linux/drivers/cpufreq/cpufreq_stats.c
Linus Torvalds b7356abb9f Power management and ACPI fixes for 3.11-rc2
- Two cpufreq commits from the 3.10 cycle introduced regressions.
   The first of them was buggy (it did way much more than it needed
   to do) and the second one attempted to fix an issue introduced by
   the first one.  Fixes from Srivatsa S Bhat revert both.
 
 - If autosleep triggers during system shutdown and the shutdown
   callbacks of some device drivers have been called already, it may
   crash the system.  Fix from Liu Shuo prevents that from happening
   by making try_to_suspend() check system_state.
 
 - The ACPI memory hotplug driver doesn't clear its driver_data on
   errors which may cause a NULL poiter dereference to happen later.
   Fix from Toshi Kani.
 
 - The ACPI namespace scanning code should not try to attach scan
   handlers to device objects that have them already, which may confuse
   things quite a bit, and it should rescan the whole namespace branch
   starting at the given node after receiving a bus check notify event
   even if the device at that particular node has been discovered
   already.  Fixes from Rafael J Wysocki.
 
 - New ACPI video blacklist entry for a system whose initial backlight
   setting from the BIOS doesn't make sense.  From Lan Tianyu.
 
 - Garbage string output avoindance for ACPI PNP from Liu Shuo.
 
 - Two Kconfig fixes for issues introduced recently in the s3c24xx
   cpufreq driver (when moving the driver to drivers/cpufreq) from
   Paul Bolle.
 
 - Trivial comment fix in pm_wakeup.h from Chanwoo Choi.
 
 /
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Merge tag 'pm+acpi-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are fixes collected over the last week, most importnatly two
  cpufreq reverts fixing regressions introduced in 3.10, an autoseelp
  fix preventing systems using it from crashing during shutdown and two
  ACPI scan fixes related to hotplug.

  Specifics:

   - Two cpufreq commits from the 3.10 cycle introduced regressions.
     The first of them was buggy (it did way much more than it needed to
     do) and the second one attempted to fix an issue introduced by the
     first one.  Fixes from Srivatsa S Bhat revert both.

   - If autosleep triggers during system shutdown and the shutdown
     callbacks of some device drivers have been called already, it may
     crash the system.  Fix from Liu Shuo prevents that from happening
     by making try_to_suspend() check system_state.

   - The ACPI memory hotplug driver doesn't clear its driver_data on
     errors which may cause a NULL poiter dereference to happen later.
     Fix from Toshi Kani.

   - The ACPI namespace scanning code should not try to attach scan
     handlers to device objects that have them already, which may
     confuse things quite a bit, and it should rescan the whole
     namespace branch starting at the given node after receiving a bus
     check notify event even if the device at that particular node has
     been discovered already.  Fixes from Rafael J Wysocki.

   - New ACPI video blacklist entry for a system whose initial backlight
     setting from the BIOS doesn't make sense.  From Lan Tianyu.

   - Garbage string output avoindance for ACPI PNP from Liu Shuo.

   - Two Kconfig fixes for issues introduced recently in the s3c24xx
     cpufreq driver (when moving the driver to drivers/cpufreq) from
     Paul Bolle.

   - Trivial comment fix in pm_wakeup.h from Chanwoo Choi"

* tag 'pm+acpi-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / video: ignore BIOS initial backlight value for Fujitsu E753
  PNP / ACPI: avoid garbage in resource name
  cpufreq: Revert commit 2f7021a8 to fix CPU hotplug regression
  cpufreq: s3c24xx: fix "depends on ARM_S3C24XX" in Kconfig
  cpufreq: s3c24xx: rename CONFIG_CPU_FREQ_S3C24XX_DEBUGFS
  PM / Sleep: Fix comment typo in pm_wakeup.h
  PM / Sleep: avoid 'autosleep' in shutdown progress
  cpufreq: Revert commit a66b2e to fix suspend/resume regression
  ACPI / memhotplug: Fix a stale pointer in error path
  ACPI / scan: Always call acpi_bus_scan() for bus check notifications
  ACPI / scan: Do not try to attach scan handlers to devices having them
2013-07-19 09:59:06 -07:00

