RE: [PATCH V11 5/7] cpufreq: amd-pstate: Update amd-pstate preferred core ranking dynamically

[Yuan, Perry]

[AMD Official Use Only - General]

> -----Original Message-----
> From: Meng, Li (Jassmine) <Li.Meng@xxxxxxx>
> Sent: Wednesday, November 29, 2023 2:55 PM
> To: Rafael J . Wysocki <rafael.j.wysocki@xxxxxxxxx>; Huang, Ray
> <Ray.Huang@xxxxxxx>
> Cc: linux-pm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; x86@xxxxxxxxxx;
> linux-acpi@xxxxxxxxxxxxxxx; Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>; linux-
> kselftest@xxxxxxxxxxxxxxx; Fontenot, Nathan <Nathan.Fontenot@xxxxxxx>;
> Sharma, Deepak <Deepak.Sharma@xxxxxxx>; Deucher, Alexander
> <Alexander.Deucher@xxxxxxx>; Limonciello, Mario
> <Mario.Limonciello@xxxxxxx>; Huang, Shimmer
> <Shimmer.Huang@xxxxxxx>; Yuan, Perry <Perry.Yuan@xxxxxxx>; Du,
> Xiaojian <Xiaojian.Du@xxxxxxx>; Viresh Kumar <viresh.kumar@xxxxxxxxxx>;
> Borislav Petkov <bp@xxxxxxxxx>; Oleksandr Natalenko
> <oleksandr@xxxxxxxxxxxxxx>; Meng, Li (Jassmine) <Li.Meng@xxxxxxx>;
> Karny, Wyes <Wyes.Karny@xxxxxxx>
> Subject: [PATCH V11 5/7] cpufreq: amd-pstate: Update amd-pstate preferred
> core ranking dynamically
>
> Preferred core rankings can be changed dynamically by the platform based on
> the workload and platform conditions and accounting for thermals and aging.
> When this occurs, cpu priority need to be set.
>
> Tested-by: Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx>
> Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> Reviewed-by: Wyes Karny <wyes.karny@xxxxxxx>
> Reviewed-by: Huang Rui <ray.huang@xxxxxxx>
> Signed-off-by: Meng Li <li.meng@xxxxxxx>
> ---
>  drivers/cpufreq/amd-pstate.c | 46
> ++++++++++++++++++++++++++++++++++++
>  include/linux/amd-pstate.h   |  6 +++++
>  2 files changed, 52 insertions(+)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 74dcf63d75f9..88df6510dcc0 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -312,6 +312,7 @@ static int pstate_init_perf(struct amd_cpudata
> *cpudata)
>       WRITE_ONCE(cpudata->nominal_perf,
> AMD_CPPC_NOMINAL_PERF(cap1));
>       WRITE_ONCE(cpudata->lowest_nonlinear_perf,
> AMD_CPPC_LOWNONLIN_PERF(cap1));
>       WRITE_ONCE(cpudata->lowest_perf,
> AMD_CPPC_LOWEST_PERF(cap1));
> +     WRITE_ONCE(cpudata->prefcore_ranking,
> AMD_CPPC_HIGHEST_PERF(cap1));
>
>       return 0;
>  }
> @@ -333,6 +334,7 @@ static int cppc_init_perf(struct amd_cpudata
> *cpudata)
>       WRITE_ONCE(cpudata->lowest_nonlinear_perf,
>                  cppc_perf.lowest_nonlinear_perf);
>       WRITE_ONCE(cpudata->lowest_perf, cppc_perf.lowest_perf);
> +     WRITE_ONCE(cpudata->prefcore_ranking, cppc_perf.highest_perf);
>
>       if (cppc_state == AMD_PSTATE_ACTIVE)
>               return 0;
> @@ -749,6 +751,34 @@ static void amd_pstate_init_prefcore(struct
> amd_cpudata *cpudata)
>       schedule_work(&sched_prefcore_work);
>  }
>
> +static void amd_pstate_update_highest_perf(unsigned int cpu) {
> +     struct cpufreq_policy *policy;
> +     struct amd_cpudata *cpudata;
> +     u32 prev_high = 0, cur_high = 0;
> +     int ret;
> +
> +     if ((!amd_pstate_prefcore) || (!cpudata->hw_prefcore))
> +             return;
> +
> +     ret = amd_pstate_get_highest_perf(cpu, &cur_high);
> +     if (ret)
> +             return;
> +
> +     policy = cpufreq_cpu_get(cpu);
> +     cpudata = policy->driver_data;
> +     prev_high = READ_ONCE(cpudata->prefcore_ranking);
> +
> +     if (prev_high != cur_high) {
> +             WRITE_ONCE(cpudata->prefcore_ranking, cur_high);
> +
> +             if (cur_high < CPPC_MAX_PERF)
> +                     sched_set_itmt_core_prio((int)cur_high, cpu);
> +     }
> +
> +     cpufreq_cpu_put(policy);
> +}
> +
>  static int amd_pstate_cpu_init(struct cpufreq_policy *policy)  {
>       int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;
> @@ -920,6 +950,17 @@ static ssize_t show_amd_pstate_highest_perf(struct
> cpufreq_policy *policy,
