linux/drivers/cpuidle/sysfs.c
Lina Iyer f49735f497 cpuidle: record state entry rejection statistics
CPUs may fail to enter the chosen idle state if there was a
pending interrupt, causing the cpuidle driver to return an error
value.

Record that and export it via sysfs along with the other idle state
statistics.

This could prove useful in understanding behavior of the governor
and the system during usecases that involve multiple CPUs.

Signed-off-by: Lina Iyer <ilina@codeaurora.org>
[ rjw: Changelog and documentation edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-23 14:10:31 +02:00

736 lines
19 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 <linux/completion.h>
#include <linux/capability.h>
#include <linux/device.h>
#include <linux/kobject.h>
#include "cpuidle.h"
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 - (CPUIDLE_NAME_LEN + 2)))
goto out;
i += scnprintf(&buf[i], CPUIDLE_NAME_LEN + 1, "%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 *drv;
spin_lock(&cpuidle_driver_lock);
drv = cpuidle_get_driver();
if (drv)
ret = sprintf(buf, "%s\n", drv->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 + 1];
int ret;
struct cpuidle_governor *gov;
ret = sscanf(buf, "%" __stringify(CPUIDLE_NAME_LEN) "s", gov_name);
if (ret != 1)
return -EINVAL;
mutex_lock(&cpuidle_lock);
ret = -EINVAL;
list_for_each_entry(gov, &cpuidle_governors, governor_list) {
if (!strncmp(gov->name, gov_name, CPUIDLE_NAME_LEN)) {
ret = cpuidle_switch_governor(gov);
break;
}
}
mutex_unlock(&cpuidle_lock);
return ret ? ret : count;
}
static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
static DEVICE_ATTR(current_governor, 0644, show_current_governor,
store_current_governor);
static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
static struct attribute *cpuidle_attrs[] = {
&dev_attr_available_governors.attr,
&dev_attr_current_driver.attr,
&dev_attr_current_governor.attr,
&dev_attr_current_governor_ro.attr,
NULL
};
static struct attribute_group cpuidle_attr_group = {
.attrs = cpuidle_attrs,
.name = "cpuidle",
};
/**
* cpuidle_add_interface - add CPU global sysfs attributes
* @dev: the target device
*/
int cpuidle_add_interface(struct device *dev)
{
return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
}
/**
* cpuidle_remove_interface - remove CPU global sysfs attributes
* @dev: the target device
*/
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 attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
struct cpuidle_device_kobj {
struct cpuidle_device *dev;
struct completion kobj_unregister;
struct kobject kobj;
};
static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
{
struct cpuidle_device_kobj *kdev =
container_of(kobj, struct cpuidle_device_kobj, kobj);
return kdev->dev;
}
static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
char *buf)
{
int ret = -EIO;
struct cpuidle_device *dev = to_cpuidle_device(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 = to_cpuidle_device(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_kobj *kdev =
container_of(kobj, struct cpuidle_device_kobj, kobj);
complete(&kdev->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 *, \
struct cpuidle_state_usage *, 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_one_state_rw(_name, show, store) \
static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
#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 define_show_state_time_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", ktime_to_us(state->_name##_ns)); \
}
define_show_state_time_function(exit_latency)
define_show_state_time_function(target_residency)
define_show_state_function(power_usage)
define_show_state_ull_function(usage)
define_show_state_ull_function(rejected)
define_show_state_str_function(name)
define_show_state_str_function(desc)
define_show_state_ull_function(above)
define_show_state_ull_function(below)
static ssize_t show_state_time(struct cpuidle_state *state,
struct cpuidle_state_usage *state_usage,
char *buf)
{
return sprintf(buf, "%llu\n", ktime_to_us(state_usage->time_ns));
}
static ssize_t show_state_disable(struct cpuidle_state *state,
struct cpuidle_state_usage *state_usage,
char *buf)
{
return sprintf(buf, "%llu\n",
state_usage->disable & CPUIDLE_STATE_DISABLED_BY_USER);
}
static ssize_t store_state_disable(struct cpuidle_state *state,
struct cpuidle_state_usage *state_usage,
const char *buf, size_t size)
{
unsigned int value;
int err;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = kstrtouint(buf, 0, &value);
if (err)
return err;
if (value)
state_usage->disable |= CPUIDLE_STATE_DISABLED_BY_USER;
else
state_usage->disable &= ~CPUIDLE_STATE_DISABLED_BY_USER;
