linux-kernel - Re: [PATCH 7/8] cppc_cpufreq: expose information on frequency domains

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Date:   Mon, 9 Nov 2020 12:39:24 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Ionela Voinescu <ionela.voinescu@....com>
Cc:     rjw@...ysocki.net, lenb@...nel.org, sudeep.holla@....com,
        morten.rasmussen@....com, jeremy.linton@....com,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 7/8] cppc_cpufreq: expose information on frequency domains

On 05-11-20, 12:55, Ionela Voinescu wrote:
> Use the existing sysfs attribute "freqdomain_cpus" to expose
> information to userspace about CPUs in the same frequency domain.
> 
> Signed-off-by: Ionela Voinescu <ionela.voinescu@....com>
> Cc: Rafael J. Wysocki <rjw@...ysocki.net>
> Cc: Viresh Kumar <viresh.kumar@...aro.org>
> ---
>  Documentation/ABI/testing/sysfs-devices-system-cpu |  3 ++-
>  drivers/cpufreq/cppc_cpufreq.c                     | 14 ++++++++++++++
>  2 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
> index 1a04ca8162ad..0eee30b27ab6 100644
> --- a/Documentation/ABI/testing/sysfs-devices-system-cpu
> +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
> @@ -264,7 +264,8 @@ Description:	Discover CPUs in the same CPU frequency coordination domain
>  		attribute is useful for user space DVFS controllers to get better
>  		power/performance results for platforms using acpi-cpufreq.
>  
> -		This file is only present if the acpi-cpufreq driver is in use.
> +		This file is only present if the acpi-cpufreq or the cppc-cpufreq
> +		drivers are in use.
>  
>  
>  What:		/sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
> diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
> index 60ac7f8049b5..b4edeeb57d04 100644
> --- a/drivers/cpufreq/cppc_cpufreq.c
> +++ b/drivers/cpufreq/cppc_cpufreq.c
> @@ -483,6 +483,19 @@ static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
>  	return 0;
>  }
>  
> +static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
> +{
> +	struct cppc_cpudata *cpu_data = policy->driver_data;
> +
> +	return cpufreq_show_cpus(cpu_data->domain->shared_cpu_map, buf);
> +}
> +cpufreq_freq_attr_ro(freqdomain_cpus);
> +
> +static struct freq_attr *cppc_cpufreq_attr[] = {
> +	&freqdomain_cpus,
> +	NULL,
> +};
> +
>  static struct cpufreq_driver cppc_cpufreq_driver = {
>  	.flags = CPUFREQ_CONST_LOOPS,
>  	.verify = cppc_verify_policy,
> @@ -491,6 +504,7 @@ static struct cpufreq_driver cppc_cpufreq_driver = {
>  	.init = cppc_cpufreq_cpu_init,
>  	.stop_cpu = cppc_cpufreq_stop_cpu,
>  	.set_boost = cppc_cpufreq_set_boost,
> +	.attr = cppc_cpufreq_attr,
>  	.name = "cppc_cpufreq",
>  };

Acked-by: Viresh Kumar <viresh.kumar@...aro.org>

-- 
viresh