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b894d20e68
Let the governors schedutil, conservative and ondemand to work, if possible on efficient frequencies only. Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
481 lines
13 KiB
C
481 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* drivers/cpufreq/cpufreq_ondemand.c
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*
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* Copyright (C) 2001 Russell King
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* (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
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* Jun Nakajima <jun.nakajima@intel.com>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/cpu.h>
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#include <linux/percpu-defs.h>
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#include <linux/slab.h>
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#include <linux/tick.h>
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#include <linux/sched/cpufreq.h>
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#include "cpufreq_ondemand.h"
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/* On-demand governor macros */
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#define DEF_FREQUENCY_UP_THRESHOLD (80)
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#define DEF_SAMPLING_DOWN_FACTOR (1)
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#define MAX_SAMPLING_DOWN_FACTOR (100000)
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#define MICRO_FREQUENCY_UP_THRESHOLD (95)
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#define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000)
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#define MIN_FREQUENCY_UP_THRESHOLD (1)
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#define MAX_FREQUENCY_UP_THRESHOLD (100)
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static struct od_ops od_ops;
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static unsigned int default_powersave_bias;
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/*
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* Not all CPUs want IO time to be accounted as busy; this depends on how
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* efficient idling at a higher frequency/voltage is.
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* Pavel Machek says this is not so for various generations of AMD and old
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* Intel systems.
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* Mike Chan (android.com) claims this is also not true for ARM.
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* Because of this, whitelist specific known (series) of CPUs by default, and
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* leave all others up to the user.
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*/
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static int should_io_be_busy(void)
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{
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#if defined(CONFIG_X86)
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/*
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* For Intel, Core 2 (model 15) and later have an efficient idle.
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*/
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if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
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boot_cpu_data.x86 == 6 &&
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boot_cpu_data.x86_model >= 15)
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return 1;
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#endif
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return 0;
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}
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/*
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* Find right freq to be set now with powersave_bias on.
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* Returns the freq_hi to be used right now and will set freq_hi_delay_us,
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* freq_lo, and freq_lo_delay_us in percpu area for averaging freqs.
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*/
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static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy,
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unsigned int freq_next, unsigned int relation)
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{
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unsigned int freq_req, freq_reduc, freq_avg;
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unsigned int freq_hi, freq_lo;
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unsigned int index;
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unsigned int delay_hi_us;
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struct policy_dbs_info *policy_dbs = policy->governor_data;
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struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
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struct dbs_data *dbs_data = policy_dbs->dbs_data;
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struct od_dbs_tuners *od_tuners = dbs_data->tuners;
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struct cpufreq_frequency_table *freq_table = policy->freq_table;
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if (!freq_table) {
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dbs_info->freq_lo = 0;
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dbs_info->freq_lo_delay_us = 0;
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return freq_next;
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}
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index = cpufreq_frequency_table_target(policy, freq_next, relation);
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freq_req = freq_table[index].frequency;
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freq_reduc = freq_req * od_tuners->powersave_bias / 1000;
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freq_avg = freq_req - freq_reduc;
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/* Find freq bounds for freq_avg in freq_table */
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index = cpufreq_table_find_index_h(policy, freq_avg,
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relation & CPUFREQ_RELATION_E);
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freq_lo = freq_table[index].frequency;
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index = cpufreq_table_find_index_l(policy, freq_avg,
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relation & CPUFREQ_RELATION_E);
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freq_hi = freq_table[index].frequency;
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/* Find out how long we have to be in hi and lo freqs */
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if (freq_hi == freq_lo) {
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dbs_info->freq_lo = 0;
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dbs_info->freq_lo_delay_us = 0;
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return freq_lo;
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}
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delay_hi_us = (freq_avg - freq_lo) * dbs_data->sampling_rate;
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delay_hi_us += (freq_hi - freq_lo) / 2;
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delay_hi_us /= freq_hi - freq_lo;
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dbs_info->freq_hi_delay_us = delay_hi_us;
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dbs_info->freq_lo = freq_lo;
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dbs_info->freq_lo_delay_us = dbs_data->sampling_rate - delay_hi_us;
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return freq_hi;
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}
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static void ondemand_powersave_bias_init(struct cpufreq_policy *policy)
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{
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struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
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dbs_info->freq_lo = 0;
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}
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static void dbs_freq_increase(struct cpufreq_policy *policy, unsigned int freq)
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{
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struct policy_dbs_info *policy_dbs = policy->governor_data;
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struct dbs_data *dbs_data = policy_dbs->dbs_data;
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struct od_dbs_tuners *od_tuners = dbs_data->tuners;
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if (od_tuners->powersave_bias)
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freq = od_ops.powersave_bias_target(policy, freq,
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CPUFREQ_RELATION_HE);
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else if (policy->cur == policy->max)
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return;
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__cpufreq_driver_target(policy, freq, od_tuners->powersave_bias ?
