From abd61c08ef349af08df0bf587d33f5bde5996a89 Mon Sep 17 00:00:00 2001 From: Perry Yuan Date: Tue, 31 Jan 2023 17:00:12 +0800 Subject: [PATCH] cpufreq: amd-pstate: add driver working mode switch support 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" Acked-by: Huang Rui Reviewed-by: Mario Limonciello Reviewed-by: Wyes Karny Tested-by: Wyes Karny Signed-off-by: Perry Yuan Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/amd-pstate.c | 118 +++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 4e3770e0d4d3..1ae2e0d56ed1 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -63,6 +63,7 @@ static struct cpufreq_driver *current_pstate_driver; static struct cpufreq_driver amd_pstate_driver; static struct cpufreq_driver amd_pstate_epp_driver; static int cppc_state = AMD_PSTATE_DISABLE; +struct kobject *amd_pstate_kobj; /* * AMD Energy Preference Performance (EPP) @@ -673,6 +674,8 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy) policy->driver_data = cpudata; amd_pstate_boost_init(cpudata); + if (!current_pstate_driver->adjust_perf) + current_pstate_driver->adjust_perf = amd_pstate_adjust_perf; return 0; @@ -813,12 +816,99 @@ 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 (!current_pstate_driver) + return sysfs_emit(buf, "disable\n"); + + return sysfs_emit(buf, "%s\n", amd_pstate_mode_string[cppc_state]); +} + +static void amd_pstate_driver_cleanup(void) +{ + current_pstate_driver = NULL; +} + +static int amd_pstate_update_status(const char *buf, size_t size) +{ + int ret; + int mode_idx; + + if (size > 7 || size < 6) + return -EINVAL; + mode_idx = get_mode_idx_from_str(buf, size); + + switch(mode_idx) { + case AMD_PSTATE_DISABLE: + if (!current_pstate_driver) + return -EINVAL; + if (cppc_state == AMD_PSTATE_ACTIVE) + return -EBUSY; + ret = cpufreq_unregister_driver(current_pstate_driver); + amd_pstate_driver_cleanup(); + break; + case AMD_PSTATE_PASSIVE: + if (current_pstate_driver) { + if (current_pstate_driver == &amd_pstate_driver) + return 0; + cpufreq_unregister_driver(current_pstate_driver); + cppc_state = AMD_PSTATE_PASSIVE; + current_pstate_driver = &amd_pstate_driver; + } + + ret = cpufreq_register_driver(current_pstate_driver); + break; + case AMD_PSTATE_ACTIVE: + if (current_pstate_driver) { + if (current_pstate_driver == &amd_pstate_epp_driver) + return 0; + cpufreq_unregister_driver(current_pstate_driver); + current_pstate_driver = &amd_pstate_epp_driver; + cppc_state = AMD_PSTATE_ACTIVE; + } + + ret = cpufreq_register_driver(current_pstate_driver); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +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, @@ -836,6 +926,15 @@ 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 int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy) { int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret; @@ -1200,6 +1299,25 @@ 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: + cpufreq_unregister_driver(current_pstate_driver); return ret; } device_initcall(amd_pstate_init);