linux-kernel - Re: [PATCH v3 5/7] cpufreq: add function to get the hardware max frequency

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Date:   Wed, 12 Feb 2020 09:44:31 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Ionela Voinescu <ionela.voinescu@....com>
Cc:     catalin.marinas@....com, will@...nel.org, mark.rutland@....com,
        maz@...nel.org, suzuki.poulose@....com, sudeep.holla@....com,
        lukasz.luba@....com, valentin.schneider@....com, rjw@...ysocki.net,
        peterz@...radead.org, mingo@...hat.com, vincent.guittot@...aro.org,
        linux-arm-kernel@...ts.infradead.org, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org
Subject: Re: [PATCH v3 5/7] cpufreq: add function to get the hardware max
 frequency

On 11-02-20, 18:45, Ionela Voinescu wrote:
> Add weak function to return the hardware maximum frequency of a
> CPU, with the default implementation returning cpuinfo.max_freq.
> 
> The default can be overwritten by a strong function in platforms
> that want to provide an alternative implementation.
> 
> Signed-off-by: Ionela Voinescu <ionela.voinescu@....com>
> Cc: Rafael J. Wysocki <rjw@...ysocki.net>
> Cc: Viresh Kumar <viresh.kumar@...aro.org>
> ---
>  drivers/cpufreq/cpufreq.c | 20 ++++++++++++++++++++
>  include/linux/cpufreq.h   |  5 +++++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 77114a3897fb..d2ff3018861d 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -1733,6 +1733,26 @@ unsigned int cpufreq_quick_get_max(unsigned int cpu)
>  }
>  EXPORT_SYMBOL(cpufreq_quick_get_max);
>  
> +/**
> + * cpufreq_get_hw_max_freq - get the max hardware frequency of the CPU
> + * @cpu: CPU number
> + *
> + * The default return value is the max_freq field of cpuinfo.
> + */
> +__weak unsigned int cpufreq_get_hw_max_freq(unsigned int cpu)
> +{
> +	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
> +	unsigned int ret_freq = 0;
> +
> +	if (policy) {
> +		ret_freq = policy->cpuinfo.max_freq;
> +		cpufreq_cpu_put(policy);
> +	}
> +
> +	return ret_freq;
> +}
> +EXPORT_SYMBOL(cpufreq_get_hw_max_freq);
> +
>  static unsigned int __cpufreq_get(struct cpufreq_policy *policy)
>  {
>  	if (unlikely(policy_is_inactive(policy)))
> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> index 31b1b0e03df8..b4423ff619f4 100644
> --- a/include/linux/cpufreq.h
> +++ b/include/linux/cpufreq.h
> @@ -194,6 +194,7 @@ extern struct kobject *cpufreq_global_kobject;
>  unsigned int cpufreq_get(unsigned int cpu);
>  unsigned int cpufreq_quick_get(unsigned int cpu);
>  unsigned int cpufreq_quick_get_max(unsigned int cpu);
> +unsigned int cpufreq_get_hw_max_freq(unsigned int cpu);
>  void disable_cpufreq(void);
>  
>  u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
> @@ -223,6 +224,10 @@ static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
>  {
>  	return 0;
>  }
> +static inline unsigned int cpufreq_get_hw_max_freq(unsigned int cpu)
> +{
> +	return 0;
> +}
>  static inline void disable_cpufreq(void) { }
>  #endif

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

-- 
viresh