kernel-ark/drivers/cpuidle/sysfs.c
Emese Revfy 52cf25d0ab Driver core: Constify struct sysfs_ops in struct kobj_type
Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:49 -08:00

386 lines
9.6 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/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 sysdev_class *class,
struct sysdev_class_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 sysdev_class *class,
struct sysdev_class_attribute *attr,
char *buf)
{
ssize_t ret;
spin_lock(&cpuidle_driver_lock);
if (cpuidle_curr_driver)
ret = sprintf(buf, "%s\n", cpuidle_curr_driver->name);
else
ret = sprintf(buf, "none\n");
spin_unlock(&cpuidle_driver_lock);
return ret;
}
static ssize_t show_current_governor(struct sysdev_class *class,
struct sysdev_class_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 sysdev_class *class,
struct sysdev_class_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 SYSDEV_CLASS_ATTR(current_driver, 0444, show_current_driver, NULL);
static SYSDEV_CLASS_ATTR(current_governor_ro, 0444, show_current_governor,
NULL);
static struct attribute *cpuclass_default_attrs[] = {
&attr_current_driver.attr,
&attr_current_governor_ro.attr,
NULL
};
static SYSDEV_CLASS_ATTR(available_governors, 0444, show_available_governors,
NULL);
static SYSDEV_CLASS_ATTR(current_governor, 0644, show_current_governor,
store_current_governor);
static struct attribute *cpuclass_switch_attrs[] = {
&attr_available_governors.attr,
&attr_current_driver.attr,
&attr_current_governor.attr,
NULL
};
static struct attribute_group cpuclass_attr_group = {
.attrs = cpuclass_default_attrs,
.name = "cpuidle",
};
/**
* cpuidle_add_class_sysfs - add CPU global sysfs attributes
*/
int cpuidle_add_class_sysfs(struct sysdev_class *cls)
{
if (sysfs_switch)
cpuclass_attr_group.attrs = cpuclass_switch_attrs;
return sysfs_create_group(&cls->kset.kobj, &cpuclass_attr_group);
}
/**
* cpuidle_remove_class_sysfs - remove CPU global sysfs attributes
*/
void cpuidle_remove_class_sysfs(struct sysdev_class *cls)
{
sysfs_remove_group(&cls->kset.kobj, &cpuclass_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 *, 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, 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, char *buf) \
{ \
return sprintf(buf, "%llu\n", state->_name);\
}
#define define_show_state_str_function(_name) \
static ssize_t show_state_##_name(struct cpuidle_state *state, 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 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_attr * cattr = attr_to_stateattr(attr);
if (cattr->show)
ret = cattr->show(state, 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 void inline 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;
/* 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 = &device->states[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
* @sysdev: the target device
*/
int cpuidle_add_sysfs(struct sys_device *sysdev)
{
int cpu = sysdev->id;
struct cpuidle_device *dev;
int error;
dev = per_cpu(cpuidle_devices, cpu);
error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &sysdev->kobj,
"cpuidle");
if (!error)
kobject_uevent(&dev->kobj, KOBJ_ADD);
return error;
}
/**
* cpuidle_remove_sysfs - deletes a sysfs instance on the target device
* @sysdev: the target device
*/
void cpuidle_remove_sysfs(struct sys_device *sysdev)
{
int cpu = sysdev->id;
struct cpuidle_device *dev;
dev = per_cpu(cpuidle_devices, cpu);
kobject_put(&dev->kobj);
}