// SPDX-License-Identifier: GPL-2.0-only
/*
* Power capping class
* Copyright (c) 2013, Intel Corporation.
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/kstrtox.h>
#include <linux/slab.h>
#include <linux/powercap.h>
#define to_powercap_zone(n) container_of(n, struct powercap_zone, dev)
#define to_powercap_control_type(n) \
container_of(n, struct powercap_control_type, dev)
/* Power zone show function */
#define define_power_zone_show(_attr) \
static ssize_t _attr##_show(struct device *dev, \
struct device_attribute *dev_attr,\
char *buf) \
{ \
u64 value; \
ssize_t len = -EINVAL; \
struct powercap_zone *power_zone = to_powercap_zone(dev); \
\
if (power_zone->ops->get_##_attr) { \
if (!power_zone->ops->get_##_attr(power_zone, &value)) \
len = sprintf(buf, "%lld\n", value); \
} \
\
return len; \
}
/* The only meaningful input is 0 (reset), others are silently ignored */
#define define_power_zone_store(_attr) \
static ssize_t _attr##_store(struct device *dev,\
struct device_attribute *dev_attr, \
const char *buf, size_t count) \
{ \
int err; \
struct powercap_zone *power_zone = to_powercap_zone(dev); \
u64 value; \
\
err = kstrtoull(buf, 10, &value); \
if (err) \
return -EINVAL; \
if (value) \
return count; \
if (power_zone->ops->reset_##_attr) { \
if (!power_zone->ops->reset_##_attr(power_zone)) \
return count; \
} \
\
return -EINVAL; \
}
/* Power zone constraint show function */
#define define_power_zone_constraint_show(_attr) \
static ssize_t show_constraint_##_attr(struct device *dev, \
struct device_attribute *dev_attr,\
char *buf) \
{ \
u64 value; \
ssize_t len = -ENODATA; \
struct powercap_zone *power_zone = to_powercap_zone(dev); \
int id; \
struct powercap_zone_constraint *pconst;\
\
if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
return -EINVAL; \
if (id >= power_zone->const_id_cnt) \
return -EINVAL; \
pconst = &power_zone->constraints[id]; \
if (pconst && pconst->ops && pconst->ops->get_##_attr) { \
if (!pconst->ops->get_##_attr(power_zone, id, &value)) \
len = sprintf(buf, "%lld\n", value); \
} \
\
return len; \
}
/* Power zone constraint store function */
#define define_power_zone_constraint_store(_attr) \
static ssize_t store_constraint_##_attr(struct device *dev,\
struct device_attribute *dev_attr, \
const char *buf, size_t count) \
{ \
int err; \
u64 value; \
struct powercap_zone *power_zone = to_powercap_zone(dev); \
int id; \
struct powercap_zone_constraint *pconst;\
\
if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id)) \
return -EINVAL; \
if (id >= power_zone->const_id_cnt) \
return -EINVAL; \
pconst = &power_zone->constraints[id]; \
err = kstrtoull(buf, 10, &value); \
if (err) \
return -EINVAL; \
if (pconst && pconst->ops && pconst->ops->set_##_attr) { \
if (!pconst->ops->set_##_attr(power_zone, id, value)) \
return count; \
} \
\
return -ENODATA; \
}
/* Power zone information callbacks */
define_power_zone_show(power_uw);
define_power_zone_show(max_power_range_uw);
define_power_zone_show(energy_uj);
define_power_zone_store(energy_uj);
define_power_zone_show(max_energy_range_uj);
/* Power zone attributes */
static DEVICE_ATTR_RO(max_power_range_uw);
static DEVICE_ATTR_RO(power_uw);
static DEVICE_ATTR_RO(max_energy_range_uj);
static DEVICE_ATTR_RW(energy_uj);
/* Power zone constraint attributes callbacks */
define_power_zone_constraint_show(power_limit_uw);
define_power_zone_constraint_store(power_limit_uw);
define_power_zone_constraint_show(time_window_us);
define_power_zone_constraint_store(time_window_us);
define_power_zone_constraint_show(max_power_uw);
