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