[PATCH v6 08/11] cpufreq: amd_pstate: add driver working mode status sysfs entry

From: Perry Yuan
Date: Fri Dec 02 2022 - 02:53:12 EST


From: Perry Yuan <Perry.Yuan@xxxxxxx>

While amd-pstate driver was loaded with specific driver mode, it will
need to check which mode is enabled for the pstate driver,add this sysfs
entry to show the current status

$ cat /sys/devices/system/cpu/amd-pstate/status
active

Signed-off-by: Perry Yuan <Perry.Yuan@xxxxxxx>
---
drivers/cpufreq/amd-pstate.c | 44 ++++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 6936df6e8642..7f748a579023 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -66,6 +66,8 @@ static bool cppc_active;
static int cppc_load __initdata;

static struct cpufreq_driver *default_pstate_driver;
+static struct cpufreq_driver amd_pstate_epp_driver;
+static struct cpufreq_driver amd_pstate_driver;
static struct amd_cpudata **all_cpu_data;
static struct amd_pstate_params global_params;

@@ -807,6 +809,46 @@ static ssize_t store_boost(struct kobject *a,
return count;
}

+static ssize_t amd_pstate_show_status(char *buf)
+{
+ if (!default_pstate_driver)
+ return sysfs_emit(buf, "off\n");
+
+ return sysfs_emit(buf, "%s\n", default_pstate_driver == &amd_pstate_epp_driver ?
+ "active" : "passive");
+}
+
+static int amd_pstate_update_status(const char *buf, size_t size)
+{
+ /* FIXME! */
+ return -EOPNOTSUPP;
+}
+
+static ssize_t show_status(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ ssize_t ret;
+
+ mutex_lock(&amd_pstate_driver_lock);
+ ret = amd_pstate_show_status(buf);
+ mutex_unlock(&amd_pstate_driver_lock);
+
+ return ret;
+}
+
+static ssize_t store_status(struct kobject *a, struct kobj_attribute *b,
+ const char *buf, size_t count)
+{
+ char *p = memchr(buf, '\n', count);
+ int ret;
+
+ mutex_lock(&amd_pstate_driver_lock);
+ ret = amd_pstate_update_status(buf, p ? p - buf : count);
+ mutex_unlock(&amd_pstate_driver_lock);
+
+ return ret < 0 ? ret : count;
+}
+
cpufreq_freq_attr_ro(amd_pstate_max_freq);
cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq);

@@ -814,6 +856,7 @@ 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);
+define_one_global_rw(status);

static struct freq_attr *amd_pstate_attr[] = {
&amd_pstate_max_freq,
@@ -833,6 +876,7 @@ static struct freq_attr *amd_pstate_epp_attr[] = {

static struct attribute *pstate_global_attributes[] = {
&boost.attr,
+ &status.attr,
NULL
};

--
2.34.1