return size;
}
static ssize_t show_state_default_status(struct cpuidle_state *state,
struct cpuidle_state_usage *state_usage,
char *buf)
{
return sprintf(buf, "%s\n",
state->flags & CPUIDLE_FLAG_OFF ? "disabled" : "enabled");
}
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(residency, show_state_target_residency);
define_one_state_ro(power, show_state_power_usage);
define_one_state_ro(usage, show_state_usage);
define_one_state_ro(rejected, show_state_rejected);
define_one_state_ro(time, show_state_time);
define_one_state_rw(disable, show_state_disable, store_state_disable);
define_one_state_ro(above, show_state_above);
define_one_state_ro(below, show_state_below);
define_one_state_ro(default_status, show_state_default_status);
static struct attribute *cpuidle_state_default_attrs[] = {
&attr_name.attr,
&attr_desc.attr,
&attr_latency.attr,
&attr_residency.attr,
&attr_power.attr,
&attr_usage.attr,
&attr_rejected.attr,
&attr_time.attr,
&attr_disable.attr,
&attr_above.attr,
&attr_below.attr,
&attr_default_status.attr,
NULL
};
struct cpuidle_state_kobj {
struct cpuidle_state *state;
struct cpuidle_state_usage *state_usage;
struct completion kobj_unregister;
struct kobject kobj;
struct cpuidle_device *device;
};
#ifdef CONFIG_SUSPEND
#define define_show_state_s2idle_ull_function(_name) \
static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
struct cpuidle_state_usage *state_usage, \
char *buf) \
{ \
return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
}
define_show_state_s2idle_ull_function(usage);
define_show_state_s2idle_ull_function(time);
#define define_one_state_s2idle_ro(_name, show) \
static struct cpuidle_state_attr attr_s2idle_##_name = \
__ATTR(_name, 0444, show, NULL)
define_one_state_s2idle_ro(usage, show_state_s2idle_usage);
define_one_state_s2idle_ro(time, show_state_s2idle_time);
static struct attribute *cpuidle_state_s2idle_attrs[] = {
&attr_s2idle_usage.attr,
&attr_s2idle_time.attr,
NULL
};
static const struct attribute_group cpuidle_state_s2idle_group = {
.name = "s2idle",
.attrs = cpuidle_state_s2idle_attrs,
};
static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
{
int ret;
if (!kobj->state->enter_s2idle)
return;
ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);
if (ret)
pr_debug("%s: sysfs attribute group not created\n", __func__);
}
static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
{
if (kobj->state->enter_s2idle)
sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);
}
#else
static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
#endif /* CONFIG_SUSPEND */
#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 kobj_to_device(k) (kobj_to_state_obj(k)->device)
#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 ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
const char *buf, size_t size)
{
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);
struct cpuidle_device *dev = kobj_to_device(kobj);
if (cattr->store)
ret = cattr->store(state, state_usage, buf, size);
/* reset poll time cache */
dev->poll_limit_ns = 0;
return ret;
}
static const struct sysfs_ops cpuidle_state_sysfs_ops = {
.show = cpuidle_state_show,
.store = cpuidle_state_store,
};
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)
{
cpuidle_remove_s2idle_attr_group(device->kobjs[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_state_sysfs - adds cpuidle states sysfs attributes
* @device: the target device
*/
static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
{
int i, ret = -ENOMEM;
struct cpuidle_state_kobj *kobj;
struct cpuidle_device_kobj *kdev = device->kobj_dev;
struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
/* state statistics */
for (i = 0; i < drv->state_count; i++) {
kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
if (!kobj) {
ret = -ENOMEM;
goto error_state;
}
kobj->state = &drv->states[i];
kobj->state_usage = &device->states_usage[i];
kobj->device = device;
init_completion(&kobj->kobj_unregister);
ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
&kdev->kobj, "state%d", i);
if (ret) {
kobject_put(&kobj->kobj);
goto error_state;
}
cpuidle_add_s2idle_attr_group(kobj);
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 the cpuidle states sysfs attributes
* @device: the target device
*/
static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
{
struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
int i;
for (i = 0; i < drv->state_count; i++)
cpuidle_free_state_kobj(device, i);
}
#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
#define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
#define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