>       return sysfs_emit(buf, "%u\n", perf);
>  }
>
> +static ssize_t show_amd_pstate_prefcore_ranking(struct cpufreq_policy
> *policy,
> +                                             char *buf)
> +{
> +     u32 perf;
> +     struct amd_cpudata *cpudata = policy->driver_data;
> +
> +     perf = READ_ONCE(cpudata->prefcore_ranking);
> +
> +     return sysfs_emit(buf, "%u\n", perf);
> +}
> +
>  static ssize_t show_amd_pstate_hw_prefcore(struct cpufreq_policy *policy,
>                                          char *buf)
>  {
> @@ -1133,6 +1174,7 @@ cpufreq_freq_attr_ro(amd_pstate_max_freq);
>  cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq);
>
>  cpufreq_freq_attr_ro(amd_pstate_highest_perf);
> +cpufreq_freq_attr_ro(amd_pstate_prefcore_ranking);
>  cpufreq_freq_attr_ro(amd_pstate_hw_prefcore);
>  cpufreq_freq_attr_rw(energy_performance_preference);
>  cpufreq_freq_attr_ro(energy_performance_available_preferences);
> @@ -1143,6 +1185,7 @@ static struct freq_attr *amd_pstate_attr[] = {
>       &amd_pstate_max_freq,
>       &amd_pstate_lowest_nonlinear_freq,
>       &amd_pstate_highest_perf,
> +     &amd_pstate_prefcore_ranking,
>       &amd_pstate_hw_prefcore,
>       NULL,
>  };
> @@ -1151,6 +1194,7 @@ static struct freq_attr *amd_pstate_epp_attr[] = {
>       &amd_pstate_max_freq,
>       &amd_pstate_lowest_nonlinear_freq,
>       &amd_pstate_highest_perf,
> +     &amd_pstate_prefcore_ranking,
>       &amd_pstate_hw_prefcore,
>       &energy_performance_preference,
>       &energy_performance_available_preferences,
> @@ -1491,6 +1535,7 @@ static struct cpufreq_driver amd_pstate_driver = {
>       .suspend        = amd_pstate_cpu_suspend,
>       .resume         = amd_pstate_cpu_resume,
>       .set_boost      = amd_pstate_set_boost,
> +     .update_highest_perf    = amd_pstate_update_highest_perf,
>       .name           = "amd-pstate",
>       .attr           = amd_pstate_attr,
>  };
> @@ -1505,6 +1550,7 @@ static struct cpufreq_driver
> amd_pstate_epp_driver = {
>       .online         = amd_pstate_epp_cpu_online,
>       .suspend        = amd_pstate_epp_suspend,
>       .resume         = amd_pstate_epp_resume,
> +     .update_highest_perf    = amd_pstate_update_highest_perf,
>       .name           = "amd-pstate-epp",
>       .attr           = amd_pstate_epp_attr,
>  };
> diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h index
> 87e140e9e6db..426822612373 100644
> --- a/include/linux/amd-pstate.h
> +++ b/include/linux/amd-pstate.h
> @@ -39,11 +39,16 @@ struct amd_aperf_mperf {
>   * @cppc_req_cached: cached performance request hints
>   * @highest_perf: the maximum performance an individual processor may
> reach,
>   *             assuming ideal conditions
> + *             For platforms that do not support the preferred core feature,
> the
> + *             highest_pef may be configured with 166 or 255, to avoid
> max frequency
> + *             calculated wrongly. we take the fixed value as the
> highest_perf.
>   * @nominal_perf: the maximum sustained performance level of the
> processor,
>   *             assuming ideal operating conditions
>   * @lowest_nonlinear_perf: the lowest performance level at which nonlinear
> power
>   *                      savings are achieved
>   * @lowest_perf: the absolute lowest performance level of the processor
> + * @prefcore_ranking: the preferred core ranking, the higher value indicates a
> higher
> + *             priority.
>   * @max_freq: the frequency that mapped to highest_perf
>   * @min_freq: the frequency that mapped to lowest_perf
>   * @nominal_freq: the frequency that mapped to nominal_perf @@ -73,6
> +78,7 @@ struct amd_cpudata {
>       u32     nominal_perf;
>       u32     lowest_nonlinear_perf;
>       u32     lowest_perf;
> +     u32     prefcore_ranking;
>
>       u32     max_freq;
>       u32     min_freq;
> --
> 2.34.1

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