Messages in this thread | | | Date | Thu, 10 Nov 2022 10:06:54 -0600 | Subject | Re: [PATCH v3 8/8] cpufreq: amd_pstate: add driver working mode status sysfs entry | From | Nathan Fontenot <> |
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On 11/7/22 11:57, Perry Yuan wrote: > 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@amd.com> > --- > 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 6958c5fd9e1c..eadcc9d61d39 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -65,6 +65,8 @@ static int disable_pstate_load __initdata; > static int epp_off __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; > @@ -819,6 +821,46 @@ static ssize_t store_pstate_dynamic_boost(struct kobject *a, > return count; > } > > +static ssize_t amd_pstate_show_status(char *buf) > +{ > + if (!default_pstate_driver) > + return sprintf(buf, "off\n"); > + > + return sprintf(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: add driver dynamic switching code */ > + return 0; > +} > + > +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);
Do we really need to take a lock to show the driver status?
-Nathan
> + > + 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); > > @@ -826,6 +868,7 @@ 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(pstate_dynamic_boost); > +define_one_global_rw(status); > > static struct freq_attr *amd_pstate_attr[] = { > &amd_pstate_max_freq, > @@ -845,6 +888,7 @@ static struct freq_attr *amd_pstate_epp_attr[] = { > > static struct attribute *pstate_global_attributes[] = { > &pstate_dynamic_boost.attr, > + &status.attr, > NULL > }; >
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