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Currently, most CPUFreq governors are registered at the core_initcall time when the given governor is the default one, and the module_init time otherwise. In preparation for letting users specify the default governor on the kernel command line, change all of them to be registered at the core_initcall unconditionally, as it is already the case for the schedutil and performance governors. This will allow us to assume that builtin governors have been registered before the built-in CPUFreq drivers probe. And since all governors have similar init/exit patterns now, introduce two new macros, cpufreq_governor_{init,exit}(), to factorize the code. Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
342 lines
8.7 KiB
C
342 lines
8.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* drivers/cpufreq/cpufreq_conservative.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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* (C) 2009 Alexander Clouter <alex@digriz.org.uk>
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*/
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#include <linux/slab.h>
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#include "cpufreq_governor.h"
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struct cs_policy_dbs_info {
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struct policy_dbs_info policy_dbs;
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unsigned int down_skip;
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unsigned int requested_freq;
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};
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static inline struct cs_policy_dbs_info *to_dbs_info(struct policy_dbs_info *policy_dbs)
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{
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return container_of(policy_dbs, struct cs_policy_dbs_info, policy_dbs);
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}
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struct cs_dbs_tuners {
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unsigned int down_threshold;
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unsigned int freq_step;
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};
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/* Conservative governor macros */
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#define DEF_FREQUENCY_UP_THRESHOLD (80)
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#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
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#define DEF_FREQUENCY_STEP (5)
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#define DEF_SAMPLING_DOWN_FACTOR (1)
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#define MAX_SAMPLING_DOWN_FACTOR (10)
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static inline unsigned int get_freq_step(struct cs_dbs_tuners *cs_tuners,
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struct cpufreq_policy *policy)
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{
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unsigned int freq_step = (cs_tuners->freq_step * policy->max) / 100;
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/* max freq cannot be less than 100. But who knows... */
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if (unlikely(freq_step == 0))
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freq_step = DEF_FREQUENCY_STEP;
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return freq_step;
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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. Every sampling_rate *
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* sampling_down_factor, we check, if current idle time is more than 80%
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* (default), then we try to decrease frequency
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*
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* Frequency updates happen at minimum steps of 5% (default) of maximum
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* frequency
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*/
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static unsigned int cs_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 cs_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
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unsigned int requested_freq = dbs_info->requested_freq;
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struct dbs_data *dbs_data = policy_dbs->dbs_data;
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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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unsigned int load = dbs_update(policy);
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unsigned int freq_step;
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/*
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* break out if we 'cannot' reduce the speed as the user might
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* want freq_step to be zero
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*/
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if (cs_tuners->freq_step == 0)
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goto out;
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/*
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* If requested_freq is out of range, it is likely that the limits
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* changed in the meantime, so fall back to current frequency in that
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* case.
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*/
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if (requested_freq > policy->max || requested_freq < policy->min) {
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requested_freq = policy->cur;
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dbs_info->requested_freq = requested_freq;
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}
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freq_step = get_freq_step(cs_tuners, policy);
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/*
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* Decrease requested_freq one freq_step for each idle period that
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* we didn't update the frequency.
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*/
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if (policy_dbs->idle_periods < UINT_MAX) {
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unsigned int freq_steps = policy_dbs->idle_periods * freq_step;
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if (requested_freq > policy->min + freq_steps)
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requested_freq -= freq_steps;
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else
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requested_freq = policy->min;
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policy_dbs->idle_periods = UINT_MAX;
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}
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/* Check for frequency increase */
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if (load > dbs_data->up_threshold) {
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dbs_info->down_skip = 0;
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/* if we are already at full speed then break out early */
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if (requested_freq == policy->max)
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goto out;
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requested_freq += freq_step;
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if (requested_freq > policy->max)
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requested_freq = policy->max;
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__cpufreq_driver_target(policy, requested_freq, CPUFREQ_RELATION_H);
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dbs_info->requested_freq = requested_freq;
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goto out;
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}
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/* if sampling_down_factor is active break out early */
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if (++dbs_info->down_skip < dbs_data->sampling_down_factor)
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goto out;
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dbs_info->down_skip = 0;
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/* Check for frequency decrease */
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if (load < cs_tuners->down_threshold) {
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/*
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* if we cannot reduce the frequency anymore, break out early
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*/
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if (requested_freq == policy->min)
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goto out;
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if (requested_freq > freq_step)
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requested_freq -= freq_step;
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else
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requested_freq = policy->min;
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__cpufreq_driver_target(policy, requested_freq, CPUFREQ_RELATION_L);
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dbs_info->requested_freq = requested_freq;
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}
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out:
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return dbs_data->sampling_rate;
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}
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/************************** sysfs interface ************************/
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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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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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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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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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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 > 100 || input <= cs_tuners->down_threshold)
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return -EINVAL;
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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_down_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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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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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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/* cannot be lower than 1 otherwise freq will not fall */
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if (ret != 1 || input < 1 || input > 100 ||
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input >= dbs_data->up_threshold)
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return -EINVAL;
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cs_tuners->down_threshold = input;
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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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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_freq_step(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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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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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 > 100)
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input = 100;
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/*
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* no need to test here if freq_step is zero as the user might actually
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* want this, they would be crazy though :)
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*/
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cs_tuners->freq_step = input;
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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(sampling_down_factor);
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gov_show_one_common(up_threshold);
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gov_show_one_common(ignore_nice_load);
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gov_show_one(cs, down_threshold);
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gov_show_one(cs, freq_step);
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gov_attr_rw(sampling_rate);
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gov_attr_rw(sampling_down_factor);
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gov_attr_rw(up_threshold);
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gov_attr_rw(ignore_nice_load);
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gov_attr_rw(down_threshold);
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gov_attr_rw(freq_step);
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static struct attribute *cs_attributes[] = {
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&sampling_rate.attr,
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&sampling_down_factor.attr,
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&up_threshold.attr,
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&down_threshold.attr,
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&ignore_nice_load.attr,
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&freq_step.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 *cs_alloc(void)
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{
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struct cs_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 cs_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 cs_init(struct dbs_data *dbs_data)
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{
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struct cs_dbs_tuners *tuners;
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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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tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
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tuners->freq_step = DEF_FREQUENCY_STEP;
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dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
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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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dbs_data->tuners = tuners;
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return 0;
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}
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static void cs_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 cs_start(struct cpufreq_policy *policy)
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{
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struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
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dbs_info->down_skip = 0;
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dbs_info->requested_freq = policy->cur;
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}
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static struct dbs_governor cs_governor = {
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.gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("conservative"),
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.kobj_type = { .default_attrs = cs_attributes },
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.gov_dbs_update = cs_dbs_update,
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.alloc = cs_alloc,
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.free = cs_free,
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.init = cs_init,
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.exit = cs_exit,
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.start = cs_start,
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};
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#define CPU_FREQ_GOV_CONSERVATIVE (cs_governor.gov)
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MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
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MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
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"Low Latency Frequency Transition capable processors "
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"optimised for use in a battery environment");
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MODULE_LICENSE("GPL");
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#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
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struct cpufreq_governor *cpufreq_default_governor(void)
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{
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return &CPU_FREQ_GOV_CONSERVATIVE;
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}
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#endif
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cpufreq_governor_init(CPU_FREQ_GOV_CONSERVATIVE);
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cpufreq_governor_exit(CPU_FREQ_GOV_CONSERVATIVE);
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