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linux-next/drivers/thermal/thermal_sysfs.c
Thara Gopinath 68000a0d98 thermal: Fix locking in cooling device sysfs update cur_state
Sysfs interface to update cooling device cur_state does not
currently holding cooling device lock sometimes leading to
stale values in cur_state if getting updated simultanelously
from user space and thermal framework. Adding the proper locking
code fixes this issue.

Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2018-11-30 16:57:51 +08:00

1005 lines
24 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* thermal.c - sysfs interface of thermal devices
*
* Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com>
*
* Highly based on original thermal_core.c
* Copyright (C) 2008 Intel Corp
* Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
* Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/sysfs.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/jiffies.h>
#include "thermal_core.h"
/* sys I/F for thermal zone */
static ssize_t
type_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
return sprintf(buf, "%s\n", tz->type);
}
static ssize_t
temp_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
int temperature, ret;
ret = thermal_zone_get_temp(tz, &temperature);
if (ret)
return ret;
return sprintf(buf, "%d\n", temperature);
}
static ssize_t
mode_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
enum thermal_device_mode mode;
int result;
if (!tz->ops->get_mode)
return -EPERM;
result = tz->ops->get_mode(tz, &mode);
if (result)
return result;
return sprintf(buf, "%s\n", mode == THERMAL_DEVICE_ENABLED ? "enabled"
: "disabled");
}
static ssize_t
mode_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
int result;
if (!tz->ops->set_mode)
return -EPERM;
if (!strncmp(buf, "enabled", sizeof("enabled") - 1))
result = tz->ops->set_mode(tz, THERMAL_DEVICE_ENABLED);
else if (!strncmp(buf, "disabled", sizeof("disabled") - 1))
result = tz->ops->set_mode(tz, THERMAL_DEVICE_DISABLED);
else
result = -EINVAL;
if (result)
return result;
return count;
}
static ssize_t
trip_point_type_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
enum thermal_trip_type type;
int trip, result;
if (!tz->ops->get_trip_type)
return -EPERM;
if (sscanf(attr->attr.name, "trip_point_%d_type", &trip) != 1)
return -EINVAL;
result = tz->ops->get_trip_type(tz, trip, &type);
if (result)
return result;
switch (type) {
case THERMAL_TRIP_CRITICAL:
return sprintf(buf, "critical\n");
case THERMAL_TRIP_HOT:
return sprintf(buf, "hot\n");
case THERMAL_TRIP_PASSIVE:
return sprintf(buf, "passive\n");
case THERMAL_TRIP_ACTIVE:
return sprintf(buf, "active\n");
default:
return sprintf(buf, "unknown\n");
}
}
static ssize_t
trip_point_temp_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
int trip, ret;
int temperature;
if (!tz->ops->set_trip_temp)
return -EPERM;
if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip) != 1)
return -EINVAL;
if (kstrtoint(buf, 10, &temperature))
return -EINVAL;
ret = tz->ops->set_trip_temp(tz, trip, temperature);
if (ret)
return ret;
thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
return count;
}
static ssize_t
trip_point_temp_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
int trip, ret;
int temperature;
if (!tz->ops->get_trip_temp)
return -EPERM;
if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip) != 1)
return -EINVAL;
ret = tz->ops->get_trip_temp(tz, trip, &temperature);
if (ret)
return ret;
return sprintf(buf, "%d\n", temperature);
}
static ssize_t
trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
int trip, ret;
int temperature;
if (!tz->ops->set_trip_hyst)
return -EPERM;
if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip) != 1)
return -EINVAL;
if (kstrtoint(buf, 10, &temperature))
return -EINVAL;
/*
* We are not doing any check on the 'temperature' value
* here. The driver implementing 'set_trip_hyst' has to
* take care of this.