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CPUFREQ_RELATION_LE : CPUFREQ_RELATION_HE);
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}
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/*
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* Every sampling_rate, we check, if current idle time is less than 20%
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* (default), then we try to increase frequency. Else, we adjust the frequency
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* proportional to load.
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*/
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static void od_update(struct cpufreq_policy *policy)
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{
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struct policy_dbs_info *policy_dbs = policy->governor_data;
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struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
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struct dbs_data *dbs_data = policy_dbs->dbs_data;
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struct od_dbs_tuners *od_tuners = dbs_data->tuners;
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unsigned int load = dbs_update(policy);
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dbs_info->freq_lo = 0;
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/* Check for frequency increase */
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if (load > dbs_data->up_threshold) {
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/* If switching to max speed, apply sampling_down_factor */
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if (policy->cur < policy->max)
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policy_dbs->rate_mult = dbs_data->sampling_down_factor;
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dbs_freq_increase(policy, policy->max);
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} else {
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/* Calculate the next frequency proportional to load */
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unsigned int freq_next, min_f, max_f;
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min_f = policy->cpuinfo.min_freq;
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max_f = policy->cpuinfo.max_freq;
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freq_next = min_f + load * (max_f - min_f) / 100;
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/* No longer fully busy, reset rate_mult */
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policy_dbs->rate_mult = 1;
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if (od_tuners->powersave_bias)
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freq_next = od_ops.powersave_bias_target(policy,
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freq_next,
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CPUFREQ_RELATION_LE);
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__cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_CE);
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}
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}
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static unsigned int od_dbs_update(struct cpufreq_policy *policy)
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{
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struct policy_dbs_info *policy_dbs = policy->governor_data;
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struct dbs_data *dbs_data = policy_dbs->dbs_data;
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struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
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int sample_type = dbs_info->sample_type;
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/* Common NORMAL_SAMPLE setup */
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dbs_info->sample_type = OD_NORMAL_SAMPLE;
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/*
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* OD_SUB_SAMPLE doesn't make sense if sample_delay_ns is 0, so ignore
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* it then.
