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

Sumit Gupta
2026-01-08T13:32:08Z

On 25/12/25 09:11, zhenglifeng (A) wrote:
> External email: Use caution opening links or attachments
>
>
> 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.

will add macro in v6.

Thank you,
Sumit Gupta

>> 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);