linux-kernel - [PATCH v3 1/8] cpufreq: CPPC: Add generic helpers for sysfs show/store

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Message-ID: <20251001150104.1275188-2-sumitg@nvidia.com>
Date: Wed, 1 Oct 2025 20:30:57 +0530
From: Sumit Gupta <sumitg@...dia.com>
To: <rafael@...nel.org>, <viresh.kumar@...aro.org>, <lenb@...nel.org>,
	<robert.moore@...el.com>, <corbet@....net>, <pierre.gondois@....com>,
	<zhenglifeng1@...wei.com>, <rdunlap@...radead.org>, <ray.huang@....com>,
	<gautham.shenoy@....com>, <mario.limonciello@....com>, <perry.yuan@....com>,
	<linux-pm@...r.kernel.org>, <linux-acpi@...r.kernel.org>,
	<linux-doc@...r.kernel.org>, <acpica-devel@...ts.linux.dev>,
	<linux-kernel@...r.kernel.org>
CC: <linux-tegra@...r.kernel.org>, <treding@...dia.com>,
	<jonathanh@...dia.com>, <vsethi@...dia.com>, <ksitaraman@...dia.com>,
	<sanjayc@...dia.com>, <bbasu@...dia.com>, <sumitg@...dia.com>
Subject: [PATCH v3 1/8] cpufreq: CPPC: Add generic helpers for sysfs show/store

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@...dia.com>
---
 drivers/cpufreq/cppc_cpufreq.c | 87 ++++++++++++++--------------------
 1 file changed, 35 insertions(+), 52 deletions(-)

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 12de0ac7bbaf..732f35096991 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -781,6 +781,36 @@ static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
 	return 0;
 }
 
+static ssize_t cppc_cpufreq_sysfs_show_u64(unsigned int cpu, int (*get_func)(int, u64 *), char *buf)
+{
+	u64 val;
+	int ret = get_func(cpu, &val);
+
+	if (ret == -EOPNOTSUPP)
+		return sysfs_emit(buf, "<unsupported>\n");
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%llu\n", val);
+}
+
+static ssize_t cppc_cpufreq_sysfs_store_u64(const char *buf, size_t count,
+					    int (*set_func)(int, u64), unsigned int cpu)
+{
+	u64 val;
+	int ret;
+
+	if (!buf || !set_func)
+		return -EINVAL;
+
+	ret = kstrtou64(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	ret = set_func((int)cpu, val);
+	return ret ? ret : count;
+}
+
 static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
 {
 	struct cppc_cpudata *cpu_data = policy->driver_data;
@@ -824,70 +854,23 @@ static ssize_t store_auto_select(struct cpufreq_policy *policy,
 
 static ssize_t show_auto_act_window(struct cpufreq_policy *policy, char *buf)
 {
-	u64 val;
-	int ret;
-
-	ret = cppc_get_auto_act_window(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_auto_act_window(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 usec;
-	int ret;
-
-	ret = kstrtou64(buf, 0, &usec);
-	if (ret)
-		return ret;
-
-	ret = cppc_set_auto_act_window(policy->cpu, usec);
-	if (ret)
-		return ret;
-
-	return count;
+	return cppc_cpufreq_sysfs_store_u64(buf, count, cppc_set_auto_act_window, policy->cpu);
 }
 
 static ssize_t show_energy_performance_preference_val(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_epp_perf, buf);
 }
 
 static ssize_t store_energy_performance_preference_val(struct cpufreq_policy *policy,
 						       const char *buf, size_t count)
 {
-	u64 val;
-	int ret;
-
-	ret = kstrtou64(buf, 0, &val);
-	if (ret)
-		return ret;
-
-	ret = cppc_set_epp(policy->cpu, val);
-	if (ret)
-		return ret;
-
-	return count;
+	return cppc_cpufreq_sysfs_store_u64(buf, count, cppc_set_epp, policy->cpu);
 }
 
 cpufreq_freq_attr_ro(freqdomain_cpus);
-- 
2.34.1