*/
ret = tz->ops->set_trip_hyst(tz, trip, temperature);
if (!ret)
thermal_zone_set_trips(tz);
return ret ? ret : count;
}
static ssize_t
trip_point_hyst_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
int trip, ret;
int temperature;
if (!tz->ops->get_trip_hyst)
return -EPERM;
if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip) != 1)
return -EINVAL;
ret = tz->ops->get_trip_hyst(tz, trip, &temperature);
return ret ? ret : sprintf(buf, "%d\n", temperature);
}
static ssize_t
passive_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
int state;
if (sscanf(buf, "%d\n", &state) != 1)
return -EINVAL;
/* sanity check: values below 1000 millicelcius don't make sense
* and can cause the system to go into a thermal heart attack
*/
if (state && state < 1000)
return -EINVAL;
if (state && !tz->forced_passive) {
if (!tz->passive_delay)
tz->passive_delay = 1000;
thermal_zone_device_rebind_exception(tz, "Processor",
sizeof("Processor"));
} else if (!state && tz->forced_passive) {
tz->passive_delay = 0;
thermal_zone_device_unbind_exception(tz, "Processor",
sizeof("Processor"));
}
tz->forced_passive = state;
thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
return count;
}
static ssize_t
passive_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
return sprintf(buf, "%d\n", tz->forced_passive);
}
static ssize_t
policy_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
char name[THERMAL_NAME_LENGTH];
int ret;
snprintf(name, sizeof(name), "%s", buf);
ret = thermal_zone_device_set_policy(tz, name);
if (!ret)
ret = count;
return ret;
}
static ssize_t
policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
return sprintf(buf, "%s\n", tz->governor->name);
}
static ssize_t
available_policies_show(struct device *dev, struct device_attribute *devattr,
char *buf)
{
return thermal_build_list_of_policies(buf);
}
#if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
static ssize_t
emul_temp_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
int ret = 0;
int temperature;
if (kstrtoint(buf, 10, &temperature))
return -EINVAL;
if (!tz->ops->set_emul_temp) {
mutex_lock(&tz->lock);
tz->emul_temperature = temperature;
mutex_unlock(&tz->lock);
} else {
ret = tz->ops->set_emul_temp(tz, temperature);
}
if (!ret)
thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
return ret ? ret : count;
}
static DEVICE_ATTR_WO(emul_temp);
#endif
static ssize_t
sustainable_power_show(struct device *dev, struct device_attribute *devattr,
char *buf)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
if (tz->tzp)
return sprintf(buf, "%u\n", tz->tzp->sustainable_power);
else
return -EIO;
}
static ssize_t
sustainable_power_store(struct device *dev, struct device_attribute *devattr,
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
u32 sustainable_power;
if (!tz->tzp)
return -EIO;
if (kstrtou32(buf, 10, &sustainable_power))
return -EINVAL;
tz->tzp->sustainable_power = sustainable_power;
return count;
}
#define create_s32_tzp_attr(name) \
static ssize_t \
name##_show(struct device *dev, struct device_attribute *devattr, \
char *buf) \
{ \
struct thermal_zone_device *tz = to_thermal_zone(dev); \
\
if (tz->tzp) \
return sprintf(buf, "%d\n", tz->tzp->name); \
else \
return -EIO; \
} \
\
static ssize_t \
name##_store(struct device *dev, struct device_attribute *devattr, \
const char *buf, size_t count) \
{ \
struct thermal_zone_device *tz = to_thermal_zone(dev); \
s32 value; \
\
if (!tz->tzp) \
return -EIO; \
\
if (kstrtos32(buf, 10, &value)) \
return -EINVAL; \
\
tz->tzp->name = value; \
\
return count; \
} \
static DEVICE_ATTR_RW(name)
create_s32_tzp_attr(k_po);
create_s32_tzp_attr(k_pu);
create_s32_tzp_attr(k_i);
create_s32_tzp_attr(k_d);
create_s32_tzp_attr(integral_cutoff);
create_s32_tzp_attr(slope);
create_s32_tzp_attr(offset);
#undef create_s32_tzp_attr
/*
* These are thermal zone device attributes that will always be present.
* All the attributes created for tzp (create_s32_tzp_attr) also are always
* present on the sysfs interface.
