// SPDX-License-Identifier: GPL-2.0-only /* * drivers/cpufreq/cpufreq_ondemand.c * * Copyright (C) 2001 Russell King * (C) 2003 Venkatesh Pallipadi . * Jun Nakajima */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include "cpufreq_ondemand.h" /* On-demand governor macros */ #if defined(CONFIG_ZEN_INTERACTIVE) #define DEF_FREQUENCY_UP_THRESHOLD (55) #define MICRO_FREQUENCY_UP_THRESHOLD (60) #define DEF_SAMPLING_DOWN_FACTOR (5) #else #define DEF_FREQUENCY_UP_THRESHOLD (80) #define MICRO_FREQUENCY_UP_THRESHOLD (95) #define DEF_SAMPLING_DOWN_FACTOR (1) #endif #define MAX_SAMPLING_DOWN_FACTOR (100000) #define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000) #define MIN_FREQUENCY_UP_THRESHOLD (1) #define MAX_FREQUENCY_UP_THRESHOLD (100) static struct od_ops od_ops; static unsigned int default_powersave_bias; /* * Not all CPUs want IO time to be accounted as busy; this depends on how * efficient idling at a higher frequency/voltage is. * Pavel Machek says this is not so for various generations of AMD and old * Intel systems. * Mike Chan (android.com) claims this is also not true for ARM. * Because of this, whitelist specific known (series) of CPUs by default, and * leave all others up to the user. */ static int should_io_be_busy(void) { #if defined(CONFIG_X86) /* * For Intel, Core 2 (model 15) and later have an efficient idle. */ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model >= 15) return 1; #endif return 0; } /* * Find right freq to be set now with powersave_bias on. * Returns the freq_hi to be used right now and will set freq_hi_delay_us, * freq_lo, and freq_lo_delay_us in percpu area for averaging freqs. */ static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy, unsigned int freq_next, unsigned int relation) { unsigned int freq_req, freq_reduc, freq_avg; unsigned int freq_hi, freq_lo; unsigned int index; unsigned int delay_hi_us; struct policy_dbs_info *policy_dbs = policy->governor_data; struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs); struct dbs_data *dbs_data = policy_dbs->dbs_data; struct od_dbs_tuners *od_tuners = dbs_data->tuners; struct cpufreq_frequency_table *freq_table = policy->freq_table; if (!freq_table) { dbs_info->freq_lo = 0; dbs_info->freq_lo_delay_us = 0; return freq_next; } index = cpufreq_frequency_table_target(policy, freq_next, relation); freq_req = freq_table[index].frequency; freq_reduc = freq_req * od_tuners->powersave_bias / 1000; freq_avg = freq_req - freq_reduc; /* Find freq bounds for freq_avg in freq_table */ index = cpufreq_table_find_index_h(policy, freq_avg, relation & CPUFREQ_RELATION_E); freq_lo = freq_table[index].frequency; index = cpufreq_table_find_index_l(policy, freq_avg, relation & CPUFREQ_RELATION_E); freq_hi = freq_table[index].frequency; /* Find out how long we have to be in hi and lo freqs */ if (freq_hi == freq_lo) { dbs_info->freq_lo = 0; dbs_info->freq_lo_delay_us = 0; return freq_lo; } delay_hi_us = (freq_avg - freq_lo) * dbs_data->sampling_rate; delay_hi_us += (freq_hi - freq_lo) / 2; delay_hi_us /= freq_hi - freq_lo; dbs_info->freq_hi_delay_us = delay_hi_us; dbs_info->freq_lo = freq_lo; dbs_info->freq_lo_delay_us = dbs_data->sampling_rate - delay_hi_us; return freq_hi; } static void ondemand_powersave_bias_init(struct cpufreq_policy *policy) { struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data); dbs_info->freq_lo = 0; } static void dbs_freq_increase(struct cpufreq_policy *policy, unsigned int freq) { struct policy_dbs_info *policy_dbs = policy->governor_data; struct dbs_data *dbs_data = policy_dbs->dbs_data; struct od_dbs_tuners *od_tuners = dbs_data->tuners; if (od_tuners->powersave_bias) freq = od_ops.powersave_bias_target(policy, freq, CPUFREQ_RELATION_HE); else if (policy->cur == policy->max) return; __cpufreq_driver_target(policy, freq, od_tuners->powersave_bias ? CPUFREQ_RELATION_LE : CPUFREQ_RELATION_HE); } /* * Every sampling_rate, we check, if current idle time is less than 20% * (default), then we try to increase frequency. Else, we adjust the frequency * proportional to load. */ static void od_update(struct cpufreq_policy *policy) { struct policy_dbs_info *policy_dbs = policy->governor_data; struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs); struct dbs_data *dbs_data = policy_dbs->dbs_data; struct od_dbs_tuners *od_tuners = dbs_data->tuners; unsigned int load = dbs_update(policy); dbs_info->freq_lo = 0; /* Check for frequency increase */ if (load > dbs_data->up_threshold) { /* If switching to max speed, apply sampling_down_factor */ if (policy->cur < policy->max) policy_dbs->rate_mult = dbs_data->sampling_down_factor; dbs_freq_increase(policy, policy->max); } else { /* Calculate the next frequency proportional to load */ unsigned int freq_next, min_f, max_f; min_f = policy->cpuinfo.min_freq; max_f = policy->cpuinfo.max_freq; freq_next = min_f + load * (max_f - min_f) / 100; /* No longer fully busy, reset rate_mult */ policy_dbs->rate_mult = 1; if (od_tuners->powersave_bias) freq_next = od_ops.powersave_bias_target(policy, freq_next, CPUFREQ_RELATION_LE); __cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_CE); } } static unsigned int od_dbs_update(struct cpufreq_policy *policy) { struct policy_dbs_info *policy_dbs = policy->governor_data; struct dbs_data *dbs_data = policy_dbs->dbs_data; struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs); int sample_type = dbs_info->sample_type; /* Common NORMAL_SAMPLE setup */ dbs_info->sample_type = OD_NORMAL_SAMPLE; /* * OD_SUB_SAMPLE doesn't make sense if sample_delay_ns is 0, so ignore * it then. */ if (sample_type == OD_SUB_SAMPLE && policy_dbs->sample_delay_ns > 0) { __cpufreq_driver_target(policy, dbs_info->freq_lo, CPUFREQ_RELATION_HE); return dbs_info->freq_lo_delay_us; } od_update(policy); if (dbs_info->freq_lo) { /* Setup SUB_SAMPLE */ dbs_info->sample_type = OD_SUB_SAMPLE; return dbs_info->freq_hi_delay_us; } return dbs_data->sampling_rate * policy_dbs->rate_mult; } /************************** sysfs interface ************************/ static struct dbs_governor od_dbs_gov; static ssize_t io_is_busy_store(struct gov_attr_set *attr_set, const char *buf, size_t count) { struct dbs_data *dbs_data = to_dbs_data(attr_set); unsigned int input; int ret; ret = sscanf(buf, "%u", &input); if (ret != 1) return -EINVAL; dbs_data->io_is_busy = !!input; /* we need to re-evaluate prev_cpu_idle */ gov_update_cpu_data(dbs_data); return count; } static ssize_t up_threshold_store(struct gov_attr_set *attr_set, const char *buf, size_t count) { struct dbs_data *dbs_data = to_dbs_data(attr_set); unsigned int input; int ret; ret = sscanf(buf, "%u", &input); if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || input < MIN_FREQUENCY_UP_THRESHOLD) { return -EINVAL; } dbs_data->up_threshold = input; return count; } static ssize_t sampling_down_factor_store(struct gov_attr_set *attr_set, const char *buf, size_t count) { struct dbs_data *dbs_data = to_dbs_data(attr_set); struct policy_dbs_info *policy_dbs; unsigned int input; int ret; ret = sscanf(buf, "%u", &input); if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) return -EINVAL; dbs_data->sampling_down_factor = input; /* Reset down sampling multiplier in case it was active */ list_for_each_entry(policy_dbs, &attr_set->policy_list, list) { /* * Doing this without locking might lead to using different * rate_mult values in od_update() and od_dbs_update(). */ mutex_lock(&policy_dbs->update_mutex); policy_dbs->rate_mult = 1; mutex_unlock(&policy_dbs->update_mutex); } return count; } static ssize_t ignore_nice_load_store(struct gov_attr_set *attr_set, const char *buf, size_t count) { struct dbs_data *dbs_data = to_dbs_data(attr_set); unsigned int input; int ret; ret = sscanf(buf, "%u", &input); if (ret != 1) return -EINVAL; if (input > 1) input = 1; if (input == dbs_data->ignore_nice_load) { /* nothing to do */ return count; } dbs_data->ignore_nice_load = input; /* we need to re-evaluate prev_cpu_idle */ gov_update_cpu_data(dbs_data); return count; } static ssize_t powersave_bias_store(struct gov_attr_set *attr_set, const char *buf, size_t count) { struct dbs_data *dbs_data = to_dbs_data(attr_set); struct od_dbs_tuners *od_tuners = dbs_data->tuners; struct policy_dbs_info *policy_dbs; unsigned int input; int ret; ret = sscanf(buf, "%u", &input); if (ret != 1) return -EINVAL; if (input > 1000) input = 1000; od_tuners->powersave_bias = input; list_for_each_entry(policy_dbs, &attr_set->policy_list, list) ondemand_powersave_bias_init(policy_dbs->policy); return count; } gov_show_one_common(sampling_rate); gov_show_one_common(up_threshold); gov_show_one_common(sampling_down_factor); gov_show_one_common(ignore_nice_load); gov_show_one_common(io_is_busy); gov_show_one(od, powersave_bias); gov_attr_rw(sampling_rate); gov_attr_rw(io_is_busy); gov_attr_rw(up_threshold); gov_attr_rw(sampling_down_factor); gov_attr_rw(ignore_nice_load); gov_attr_rw(powersave_bias); static struct attribute *od_attrs[] = { &sampling_rate.attr, &up_threshold.attr, &sampling_down_factor.attr, &ignore_nice_load.attr, &powersave_bias.attr, &io_is_busy.attr, NULL }; ATTRIBUTE_GROUPS(od); /************************** sysfs end ************************/ static struct policy_dbs_info *od_alloc(void) { struct od_policy_dbs_info *dbs_info; dbs_info = kzalloc(sizeof(*dbs_info), GFP_KERNEL); return dbs_info ? &dbs_info->policy_dbs : NULL; } static void od_free(struct policy_dbs_info *policy_dbs) { kfree(to_dbs_info(policy_dbs)); } static int od_init(struct dbs_data *dbs_data) { struct od_dbs_tuners *tuners; u64 idle_time; int cpu; tuners = kzalloc(sizeof(*tuners), GFP_KERNEL); if (!tuners) return -ENOMEM; cpu = get_cpu(); idle_time = get_cpu_idle_time_us(cpu, NULL); put_cpu(); if (idle_time != -1ULL) { /* Idle micro accounting is supported. Use finer thresholds */ dbs_data->up_threshold = MICRO_FREQUENCY_UP_THRESHOLD; } else { dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD; } dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR; dbs_data->ignore_nice_load = 0; tuners->powersave_bias = default_powersave_bias; dbs_data->io_is_busy = should_io_be_busy(); dbs_data->tuners = tuners; return 0; } static void od_exit(struct dbs_data *dbs_data) { kfree(dbs_data->tuners); } static void od_start(struct cpufreq_policy *policy) { struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data); dbs_info->sample_type = OD_NORMAL_SAMPLE; ondemand_powersave_bias_init(policy); } static struct od_ops od_ops = { .powersave_bias_target = generic_powersave_bias_target, }; static struct dbs_governor od_dbs_gov = { .gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("ondemand"), .kobj_type = { .default_groups = od_groups }, .gov_dbs_update = od_dbs_update, .alloc = od_alloc, .free = od_free, .init = od_init, .exit = od_exit, .start = od_start, }; #define CPU_FREQ_GOV_ONDEMAND (od_dbs_gov.gov) static void od_set_powersave_bias(unsigned int powersave_bias) { unsigned int cpu; cpumask_var_t done; if (!alloc_cpumask_var(&done, GFP_KERNEL)) return; default_powersave_bias = powersave_bias; cpumask_clear(done); cpus_read_lock(); for_each_online_cpu(cpu) { struct cpufreq_policy *policy; struct policy_dbs_info *policy_dbs; struct dbs_data *dbs_data; struct od_dbs_tuners *od_tuners; if (cpumask_test_cpu(cpu, done)) continue; policy = cpufreq_cpu_get_raw(cpu); if (!policy || policy->governor != &CPU_FREQ_GOV_ONDEMAND) continue; policy_dbs = policy->governor_data; if (!policy_dbs) continue; cpumask_or(done, done, policy->cpus); dbs_data = policy_dbs->dbs_data; od_tuners = dbs_data->tuners; od_tuners->powersave_bias = default_powersave_bias; } cpus_read_unlock(); free_cpumask_var(done); } void od_register_powersave_bias_handler(unsigned int (*f) (struct cpufreq_policy *, unsigned int, unsigned int), unsigned int powersave_bias) { od_ops.powersave_bias_target = f; od_set_powersave_bias(powersave_bias); } EXPORT_SYMBOL_GPL(od_register_powersave_bias_handler); void od_unregister_powersave_bias_handler(void) { od_ops.powersave_bias_target = generic_powersave_bias_target; od_set_powersave_bias(0); } EXPORT_SYMBOL_GPL(od_unregister_powersave_bias_handler); MODULE_AUTHOR("Venkatesh Pallipadi "); MODULE_AUTHOR("Alexey Starikovskiy "); MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for " "Low Latency Frequency Transition capable processors"); MODULE_LICENSE("GPL"); #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND struct cpufreq_governor *cpufreq_default_governor(void) { return &CPU_FREQ_GOV_ONDEMAND; } #endif cpufreq_governor_init(CPU_FREQ_GOV_ONDEMAND); cpufreq_governor_exit(CPU_FREQ_GOV_ONDEMAND);