431 lines
10 KiB
C

/*
* drivers/cpufreq/cpufreq_stats.c
*
* Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
* (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
*
* 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/kernel.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <linux/sysfs.h>
#include <linux/cpufreq.h>
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/percpu.h>
#include <linux/kobject.h>
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <asm/cputime.h>
static spinlock_t cpufreq_stats_lock;
struct cpufreq_stats {
unsigned int cpu;
unsigned int total_trans;
unsigned long long last_time;
unsigned int max_state;
unsigned int state_num;
unsigned int last_index;
u64 *time_in_state;
unsigned int *freq_table;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
unsigned int *trans_table;
#endif
};
static DEFINE_PER_CPU(struct cpufreq_stats *, cpufreq_stats_table);
struct cpufreq_stats_attribute {
struct attribute attr;
ssize_t(*show) (struct cpufreq_stats *, char *);
};
static int cpufreq_stats_update(unsigned int cpu)
{
struct cpufreq_stats *stat;
unsigned long long cur_time;
cur_time = get_jiffies_64();
spin_lock(&cpufreq_stats_lock);
stat = per_cpu(cpufreq_stats_table, cpu);
if (stat->time_in_state)
stat->time_in_state[stat->last_index] +=
cur_time - stat->last_time;
stat->last_time = cur_time;
spin_unlock(&cpufreq_stats_lock);
return 0;
}
static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
{
struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
if (!stat)
return 0;
return sprintf(buf, "%d\n",
per_cpu(cpufreq_stats_table, stat->cpu)->total_trans);
}
static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
{
ssize_t len = 0;
int i;
struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
if (!stat)
return 0;
cpufreq_stats_update(stat->cpu);
for (i = 0; i < stat->state_num; i++) {
len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
(unsigned long long)
cputime64_to_clock_t(stat->time_in_state[i]));
}
return len;
}
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
{
ssize_t len = 0;
int i, j;
struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
if (!stat)
return 0;
cpufreq_stats_update(stat->cpu);
len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
len += snprintf(buf + len, PAGE_SIZE - len, " : ");
for (i = 0; i < stat->state_num; i++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
stat->freq_table[i]);
}
if (len >= PAGE_SIZE)
return PAGE_SIZE;
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
for (i = 0; i < stat->state_num; i++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
stat->freq_table[i]);
for (j = 0; j < stat->state_num; j++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
stat->trans_table[i*stat->max_state+j]);
}
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
}
if (len >= PAGE_SIZE)
return PAGE_SIZE;
return len;
}
cpufreq_freq_attr_ro(trans_table);
#endif
cpufreq_freq_attr_ro(total_trans);
cpufreq_freq_attr_ro(time_in_state);
static struct attribute *default_attrs[] = {
&total_trans.attr,
&time_in_state.attr,
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
&trans_table.attr,
#endif
NULL
};
static struct attribute_group stats_attr_group = {
.attrs = default_attrs,
.name = "stats"
};
static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
{
int index;
for (index = 0; index < stat->max_state; index++)
if (stat->freq_table[index] == freq)
return index;
return -1;
}
/* should be called late in the CPU removal sequence so that the stats
* memory is still available in case someone tries to use it.
*/
static void cpufreq_stats_free_table(unsigned int cpu)
{
struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
if (stat) {
pr_debug("%s: Free stat table\n", __func__);
kfree(stat->time_in_state);
kfree(stat);
per_cpu(cpufreq_stats_table, cpu) = NULL;
}
}
/* must be called early in the CPU removal sequence (before
* cpufreq_remove_dev) so that policy is still valid.
*/
static void cpufreq_stats_free_sysfs(unsigned int cpu)
{
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
if (!policy)
return;
if (!cpufreq_frequency_get_table(cpu))
goto put_ref;
if (!policy_is_shared(policy)) {
pr_debug("%s: Free sysfs stat\n", __func__);
sysfs_remove_group(&policy->kobj, &stats_attr_group);
}
put_ref:
cpufreq_cpu_put(policy);
}
static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table)
{
unsigned int i, j, count = 0, ret = 0;
struct cpufreq_stats *stat;
struct cpufreq_policy *data;
unsigned int alloc_size;
unsigned int cpu = policy->cpu;
if (per_cpu(cpufreq_stats_table, cpu))
return -EBUSY;
stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
if ((stat) == NULL)
return -ENOMEM;
data = cpufreq_cpu_get(cpu);
if (data == NULL) {
ret = -EINVAL;
goto error_get_fail;
}
ret = sysfs_create_group(&data->kobj, &stats_attr_group);
if (ret)
goto error_out;
stat->cpu = cpu;
per_cpu(cpufreq_stats_table, cpu) = stat;
