Re: [PATCH 10/19] cpufreq: amd: add amd-pstate frequencies attributes

Fontenot, Nathan
2021-09-08T18:13:52Z

On 9/8/2021 9:59 AM, Huang Rui wrote:
> Introduce sysfs attributes to get the different level processor
> frequencies.
>
> Signed-off-by: Huang Rui <ray.huang@amd.com>
> ---
> drivers/cpufreq/amd-pstate.c | 80 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 79 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 48dedd5af101..3c727a22cb69 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -577,16 +577,94 @@ static int amd_pstate_cpu_exit(struct cpufreq_policy *policy)
> return 0;
> }
>
> -static ssize_t show_is_amd_pstate_enabled(struct cpufreq_policy *policy,
> +/* Sysfs attributes */
> +
> +static ssize_t show_amd_pstate_max_freq(struct cpufreq_policy *policy,
> char *buf)
> +{
> + int ret = 0, max_freq;
> + struct amd_cpudata *cpudata;
> +
> + cpudata = policy->driver_data;
> +
> + max_freq = amd_get_max_freq(cpudata);
> + if (max_freq < 0)
> + return max_freq;
> +
> + ret += sprintf(&buf[ret], "%u\n", max_freq);
> +
> + return ret;

Here, and in the functions below, you could just do

return sprintf(&buf[ret], "%u\n", max_freq);

and get rid of the intermediary 'ret' variable.

-Nathan

> +}
> +
> +static ssize_t show_amd_pstate_nominal_freq(struct cpufreq_policy *policy,
> + char *buf)
> +{
> + int ret = 0, nominal_freq;
> + struct amd_cpudata *cpudata;
> +
> + cpudata = policy->driver_data;
> +
> + nominal_freq = amd_get_nominal_freq(cpudata);
> + if (nominal_freq < 0)
> + return nominal_freq;
> +
> + ret += sprintf(&buf[ret], "%u\n", nominal_freq);
> +
> + return ret;
> +}
> +
> +static ssize_t
> +show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *policy, char *buf)
> +{
> + int ret = 0, freq;
> + struct amd_cpudata *cpudata;
> +
> + cpudata = policy->driver_data;
> +
> + freq = amd_get_lowest_nonlinear_freq(cpudata);
> + if (freq < 0)
> + return freq;
> +
> + ret += sprintf(&buf[ret], "%u\n", freq);
> +
> + return ret;
> +}
> +
> +static ssize_t show_amd_pstate_min_freq(struct cpufreq_policy *policy, char *buf)
> +{
> + int ret = 0;
> + int freq;
> + struct amd_cpudata *cpudata;
> +
> + cpudata = policy->driver_data;
> +
> + freq = amd_get_min_freq(cpudata);
> + if (freq < 0)
> + return freq;
> +
> + ret += sprintf(&buf[ret], "%u\n", freq);
> +
> + return ret;
> +}
> +
> +static ssize_t show_is_amd_pstate_enabled(struct cpufreq_policy *policy,
> + char *buf)
> {
> return sprintf(&buf[0], "%d\n", acpi_cpc_valid() ? 1 : 0);
> }
>
> cpufreq_freq_attr_ro(is_amd_pstate_enabled);
> +cpufreq_freq_attr_ro(amd_pstate_max_freq);
> +cpufreq_freq_attr_ro(amd_pstate_nominal_freq);
> +cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq);
> +cpufreq_freq_attr_ro(amd_pstate_min_freq);
>
> static struct freq_attr *amd_pstate_attr[] = {
> &is_amd_pstate_enabled,
> + &amd_pstate_max_freq,
> + &amd_pstate_nominal_freq,
> + &amd_pstate_lowest_nonlinear_freq,
> + &amd_pstate_min_freq,
> NULL,
> };
>
> --
> 2.25.1
>