define_power_zone_constraint_show(min_power_uw);
define_power_zone_constraint_show(max_time_window_us);
define_power_zone_constraint_show(min_time_window_us);
/* For one time seeding of constraint device attributes */
struct powercap_constraint_attr {
struct device_attribute power_limit_attr;
struct device_attribute time_window_attr;
struct device_attribute max_power_attr;
struct device_attribute min_power_attr;
struct device_attribute max_time_window_attr;
struct device_attribute min_time_window_attr;
struct device_attribute name_attr;
};
static struct powercap_constraint_attr
constraint_attrs[MAX_CONSTRAINTS_PER_ZONE];
/* A list of powercap control_types */
static LIST_HEAD(powercap_cntrl_list);
/* Mutex to protect list of powercap control_types */
static DEFINE_MUTEX(powercap_cntrl_list_lock);
#define POWERCAP_CONSTRAINT_NAME_LEN 30 /* Some limit to avoid overflow */
static ssize_t show_constraint_name(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
const char *name;
struct powercap_zone *power_zone = to_powercap_zone(dev);
int id;
ssize_t len = -ENODATA;
struct powercap_zone_constraint *pconst;
if (!sscanf(dev_attr->attr.name, "constraint_%d_", &id))
return -EINVAL;
if (id >= power_zone->const_id_cnt)
return -EINVAL;
pconst = &power_zone->constraints[id];
if (pconst && pconst->ops && pconst->ops->get_name) {
name = pconst->ops->get_name(power_zone, id);
if (name) {
sprintf(buf, "%.*s\n", POWERCAP_CONSTRAINT_NAME_LEN - 1,
name);
len = strlen(buf);
}
}
return len;
}
static int create_constraint_attribute(int id, const char *name,
int mode,
struct device_attribute *dev_attr,
ssize_t (*show)(struct device *,
struct device_attribute *, char *),
ssize_t (*store)(struct device *,
struct device_attribute *,
const char *, size_t)
)
{
dev_attr->attr.name = kasprintf(GFP_KERNEL, "constraint_%d_%s",
id, name);
if (!dev_attr->attr.name)
return -ENOMEM;
dev_attr->attr.mode = mode;
dev_attr->show = show;
dev_attr->store = store;
return 0;
}
static void free_constraint_attributes(void)
{
int i;
for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
kfree(constraint_attrs[i].power_limit_attr.attr.name);
kfree(constraint_attrs[i].time_window_attr.attr.name);
kfree(constraint_attrs[i].name_attr.attr.name);
kfree(constraint_attrs[i].max_power_attr.attr.name);
kfree(constraint_attrs[i].min_power_attr.attr.name);
kfree(constraint_attrs[i].max_time_window_attr.attr.name);
kfree(constraint_attrs[i].min_time_window_attr.attr.name);
}
}
static int seed_constraint_attributes(void)
{
int i;
int ret;
for (i = 0; i < MAX_CONSTRAINTS_PER_ZONE; ++i) {
ret = create_constraint_attribute(i, "power_limit_uw",
S_IWUSR | S_IRUGO,
&constraint_attrs[i].power_limit_attr,
show_constraint_power_limit_uw,
store_constraint_power_limit_uw);
if (ret)
goto err_alloc;
ret = create_constraint_attribute(i, "time_window_us",
S_IWUSR | S_IRUGO,
&constraint_attrs[i].time_window_attr,
show_constraint_time_window_us,
store_constraint_time_window_us);
if (ret)
goto err_alloc;
ret = create_constraint_attribute(i, "name", S_IRUGO,
&constraint_attrs[i].name_attr,
show_constraint_name,
NULL);
if (ret)
goto err_alloc;
ret = create_constraint_attribute(i, "max_power_uw", S_IRUGO,
&constraint_attrs[i].max_power_attr,
show_constraint_max_power_uw,
NULL);
if (ret)
goto err_alloc;
ret = create_constraint_attribute(i, "min_power_uw", S_IRUGO,
&constraint_attrs[i].min_power_attr,
show_constraint_min_power_uw,
NULL);
if (ret)
goto err_alloc;
ret = create_constraint_attribute(i, "max_time_window_us",
S_IRUGO,
