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SubjectRe: [PATCH 3/6] cpufreq:amd-pstate: initialize nominal_freq of each cpudata
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On 1/31/2024 02:50, Perry Yuan wrote:
> Optimizes the process of retrieving the nominal frequency by utilizing
> 'cpudata->nominal_freq' instead of repeatedly accessing the cppc_acpi interface.
>
> To enhance efficiency and reduce the CPU load, shifted to using
> 'cpudata->nominal_freq'. It allows for the nominal frequency to be accessed
> directly from the cached data in 'cpudata' of each CPU.
> It will also slightly reduce the frequency change latency while using pstate
> driver passive mode.
>
> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> drivers/cpufreq/amd-pstate.c | 26 ++++++++++++++------------
> 1 file changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 9291a22bd3cc..db7b36afdce2 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -600,7 +600,7 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata)
> if (ret)
> return ret;
>
> - nominal_freq = cppc_perf.nominal_freq;
> + nominal_freq = READ_ONCE(cpudata->nominal_freq);
> nominal_perf = READ_ONCE(cpudata->nominal_perf);
> max_perf = READ_ONCE(cpudata->highest_perf);
>
> @@ -639,7 +639,7 @@ static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
> if (ret)
> return ret;
>
> - nominal_freq = cppc_perf.nominal_freq;
> + nominal_freq = READ_ONCE(cpudata->nominal_freq);
> nominal_perf = READ_ONCE(cpudata->nominal_perf);
>
> lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
> @@ -712,13 +712,15 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
> amd_pstate_boost_init(cpudata);
>
> min_freq = amd_get_min_freq(cpudata);
> - max_freq = amd_get_max_freq(cpudata);
> nominal_freq = amd_get_nominal_freq(cpudata);
> + cpudata->nominal_freq = nominal_freq;
> + max_freq = amd_get_max_freq(cpudata);
> lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata);
>
> - if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
> - dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
> - min_freq, max_freq);
> + if (min_freq < 0 || max_freq < 0 || min_freq > max_freq || nominal_freq == 0) {
> + dev_err(dev, "min_freq(%d) or max_freq(%d) or nominal_freq(%d) \
> + value is incorrect\n", \
> + min_freq, max_freq, nominal_freq);
> ret = -EINVAL;
> goto free_cpudata1;
> }
> @@ -755,7 +757,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
> /* Initial processor data capability frequencies */
> cpudata->max_freq = max_freq;
> cpudata->min_freq = min_freq;
> - cpudata->nominal_freq = nominal_freq;
> cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
>
> policy->driver_data = cpudata;
> @@ -1266,12 +1267,14 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
> amd_pstate_boost_init(cpudata);
>
> min_freq = amd_get_min_freq(cpudata);
> - max_freq = amd_get_max_freq(cpudata);
> nominal_freq = amd_get_nominal_freq(cpudata);
> + cpudata->nominal_freq = nominal_freq;
> + max_freq = amd_get_max_freq(cpudata);
> lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata);
> - if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
> - dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
> - min_freq, max_freq);
> + if (min_freq < 0 || max_freq < 0 || min_freq > max_freq || nominal_freq == 0) {
> + dev_err(dev, "min_freq(%d) or max_freq(%d) or nominal_freq(%d) \
> + value is incorrect\n", \
> + min_freq, max_freq, nominal_freq);
> ret = -EINVAL;
> goto free_cpudata1;
> }
> @@ -1284,7 +1287,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
> /* Initial processor data capability frequencies */
> cpudata->max_freq = max_freq;
> cpudata->min_freq = min_freq;
> - cpudata->nominal_freq = nominal_freq;
> cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
>
> policy->driver_data = cpudata;


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