1 files changed, 493 insertions, 0 deletions

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
new file mode 100644
index 000000000..6b423eebf
--- /dev/null
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -0,0 +1,493 @@
+/*
+ *  drivers/cpufreq/cpufreq_ondemand.c
+ *
+ *  Copyright (C)  2001 Russell King
+ *            (C)  2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
+ *                      Jun Nakajima <jun.nakajima@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#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);
+
+static int __init cpufreq_gov_dbs_init(void)
+{
+	return cpufreq_register_governor(CPU_FREQ_GOV_ONDEMAND);
+}
+
+static void __exit cpufreq_gov_dbs_exit(void)
+{
+	cpufreq_unregister_governor(CPU_FREQ_GOV_ONDEMAND);
+}
+
+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;
+}
+
+fs_initcall(cpufreq_gov_dbs_init);
+#else
+module_init(cpufreq_gov_dbs_init);
+#endif
+module_exit(cpufreq_gov_dbs_exit);