&constraint_attrs[i].max_time_window_attr,
show_constraint_max_time_window_us,
NULL);
if (ret)
goto err_alloc;
ret = create_constraint_attribute(i, "min_time_window_us",
S_IRUGO,
&constraint_attrs[i].min_time_window_attr,
show_constraint_min_time_window_us,
NULL);
if (ret)
goto err_alloc;
}
return 0;
err_alloc:
free_constraint_attributes();
return ret;
}
static int create_constraints(struct powercap_zone *power_zone,
int nr_constraints,
const struct powercap_zone_constraint_ops *const_ops)
{
int i;
int ret = 0;
int count;
struct powercap_zone_constraint *pconst;
if (!power_zone || !const_ops || !const_ops->get_power_limit_uw ||
!const_ops->set_power_limit_uw ||
!const_ops->get_time_window_us ||
!const_ops->set_time_window_us)
return -EINVAL;
count = power_zone->zone_attr_count;
for (i = 0; i < nr_constraints; ++i) {
pconst = &power_zone->constraints[i];
pconst->ops = const_ops;
pconst->id = power_zone->const_id_cnt;
power_zone->const_id_cnt++;
power_zone->zone_dev_attrs[count++] =
&constraint_attrs[i].power_limit_attr.attr;
power_zone->zone_dev_attrs[count++] =
&constraint_attrs[i].time_window_attr.attr;
if (pconst->ops->get_name)
power_zone->zone_dev_attrs[count++] =
&constraint_attrs[i].name_attr.attr;
if (pconst->ops->get_max_power_uw)
power_zone->zone_dev_attrs[count++] =
&constraint_attrs[i].max_power_attr.attr;
if (pconst->ops->get_min_power_uw)
power_zone->zone_dev_attrs[count++] =
&constraint_attrs[i].min_power_attr.attr;
if (pconst->ops->get_max_time_window_us)
power_zone->zone_dev_attrs[count++] =
&constraint_attrs[i].max_time_window_attr.attr;
if (pconst->ops->get_min_time_window_us)
power_zone->zone_dev_attrs[count++] =
&constraint_attrs[i].min_time_window_attr.attr;
}
power_zone->zone_attr_count = count;
return ret;
}
static bool control_type_valid(void *control_type)
{
struct powercap_control_type *pos = NULL;
bool found = false;
mutex_lock(&powercap_cntrl_list_lock);
list_for_each_entry(pos, &powercap_cntrl_list, node) {
if (pos == control_type) {
found = true;
break;
}
}
mutex_unlock(&powercap_cntrl_list_lock);
return found;
}
static ssize_t name_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct powercap_zone *power_zone = to_powercap_zone(dev);
return sprintf(buf, "%s\n", power_zone->name);
}
static DEVICE_ATTR_RO(name);
/* Create zone and attributes in sysfs */
static void create_power_zone_common_attributes(
struct powercap_zone *power_zone)
{
int count = 0;
power_zone->zone_dev_attrs[count++] = &dev_attr_name.attr;
if (power_zone->ops->get_max_energy_range_uj)
power_zone->zone_dev_attrs[count++] =
&dev_attr_max_energy_range_uj.attr;
if (power_zone->ops->get_energy_uj) {
if (power_zone->ops->reset_energy_uj)
dev_attr_energy_uj.attr.mode = S_IWUSR | S_IRUSR;
else
dev_attr_energy_uj.attr.mode = S_IRUSR;
power_zone->zone_dev_attrs[count++] =
&dev_attr_energy_uj.attr;
}
if (power_zone->ops->get_power_uw)
power_zone->zone_dev_attrs[count++] =
&dev_attr_power_uw.attr;
if (power_zone->ops->get_max_power_range_uw)
power_zone->zone_dev_attrs[count++] =
&dev_attr_max_power_range_uw.attr;
power_zone->zone_dev_attrs[count] = NULL;
power_zone->zone_attr_count = count;
}
static void powercap_release(struct device *dev)
{
bool allocated;
if (dev->parent) {
struct powercap_zone *power_zone = to_powercap_zone(dev);
/* Store flag as the release() may free memory */
allocated = power_zone->allocated;
/* Remove id from parent idr struct */
idr_remove(power_zone->parent_idr, power_zone->id);
/* Destroy idrs allocated for this zone */
idr_destroy(&power_zone->idr);
kfree(power_zone->name);
