/*
* linux/drivers/cpufreq/cpufreq_userspace.c
*
* Copyright (C) 2001 Russell King
* (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
*
* 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.
*
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/ctype.h>
#include <linux/cpufreq.h>
#include <linux/sysctl.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/sysfs.h>
#include <asm/uaccess.h>
#define CTL_CPU_VARS_SPEED_MAX(cpunr) { \
.ctl_name = CPU_NR_FREQ_MAX, \
.data = &cpu_max_freq[cpunr], \
.procname = "speed-max", \
.maxlen = sizeof(cpu_max_freq[cpunr]),\
.mode = 0444, \
.proc_handler = proc_dointvec, }
#define CTL_CPU_VARS_SPEED_MIN(cpunr) { \
.ctl_name = CPU_NR_FREQ_MIN, \
.data = &cpu_min_freq[cpunr], \
.procname = "speed-min", \
.maxlen = sizeof(cpu_min_freq[cpunr]),\
.mode = 0444, \
.proc_handler = proc_dointvec, }
#define CTL_CPU_VARS_SPEED(cpunr) { \
.ctl_name = CPU_NR_FREQ, \
.procname = "speed", \
.mode = 0644, \
.proc_handler = cpufreq_procctl, \
.strategy = cpufreq_sysctl, \
.extra1 = (void*) (cpunr), }
#define CTL_TABLE_CPU_VARS(cpunr) static ctl_table ctl_cpu_vars_##cpunr[] = {\
CTL_CPU_VARS_SPEED_MAX(cpunr), \
CTL_CPU_VARS_SPEED_MIN(cpunr), \
CTL_CPU_VARS_SPEED(cpunr), \
{ .ctl_name = 0, }, }
/* the ctl_table entry for each CPU */
#define CPU_ENUM(s) { \
.ctl_name = (CPU_NR + s), \
.procname = #s, \
.mode = 0555, \
.child = ctl_cpu_vars_##s }
/**
* A few values needed by the userspace governor
*/
static unsigned int cpu_max_freq[NR_CPUS];
static unsigned int cpu_min_freq[NR_CPUS];
static unsigned int cpu_cur_freq[NR_CPUS];
static unsigned int cpu_is_managed[NR_CPUS];
static struct cpufreq_policy current_policy[NR_CPUS];
static DECLARE_MUTEX (userspace_sem);
/* keep track of frequency transitions */
static int
userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
void *data)
{
struct cpufreq_freqs *freq = data;
/* Don't update cur_freq if CPU is managed and we're
* waking up: else we won't remember what frequency
* we need to set the CPU to.
*/
if (cpu_is_managed[freq->cpu] && (val == CPUFREQ_RESUMECHANGE))
return 0;
cpu_cur_freq[freq->cpu] = freq->new;
return 0;
}
static struct notifier_block userspace_cpufreq_notifier_block = {
.notifier_call = userspace_cpufreq_notifier
};
/**
* cpufreq_set - set the CPU frequency
* @freq: target frequency in kHz
* @cpu: CPU for which the frequency is to be set
*
* Sets the CPU frequency to freq.
*/
int cpufreq_set(unsigned int freq, unsigned int cpu)
{
int ret = -EINVAL;
down(&userspace_sem);
if (!cpu_is_managed[cpu])
goto err;
if (freq < cpu_min_freq[cpu])
freq = cpu_min_freq[cpu];
if (freq > cpu_max_freq[cpu])
freq = cpu_max_freq[cpu];
/*
* We're safe from concurrent calls to ->target() here
* as we hold the userspace_sem lock. If we were calling
* cpufreq_driver_target, a deadlock situation might occur:
* A: cpufreq_set (lock userspace_sem) -> cpufreq_driver_target(lock policy->lock)
* B: cpufreq_set_policy(lock policy->lock) -> __cpufreq_governor -> cpufreq_governor_userspace (lock userspace_sem)
*/
ret = __cpufreq_driver_target(¤t_policy[cpu], freq,
CPUFREQ_RELATION_L);
err:
up(&userspace_sem);
return ret;
}
EXPORT_SYMBOL_GPL(cpufreq_set);
/**
* cpufreq_setmax - set the CPU to the maximum frequency
* @cpu - affected cpu;
*
* Sets the CPU frequency to the maximum frequency supported by
* this CPU.
