linux-kernel - RE: [PATCH 4/8] x86/amd: Move amd_get_highest

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Message-ID:
 <CYYPR12MB8655A7CB43CC2A719FE269049C942@CYYPR12MB8655.namprd12.prod.outlook.com>
Date: Tue, 27 Aug 2024 06:46:56 +0000
From: "Yuan, Perry" <Perry.Yuan@....com>
To: Mario Limonciello <superm1@...nel.org>, Borislav Petkov <bp@...en8.de>,
	"Shenoy, Gautham Ranjal" <gautham.shenoy@....com>
CC: "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@...nel.org>,
	"Rafael J . Wysocki" <rafael@...nel.org>, "open list:X86 ARCHITECTURE (32-BIT
 AND 64-BIT)" <linux-kernel@...r.kernel.org>, "open list:ACPI"
	<linux-acpi@...r.kernel.org>, "open list:CPU FREQUENCY SCALING FRAMEWORK"
	<linux-pm@...r.kernel.org>, "Limonciello, Mario" <Mario.Limonciello@....com>
Subject: RE: [PATCH 4/8] x86/amd: Move amd_get_highest_perf() out of
 amd-pstate

[AMD Official Use Only - AMD Internal Distribution Only]

> -----Original Message-----
> From: Mario Limonciello <superm1@...nel.org>
> Sent: Tuesday, August 27, 2024 5:14 AM
> To: Borislav Petkov <bp@...en8.de>; Shenoy, Gautham Ranjal
> <gautham.shenoy@....com>; Yuan, Perry <Perry.Yuan@....com>
> Cc: maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT) <x86@...nel.org>;
> Rafael J . Wysocki <rafael@...nel.org>; open list:X86 ARCHITECTURE (32-BIT
> AND 64-BIT) <linux-kernel@...r.kernel.org>; open list:ACPI <linux-
> acpi@...r.kernel.org>; open list:CPU FREQUENCY SCALING FRAMEWORK
> <linux-pm@...r.kernel.org>; Limonciello, Mario
> <Mario.Limonciello@....com>
> Subject: [PATCH 4/8] x86/amd: Move amd_get_highest_perf() out of amd-
> pstate
>
> From: Mario Limonciello <mario.limonciello@....com>
>
> amd_get_highest_perf() is a helper used to get the highest perf value on AMD
> systems.  It's used in amd-pstate as part of preferred core handling, but
> applicable for acpi-cpufreq as well.
>
> Move it out to cppc handling code.
>
> Signed-off-by: Mario Limonciello <mario.limonciello@....com>
> ---
>  arch/x86/kernel/acpi/cppc.c  | 30 ++++++++++++++++++++++++++++++
> drivers/cpufreq/amd-pstate.c | 34 ++--------------------------------
>  include/acpi/cppc_acpi.h     |  2 ++
>  3 files changed, 34 insertions(+), 32 deletions(-)
>
> diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c index
> e94507110ca24..5a6c01a1b0d95 100644
> --- a/arch/x86/kernel/acpi/cppc.c
> +++ b/arch/x86/kernel/acpi/cppc.c
> @@ -119,6 +119,36 @@ void init_freq_invariance_cppc(void)
>       mutex_unlock(&freq_invariance_lock);
>  }
>
> +/*
> + * Get the highest performance register value.
> + * @cpu: CPU from which to get highest performance.
> + * @highest_perf: Return address for highest performance value.
> + *
> + * Return: 0 for success, negative error code otherwise.
> + */
> +int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf) {
> +     u64 val;
> +     int ret;
> +
> +     if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
> +             ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &val);
> +             if (ret)
> +                     goto out;
> +
> +             val = AMD_CPPC_HIGHEST_PERF(val);
> +     } else {
> +             ret = cppc_get_highest_perf(cpu, &val);
> +             if (ret)
> +                     goto out;
> +     }
> +
> +     WRITE_ONCE(*highest_perf, (u32)val);
> +out:
> +     return ret;
> +}
> +EXPORT_SYMBOL_GPL(amd_get_highest_perf);
> +
>  /**
>   * amd_get_boost_ratio_numerator: Get the numerator to use for boost ratio
> calculation
>   * @cpu: CPU to get numerator for.
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 89bda7a2bb8d1..f470b5700db58 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -803,36 +803,6 @@ static void
> amd_pstste_sched_prefcore_workfn(struct work_struct *work)  }  static
> DECLARE_WORK(sched_prefcore_work,
> amd_pstste_sched_prefcore_workfn);
>
> -/*
> - * Get the highest performance register value.
> - * @cpu: CPU from which to get highest performance.
> - * @highest_perf: Return address.
> - *
> - * Return: 0 for success, -EIO otherwise.
> - */
> -static int amd_pstate_get_highest_perf(int cpu, u32 *highest_perf) -{
> -     int ret;
> -
> -     if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
> -             u64 cap1;
> -
> -             ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1,
> &cap1);
> -             if (ret)
> -                     return ret;
> -             WRITE_ONCE(*highest_perf,
> AMD_CPPC_HIGHEST_PERF(cap1));
> -     } else {
> -             u64 cppc_highest_perf;
> -
> -             ret = cppc_get_highest_perf(cpu, &cppc_highest_perf);
> -             if (ret)
> -                     return ret;
> -             WRITE_ONCE(*highest_perf, cppc_highest_perf);
> -     }
> -
> -     return (ret);
> -}
> -
>  #define CPPC_MAX_PERF        U8_MAX
>
>  static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata) @@ -
> 840,7 +810,7 @@ static void amd_pstate_init_prefcore(struct amd_cpudata
> *cpudata)
>       int ret, prio;
>       u32 highest_perf;
>
> -     ret = amd_pstate_get_highest_perf(cpudata->cpu, &highest_perf);
> +     ret = amd_get_highest_perf(cpudata->cpu, &highest_perf);
>       if (ret)
>               return;
>
> @@ -879,7 +849,7 @@ static void amd_pstate_update_limits(unsigned int
> cpu)
>       if ((!amd_pstate_prefcore) || (!cpudata->hw_prefcore))
>               goto free_cpufreq_put;
>
> -     ret = amd_pstate_get_highest_perf(cpu, &cur_high);
> +     ret = amd_get_highest_perf(cpu, &cur_high);
>       if (ret)
>               goto free_cpufreq_put;
>
> diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h index
> f25a881cd46dd..2246ce0630362 100644
> --- a/include/acpi/cppc_acpi.h
> +++ b/include/acpi/cppc_acpi.h
> @@ -137,8 +137,10 @@ struct cppc_cpudata {  };
>
>  #ifdef CONFIG_CPU_SUP_AMD
> +extern int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf);
>  extern int amd_get_boost_ratio_numerator(unsigned int cpu, u64
> *numerator);  #else /* !CONFIG_CPU_SUP_AMD */
> +static inline int amd_get_highest_perf(unsigned int cpu, u32
> +*highest_perf) { return -ENODEV; }
>  static inline int amd_get_boost_ratio_numerator(unsigned int cpu, u64
> *numerator) { return -ENODEV; }  #endif /* !CONFIG_CPU_SUP_AMD */
>
> --
> 2.43.0
>

LGTM, thank you.

Reviewed-by: Perry Yuan <perry.yuan@....com>


Best Regards.

Perry.