kfree(power_zone->zone_dev_attrs);
kfree(power_zone->constraints);
if (power_zone->ops->release)
power_zone->ops->release(power_zone);
if (allocated)
kfree(power_zone);
} else {
struct powercap_control_type *control_type =
to_powercap_control_type(dev);
/* Store flag as the release() may free memory */
allocated = control_type->allocated;
idr_destroy(&control_type->idr);
mutex_destroy(&control_type->lock);
if (control_type->ops && control_type->ops->release)
control_type->ops->release(control_type);
if (allocated)
kfree(control_type);
}
}
static ssize_t enabled_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
bool mode = true;
/* Default is enabled */
if (dev->parent) {
struct powercap_zone *power_zone = to_powercap_zone(dev);
if (power_zone->ops->get_enable)
if (power_zone->ops->get_enable(power_zone, &mode))
mode = false;
} else {
struct powercap_control_type *control_type =
to_powercap_control_type(dev);
if (control_type->ops && control_type->ops->get_enable)
if (control_type->ops->get_enable(control_type, &mode))
mode = false;
}
return sprintf(buf, "%d\n", mode);
}
static ssize_t enabled_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
bool mode;
if (kstrtobool(buf, &mode))
return -EINVAL;
if (dev->parent) {
struct powercap_zone *power_zone = to_powercap_zone(dev);
if (power_zone->ops->set_enable)
if (!power_zone->ops->set_enable(power_zone, mode))
return len;
} else {
struct powercap_control_type *control_type =
to_powercap_control_type(dev);
if (control_type->ops && control_type->ops->set_enable)
if (!control_type->ops->set_enable(control_type, mode))
return len;
}
return -ENOSYS;
}
static DEVICE_ATTR_RW(enabled);
static struct attribute *powercap_attrs[] = {
&dev_attr_enabled.attr,
NULL,
};
ATTRIBUTE_GROUPS(powercap);
static struct class powercap_class = {
.name = "powercap",
.dev_release = powercap_release,
.dev_groups = powercap_groups,
};
struct powercap_zone *powercap_register_zone(
struct powercap_zone *power_zone,
struct powercap_control_type *control_type,
const char *name,
struct powercap_zone *parent,
const struct powercap_zone_ops *ops,
int nr_constraints,
const struct powercap_zone_constraint_ops *const_ops)
{
int result;
int nr_attrs;
if (!name || !control_type || !ops ||
nr_constraints > MAX_CONSTRAINTS_PER_ZONE ||
(!ops->get_energy_uj && !ops->get_power_uw) ||
!control_type_valid(control_type))
return ERR_PTR(-EINVAL);
if (power_zone) {
if (!ops->release)
return ERR_PTR(-EINVAL);
memset(power_zone, 0, sizeof(*power_zone));
} else {
power_zone = kzalloc(sizeof(*power_zone), GFP_KERNEL);
if (!power_zone)
return ERR_PTR(-ENOMEM);
power_zone->allocated = true;
}
power_zone->ops = ops;
power_zone->control_type_inst = control_type;
if (!parent) {
power_zone->dev.parent = &control_type->dev;
power_zone->parent_idr = &control_type->idr;
} else {
power_zone->dev.parent = &parent->dev;
power_zone->parent_idr = &parent->idr;
}
power_zone->dev.class = &powercap_class;
mutex_lock(&control_type->lock);
/* Using idr to get the unique id */
result = idr_alloc(power_zone->parent_idr, NULL, 0, 0, GFP_KERNEL);
if (result < 0)
goto err_idr_alloc;
power_zone->id = result;
idr_init(&power_zone->idr);
result = -ENOMEM;
power_zone->name = kstrdup(name, GFP_KERNEL);
if (!power_zone->name)
goto err_name_alloc;
power_zone->constraints = kcalloc(nr_constraints,
sizeof(*power_zone->constraints),
GFP_KERNEL);
if (!power_zone->constraints)
goto err_const_alloc;
nr_attrs = nr_constraints * POWERCAP_CONSTRAINTS_ATTRS +
POWERCAP_ZONE_MAX_ATTRS + 1;
power_zone->zone_dev_attrs = kcalloc(nr_attrs, sizeof(void *),