*/
int cpufreq_setmax(unsigned int cpu)
{
if (!cpu_is_managed[cpu] || !cpu_online(cpu))
return -EINVAL;
return cpufreq_set(cpu_max_freq[cpu], cpu);
}
EXPORT_SYMBOL_GPL(cpufreq_setmax);
#ifdef CONFIG_CPU_FREQ_24_API
#warning The /proc/sys/cpu/ and sysctl interface to cpufreq will be removed from the 2.6. kernel series soon after 2005-01-01
static unsigned int warning_print = 0;
/*********************** cpufreq_sysctl interface ********************/
static int
cpufreq_procctl(ctl_table *ctl, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
char buf[16], *p;
int cpu = (long) ctl->extra1;
unsigned int len, left = *lenp;
if (!left || (*ppos && !write) || !cpu_online(cpu)) {
*lenp = 0;
return 0;
}
if (!warning_print) {
warning_print++;
printk(KERN_INFO "Access to /proc/sys/cpu/ is deprecated and "
"will be removed from (new) 2.6. kernels soon "
"after 2005-01-01\n");
}
if (write) {
unsigned int freq;
len = left;
if (left > sizeof(buf))
left = sizeof(buf);
if (copy_from_user(buf, buffer, left))
return -EFAULT;
buf[sizeof(buf) - 1] = '\0';
freq = simple_strtoul(buf, &p, 0);
cpufreq_set(freq, cpu);
} else {
len = sprintf(buf, "%d\n", cpufreq_get(cpu));
if (len > left)
len = left;
if (copy_to_user(buffer, buf, len))
return -EFAULT;
}
*lenp = len;
*ppos += len;
return 0;
}
static int
cpufreq_sysctl(ctl_table *table, int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen, void **context)
{
int cpu = (long) table->extra1;
if (!cpu_online(cpu))
return -EINVAL;
if (!warning_print) {
warning_print++;
printk(KERN_INFO "Access to /proc/sys/cpu/ is deprecated and "
"will be removed from (new) 2.6. kernels soon "
"after 2005-01-01\n");
}
if (oldval && oldlenp) {
size_t oldlen;
if (get_user(oldlen, oldlenp))
return -EFAULT;
if (oldlen != sizeof(unsigned int))
return -EINVAL;
if (put_user(cpufreq_get(cpu), (unsigned int __user *)oldval) ||
put_user(sizeof(unsigned int), oldlenp))
return -EFAULT;
}
if (newval && newlen) {
unsigned int freq;
if (newlen != sizeof(unsigned int))
return -EINVAL;
if (get_user(freq, (unsigned int __user *)newval))
return -EFAULT;
cpufreq_set(freq, cpu);
}
return 1;
}
/* ctl_table ctl_cpu_vars_{0,1,...,(NR_CPUS-1)} */
/* due to NR_CPUS tweaking, a lot of if/endifs are required, sorry */
CTL_TABLE_CPU_VARS(0);
#if NR_CPUS > 1
CTL_TABLE_CPU_VARS(1);
#endif
#if NR_CPUS > 2
CTL_TABLE_CPU_VARS(2);
#endif
#if NR_CPUS > 3
CTL_TABLE_CPU_VARS(3);
#endif
#if NR_CPUS > 4
CTL_TABLE_CPU_VARS(4);
#endif
#if NR_CPUS > 5
CTL_TABLE_CPU_VARS(5);
#endif
#if NR_CPUS > 6
CTL_TABLE_CPU_VARS(6);
#endif
#if NR_CPUS > 7
CTL_TABLE_CPU_VARS(7);
#endif
#if NR_CPUS > 8
CTL_TABLE_CPU_VARS(8);
#endif
#if NR_CPUS > 9
CTL_TABLE_CPU_VARS(9);
#endif
#if NR_CPUS > 10
CTL_TABLE_CPU_VARS(10);
#endif
#if NR_CPUS > 11
CTL_TABLE_CPU_VARS(11);
#endif
#if NR_CPUS > 12
CTL_TABLE_CPU_VARS(12);
#endif
#if NR_CPUS > 13
