linux/drivers/cpuidle/sysfs.c
Kay Sievers 8a25a2fd12 cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystem
This moves the 'cpu sysdev_class' over to a regular 'cpu' subsystem
and converts the devices to regular devices. The sysdev drivers are
implemented as subsystem interfaces now.

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Userspace relies on events and generic sysfs subsystem infrastructure
from sysdev devices, which are made available with this conversion.

Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-12-21 14:29:42 -08:00

394 lines
9.9 KiB
C

/*
* sysfs.c - sysfs support
*
* (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
*
* This code is licenced under the GPL.
*/
#include <linux/kernel.h>
#include <linux/cpuidle.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include "cpuidle.h"
static unsigned int sysfs_switch;
static int __init cpuidle_sysfs_setup(char *unused)
{
sysfs_switch = 1;
return 1;
}
__setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
static ssize_t show_available_governors(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t i = 0;
struct cpuidle_governor *tmp;
mutex_lock(&cpuidle_lock);
list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
goto out;
i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
}
out:
i+= sprintf(&buf[i], "\n");
mutex_unlock(&cpuidle_lock);
return i;
}
static ssize_t show_current_driver(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret;
struct cpuidle_driver *cpuidle_driver = cpuidle_get_driver();
spin_lock(&cpuidle_driver_lock);
if (cpuidle_driver)
ret = sprintf(buf, "%s\n", cpuidle_driver->name);
else
ret = sprintf(buf, "none\n");
spin_unlock(&cpuidle_driver_lock);
return ret;
}
static ssize_t show_current_governor(struct device *dev,
struct device_attribute *attr,
char *buf)
{
ssize_t ret;
mutex_lock(&cpuidle_lock);
if (cpuidle_curr_governor)
ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
else
ret = sprintf(buf, "none\n");
mutex_unlock(&cpuidle_lock);
return ret;
}
static ssize_t store_current_governor(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
char gov_name[CPUIDLE_NAME_LEN];
int ret = -EINVAL;
size_t len = count;
struct cpuidle_governor *gov;
if (!len || len >= sizeof(gov_name))
return -EINVAL;
memcpy(gov_name, buf, len);
gov_name[len] = '\0';
if (gov_name[len - 1] == '\n')
gov_name[--len] = '\0';
mutex_lock(&cpuidle_lock);
list_for_each_entry(gov, &cpuidle_governors, governor_list) {
if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
ret = cpuidle_switch_governor(gov);
break;
}
}
mutex_unlock(&cpuidle_lock);
if (ret)
return ret;
else
return count;
}
static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
static struct attribute *cpuidle_default_attrs[] = {
&dev_attr_current_driver.attr,
&dev_attr_current_governor_ro.attr,
NULL
};
static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
static DEVICE_ATTR(current_governor, 0644, show_current_governor,
store_current_governor);
static struct attribute *cpuidle_switch_attrs[] = {
&dev_attr_available_governors.attr,
&dev_attr_current_driver.attr,
&dev_attr_current_governor.attr,
NULL
};
static struct attribute_group cpuidle_attr_group = {
.attrs = cpuidle_default_attrs,
.name = "cpuidle",
};
/**
* cpuidle_add_interface - add CPU global sysfs attributes
*/
int cpuidle_add_interface(struct device *dev)
{
if (sysfs_switch)
cpuidle_attr_group.attrs = cpuidle_switch_attrs;
return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
}
/**
* cpuidle_remove_interface - remove CPU global sysfs attributes
*/
void cpuidle_remove_interface(struct device *dev)
{
sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
}
struct cpuidle_attr {
struct attribute attr;
ssize_t (*show)(struct cpuidle_device *, char *);
ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
};
#define define_one_ro(_name, show) \
static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
#define define_one_rw(_name, show, store) \
static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
#define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
#define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
{
int ret = -EIO;
struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
if (cattr->show) {
mutex_lock(&cpuidle_lock);
ret = cattr->show(dev, buf);
mutex_unlock(&cpuidle_lock);
}
return ret;
}
static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
const char * buf, size_t count)
{
int ret = -EIO;
struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
if (cattr->store) {
mutex_lock(&cpuidle_lock);
ret = cattr->store(dev, buf, count);
mutex_unlock(&cpuidle_lock);
}
return ret;
}
static const struct sysfs_ops cpuidle_sysfs_ops = {
.show = cpuidle_show,
.store = cpuidle_store,
};
static void cpuidle_sysfs_release(struct kobject *kobj)
{
struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
complete(&dev->kobj_unregister);
}
static struct kobj_type ktype_cpuidle = {
.sysfs_ops = &cpuidle_sysfs_ops,
.release = cpuidle_sysfs_release,
};
struct cpuidle_state_attr {
struct attribute attr;
ssize_t (*show)(struct cpuidle_state *, \
struct cpuidle_state_usage *, char *);
ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
};
#define define_one_state_ro(_name, show) \
static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
#define define_show_state_function(_name) \
static ssize_t show_state_##_name(struct cpuidle_state *state, \
struct cpuidle_state_usage *state_usage, char *buf) \
{ \
return sprintf(buf, "%u\n", state->_name);\
}
#define define_show_state_ull_function(_name) \
static ssize_t show_state_##_name(struct cpuidle_state *state, \
struct cpuidle_state_usage *state_usage, char *buf) \
{ \
return sprintf(buf, "%llu\n", state_usage->_name);\
}
#define define_show_state_str_function(_name) \
static ssize_t show_state_##_name(struct cpuidle_state *state, \
struct cpuidle_state_usage *state_usage, char *buf) \
{ \
if (state->_name[0] == '\0')\
return sprintf(buf, "<null>\n");\
return sprintf(buf, "%s\n", state->_name);\
}
define_show_state_function(exit_latency)
define_show_state_function(power_usage)
define_show_state_ull_function(usage)
define_show_state_ull_function(time)
define_show_state_str_function(name)
define_show_state_str_function(desc)
define_one_state_ro(name, show_state_name);
define_one_state_ro(desc, show_state_desc);
define_one_state_ro(latency, show_state_exit_latency);
define_one_state_ro(power, show_state_power_usage);
define_one_state_ro(usage, show_state_usage);
define_one_state_ro(time, show_state_time);
static struct attribute *cpuidle_state_default_attrs[] = {
&attr_name.attr,
&attr_desc.attr,
&attr_latency.attr,
&attr_power.attr,
&attr_usage.attr,
&attr_time.attr,
NULL
};
#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
#define kobj_to_state(k) (kobj_to_state_obj(k)->state)
#define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
#define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
static ssize_t cpuidle_state_show(struct kobject * kobj,
struct attribute * attr ,char * buf)
{
int ret = -EIO;
struct cpuidle_state *state = kobj_to_state(kobj);
struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
if (cattr->show)
ret = cattr->show(state, state_usage, buf);
return ret;
}
static const struct sysfs_ops cpuidle_state_sysfs_ops = {
.show = cpuidle_state_show,
};
static void cpuidle_state_sysfs_release(struct kobject *kobj)
{
struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
complete(&state_obj->kobj_unregister);
}
static struct kobj_type ktype_state_cpuidle = {
.sysfs_ops = &cpuidle_state_sysfs_ops,
.default_attrs = cpuidle_state_default_attrs,
.release = cpuidle_state_sysfs_release,
};
static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
{
kobject_put(&device->kobjs[i]->kobj);
wait_for_completion(&device->kobjs[i]->kobj_unregister);
kfree(device->kobjs[i]);
device->kobjs[i] = NULL;
}
/**
* cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
* @device: the target device
*/
int cpuidle_add_state_sysfs(struct cpuidle_device *device)
{
int i, ret = -ENOMEM;
struct cpuidle_state_kobj *kobj;
struct cpuidle_driver *drv = cpuidle_get_driver();
/* state statistics */
for (i = 0; i < device->state_count; i++) {
kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
if (!kobj)
goto error_state;
kobj->state = &drv->states[i];
kobj->state_usage = &device->states_usage[i];
init_completion(&kobj->kobj_unregister);
ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle, &device->kobj,
"state%d", i);
if (ret) {
kfree(kobj);
goto error_state;
}
kobject_uevent(&kobj->kobj, KOBJ_ADD);
device->kobjs[i] = kobj;
}
return 0;
error_state:
for (i = i - 1; i >= 0; i--)
cpuidle_free_state_kobj(device, i);
return ret;
}
/**
* cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
* @device: the target device
*/
void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
{
int i;
for (i = 0; i < device->state_count; i++)
cpuidle_free_state_kobj(device, i);
}
/**
* cpuidle_add_sysfs - creates a sysfs instance for the target device
* @dev: the target device
*/
int cpuidle_add_sysfs(struct device *cpu_dev)
{
int cpu = cpu_dev->id;
struct cpuidle_device *dev;
int error;
dev = per_cpu(cpuidle_devices, cpu);
error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
"cpuidle");
if (!error)
kobject_uevent(&dev->kobj, KOBJ_ADD);
return error;
}
/**
* cpuidle_remove_sysfs - deletes a sysfs instance on the target device
* @dev: the target device
*/
void cpuidle_remove_sysfs(struct device *cpu_dev)
{
int cpu = cpu_dev->id;
struct cpuidle_device *dev;
dev = per_cpu(cpuidle_devices, cpu);
kobject_put(&dev->kobj);
}