = clamp(limit_freq_khz, policy->cpuinfo.min_freq, policy->cpuinfo.max_freq);
>
> I don't think that the above is needed or correct, the cpufreq qos
> notifier will take care of updating policy->max with handle_update()
Fixed this in the next re-spin. Thanks again for the review.
-Sibi
>
>> +
>> + ret = freq_qos_update_request(&priv->limits_freq_req, policy->max);
>> + if (ret < 0)
>> + pr_warn("failed to update freq constraint: %d\n", ret);
>> +
>> + return NOTIFY_OK;
>> +}
>> +
>> static int scmi_cpufreq_init(struct cpufreq_policy *policy)
>> {
>> int ret, nr_opp, domain;
>> @@ -181,6 +204,7 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
>> struct device *cpu_dev;
>> struct scmi_data *priv;
>> struct cpufreq_frequency_table *freq_table;
>> + struct scmi_device *sdev = cpufreq_get_driver_data();
>>
>> cpu_dev = get_cpu_device(policy->cpu);
>> if (!cpu_dev) {
>> @@ -294,6 +318,25 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
>> }
>> }
>>
>> + ret = freq_qos_add_request(&policy->constraints, &priv->limits_freq_req, FREQ_QOS_MAX,
>> + FREQ_QOS_MAX_DEFAULT_VALUE);
>> + if (ret < 0) {
>> + dev_err(cpu_dev, "failed to add qos limits request: %d\n", ret);
>> + goto out_free_table;
>> + }
>> +
>> + priv->limit_notify_nb.notifier_call = scmi_limit_notify_cb;
>> + ret = sdev->handle->notify_ops->event_notifier_register(sdev->handle, SCMI_PROTOCOL_PERF,
>> + SCMI_EVENT_PERFORMANCE_LIMITS_CHANGED,
>> + &priv->domain_id,
>> + &priv->limit_notify_nb);
>> + if (ret)
>> + dev_warn(&sdev->dev,
>> + "failed to register for limits change notifier for domain %d\n",
>> + priv->domain_id);
>> +
>> + priv->policy = policy;
>> +
>> return 0;
>>
>> out_free_table:
>> @@ -313,7 +356,13 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
>> static void scmi_cpufreq_exit(struct cpufreq_policy *policy)
>> {
>> struct scmi_data *priv = policy->driver_data;
>> + struct scmi_device *sdev = cpufreq_get_driver_data();
>>
>> + sdev->handle->notify_ops->event_notifier_unregister(sdev->handle, SCMI_PROTOCOL_PERF,
>> + SCMI_EVENT_PERFORMANCE_LIMITS_CHANGED,
>> + &priv->domain_id,
>> + &priv->limit_notify_nb);
>> + freq_qos_remove_request(&priv->limits_freq_req);
>> dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
>> dev_pm_opp_remove_all_dynamic(priv->cpu_dev);
>> free_cpumask_var(priv->opp_shared_cpus);
>> @@ -372,6 +421,8 @@ static int scmi_cpufreq_probe(struct scmi_device *sdev)
>> if (!handle)
>> return -ENODEV;
>>
>> + scmi_cpufreq_driver.driver_data = sdev;
>> +
>> perf_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_PERF, &ph);
>> if (IS_ERR(perf_ops))
>> return PTR_ERR(perf_ops);
>> --
>> 2.34.1
>>
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