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/*
* linux/drivers/cpufreq/freq_table.c
*
* Copyright (C) 2002 - 2003 Dominik Brodowski
*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
/*********************************************************************
* FREQUENCY TABLE HELPERS *
*********************************************************************/
int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table)
{
unsigned int min_freq = ~0;
unsigned int max_freq = 0;
unsigned int i;
for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
unsigned int freq = table[i].frequency;
if (freq == CPUFREQ_ENTRY_INVALID) {
pr_debug("table entry %u is invalid, skipping\n", i);
continue;
}
pr_debug("table entry %u: %u kHz, %u index\n",
i, freq, table[i].index);
if (freq < min_freq)
min_freq = freq;
if (freq > max_freq)
max_freq = freq;
}
policy->min = policy->cpuinfo.min_freq = min_freq;
policy->max = policy->cpuinfo.max_freq = max_freq;
if (policy->min == ~0)
return -EINVAL;
else
return 0;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo);
int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table)
{
unsigned int next_larger = ~0;
unsigned int i;
unsigned int count = 0;
pr_debug("request for verification of policy (%u - %u kHz) for cpu %u\n",
policy->min, policy->max, policy->cpu);
cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
policy->cpuinfo.max_freq);
for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
unsigned int freq = table[i].frequency;
if (freq == CPUFREQ_ENTRY_INVALID)
continue;
if ((freq >= policy->min) && (freq <= policy->max))
count++;
else if ((next_larger > freq) && (freq > policy->max))
next_larger = freq;
}
if (!count)
policy->max = next_larger;
cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
policy->cpuinfo.max_freq);
pr_debug("verification lead to (%u - %u kHz) for cpu %u\n",
policy->min, policy->max, policy->cpu);
return 0;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table,
unsigned int target_freq,
unsigned int relation,
unsigned int *index)
{
struct cpufreq_frequency_table optimal = {
.index = ~0,
.frequency = 0,
};
struct cpufreq_frequency_table suboptimal = {
.index = ~0,
.frequency = 0,
};
unsigned int i;
pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
target_freq, relation, policy->cpu);
switch (relation) {
case CPUFREQ_RELATION_H:
suboptimal.frequency = ~0;
break;
case CPUFREQ_RELATION_L:
optimal.frequency = ~0;
break;
}
for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
unsigned int freq = table[i].frequency;
if (freq == CPUFREQ_ENTRY_INVALID)
continue;
if ((freq < policy->min) || (freq > policy->max))
continue;
switch (relation) {
case CPUFREQ_RELATION_H:
if (freq <= target_freq) {
if (freq >= optimal.frequency) {
optimal.frequency = freq;
optimal.index = i;
}
} else {
if (freq <= suboptimal.frequency) {
suboptimal.frequency = freq;
suboptimal.index = i;
}
}
break;
case CPUFREQ_RELATION_L:
if (freq >= target_freq) {
if (freq <= optimal.frequency) {
optimal.frequency = freq;
optimal.index = i;
}
} else {
if (freq >= suboptimal.frequency) {
suboptimal.frequency = freq;
suboptimal.index = i;
}
}
break;
}
}
if (optimal.index > i) {
if (suboptimal.index > i)
return -EINVAL;
*index = suboptimal.index;
} else
*index = optimal.index;
pr_debug("target is %u (%u kHz, %u)\n", *index, table[*index].frequency,
table[*index].index);
return 0;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
static DEFINE_PER_CPU(struct cpufreq_frequency_table *, cpufreq_show_table);
/**
* show_available_freqs - show available frequencies for the specified CPU
*/
static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf)
{
unsigned int i = 0;
unsigned int cpu = policy->cpu;
ssize_t count = 0;
struct cpufreq_frequency_table *table;
if (!per_cpu(cpufreq_show_table, cpu))
return -ENODEV;
table = per_cpu(cpufreq_show_table, cpu);
for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
continue;
count += sprintf(&buf[count], "%d ", table[i].frequency);
}
count += sprintf(&buf[count], "\n");
return count;
}
struct freq_attr cpufreq_freq_attr_scaling_available_freqs = {
.attr = { .name = "scaling_available_frequencies",
.mode = 0444,
},
.show = show_available_freqs,
};
EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
/*
* if you use these, you must assure that the frequency table is valid
* all the time between get_attr and put_attr!
*/
void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
unsigned int cpu)
{
pr_debug("setting show_table for cpu %u to %p\n", cpu, table);
per_cpu(cpufreq_show_table, cpu) = table;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
void cpufreq_frequency_table_put_attr(unsigned int cpu)
{
pr_debug("clearing show_table for cpu %u\n", cpu);
per_cpu(cpufreq_show_table, cpu) = NULL;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy)
{
pr_debug("Updating show_table for new_cpu %u from last_cpu %u\n",
policy->cpu, policy->last_cpu);
per_cpu(cpufreq_show_table, policy->cpu) = per_cpu(cpufreq_show_table,
policy->last_cpu);
per_cpu(cpufreq_show_table, policy->last_cpu) = NULL;
}
struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
{
return per_cpu(cpufreq_show_table, cpu);
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
MODULE_DESCRIPTION("CPUfreq frequency table helpers");
MODULE_LICENSE("GPL");
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