linux-kernel - [PATCH v4 7/9] cpufreq: amd-pstate: add frequency dynamic boost sysfs control

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Date:   Fri, 11 Nov 2022 01:58:45 +0800
From:   Perry Yuan <Perry.Yuan@....com>
To:     <rafael.j.wysocki@...el.com>, <Mario.Limonciello@....com>,
        <ray.huang@....com>, <viresh.kumar@...aro.org>
CC:     <Deepak.Sharma@....com>, <Nathan.Fontenot@....com>,
        <Alexander.Deucher@....com>, <Shimmer.Huang@....com>,
        <Xiaojian.Du@....com>, <Li.Meng@....com>, <wyes.karny@....com>,
        <linux-pm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        Perry Yuan <Perry.Yuan@....com>
Subject: [PATCH v4 7/9] cpufreq: amd-pstate: add frequency dynamic boost sysfs control

Add one sysfs entry to control the CPU cores frequency boost state
The attribute file can allow user to set max performance boosted or
keeping at normal perf level.

Signed-off-by: Perry Yuan <Perry.Yuan@....com>
---
 drivers/cpufreq/amd-pstate.c | 66 ++++++++++++++++++++++++++++++++++--
 1 file changed, 64 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 645706d65173..b71bfbbb7639 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -765,12 +765,46 @@ static ssize_t show_energy_performance_preference(
 	return  sprintf(buf, "%s\n", energy_perf_strings[preference]);
 }
 
+static void amd_pstate_update_policies(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		cpufreq_update_policy(cpu);
+}
+
+static ssize_t show_boost(struct kobject *kobj,
+				struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%u\n", cppc_boost);
+}
+
+static ssize_t store_boost(struct kobject *a,
+				       struct kobj_attribute *b,
+				       const char *buf, size_t count)
+{
+	bool new_state;
+	int ret;
+
+	ret = kstrtobool(buf, &new_state);
+	if (ret)
+		return -EINVAL;
+
+	mutex_lock(&amd_pstate_driver_lock);
+	cppc_boost = !!new_state;
+	amd_pstate_update_policies();
+	mutex_unlock(&amd_pstate_driver_lock);
+
+	return count;
+}
+
 cpufreq_freq_attr_ro(amd_pstate_max_freq);
 cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq);
 
 cpufreq_freq_attr_ro(amd_pstate_highest_perf);
 cpufreq_freq_attr_rw(energy_performance_preference);
 cpufreq_freq_attr_ro(energy_performance_available_preferences);
+define_one_global_rw(boost);
 
 static struct freq_attr *amd_pstate_attr[] = {
 	&amd_pstate_max_freq,
@@ -788,6 +822,15 @@ static struct freq_attr *amd_pstate_epp_attr[] = {
 	NULL,
 };
 
+static struct attribute *pstate_global_attributes[] = {
+	&boost.attr,
+	NULL
+};
+
+static const struct attribute_group amd_pstate_global_attr_group = {
+	.attrs = pstate_global_attributes,
+};
+
 static inline void update_boost_state(void)
 {
 	u64 misc_en;
@@ -1398,9 +1441,28 @@ static int __init amd_pstate_init(void)
 
 	ret = cpufreq_register_driver(default_pstate_driver);
 	if (ret)
-		pr_err("failed to register amd pstate driver with return %d\n",
-		       ret);
+		pr_err("failed to register driver with return %d\n", ret);
+
+	amd_pstate_kobj = kobject_create_and_add("amd-pstate", &cpu_subsys.dev_root->kobj);
+	if (!amd_pstate_kobj) {
+		ret = -EINVAL;
+		pr_err("global sysfs registration failed.\n");
+		goto kobject_free;
+	}
+
+	ret = sysfs_create_group(amd_pstate_kobj, &amd_pstate_global_attr_group);
+	if (ret) {
+		pr_err("sysfs attribute export failed with error %d.\n", ret);
+		goto global_attr_free;
+	}
+
+	return ret;
 
+global_attr_free:
+	kobject_put(amd_pstate_kobj);
+kobject_free:
+	kfree(cpudata);
+	cpufreq_unregister_driver(default_pstate_driver);
 	return ret;
 }
 device_initcall(amd_pstate_init);
-- 
2.34.1