cpufreq: governors: remove redundant code

Initially ondemand governor was written and then using its code conservative
governor is written. It used a lot of code from ondemand governor, but copy of
code was created instead of using the same routines from both governors. Which
increased code redundancy, which is difficult to manage.

This patch is an attempt to move common part of both the governors to
cpufreq_governor.c file to come over above mentioned issues.

This shouldn't change anything from functionality point of view.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 271 insertions, 5 deletions

diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index 679842a8d34a..5ea2c829a796 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -3,19 +3,31 @@
  *
  * CPUFREQ governors common code
  *
+ * Copyright	(C) 2001 Russell King
+ *		(C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
+ *		(C) 2003 Jun Nakajima <jun.nakajima@intel.com>
+ *		(C) 2009 Alexander Clouter <alex@digriz.org.uk>
+ *		(c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
+ *
  * 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 <asm/cputime.h>
+#include <linux/cpufreq.h>
+#include <linux/cpumask.h>
 #include <linux/export.h>
 #include <linux/kernel_stat.h>
+#include <linux/mutex.h>
 #include <linux/tick.h>
 #include <linux/types.h>
-/*
- * Code picked from earlier governer implementations
- */
+#include <linux/workqueue.h>
+
+#include "cpufreq_governor.h"
+
 static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
 {
 	u64 idle_time;
@@ -33,9 +45,9 @@ static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
 
 	idle_time = cur_wall_time - busy_time;
 	if (wall)
-		*wall = cputime_to_usecs(cur_wall_time);
+		*wall = jiffies_to_usecs(cur_wall_time);
 