#define define_one_driver_ro(_name, show) \
static struct cpuidle_driver_attr attr_driver_##_name = \
__ATTR(_name, 0444, show, NULL)
struct cpuidle_driver_kobj {
struct cpuidle_driver *drv;
struct completion kobj_unregister;
struct kobject kobj;
};
struct cpuidle_driver_attr {
struct attribute attr;
ssize_t (*show)(struct cpuidle_driver *, char *);
ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
};
static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
{
ssize_t ret;
spin_lock(&cpuidle_driver_lock);
ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
spin_unlock(&cpuidle_driver_lock);
return ret;
}
static void cpuidle_driver_sysfs_release(struct kobject *kobj)
{
struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
complete(&driver_kobj->kobj_unregister);
}
static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
char *buf)
{
int ret = -EIO;
struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
if (dattr->show)
ret = dattr->show(driver_kobj->drv, buf);
return ret;
}
static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
const char *buf, size_t size)
{
int ret = -EIO;
struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
if (dattr->store)
ret = dattr->store(driver_kobj->drv, buf, size);
return ret;
}
define_one_driver_ro(name, show_driver_name);
static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
.show = cpuidle_driver_show,
.store = cpuidle_driver_store,
};
static struct attribute *cpuidle_driver_default_attrs[] = {
&attr_driver_name.attr,
NULL
};
static struct kobj_type ktype_driver_cpuidle = {
.sysfs_ops = &cpuidle_driver_sysfs_ops,
.default_attrs = cpuidle_driver_default_attrs,
.release = cpuidle_driver_sysfs_release,
};
/**
* cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
* @dev: the target device
*/
static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
{
struct cpuidle_driver_kobj *kdrv;
struct cpuidle_device_kobj *kdev = dev->kobj_dev;
struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
int ret;
kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
if (!kdrv)
return -ENOMEM;
kdrv->drv = drv;
init_completion(&kdrv->kobj_unregister);
ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
&kdev->kobj, "driver");
if (ret) {
kobject_put(&kdrv->kobj);
return ret;
}
kobject_uevent(&kdrv->kobj, KOBJ_ADD);
dev->kobj_driver = kdrv;
return ret;
}
/**
* cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
* @dev: the target device
*/
static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
{
struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
kobject_put(&kdrv->kobj);
wait_for_completion(&kdrv->kobj_unregister);
kfree(kdrv);
}
#else
static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
{
return 0;
}
static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
{
;
}
#endif
/**
* cpuidle_add_device_sysfs - adds device specific sysfs attributes
* @device: the target device
*/
int cpuidle_add_device_sysfs(struct cpuidle_device *device)
{
int ret;
ret = cpuidle_add_state_sysfs(device);
if (ret)
return ret;
ret = cpuidle_add_driver_sysfs(device);
if (ret)
cpuidle_remove_state_sysfs(device);
return ret;
}
/**
* cpuidle_remove_device_sysfs : removes device specific sysfs attributes
* @device : the target device
*/
void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
{
cpuidle_remove_driver_sysfs(device);
cpuidle_remove_state_sysfs(device);
}
/**
* cpuidle_add_sysfs - creates a sysfs instance for the target device
* @dev: the target device
*/
int cpuidle_add_sysfs(struct cpuidle_device *dev)
{
struct cpuidle_device_kobj *kdev;
struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
int error;
/*
* Return if cpu_device is not setup for this CPU.
*
* This could happen if the arch did not set up cpu_device
* since this CPU is not in cpu_present mask and the
* driver did not send a correct CPU mask during registration.
* Without this check we would end up passing bogus
* value for &cpu_dev->kobj in kobject_init_and_add()
*/
if (!cpu_dev)
return -ENODEV;
kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
if (!kdev)
return -ENOMEM;
kdev->dev = dev;
dev->kobj_dev = kdev;
init_completion(&kdev->kobj_unregister);
error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
"cpuidle");
if (error) {
kobject_put(&kdev->kobj);
return error;
}
kobject_uevent(&kdev->kobj, KOBJ_ADD);
return 0;
}
/**
* cpuidle_remove_sysfs - deletes a sysfs instance on the target device
* @dev: the target device
*/
void cpuidle_remove_sysfs(struct cpuidle_device *dev)
{
struct cpuidle_device_kobj *kdev = dev->kobj_dev;
kobject_put(&kdev->kobj);
wait_for_completion(&kdev->kobj_unregister);
kfree(kdev);
}