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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/cpufreq/cpufreq_ondemand.c | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/cpufreq/cpufreq_ondemand.c')
-rw-r--r-- | drivers/cpufreq/cpufreq_ondemand.c | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c new file mode 100644 index 000000000..ac361a8b1 --- /dev/null +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -0,0 +1,478 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * drivers/cpufreq/cpufreq_ondemand.c + * + * Copyright (C) 2001 Russell King + * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>. + * Jun Nakajima <jun.nakajima@intel.com> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cpu.h> +#include <linux/percpu-defs.h> +#include <linux/slab.h> +#include <linux/tick.h> +#include <linux/sched/cpufreq.h> + +#include "cpufreq_ondemand.h" + +/* On-demand governor macros */ +#define DEF_FREQUENCY_UP_THRESHOLD (80) +#define DEF_SAMPLING_DOWN_FACTOR (1) +#define MAX_SAMPLING_DOWN_FACTOR (100000) +#define MICRO_FREQUENCY_UP_THRESHOLD (95) +#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); + freq_lo = freq_table[index].frequency; + index = cpufreq_table_find_index_l(policy, freq_avg); + 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_H); + else if (policy->cur == policy->max) + return; + + __cpufreq_driver_target(policy, freq, od_tuners->powersave_bias ? + CPUFREQ_RELATION_L : CPUFREQ_RELATION_H); +} + +/* + * 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_L); + + __cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_C); + } +} + +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_H); + 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 store_io_is_busy(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 store_up_threshold(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 store_sampling_down_factor(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 store_ignore_nice_load(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 store_powersave_bias(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_attributes[] = { + &sampling_rate.attr, + &up_threshold.attr, + &sampling_down_factor.attr, + &ignore_nice_load.attr, + &powersave_bias.attr, + &io_is_busy.attr, + NULL +}; + +/************************** 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_attrs = od_attributes }, + .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_t done; + + default_powersave_bias = powersave_bias; + cpumask_clear(&done); + + get_online_cpus(); + 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; + } + put_online_cpus(); +} + +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 <venkatesh.pallipadi@intel.com>"); +MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>"); +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); |