GFP_KERNEL);
if (!power_zone->zone_dev_attrs)
goto err_attr_alloc;
create_power_zone_common_attributes(power_zone);
result = create_constraints(power_zone, nr_constraints, const_ops);
if (result)
goto err_dev_ret;
power_zone->zone_dev_attrs[power_zone->zone_attr_count] = NULL;
power_zone->dev_zone_attr_group.attrs = power_zone->zone_dev_attrs;
power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
power_zone->dev_attr_groups[1] = NULL;
power_zone->dev.groups = power_zone->dev_attr_groups;
dev_set_name(&power_zone->dev, "%s:%x",
dev_name(power_zone->dev.parent),
power_zone->id);
result = device_register(&power_zone->dev);
if (result) {
put_device(&power_zone->dev);
mutex_unlock(&control_type->lock);
return ERR_PTR(result);
}
control_type->nr_zones++;
mutex_unlock(&control_type->lock);
return power_zone;
err_dev_ret:
kfree(power_zone->zone_dev_attrs);
err_attr_alloc:
kfree(power_zone->constraints);
err_const_alloc:
kfree(power_zone->name);
err_name_alloc:
idr_remove(power_zone->parent_idr, power_zone->id);
err_idr_alloc:
if (power_zone->allocated)
kfree(power_zone);
mutex_unlock(&control_type->lock);
return ERR_PTR(result);
}
EXPORT_SYMBOL_GPL(powercap_register_zone);
int powercap_unregister_zone(struct powercap_control_type *control_type,
struct powercap_zone *power_zone)
{
if (!power_zone || !control_type)
return -EINVAL;
mutex_lock(&control_type->lock);
control_type->nr_zones--;
mutex_unlock(&control_type->lock);
device_unregister(&power_zone->dev);
return 0;
}
EXPORT_SYMBOL_GPL(powercap_unregister_zone);
struct powercap_control_type *powercap_register_control_type(
struct powercap_control_type *control_type,
const char *name,
const struct powercap_control_type_ops *ops)
{
int result;
if (!name)
return ERR_PTR(-EINVAL);
if (control_type) {
if (!ops || !ops->release)
return ERR_PTR(-EINVAL);
memset(control_type, 0, sizeof(*control_type));
} else {
control_type = kzalloc(sizeof(*control_type), GFP_KERNEL);
if (!control_type)
return ERR_PTR(-ENOMEM);
control_type->allocated = true;
}
mutex_init(&control_type->lock);
control_type->ops = ops;
INIT_LIST_HEAD(&control_type->node);
control_type->dev.class = &powercap_class;
dev_set_name(&control_type->dev, "%s", name);
result = device_register(&control_type->dev);
if (result) {
if (control_type->allocated)
kfree(control_type);
return ERR_PTR(result);
}
idr_init(&control_type->idr);
mutex_lock(&powercap_cntrl_list_lock);
list_add_tail(&control_type->node, &powercap_cntrl_list);
mutex_unlock(&powercap_cntrl_list_lock);
return control_type;
}
EXPORT_SYMBOL_GPL(powercap_register_control_type);
int powercap_unregister_control_type(struct powercap_control_type *control_type)
{
struct powercap_control_type *pos = NULL;
if (control_type->nr_zones) {
dev_err(&control_type->dev, "Zones of this type still not freed\n");
return -EINVAL;
}
mutex_lock(&powercap_cntrl_list_lock);
list_for_each_entry(pos, &powercap_cntrl_list, node) {
if (pos == control_type) {
list_del(&control_type->node);
mutex_unlock(&powercap_cntrl_list_lock);
device_unregister(&control_type->dev);
return 0;
}
}
mutex_unlock(&powercap_cntrl_list_lock);
return -ENODEV;
}
EXPORT_SYMBOL_GPL(powercap_unregister_control_type);
static int __init powercap_init(void)
{
int result;
result = seed_constraint_attributes();
if (result)
return result;
return class_register(&powercap_class);
}
fs_initcall(powercap_init);
MODULE_DESCRIPTION("PowerCap sysfs Driver");
MODULE_AUTHOR("Srinivas Pandruvada <[email protected]>");
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