Messages in this thread |  | | From | "Yuan, Perry" <> | Subject | RE: [PATCH v8 09/13] cpufreq: amd-pstate: add driver working mode switch support | Date | Sun, 25 Dec 2022 16:41:50 +0000 |
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[AMD Official Use Only - General]
> -----Original Message----- > From: Huang, Ray <Ray.Huang@amd.com> > Sent: Friday, December 23, 2022 4:56 PM > To: Yuan, Perry <Perry.Yuan@amd.com> > Cc: rafael.j.wysocki@intel.com; Limonciello, Mario > <Mario.Limonciello@amd.com>; viresh.kumar@linaro.org; Sharma, Deepak > <Deepak.Sharma@amd.com>; Fontenot, Nathan > <Nathan.Fontenot@amd.com>; Deucher, Alexander > <Alexander.Deucher@amd.com>; Huang, Shimmer > <Shimmer.Huang@amd.com>; Du, Xiaojian <Xiaojian.Du@amd.com>; Meng, > Li (Jassmine) <Li.Meng@amd.com>; Karny, Wyes <Wyes.Karny@amd.com>; > linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH v8 09/13] cpufreq: amd-pstate: add driver working mode > switch support > > On Mon, Dec 19, 2022 at 02:40:38PM +0800, Yuan, Perry wrote: > > From: Perry Yuan <Perry.Yuan@amd.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@amd.com> > > --- > > drivers/cpufreq/amd-pstate.c | 128 > > +++++++++++++++++++++++++++++++++++ > > 1 file changed, 128 insertions(+) > > > > diff --git a/drivers/cpufreq/amd-pstate.c > > b/drivers/cpufreq/amd-pstate.c index fc12d35bc7bd..e8996e937e63 > 100644 > > --- a/drivers/cpufreq/amd-pstate.c > > +++ b/drivers/cpufreq/amd-pstate.c > > @@ -64,6 +64,7 @@ static struct cpufreq_driver amd_pstate_driver; > > static struct cpufreq_driver amd_pstate_epp_driver; static struct > > amd_cpudata **all_cpu_data; static int cppc_state = > > AMD_PSTATE_DISABLE; > > +struct kobject *amd_pstate_kobj; > > > > static inline int get_mode_idx_from_str(const char *str, size_t size) > > { @@ -90,6 +91,8 @@ static struct amd_pstate_params global_params; > > static DEFINE_MUTEX(amd_pstate_limits_lock); > > static DEFINE_MUTEX(amd_pstate_driver_lock); > > > > +static DEFINE_SPINLOCK(cppc_notify_lock); > > + > > static s16 amd_pstate_get_epp(struct amd_cpudata *cpudata, u64 > > cppc_req_cached) { > > u64 epp; > > @@ -644,6 +647,8 @@ 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; > > If default_driver is passive driver, it will be programed as > amd_pstate_adjust_perf. If not, the epp driver won't need adjust_perf. > > Thanks, > Ray
The adjust_perf() should be set again when switching from epp to cppc driver. The above amd_pstate_cpu_init () is called when amd-pstate driver loading, epp driver will not load it.
> > > > > return 0; > > > > @@ -784,12 +789,106 @@ static ssize_t > show_energy_performance_preference( > > return sysfs_emit(buf, "%s\n", energy_perf_strings[preference]); } > > > > +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_driver_cleanup(void) { > > + unsigned int cpu; > > + > > + cpus_read_lock(); > > + for_each_online_cpu(cpu) { > > + if (all_cpu_data[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_state == AMD_PSTATE_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; > > + cppc_state = AMD_PSTATE_ACTIVE; > > + } > > + > > + 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); > > + cppc_state = AMD_PSTATE_PASSIVE; > > + 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); > > > > 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(status); > > > > static struct freq_attr *amd_pstate_attr[] = { > > &amd_pstate_max_freq, > > @@ -807,6 +906,15 @@ static struct freq_attr *amd_pstate_epp_attr[] = { > > NULL, > > }; > > > > +static struct attribute *pstate_global_attributes[] = { > > + &status.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; > > @@ -1228,6 +1336,26 @@ static int __init amd_pstate_init(void) > > if (ret) > > pr_err("failed to register 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 > >
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