[PATCH v5 6/9] cpufreq: amd-pstate: add frequency dynamic boost sysfs control

From: Perry Yuan
Date: Mon Nov 28 2022 - 12:09:52 EST


From: Perry Yuan <Perry.Yuan@xxxxxxx>

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@xxxxxxx>
---
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 3626ae1e8f9a..3335e7aa76f1 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -774,12 +774,46 @@ static ssize_t show_energy_performance_preference(
return sysfs_emit(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 sysfs_emit(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,
@@ -797,6 +831,15 @@ 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;
@@ -1407,9 +1450,28 @@ 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