-	return cputime_to_usecs(idle_time);
+	return jiffies_to_usecs(idle_time);
 }
 
 cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
@@ -50,3 +62,257 @@ cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
 	return idle_time;
 }
 EXPORT_SYMBOL_GPL(get_cpu_idle_time);
+
+void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
+{
+	struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu);
+	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
+	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
+	struct cpufreq_policy *policy;
+	unsigned int max_load = 0;
+	unsigned int ignore_nice;
+	unsigned int j;
+
+	if (dbs_data->governor == GOV_ONDEMAND)
+		ignore_nice = od_tuners->ignore_nice;
+	else
+		ignore_nice = cs_tuners->ignore_nice;
+
+	policy = cdbs->cur_policy;
+
+	/* Get Absolute Load (in terms of freq for ondemand gov) */
+	for_each_cpu(j, policy->cpus) {
+		struct cpu_dbs_common_info *j_cdbs;
+		cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time;
+		unsigned int idle_time, wall_time, iowait_time;
+		unsigned int load;
+
+		j_cdbs = dbs_data->get_cpu_cdbs(j);
+
+		cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
+
+		wall_time = (unsigned int)
+			(cur_wall_time - j_cdbs->prev_cpu_wall);
+		j_cdbs->prev_cpu_wall = cur_wall_time;
+
+		idle_time = (unsigned int)
+			(cur_idle_time - j_cdbs->prev_cpu_idle);
+		j_cdbs->prev_cpu_idle = cur_idle_time;
+
+		if (ignore_nice) {
+			u64 cur_nice;
+			unsigned long cur_nice_jiffies;
+
+			cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
+					 cdbs->prev_cpu_nice;
+			/*
+			 * Assumption: nice time between sampling periods will
+			 * be less than 2^32 jiffies for 32 bit sys
+			 */
+			cur_nice_jiffies = (unsigned long)
+					cputime64_to_jiffies64(cur_nice);
+
+			cdbs->prev_cpu_nice =
+				kcpustat_cpu(j).cpustat[CPUTIME_NICE];
+			idle_time += jiffies_to_usecs(cur_nice_jiffies);
+		}
+
+		if (dbs_data->governor == GOV_ONDEMAND) {
+			struct od_cpu_dbs_info_s *od_j_dbs_info =
+				dbs_data->get_cpu_dbs_info_s(cpu);
+
+			cur_iowait_time = get_cpu_iowait_time_us(j,
+					&cur_wall_time);
+			if (cur_iowait_time == -1ULL)
+				cur_iowait_time = 0;
+
+			iowait_time = (unsigned int) (cur_iowait_time -
+					od_j_dbs_info->prev_cpu_iowait);
+			od_j_dbs_info->prev_cpu_iowait = cur_iowait_time;
+
+			/*
+			 * For the purpose of ondemand, waiting for disk IO is
+			 * an indication that you're performance critical, and
+			 * not that the system is actually idle. So subtract the
+			 * iowait time from the cpu idle time.
+			 */
+			if (od_tuners->io_is_busy && idle_time >= iowait_time)
+				idle_time -= iowait_time;
+		}
+
+		if (unlikely(!wall_time || wall_time < idle_time))
+			continue;
+
+		load = 100 * (wall_time - idle_time) / wall_time;
+
+		if (dbs_data->governor == GOV_ONDEMAND) {
+			int freq_avg = __cpufreq_driver_getavg(policy, j);
+			if (freq_avg <= 0)
+				freq_avg = policy->cur;
+
+			load *= freq_avg;
+		}
+
+		if (load > max_load)
+			max_load = load;
+	}
+
+	dbs_data->gov_check_cpu(cpu, max_load);
+}
+EXPORT_SYMBOL_GPL(dbs_check_cpu);
+
+static inline void dbs_timer_init(struct dbs_data *dbs_data,
+		struct cpu_dbs_common_info *cdbs, unsigned int sampling_rate)
+{
+	int delay = delay_for_sampling_rate(sampling_rate);
+
+	INIT_DEFERRABLE_WORK(&cdbs->work, dbs_data->gov_dbs_timer);
+	schedule_delayed_work_on(cdbs->cpu, &cdbs->work, delay);
+}
+
+static inline void dbs_timer_exit(struct cpu_dbs_common_info *cdbs)
+{
+	cancel_delayed_work_sync(&cdbs->work);
+}
+
+int cpufreq_governor_dbs(struct dbs_data *dbs_data,
+		struct cpufreq_policy *policy, unsigned int event)
+{
+	struct od_cpu_dbs_info_s *od_dbs_info = NULL;
+	struct cs_cpu_dbs_info_s *cs_dbs_info = NULL;
+	struct od_dbs_tuners *od_tuners = dbs_data->tuners;
+	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
