kernel-ark/drivers/cpufreq/freq_table.c
Tejun Heo 7b595756ec sysfs: kill unnecessary attribute->owner
sysfs is now completely out of driver/module lifetime game.  After
deletion, a sysfs node doesn't access anything outside sysfs proper,
so there's no reason to hold onto the attribute owners.  Note that
often the wrong modules were accounted for as owners leading to
accessing removed modules.

This patch kills now unnecessary attribute->owner.  Note that with
this change, userland holding a sysfs node does not prevent the
backing module from being unloaded.

For more info regarding lifetime rule cleanup, please read the
following message.

  http://article.gmane.org/gmane.linux.kernel/510293

(tweaked by Greg to not delete the field just yet, to make it easier to
merge things properly.)

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-11 16:09:06 -07:00

235 lines
5.8 KiB
C

/*
* linux/drivers/cpufreq/freq_table.c
*
* Copyright (C) 2002 - 2003 Dominik Brodowski
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#define dprintk(msg...) \
cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "freq-table", msg)
/*********************************************************************
* 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) {
dprintk("table entry %u is invalid, skipping\n", i);
continue;
}
dprintk("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;
dprintk("request for verification of policy (%u - %u kHz) for cpu %u\n",
policy->min, policy->max, policy->cpu);
if (!cpu_online(policy->cpu))
return -EINVAL;
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);
dprintk("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;
dprintk("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;
}
if (!cpu_online(policy->cpu))
return -EINVAL;
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;
dprintk("target is %u (%u kHz, %u)\n", *index, table[*index].frequency,
table[*index].index);
return 0;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
static struct cpufreq_frequency_table *show_table[NR_CPUS];
/**
* show_scaling_governor - show the current policy 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 (!show_table[cpu])
return -ENODEV;
table = 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)
{
dprintk("setting show_table for cpu %u to %p\n", cpu, table);
show_table[cpu] = table;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
void cpufreq_frequency_table_put_attr(unsigned int cpu)
{
dprintk("clearing show_table for cpu %u\n", cpu);
show_table[cpu] = NULL;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
{
return 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");