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

Sumit Gupta
2025-12-23T12:13:51Z

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.

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);
--
2.34.1