+	struct cpu_dbs_common_info *cpu_cdbs;
+	unsigned int *sampling_rate, latency, ignore_nice, j, cpu = policy->cpu;
+	int rc;
+
+	cpu_cdbs = dbs_data->get_cpu_cdbs(cpu);
+
+	if (dbs_data->governor == GOV_CONSERVATIVE) {
+		cs_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
+		sampling_rate = &cs_tuners->sampling_rate;
+		ignore_nice = cs_tuners->ignore_nice;
+	} else {
+		od_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
+		sampling_rate = &od_tuners->sampling_rate;
+		ignore_nice = od_tuners->ignore_nice;
+	}
+
+	switch (event) {
+	case CPUFREQ_GOV_START:
+		if ((!cpu_online(cpu)) || (!policy->cur))
+			return -EINVAL;
+
+		mutex_lock(&dbs_data->mutex);
+
+		dbs_data->enable++;
+		cpu_cdbs->cpu = cpu;
+		for_each_cpu(j, policy->cpus) {
+			struct cpu_dbs_common_info *j_cdbs;
+			j_cdbs = dbs_data->get_cpu_cdbs(j);
+
+			j_cdbs->cur_policy = policy;
+			j_cdbs->prev_cpu_idle = get_cpu_idle_time(j,
+					&j_cdbs->prev_cpu_wall);
+			if (ignore_nice)
+				j_cdbs->prev_cpu_nice =
+					kcpustat_cpu(j).cpustat[CPUTIME_NICE];
+		}
+
+		/*
+		 * Start the timerschedule work, when this governor is used for
+		 * first time
+		 */
+		if (dbs_data->enable != 1)
+			goto second_time;
+
+		rc = sysfs_create_group(cpufreq_global_kobject,
+				dbs_data->attr_group);
+		if (rc) {
+			mutex_unlock(&dbs_data->mutex);
+			return rc;
+		}
+
+		/* policy latency is in nS. Convert it to uS first */
+		latency = policy->cpuinfo.transition_latency / 1000;
+		if (latency == 0)
+			latency = 1;
+
+		/*
+		 * conservative does not implement micro like ondemand
+		 * governor, thus we are bound to jiffes/HZ
+		 */
+		if (dbs_data->governor == GOV_CONSERVATIVE) {
+			struct cs_ops *ops = dbs_data->gov_ops;
+
+			cpufreq_register_notifier(ops->notifier_block,
+					CPUFREQ_TRANSITION_NOTIFIER);
+
+			dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
+				jiffies_to_usecs(10);
+		} else {
+			struct od_ops *ops = dbs_data->gov_ops;
+
+			od_tuners->io_is_busy = ops->io_busy();
+		}
+
+		/* Bring kernel and HW constraints together */
+		dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate,
+				MIN_LATENCY_MULTIPLIER * latency);
+		*sampling_rate = max(dbs_data->min_sampling_rate, latency *
+				LATENCY_MULTIPLIER);
+
+second_time:
+		if (dbs_data->governor == GOV_CONSERVATIVE) {
+			cs_dbs_info->down_skip = 0;
+			cs_dbs_info->enable = 1;
+			cs_dbs_info->requested_freq = policy->cur;
+		} else {
+			struct od_ops *ops = dbs_data->gov_ops;
+			od_dbs_info->rate_mult = 1;
+			od_dbs_info->sample_type = OD_NORMAL_SAMPLE;
+			ops->powersave_bias_init_cpu(cpu);
+		}
+		mutex_unlock(&dbs_data->mutex);
+
+		mutex_init(&cpu_cdbs->timer_mutex);
+		dbs_timer_init(dbs_data, cpu_cdbs, *sampling_rate);
+		break;
+
+	case CPUFREQ_GOV_STOP:
+		if (dbs_data->governor == GOV_CONSERVATIVE)
+			cs_dbs_info->enable = 0;
+
+		dbs_timer_exit(cpu_cdbs);
+
+		mutex_lock(&dbs_data->mutex);
+		mutex_destroy(&cpu_cdbs->timer_mutex);
+		dbs_data->enable--;
+		if (!dbs_data->enable) {
+			struct cs_ops *ops = dbs_data->gov_ops;
+
+			sysfs_remove_group(cpufreq_global_kobject,
+					dbs_data->attr_group);
+			if (dbs_data->governor == GOV_CONSERVATIVE)
+				cpufreq_unregister_notifier(ops->notifier_block,
+						CPUFREQ_TRANSITION_NOTIFIER);
+		}
+		mutex_unlock(&dbs_data->mutex);
+
+		break;
+
+	case CPUFREQ_GOV_LIMITS:
+		mutex_lock(&cpu_cdbs->timer_mutex);
+		if (policy->max < cpu_cdbs->cur_policy->cur)
+			__cpufreq_driver_target(cpu_cdbs->cur_policy,
+					policy->max, CPUFREQ_RELATION_H);
+		else if (policy->min > cpu_cdbs->cur_policy->cur)
+			__cpufreq_driver_target(cpu_cdbs->cur_policy,
+					policy->min, CPUFREQ_RELATION_L);
+		dbs_check_cpu(dbs_data, cpu);
+		mutex_unlock(&cpu_cdbs->timer_mutex);
+		break;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_governor_dbs);