*/
static DEVICE_ATTR_RO(type);
static DEVICE_ATTR_RO(temp);
static DEVICE_ATTR_RW(policy);
static DEVICE_ATTR_RO(available_policies);
static DEVICE_ATTR_RW(sustainable_power);
/* These thermal zone device attributes are created based on conditions */
static DEVICE_ATTR_RW(mode);
static DEVICE_ATTR_RW(passive);
/* These attributes are unconditionally added to a thermal zone */
static struct attribute *thermal_zone_dev_attrs[] = {
&dev_attr_type.attr,
&dev_attr_temp.attr,
#if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
&dev_attr_emul_temp.attr,
#endif
&dev_attr_policy.attr,
&dev_attr_available_policies.attr,
&dev_attr_sustainable_power.attr,
&dev_attr_k_po.attr,
&dev_attr_k_pu.attr,
&dev_attr_k_i.attr,
&dev_attr_k_d.attr,
&dev_attr_integral_cutoff.attr,
&dev_attr_slope.attr,
&dev_attr_offset.attr,
NULL,
};
static struct attribute_group thermal_zone_attribute_group = {
.attrs = thermal_zone_dev_attrs,
};
/* We expose mode only if .get_mode is present */
static struct attribute *thermal_zone_mode_attrs[] = {
&dev_attr_mode.attr,
NULL,
};
static umode_t thermal_zone_mode_is_visible(struct kobject *kobj,
struct attribute *attr,
int attrno)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct thermal_zone_device *tz;
tz = container_of(dev, struct thermal_zone_device, device);
if (tz->ops->get_mode)
return attr->mode;
return 0;
}
static struct attribute_group thermal_zone_mode_attribute_group = {
.attrs = thermal_zone_mode_attrs,
.is_visible = thermal_zone_mode_is_visible,
};
/* We expose passive only if passive trips are present */
static struct attribute *thermal_zone_passive_attrs[] = {
&dev_attr_passive.attr,
NULL,
};
static umode_t thermal_zone_passive_is_visible(struct kobject *kobj,
struct attribute *attr,
int attrno)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct thermal_zone_device *tz;
enum thermal_trip_type trip_type;
int count, passive = 0;
tz = container_of(dev, struct thermal_zone_device, device);
for (count = 0; count < tz->trips && !passive; count++) {
tz->ops->get_trip_type(tz, count, &trip_type);
if (trip_type == THERMAL_TRIP_PASSIVE)
passive = 1;
}
if (!passive)
return attr->mode;
return 0;
}
static struct attribute_group thermal_zone_passive_attribute_group = {
.attrs = thermal_zone_passive_attrs,
.is_visible = thermal_zone_passive_is_visible,
};
static const struct attribute_group *thermal_zone_attribute_groups[] = {
&thermal_zone_attribute_group,
&thermal_zone_mode_attribute_group,
&thermal_zone_passive_attribute_group,
/* This is not NULL terminated as we create the group dynamically */
};
/**
* create_trip_attrs() - create attributes for trip points
* @tz: the thermal zone device
* @mask: Writeable trip point bitmap.
*
* helper function to instantiate sysfs entries for every trip
* point and its properties of a struct thermal_zone_device.
*
* Return: 0 on success, the proper error value otherwise.
