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Message-ID: <20221208111852.386731-10-perry.yuan@amd.com>
Date: Thu, 8 Dec 2022 19:18:48 +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>
Subject: [PATCH v7 09/13] cpufreq: amd-pstate: add driver working mode status sysfs entry
From: Perry Yuan <Perry.Yuan@....com>
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
Meanwhile, user can switch the pstate driver mode with writing mode
string to sysfs entry as below.
Enable passive mode:
$ sudo bash -c "echo passive > /sys/devices/system/cpu/amd-pstate/status"
Enable active mode (EPP driver mode):
$ sudo bash -c "echo active > /sys/devices/system/cpu/amd-pstate/status"
Signed-off-by: Perry Yuan <Perry.Yuan@....com>
---
drivers/cpufreq/amd-pstate.c | 101 +++++++++++++++++++++++++++++++++++
1 file changed, 101 insertions(+)
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 4cd53c010215..c90aee3ee42d 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -64,6 +64,8 @@ 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;
@@ -72,6 +74,7 @@ static DEFINE_MUTEX(amd_pstate_driver_lock);
struct kobject *amd_pstate_kobj;
static bool cppc_boost __read_mostly;
+static DEFINE_SPINLOCK(cppc_notify_lock);
static s16 amd_pstate_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached)
{
@@ -629,6 +632,8 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
policy->driver_data = cpudata;
amd_pstate_boost_init(cpudata);
+ if (!default_pstate_driver->adjust_perf)
+ default_pstate_driver->adjust_perf = amd_pstate_adjust_perf;
return 0;
@@ -802,6 +807,100 @@ static ssize_t store_cppc_dynamic_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 void amd_pstate_clear_update_util_hook(unsigned int cpu);
+static void amd_pstate_driver_cleanup(void)
+{
+ unsigned int cpu;
+
+ cpus_read_lock();
+ for_each_online_cpu(cpu) {
+ if (all_cpu_data[cpu]) {
+ if (default_pstate_driver == &amd_pstate_epp_driver)
+ amd_pstate_clear_update_util_hook(cpu);
+
+ spin_lock(&cppc_notify_lock);
+ kfree(all_cpu_data[cpu]);
+ WRITE_ONCE(all_cpu_data[cpu], NULL);
+ spin_unlock(&cppc_notify_lock);
+ }
+ }
+ cpus_read_unlock();
+
+ default_pstate_driver = NULL;
+}
+
+static int amd_pstate_update_status(const char *buf, size_t size)
+{
+ if (size == 3 && !strncmp(buf, "off", size)) {
+ if (!default_pstate_driver)
+ return -EINVAL;
+
+ if (cppc_active)
+ return -EBUSY;
+
+ cpufreq_unregister_driver(default_pstate_driver);
+ amd_pstate_driver_cleanup();
+ return 0;
+ }
+
+ if (size == 6 && !strncmp(buf, "active", size)) {
+ if (default_pstate_driver) {
+ if (default_pstate_driver == &amd_pstate_epp_driver)
+ return 0;
+ cpufreq_unregister_driver(default_pstate_driver);
+ default_pstate_driver = &amd_pstate_epp_driver;
+ }
+
+ return cpufreq_register_driver(default_pstate_driver);
+ }
+
+ if (size == 7 && !strncmp(buf, "passive", size)) {
+ if (default_pstate_driver) {
+ if (default_pstate_driver == &amd_pstate_driver)
+ return 0;
+ cpufreq_unregister_driver(default_pstate_driver);
+ }
+ default_pstate_driver = &amd_pstate_driver;
+ return cpufreq_register_driver(default_pstate_driver);
+ }
+
+ return -EINVAL;
+}
+
+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);
@@ -809,6 +908,7 @@ 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(cppc_dynamic_boost);
+define_one_global_rw(status);
static struct freq_attr *amd_pstate_attr[] = {
&amd_pstate_max_freq,
@@ -828,6 +928,7 @@ static struct freq_attr *amd_pstate_epp_attr[] = {
static struct attribute *pstate_global_attributes[] = {
&cppc_dynamic_boost.attr,
+ &status.attr,
NULL
};
--
2.34.1
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