Re: [PATCH v5 01/11] cpufreq: CPPC: Add generic helpers for sysfs show/store

zhenglifeng (A)
2025-12-25T03:41:29Z

On 2025/12/23 20:12, Sumit Gupta wrote:
> Add generic show/store helper functions for u64 sysfs attributes:
> - cppc_cpufreq_sysfs_show_u64()
> - cppc_cpufreq_sysfs_store_u64()
>
> Refactor auto_act_window and energy_performance_preference_val
> attributes to use these helpers, eliminating code duplication.

How about adding a macro to generate show_xxx and store_xxx in one line?

Just a suggestion.

>
> No functional changes.
>
> Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
> ---
> drivers/cpufreq/cppc_cpufreq.c | 71 +++++++++++++++-------------------
> 1 file changed, 31 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
> index 9eac77c4f294..7c26ce554e29 100644
> --- a/drivers/cpufreq/cppc_cpufreq.c
> +++ b/drivers/cpufreq/cppc_cpufreq.c
> @@ -831,72 +831,63 @@ static ssize_t store_auto_select(struct cpufreq_policy *policy,
> return count;
> }
>
> -static ssize_t show_auto_act_window(struct cpufreq_policy *policy, char *buf)
> +static ssize_t cppc_cpufreq_sysfs_show_u64(unsigned int cpu,
> + int (*get_func)(int, u64 *),
> + char *buf)
> {
> u64 val;
> - int ret;
> -
> - ret = cppc_get_auto_act_window(policy->cpu, &val);
> + int ret = get_func((int)cpu, &val);
>
> - /* show "<unsupported>" when this register is not supported by cpc */
> if (ret == -EOPNOTSUPP)
> return sysfs_emit(buf, "<unsupported>\n");
> -
> if (ret)
> return ret;
>
> return sysfs_emit(buf, "%llu\n", val);
> }
>
> -static ssize_t store_auto_act_window(struct cpufreq_policy *policy,
> - const char *buf, size_t count)
> +static ssize_t cppc_cpufreq_sysfs_store_u64(unsigned int cpu,
> + int (*set_func)(int, u64),
> + const char *buf, size_t count)
> {
> - u64 usec;
> + u64 val;
> int ret;
>
> - ret = kstrtou64(buf, 0, &usec);
> + ret = kstrtou64(buf, 0, &val);
> if (ret)
> return ret;
>
> - ret = cppc_set_auto_act_window(policy->cpu, usec);
> - if (ret)
> - return ret;
> + ret = set_func((int)cpu, val);
>
> - return count;
> + return ret ? ret : count;
> }
>
> -static ssize_t show_energy_performance_preference_val(struct cpufreq_policy *policy, char *buf)
> +static ssize_t show_auto_act_window(struct cpufreq_policy *policy, char *buf)
> {
> - u64 val;
> - int ret;
> -
> - ret = cppc_get_epp_perf(policy->cpu, &val);
> -
> - /* show "<unsupported>" when this register is not supported by cpc */
> - if (ret == -EOPNOTSUPP)
> - return sysfs_emit(buf, "<unsupported>\n");
> -
> - if (ret)
> - return ret;
> -
> - return sysfs_emit(buf, "%llu\n", val);
> + return cppc_cpufreq_sysfs_show_u64(policy->cpu,
> + cppc_get_auto_act_window, buf);
> }
>
> -static ssize_t store_energy_performance_preference_val(struct cpufreq_policy *policy,
> - const char *buf, size_t count)
> +static ssize_t store_auto_act_window(struct cpufreq_policy *policy,
> + const char *buf, size_t count)
> {
> - u64 val;
> - int ret;
> -
> - ret = kstrtou64(buf, 0, &val);
> - if (ret)
> - return ret;
> + return cppc_cpufreq_sysfs_store_u64(policy->cpu,
> + cppc_set_auto_act_window,
> + buf, count);
> +}
>
> - ret = cppc_set_epp(policy->cpu, val);
> - if (ret)
> - return ret;
> +static ssize_t
> +show_energy_performance_preference_val(struct cpufreq_policy *policy, char *buf)
> +{
> + return cppc_cpufreq_sysfs_show_u64(policy->cpu, cppc_get_epp_perf, buf);
> +}
>
> - return count;
> +static ssize_t
> +store_energy_performance_preference_val(struct cpufreq_policy *policy,
> + const char *buf, size_t count)
> +{
> + return cppc_cpufreq_sysfs_store_u64(policy->cpu, cppc_set_epp,
> + buf, count);
> }
>
> cpufreq_freq_attr_ro(freqdomain_cpus);