*/
static int create_trip_attrs(struct thermal_zone_device *tz, int mask)
{
struct attribute **attrs;
int indx;
/* This function works only for zones with at least one trip */
if (tz->trips <= 0)
return -EINVAL;
tz->trip_type_attrs = kcalloc(tz->trips, sizeof(*tz->trip_type_attrs),
GFP_KERNEL);
if (!tz->trip_type_attrs)
return -ENOMEM;
tz->trip_temp_attrs = kcalloc(tz->trips, sizeof(*tz->trip_temp_attrs),
GFP_KERNEL);
if (!tz->trip_temp_attrs) {
kfree(tz->trip_type_attrs);
return -ENOMEM;
}
if (tz->ops->get_trip_hyst) {
tz->trip_hyst_attrs = kcalloc(tz->trips,
sizeof(*tz->trip_hyst_attrs),
GFP_KERNEL);
if (!tz->trip_hyst_attrs) {
kfree(tz->trip_type_attrs);
kfree(tz->trip_temp_attrs);
return -ENOMEM;
}
}
attrs = kcalloc(tz->trips * 3 + 1, sizeof(*attrs), GFP_KERNEL);
if (!attrs) {
kfree(tz->trip_type_attrs);
kfree(tz->trip_temp_attrs);
if (tz->ops->get_trip_hyst)
kfree(tz->trip_hyst_attrs);
return -ENOMEM;
}
for (indx = 0; indx < tz->trips; indx++) {
/* create trip type attribute */
snprintf(tz->trip_type_attrs[indx].name, THERMAL_NAME_LENGTH,
"trip_point_%d_type", indx);
sysfs_attr_init(&tz->trip_type_attrs[indx].attr.attr);
tz->trip_type_attrs[indx].attr.attr.name =
tz->trip_type_attrs[indx].name;
tz->trip_type_attrs[indx].attr.attr.mode = S_IRUGO;
tz->trip_type_attrs[indx].attr.show = trip_point_type_show;
attrs[indx] = &tz->trip_type_attrs[indx].attr.attr;
/* create trip temp attribute */
snprintf(tz->trip_temp_attrs[indx].name, THERMAL_NAME_LENGTH,
"trip_point_%d_temp", indx);
sysfs_attr_init(&tz->trip_temp_attrs[indx].attr.attr);
tz->trip_temp_attrs[indx].attr.attr.name =
tz->trip_temp_attrs[indx].name;
tz->trip_temp_attrs[indx].attr.attr.mode = S_IRUGO;
tz->trip_temp_attrs[indx].attr.show = trip_point_temp_show;
if (IS_ENABLED(CONFIG_THERMAL_WRITABLE_TRIPS) &&
mask & (1 << indx)) {
tz->trip_temp_attrs[indx].attr.attr.mode |= S_IWUSR;
tz->trip_temp_attrs[indx].attr.store =
trip_point_temp_store;
}
attrs[indx + tz->trips] = &tz->trip_temp_attrs[indx].attr.attr;
/* create Optional trip hyst attribute */
if (!tz->ops->get_trip_hyst)
continue;
snprintf(tz->trip_hyst_attrs[indx].name, THERMAL_NAME_LENGTH,
"trip_point_%d_hyst", indx);
sysfs_attr_init(&tz->trip_hyst_attrs[indx].attr.attr);
tz->trip_hyst_attrs[indx].attr.attr.name =
tz->trip_hyst_attrs[indx].name;
tz->trip_hyst_attrs[indx].attr.attr.mode = S_IRUGO;
tz->trip_hyst_attrs[indx].attr.show = trip_point_hyst_show;
if (tz->ops->set_trip_hyst) {
tz->trip_hyst_attrs[indx].attr.attr.mode |= S_IWUSR;
tz->trip_hyst_attrs[indx].attr.store =
trip_point_hyst_store;
}
attrs[indx + tz->trips * 2] =
&tz->trip_hyst_attrs[indx].attr.attr;
}
attrs[tz->trips * 3] = NULL;
tz->trips_attribute_group.attrs = attrs;
return 0;
}
/**
* destroy_trip_attrs() - destroy attributes for trip points
* @tz: the thermal zone device
*
* helper function to free resources allocated by create_trip_attrs()
*/
static void destroy_trip_attrs(struct thermal_zone_device *tz)
{
if (!tz)
return;
kfree(tz->trip_type_attrs);
kfree(tz->trip_temp_attrs);
if (tz->ops->get_trip_hyst)
kfree(tz->trip_hyst_attrs);
kfree(tz->trips_attribute_group.attrs);
}
int thermal_zone_create_device_groups(struct thermal_zone_device *tz,
int mask)
{
const struct attribute_group **groups;
int i, size, result;
/* we need one extra for trips and the NULL to terminate the array */
size = ARRAY_SIZE(thermal_zone_attribute_groups) + 2;
/* This also takes care of API requirement to be NULL terminated */
groups = kcalloc(size, sizeof(*groups), GFP_KERNEL);
if (!groups)
return -ENOMEM;
for (i = 0; i < size - 2; i++)
groups[i] = thermal_zone_attribute_groups[i];
if (tz->trips) {
result = create_trip_attrs(tz, mask);
if (result) {
kfree(groups);
return result;
}
