linux-kernel - Re: [PATCH v5 2/3] cpufreq: Add a new function to get cpufreq policy without checking if the CPU is online

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Message-ID: <CAJZ5v0i7g8i8m9GPi9=-Y0x36491Ng3akUfVP2vPOBS-OAEg=w@mail.gmail.com>
Date: Tue, 19 Aug 2025 21:05:03 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Lifeng Zheng <zhenglifeng1@...wei.com>
Cc: catalin.marinas@....com, will@...nel.org, rafael@...nel.org, 
	viresh.kumar@...aro.org, beata.michalska@....com, sudeep.holla@....com, 
	linux-arm-kernel@...ts.infradead.org, linux-pm@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linuxarm@...wei.com, 
	jonathan.cameron@...wei.com, vincent.guittot@...aro.org, 
	yangyicong@...ilicon.com, zhanjie9@...ilicon.com, lihuisong@...wei.com, 
	yubowen8@...wei.com, zhangpengjie2@...wei.com, linhongye@...artners.com
Subject: Re: [PATCH v5 2/3] cpufreq: Add a new function to get cpufreq policy
 without checking if the CPU is online

On Tue, Aug 19, 2025 at 9:30 AM Lifeng Zheng <zhenglifeng1@...wei.com> wrote:
>
> cpufreq_cpu_get_raw() gets cpufreq policy only if the CPU is in
> policy->cpus mask, which means the CPU is already online. But in some
> cases, the policy is needed before the CPU is added to cpus mask. Add a
> function to get the policy in these cases.

I'd prefer the subject to be somewhat shorter.  For instance, something like

cpufreq: Add new helper function returning cpufreq policy

would suffice because the changelog explains the details.

With that addressed

Reviewed-by: Rafael J. Wysocki (Intel) <rafael@...nel.org>

> Signed-off-by: Lifeng Zheng <zhenglifeng1@...wei.com>
> ---
>  drivers/cpufreq/cpufreq.c | 6 ++++++
>  include/linux/cpufreq.h   | 5 +++++
>  2 files changed, 11 insertions(+)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index fc7eace8b65b..78ca68ea754d 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -198,6 +198,12 @@ struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
>  }
>  EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw);
>
> +struct cpufreq_policy *cpufreq_cpu_policy(unsigned int cpu)
> +{
> +       return per_cpu(cpufreq_cpu_data, cpu);
> +}
> +EXPORT_SYMBOL_GPL(cpufreq_cpu_policy);
> +
>  unsigned int cpufreq_generic_get(unsigned int cpu)
>  {
>         struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> index 95f3807c8c55..26b3c3310d5b 100644
> --- a/include/linux/cpufreq.h
> +++ b/include/linux/cpufreq.h
> @@ -205,6 +205,7 @@ struct cpufreq_freqs {
>
>  #ifdef CONFIG_CPU_FREQ
>  struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu);
> +struct cpufreq_policy *cpufreq_cpu_policy(unsigned int cpu);
>  struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
>  void cpufreq_cpu_put(struct cpufreq_policy *policy);
>  #else
> @@ -212,6 +213,10 @@ static inline struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu)
>  {
>         return NULL;
>  }
> +static inline struct cpufreq_policy *cpufreq_cpu_policy(unsigned int cpu)
> +{
> +       return NULL;
> +}
>  static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
>  {
>         return NULL;
> --
> 2.33.0
>
>