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*/
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if (sample_type == OD_SUB_SAMPLE && policy_dbs->sample_delay_ns > 0) {
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__cpufreq_driver_target(policy, dbs_info->freq_lo,
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CPUFREQ_RELATION_HE);
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return dbs_info->freq_lo_delay_us;
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}
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od_update(policy);
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if (dbs_info->freq_lo) {
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/* Setup SUB_SAMPLE */
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dbs_info->sample_type = OD_SUB_SAMPLE;
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return dbs_info->freq_hi_delay_us;
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}
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return dbs_data->sampling_rate * policy_dbs->rate_mult;
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}
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/************************** sysfs interface ************************/
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static struct dbs_governor od_dbs_gov;
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static ssize_t store_io_is_busy(struct gov_attr_set *attr_set, const char *buf,
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size_t count)
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{
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struct dbs_data *dbs_data = to_dbs_data(attr_set);
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unsigned int input;
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int ret;
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ret = sscanf(buf, "%u", &input);
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if (ret != 1)
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return -EINVAL;
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dbs_data->io_is_busy = !!input;
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/* we need to re-evaluate prev_cpu_idle */
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gov_update_cpu_data(dbs_data);
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return count;
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}
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static ssize_t store_up_threshold(struct gov_attr_set *attr_set,
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const char *buf, size_t count)
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{
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struct dbs_data *dbs_data = to_dbs_data(attr_set);
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unsigned int input;
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int ret;
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ret = sscanf(buf, "%u", &input);
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if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD ||
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input < MIN_FREQUENCY_UP_THRESHOLD) {
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return -EINVAL;
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}
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dbs_data->up_threshold = input;
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return count;
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}
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static ssize_t store_sampling_down_factor(struct gov_attr_set *attr_set,
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const char *buf, size_t count)
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{
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struct dbs_data *dbs_data = to_dbs_data(attr_set);
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struct policy_dbs_info *policy_dbs;
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unsigned int input;
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int ret;
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ret = sscanf(buf, "%u", &input);
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if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
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return -EINVAL;
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dbs_data->sampling_down_factor = input;
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/* Reset down sampling multiplier in case it was active */
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list_for_each_entry(policy_dbs, &attr_set->policy_list, list) {
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/*
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* Doing this without locking might lead to using different
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* rate_mult values in od_update() and od_dbs_update().
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*/
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mutex_lock(&policy_dbs->update_mutex);
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policy_dbs->rate_mult = 1;
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mutex_unlock(&policy_dbs->update_mutex);
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}
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return count;
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}
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static ssize_t store_ignore_nice_load(struct gov_attr_set *attr_set,
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const char *buf, size_t count)
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{
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struct dbs_data *dbs_data = to_dbs_data(attr_set);
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unsigned int input;
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int ret;
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ret = sscanf(buf, "%u", &input);
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if (ret != 1)
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return -EINVAL;
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if (input > 1)
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input = 1;
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if (input == dbs_data->ignore_nice_load) { /* nothing to do */
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return count;
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}
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dbs_data->ignore_nice_load = input;
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/* we need to re-evaluate prev_cpu_idle */
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gov_update_cpu_data(dbs_data);
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return count;
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}
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static ssize_t store_powersave_bias(struct gov_attr_set *attr_set,
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const char *buf, size_t count)
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{
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struct dbs_data *dbs_data = to_dbs_data(attr_set);
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struct od_dbs_tuners *od_tuners = dbs_data->tuners;
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struct policy_dbs_info *policy_dbs;
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unsigned int input;
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int ret;
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ret = sscanf(buf, "%u", &input);
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if (ret != 1)
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return -EINVAL;
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if (input > 1000)
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input = 1000;
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od_tuners->powersave_bias = input;
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list_for_each_entry(policy_dbs, &attr_set->policy_list, list)
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ondemand_powersave_bias_init(policy_dbs->policy);
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return count;
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}
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gov_show_one_common(sampling_rate);
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gov_show_one_common(up_threshold);
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gov_show_one_common(sampling_down_factor);
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gov_show_one_common(ignore_nice_load);
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gov_show_one_common(io_is_busy);
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gov_show_one(od, powersave_bias);
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gov_attr_rw(sampling_rate);
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gov_attr_rw(io_is_busy);
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gov_attr_rw(up_threshold);
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gov_attr_rw(sampling_down_factor);
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gov_attr_rw(ignore_nice_load);
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gov_attr_rw(powersave_bias);
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static struct attribute *od_attributes[] = {
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&sampling_rate.attr,
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&up_threshold.attr,
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&sampling_down_factor.attr,
