linux-kernel - Re: [PATCH V5 2/7] acpi: cppc: Add get the highest performance cppc control

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Date:   Wed, 6 Sep 2023 21:11:04 +0800
From:   Huang Rui <ray.huang@....com>
To:     "Meng, Li (Jassmine)" <Li.Meng@....com>
Cc:     "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "x86@...nel.org" <x86@...nel.org>,
        "linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
        Shuah Khan <skhan@...uxfoundation.org>,
        "linux-kselftest@...r.kernel.org" <linux-kselftest@...r.kernel.org>,
        "Fontenot, Nathan" <Nathan.Fontenot@....com>,
        "Sharma, Deepak" <Deepak.Sharma@....com>,
        "Deucher, Alexander" <Alexander.Deucher@....com>,
        "Limonciello, Mario" <Mario.Limonciello@....com>,
        "Huang, Shimmer" <Shimmer.Huang@....com>,
        "Yuan, Perry" <Perry.Yuan@....com>,
        "Du, Xiaojian" <Xiaojian.Du@....com>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Borislav Petkov <bp@...en8.de>,
        "Karny, Wyes" <Wyes.Karny@....com>
Subject: Re: [PATCH V5 2/7] acpi: cppc: Add get the highest performance cppc
 control

On Tue, Sep 05, 2023 at 09:51:11AM +0800, Meng, Li (Jassmine) wrote:
> Add support for getting the highest performance to the
> generic CPPC driver. This enables downstream drivers
> such as amd-pstate to discover and use these values.
> 
> Please refer to the ACPI_Spec for details on continuous
> performance control of CPPC.
> 
> Signed-off-by: Meng Li <li.meng@....com>
> Reviewed-by: Mario Limonciello <mario.limonciello@....com>
> Reviewed-by: Wyes Karny <wyes.karny@....com>
> Link: https://uefi.org/specs/ACPI/6.5/08_Processor_Configuration_and_Control.html?highlight=cppc#cpc-continuous-performance-control

Acked-by: Huang Rui <ray.huang@....com>

> ---
>  drivers/acpi/cppc_acpi.c | 13 +++++++++++++
>  include/acpi/cppc_acpi.h |  5 +++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 7ff269a78c20..ad388a0e8484 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -1154,6 +1154,19 @@ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf)
>  	return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf);
>  }
>  
> +/**
> + * cppc_get_highest_perf - Get the highest performance register value.
> + * @cpunum: CPU from which to get highest performance.
> + * @highest_perf: Return address.
> + *
> + * Return: 0 for success, -EIO otherwise.
> + */
> +int cppc_get_highest_perf(int cpunum, u64 *highest_perf)
> +{
> +	return cppc_get_perf(cpunum, HIGHEST_PERF, highest_perf);
> +}
> +EXPORT_SYMBOL_GPL(cppc_get_highest_perf);
> +
>  /**
>   * cppc_get_epp_perf - Get the epp register value.
>   * @cpunum: CPU from which to get epp preference value.
> diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
> index 6126c977ece0..c0b69ffe7bdb 100644
> --- a/include/acpi/cppc_acpi.h
> +++ b/include/acpi/cppc_acpi.h
> @@ -139,6 +139,7 @@ struct cppc_cpudata {
>  #ifdef CONFIG_ACPI_CPPC_LIB
>  extern int cppc_get_desired_perf(int cpunum, u64 *desired_perf);
>  extern int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf);
> +extern int cppc_get_highest_perf(int cpunum, u64 *highest_perf);
>  extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs);
>  extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls);
>  extern int cppc_set_enable(int cpu, bool enable);
> @@ -165,6 +166,10 @@ static inline int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf)
>  {
>  	return -ENOTSUPP;
>  }
> +static inline int cppc_get_highest_perf(int cpunum, u64 *highest_perf)
> +{
> +	return -ENOTSUPP;
> +}
>  static inline int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
>  {
>  	return -ENOTSUPP;
> -- 
> 2.34.1
>