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: <cbecda55-db03-409a-b892-65171e00f6bc@huawei.com>
Date: Wed, 20 Aug 2025 09:50:47 +0800
From: "zhenglifeng (A)" <zhenglifeng1@...wei.com>
To: "Rafael J. Wysocki" <rafael@...nel.org>
CC: <catalin.marinas@....com>, <will@...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 2025/8/20 3:05, Rafael J. Wysocki wrote:

> 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>

Thanks! Will shorten it in the next version.

> 
>> 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
>>
>>
>