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&ignore_nice_load.attr,
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&powersave_bias.attr,
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&io_is_busy.attr,
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NULL
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};
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/************************** sysfs end ************************/
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static struct policy_dbs_info *od_alloc(void)
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{
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struct od_policy_dbs_info *dbs_info;
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dbs_info = kzalloc(sizeof(*dbs_info), GFP_KERNEL);
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return dbs_info ? &dbs_info->policy_dbs : NULL;
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}
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static void od_free(struct policy_dbs_info *policy_dbs)
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{
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kfree(to_dbs_info(policy_dbs));
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}
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static int od_init(struct dbs_data *dbs_data)
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{
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struct od_dbs_tuners *tuners;
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u64 idle_time;
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int cpu;
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tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
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if (!tuners)
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return -ENOMEM;
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cpu = get_cpu();
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idle_time = get_cpu_idle_time_us(cpu, NULL);
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put_cpu();
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if (idle_time != -1ULL) {
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/* Idle micro accounting is supported. Use finer thresholds */
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dbs_data->up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
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} else {
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dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
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}
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dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
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dbs_data->ignore_nice_load = 0;
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tuners->powersave_bias = default_powersave_bias;
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dbs_data->io_is_busy = should_io_be_busy();
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dbs_data->tuners = tuners;
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return 0;
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}
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static void od_exit(struct dbs_data *dbs_data)
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{
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kfree(dbs_data->tuners);
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}
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static void od_start(struct cpufreq_policy *policy)
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{
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struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
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dbs_info->sample_type = OD_NORMAL_SAMPLE;
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ondemand_powersave_bias_init(policy);
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}
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static struct od_ops od_ops = {
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.powersave_bias_target = generic_powersave_bias_target,
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};
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static struct dbs_governor od_dbs_gov = {
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.gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("ondemand"),
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.kobj_type = { .default_attrs = od_attributes },
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.gov_dbs_update = od_dbs_update,
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.alloc = od_alloc,
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.free = od_free,
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.init = od_init,
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.exit = od_exit,
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.start = od_start,
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};
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#define CPU_FREQ_GOV_ONDEMAND (od_dbs_gov.gov)
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static void od_set_powersave_bias(unsigned int powersave_bias)
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{
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unsigned int cpu;
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cpumask_t done;
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default_powersave_bias = powersave_bias;
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cpumask_clear(&done);
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cpus_read_lock();
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for_each_online_cpu(cpu) {
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struct cpufreq_policy *policy;
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struct policy_dbs_info *policy_dbs;
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struct dbs_data *dbs_data;
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struct od_dbs_tuners *od_tuners;
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if (cpumask_test_cpu(cpu, &done))
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continue;
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policy = cpufreq_cpu_get_raw(cpu);
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if (!policy || policy->governor != &CPU_FREQ_GOV_ONDEMAND)
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continue;
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policy_dbs = policy->governor_data;
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if (!policy_dbs)
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continue;
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cpumask_or(&done, &done, policy->cpus);
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dbs_data = policy_dbs->dbs_data;
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od_tuners = dbs_data->tuners;
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od_tuners->powersave_bias = default_powersave_bias;
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}
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cpus_read_unlock();
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}
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void od_register_powersave_bias_handler(unsigned int (*f)
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(struct cpufreq_policy *, unsigned int, unsigned int),
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unsigned int powersave_bias)
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{
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od_ops.powersave_bias_target = f;
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od_set_powersave_bias(powersave_bias);
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}
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EXPORT_SYMBOL_GPL(od_register_powersave_bias_handler);
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void od_unregister_powersave_bias_handler(void)
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{
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od_ops.powersave_bias_target = generic_powersave_bias_target;
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od_set_powersave_bias(0);
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}
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EXPORT_SYMBOL_GPL(od_unregister_powersave_bias_handler);
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MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>");
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MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>");
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MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for "
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"Low Latency Frequency Transition capable processors");
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MODULE_LICENSE("GPL");
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#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
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struct cpufreq_governor *cpufreq_default_governor(void)
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{
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return &CPU_FREQ_GOV_ONDEMAND;
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}
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#endif
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cpufreq_governor_init(CPU_FREQ_GOV_ONDEMAND);
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cpufreq_governor_exit(CPU_FREQ_GOV_ONDEMAND);
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