CTL_TABLE_CPU_VARS(13);
#endif
#if NR_CPUS > 14
CTL_TABLE_CPU_VARS(14);
#endif
#if NR_CPUS > 15
CTL_TABLE_CPU_VARS(15);
#endif
#if NR_CPUS > 16
CTL_TABLE_CPU_VARS(16);
#endif
#if NR_CPUS > 17
CTL_TABLE_CPU_VARS(17);
#endif
#if NR_CPUS > 18
CTL_TABLE_CPU_VARS(18);
#endif
#if NR_CPUS > 19
CTL_TABLE_CPU_VARS(19);
#endif
#if NR_CPUS > 20
CTL_TABLE_CPU_VARS(20);
#endif
#if NR_CPUS > 21
CTL_TABLE_CPU_VARS(21);
#endif
#if NR_CPUS > 22
CTL_TABLE_CPU_VARS(22);
#endif
#if NR_CPUS > 23
CTL_TABLE_CPU_VARS(23);
#endif
#if NR_CPUS > 24
CTL_TABLE_CPU_VARS(24);
#endif
#if NR_CPUS > 25
CTL_TABLE_CPU_VARS(25);
#endif
#if NR_CPUS > 26
CTL_TABLE_CPU_VARS(26);
#endif
#if NR_CPUS > 27
CTL_TABLE_CPU_VARS(27);
#endif
#if NR_CPUS > 28
CTL_TABLE_CPU_VARS(28);
#endif
#if NR_CPUS > 29
CTL_TABLE_CPU_VARS(29);
#endif
#if NR_CPUS > 30
CTL_TABLE_CPU_VARS(30);
#endif
#if NR_CPUS > 31
CTL_TABLE_CPU_VARS(31);
#endif
#if NR_CPUS > 32
#error please extend CPU enumeration
#endif
/* due to NR_CPUS tweaking, a lot of if/endifs are required, sorry */
static ctl_table ctl_cpu_table[NR_CPUS + 1] = {
CPU_ENUM(0),
#if NR_CPUS > 1
CPU_ENUM(1),
#endif
#if NR_CPUS > 2
CPU_ENUM(2),
#endif
#if NR_CPUS > 3
CPU_ENUM(3),
#endif
#if NR_CPUS > 4
CPU_ENUM(4),
#endif
#if NR_CPUS > 5
CPU_ENUM(5),
#endif
#if NR_CPUS > 6
CPU_ENUM(6),
#endif
#if NR_CPUS > 7
CPU_ENUM(7),
#endif
#if NR_CPUS > 8
CPU_ENUM(8),
#endif
#if NR_CPUS > 9
CPU_ENUM(9),
#endif
#if NR_CPUS > 10
CPU_ENUM(10),
#endif
#if NR_CPUS > 11
CPU_ENUM(11),
#endif
#if NR_CPUS > 12
CPU_ENUM(12),
#endif
#if NR_CPUS > 13
CPU_ENUM(13),
#endif
#if NR_CPUS > 14
CPU_ENUM(14),
#endif
#if NR_CPUS > 15
CPU_ENUM(15),
#endif
#if NR_CPUS > 16
CPU_ENUM(16),
#endif
#if NR_CPUS > 17
CPU_ENUM(17),
#endif
#if NR_CPUS > 18
CPU_ENUM(18),
#endif
#if NR_CPUS > 19
CPU_ENUM(19),
#endif
#if NR_CPUS > 20
CPU_ENUM(20),
#endif
#if NR_CPUS > 21
CPU_ENUM(21),
#endif
#if NR_CPUS > 22
CPU_ENUM(22),
#endif
#if NR_CPUS > 23
CPU_ENUM(23),
#endif
#if NR_CPUS > 24
CPU_ENUM(24),
#endif
#if NR_CPUS > 25
CPU_ENUM(25),
#endif
#if NR_CPUS > 26
CPU_ENUM(26),
#endif
#if NR_CPUS > 27
CPU_ENUM(27),
#endif
#if NR_CPUS > 28
CPU_ENUM(28),
#endif
#if NR_CPUS > 29
CPU_ENUM(29),
#endif
#if NR_CPUS > 30
CPU_ENUM(30),
#endif
#if NR_CPUS > 31
CPU_ENUM(31),
#endif
#if NR_CPUS > 32
#error please extend CPU enumeration
#endif
{
.ctl_name = 0,
}
};
static ctl_table ctl_cpu[2] = {
{
.ctl_name = CTL_CPU,
.procname = "cpu",
.mode = 0555,
.child = ctl_cpu_table,
},
{
.ctl_name = 0,
}
};
struct ctl_table_header *cpufreq_sysctl_table;
static inline void cpufreq_sysctl_init(void)
{
cpufreq_sysctl_table = register_sysctl_table(ctl_cpu, 0);
}
static inline void cpufreq_sysctl_exit(void)
{
unregister_sysctl_table(cpufreq_sysctl_table);
}
#else
#define cpufreq_sysctl_init() do {} while(0)
#define cpufreq_sysctl_exit() do {} while(0)
#endif /* CONFIG_CPU_FREQ_24API */