groups[size - 2] = &tz->trips_attribute_group;
}
tz->device.groups = groups;
return 0;
}
void thermal_zone_destroy_device_groups(struct thermal_zone_device *tz)
{
if (!tz)
return;
if (tz->trips)
destroy_trip_attrs(tz);
kfree(tz->device.groups);
}
/* sys I/F for cooling device */
static ssize_t
cdev_type_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
return sprintf(buf, "%s\n", cdev->type);
}
static ssize_t max_state_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
unsigned long state;
int ret;
ret = cdev->ops->get_max_state(cdev, &state);
if (ret)
return ret;
return sprintf(buf, "%ld\n", state);
}
static ssize_t cur_state_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
unsigned long state;
int ret;
ret = cdev->ops->get_cur_state(cdev, &state);
if (ret)
return ret;
return sprintf(buf, "%ld\n", state);
}
static ssize_t
cur_state_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
unsigned long state;
int result;
if (sscanf(buf, "%ld\n", &state) != 1)
return -EINVAL;
if ((long)state < 0)
return -EINVAL;
mutex_lock(&cdev->lock);
result = cdev->ops->set_cur_state(cdev, state);
if (!result)
thermal_cooling_device_stats_update(cdev, state);
mutex_unlock(&cdev->lock);
return result ? result : count;
}
static struct device_attribute
dev_attr_cdev_type = __ATTR(type, 0444, cdev_type_show, NULL);
static DEVICE_ATTR_RO(max_state);
static DEVICE_ATTR_RW(cur_state);
static struct attribute *cooling_device_attrs[] = {
&dev_attr_cdev_type.attr,
&dev_attr_max_state.attr,
&dev_attr_cur_state.attr,
NULL,
};
static const struct attribute_group cooling_device_attr_group = {
.attrs = cooling_device_attrs,
};
static const struct attribute_group *cooling_device_attr_groups[] = {
&cooling_device_attr_group,
NULL, /* Space allocated for cooling_device_stats_attr_group */
NULL,
};
#ifdef CONFIG_THERMAL_STATISTICS
struct cooling_dev_stats {
spinlock_t lock;
unsigned int total_trans;
unsigned long state;
unsigned long max_states;
ktime_t last_time;
ktime_t *time_in_state;
unsigned int *trans_table;
};
static void update_time_in_state(struct cooling_dev_stats *stats)
{
ktime_t now = ktime_get(), delta;
delta = ktime_sub(now, stats->last_time);
stats->time_in_state[stats->state] =
ktime_add(stats->time_in_state[stats->state], delta);
stats->last_time = now;
}
void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev,
unsigned long new_state)
{
struct cooling_dev_stats *stats = cdev->stats;
spin_lock(&stats->lock);
if (stats->state == new_state)
goto unlock;
update_time_in_state(stats);
stats->trans_table[stats->state * stats->max_states + new_state]++;
stats->state = new_state;
stats->total_trans++;
unlock:
spin_unlock(&stats->lock);
}
static ssize_t total_trans_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
struct cooling_dev_stats *stats = cdev->stats;
int ret;
spin_lock(&stats->lock);
ret = sprintf(buf, "%u\n", stats->total_trans);
spin_unlock(&stats->lock);
return ret;
}
static ssize_t
time_in_state_ms_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
struct cooling_dev_stats *stats = cdev->stats;
ssize_t len = 0;
int i;
spin_lock(&stats->lock);
update_time_in_state(stats);
for (i = 0; i < stats->max_states; i++) {
len += sprintf(buf + len, "state%u\t%llu\n", i,
ktime_to_ms(stats->time_in_state[i]));
}
spin_unlock(&stats->lock);
return len;
}
static ssize_t
reset_store(struct device *dev, struct device_attribute *attr, const char *buf,
size_t count)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
struct cooling_dev_stats *stats = cdev->stats;
int i, states = stats->max_states;
spin_lock(&stats->lock);
stats->total_trans = 0;
stats->last_time = ktime_get();
memset(stats->trans_table, 0,
states * states * sizeof(*stats->trans_table));
for (i = 0; i < stats->max_states; i++)