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
unsigned int freq = table[i].frequency;
if (freq == CPUFREQ_ENTRY_INVALID)
continue;
count++;
}
alloc_size = count * sizeof(int) + count * sizeof(u64);
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
alloc_size += count * count * sizeof(int);
#endif
stat->max_state = count;
stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
if (!stat->time_in_state) {
ret = -ENOMEM;
goto error_out;
}
stat->freq_table = (unsigned int *)(stat->time_in_state + count);
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
stat->trans_table = stat->freq_table + count;
#endif
j = 0;
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
unsigned int freq = table[i].frequency;
if (freq == CPUFREQ_ENTRY_INVALID)
continue;
if (freq_table_get_index(stat, freq) == -1)
stat->freq_table[j++] = freq;
}
stat->state_num = j;
spin_lock(&cpufreq_stats_lock);
stat->last_time = get_jiffies_64();
stat->last_index = freq_table_get_index(stat, policy->cur);
spin_unlock(&cpufreq_stats_lock);
cpufreq_cpu_put(data);
return 0;
error_out:
cpufreq_cpu_put(data);
error_get_fail:
kfree(stat);
per_cpu(cpufreq_stats_table, cpu) = NULL;
return ret;
}
static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
{
struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
policy->last_cpu);
pr_debug("Updating stats_table for new_cpu %u from last_cpu %u\n",
policy->cpu, policy->last_cpu);
per_cpu(cpufreq_stats_table, policy->cpu) = per_cpu(cpufreq_stats_table,
policy->last_cpu);
per_cpu(cpufreq_stats_table, policy->last_cpu) = NULL;
stat->cpu = policy->cpu;
}
static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
unsigned long val, void *data)
{
int ret;
struct cpufreq_policy *policy = data;
struct cpufreq_frequency_table *table;
unsigned int cpu = policy->cpu;
if (val == CPUFREQ_UPDATE_POLICY_CPU) {
cpufreq_stats_update_policy_cpu(policy);
return 0;
}
if (val != CPUFREQ_NOTIFY)
return 0;
table = cpufreq_frequency_get_table(cpu);
if (!table)
return 0;
ret = cpufreq_stats_create_table(policy, table);
if (ret)
return ret;
return 0;
}
static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
unsigned long val, void *data)
{
struct cpufreq_freqs *freq = data;
struct cpufreq_stats *stat;
int old_index, new_index;
if (val != CPUFREQ_POSTCHANGE)
return 0;
stat = per_cpu(cpufreq_stats_table, freq->cpu);
if (!stat)
return 0;
old_index = stat->last_index;
new_index = freq_table_get_index(stat, freq->new);
/* We can't do stat->time_in_state[-1]= .. */
if (old_index == -1 || new_index == -1)
return 0;
cpufreq_stats_update(freq->cpu);
if (old_index == new_index)
return 0;
spin_lock(&cpufreq_stats_lock);
stat->last_index = new_index;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
stat->trans_table[old_index * stat->max_state + new_index]++;
#endif
stat->total_trans++;
spin_unlock(&cpufreq_stats_lock);
return 0;
}
static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
unsigned long action,
void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
cpufreq_update_policy(cpu);
break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
cpufreq_stats_free_sysfs(cpu);
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
cpufreq_stats_free_table(cpu);
break;
}
return NOTIFY_OK;
}
/* priority=1 so this will get called before cpufreq_remove_dev */
static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
.notifier_call = cpufreq_stat_cpu_callback,
.priority = 1,
};
static struct notifier_block notifier_policy_block = {
.notifier_call = cpufreq_stat_notifier_policy
};
static struct notifier_block notifier_trans_block = {
.notifier_call = cpufreq_stat_notifier_trans
};
static int __init cpufreq_stats_init(void)
{
int ret;
unsigned int cpu;
spin_lock_init(&cpufreq_stats_lock);
ret = cpufreq_register_notifier(&notifier_policy_block,
CPUFREQ_POLICY_NOTIFIER);
if (ret)
return ret;
register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
for_each_online_cpu(cpu)
cpufreq_update_policy(cpu);
ret = cpufreq_register_notifier(&notifier_trans_block,
CPUFREQ_TRANSITION_NOTIFIER);
if (ret) {
cpufreq_unregister_notifier(&notifier_policy_block,
CPUFREQ_POLICY_NOTIFIER);
unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
for_each_online_cpu(cpu)
cpufreq_stats_free_table(cpu);
return ret;
}
return 0;
}
static void __exit cpufreq_stats_exit(void)
{
unsigned int cpu;
cpufreq_unregister_notifier(&notifier_policy_block,
CPUFREQ_POLICY_NOTIFIER);
cpufreq_unregister_notifier(&notifier_trans_block,
CPUFREQ_TRANSITION_NOTIFIER);
unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
for_each_online_cpu(cpu) {
cpufreq_stats_free_table(cpu);
cpufreq_stats_free_sysfs(cpu);
}
}
MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");
MODULE_DESCRIPTION("'cpufreq_stats' - A driver to export cpufreq stats "
"through sysfs filesystem");
MODULE_LICENSE("GPL");
module_init(cpufreq_stats_init);
module_exit(cpufreq_stats_exit);