/************************** sysfs interface ************************/
static ssize_t show_speed (struct cpufreq_policy *policy, char *buf)
{
return sprintf (buf, "%u\n", cpu_cur_freq[policy->cpu]);
}
static ssize_t
store_speed (struct cpufreq_policy *policy, const char *buf, size_t count)
{
unsigned int freq = 0;
unsigned int ret;
ret = sscanf (buf, "%u", &freq);
if (ret != 1)
return -EINVAL;
cpufreq_set(freq, policy->cpu);
return count;
}
static struct freq_attr freq_attr_scaling_setspeed = {
.attr = { .name = "scaling_setspeed", .mode = 0644 },
.show = show_speed,
.store = store_speed,
};
static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
unsigned int event)
{
unsigned int cpu = policy->cpu;
switch (event) {
case CPUFREQ_GOV_START:
if ((!cpu_online(cpu)) || (!try_module_get(THIS_MODULE)))
return -EINVAL;
BUG_ON(!policy->cur);
down(&userspace_sem);
cpu_is_managed[cpu] = 1;
cpu_min_freq[cpu] = policy->min;
cpu_max_freq[cpu] = policy->max;
cpu_cur_freq[cpu] = policy->cur;
sysfs_create_file (&policy->kobj, &freq_attr_scaling_setspeed.attr);
memcpy (¤t_policy[cpu], policy, sizeof(struct cpufreq_policy));
up(&userspace_sem);
break;
case CPUFREQ_GOV_STOP:
down(&userspace_sem);
cpu_is_managed[cpu] = 0;
cpu_min_freq[cpu] = 0;
cpu_max_freq[cpu] = 0;
sysfs_remove_file (&policy->kobj, &freq_attr_scaling_setspeed.attr);
up(&userspace_sem);
module_put(THIS_MODULE);
break;
case CPUFREQ_GOV_LIMITS:
down(&userspace_sem);
cpu_min_freq[cpu] = policy->min;
cpu_max_freq[cpu] = policy->max;
if (policy->max < cpu_cur_freq[cpu])
__cpufreq_driver_target(¤t_policy[cpu], policy->max,
CPUFREQ_RELATION_H);
else if (policy->min > cpu_cur_freq[cpu])
__cpufreq_driver_target(¤t_policy[cpu], policy->min,
CPUFREQ_RELATION_L);
else
__cpufreq_driver_target(¤t_policy[cpu], cpu_cur_freq[cpu],
CPUFREQ_RELATION_L);
memcpy (¤t_policy[cpu], policy, sizeof(struct cpufreq_policy));
up(&userspace_sem);
break;
}
return 0;
}
struct cpufreq_governor cpufreq_gov_userspace = {
.name = "userspace",
.governor = cpufreq_governor_userspace,
.owner = THIS_MODULE,
};
EXPORT_SYMBOL(cpufreq_gov_userspace);
static int __init cpufreq_gov_userspace_init(void)
{
cpufreq_sysctl_init();
cpufreq_register_notifier(&userspace_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
return cpufreq_register_governor(&cpufreq_gov_userspace);
}
static void __exit cpufreq_gov_userspace_exit(void)
{
cpufreq_unregister_governor(&cpufreq_gov_userspace);
cpufreq_unregister_notifier(&userspace_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
cpufreq_sysctl_exit();
}
MODULE_AUTHOR ("Dominik Brodowski <linux@brodo.de>, Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION ("CPUfreq policy governor 'userspace'");
MODULE_LICENSE ("GPL");
fs_initcall(cpufreq_gov_userspace_init);
module_exit(cpufreq_gov_userspace_exit);
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