stats->time_in_state[i] = ktime_set(0, 0);
spin_unlock(&stats->lock);
return count;
}
static ssize_t trans_table_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
struct cooling_dev_stats *stats = cdev->stats;
ssize_t len = 0;
int i, j;
len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
len += snprintf(buf + len, PAGE_SIZE - len, " : ");
for (i = 0; i < stats->max_states; i++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "state%2u ", i);
}
if (len >= PAGE_SIZE)
return PAGE_SIZE;
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
for (i = 0; i < stats->max_states; i++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
for (j = 0; j < stats->max_states; j++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%8u ",
stats->trans_table[i * stats->max_states + j]);
}
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
}
if (len >= PAGE_SIZE) {
pr_warn_once("Thermal transition table exceeds PAGE_SIZE. Disabling\n");
return -EFBIG;
}
return len;
}
static DEVICE_ATTR_RO(total_trans);
static DEVICE_ATTR_RO(time_in_state_ms);
static DEVICE_ATTR_WO(reset);
static DEVICE_ATTR_RO(trans_table);
static struct attribute *cooling_device_stats_attrs[] = {
&dev_attr_total_trans.attr,
&dev_attr_time_in_state_ms.attr,
&dev_attr_reset.attr,
&dev_attr_trans_table.attr,
NULL
};
static const struct attribute_group cooling_device_stats_attr_group = {
.attrs = cooling_device_stats_attrs,
.name = "stats"
};
static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
{
struct cooling_dev_stats *stats;
unsigned long states;
int var;
if (cdev->ops->get_max_state(cdev, &states))
return;
states++; /* Total number of states is highest state + 1 */
var = sizeof(*stats);
var += sizeof(*stats->time_in_state) * states;
var += sizeof(*stats->trans_table) * states * states;
stats = kzalloc(var, GFP_KERNEL);
if (!stats)
return;
stats->time_in_state = (ktime_t *)(stats + 1);
stats->trans_table = (unsigned int *)(stats->time_in_state + states);
cdev->stats = stats;
stats->last_time = ktime_get();
stats->max_states = states;
spin_lock_init(&stats->lock);
/* Fill the empty slot left in cooling_device_attr_groups */
var = ARRAY_SIZE(cooling_device_attr_groups) - 2;
cooling_device_attr_groups[var] = &cooling_device_stats_attr_group;
}
static void cooling_device_stats_destroy(struct thermal_cooling_device *cdev)
{
kfree(cdev->stats);
cdev->stats = NULL;
}
#else
static inline void
cooling_device_stats_setup(struct thermal_cooling_device *cdev) {}
static inline void
cooling_device_stats_destroy(struct thermal_cooling_device *cdev) {}
#endif /* CONFIG_THERMAL_STATISTICS */
void thermal_cooling_device_setup_sysfs(struct thermal_cooling_device *cdev)
{
cooling_device_stats_setup(cdev);
cdev->device.groups = cooling_device_attr_groups;
}
void thermal_cooling_device_destroy_sysfs(struct thermal_cooling_device *cdev)
{
cooling_device_stats_destroy(cdev);
}
/* these helper will be used only at the time of bindig */
ssize_t
trip_point_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct thermal_instance *instance;
instance =
container_of(attr, struct thermal_instance, attr);
if (instance->trip == THERMAL_TRIPS_NONE)
return sprintf(buf, "-1\n");
else
return sprintf(buf, "%d\n", instance->trip);
}
ssize_t
weight_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct thermal_instance *instance;
instance = container_of(attr, struct thermal_instance, weight_attr);
return sprintf(buf, "%d\n", instance->weight);
}
ssize_t weight_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct thermal_instance *instance;
int ret, weight;
ret = kstrtoint(buf, 0, &weight);
if (ret)
return ret;
instance = container_of(attr, struct thermal_instance, weight_attr);
instance->weight = weight;
return count;
}