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hwmon: (pmbus) Use krealloc to allocate attribute memory

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So far, attribute memory was allocated by pre-calculating the maximum possible
amount of attributes. Not only does this waste memory, it is also risky because
the calculation might be wrong. It also requires a lot of defines to specify
the maximum number of attributes per class.

Allocate attribute memory using krealloc() instead. That means we have to use
kfree(), since devm_krealloc() does not exist, but that is still less costly
and less risky than trying to predict the number of attributes at the beginning.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Guenter Roeck 2013-01-20 21:00:01 -08:00
parent e1e081a7e3
commit 85cfb3a835
1 changed files with 31 additions and 109 deletions
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140
drivers/hwmon/pmbus/pmbus_core.c
View file

@ -31,39 +31,10 @@
#include "pmbus.h"
/*
* Constants needed to determine number of sensors, booleans, and labels.
* Number of additional attribute pointers to allocate
* with each call to krealloc
*/
#define PMBUS_MAX_INPUT_SENSORS 22 /* 10*volt, 7*curr, 5*power */
#define PMBUS_VOUT_SENSORS_PER_PAGE 9 /* input, min, max, lcrit,
crit, lowest, highest, avg,
reset */
#define PMBUS_IOUT_SENSORS_PER_PAGE 8 /* input, min, max, crit,
lowest, highest, avg,
reset */
#define PMBUS_POUT_SENSORS_PER_PAGE 7 /* input, cap, max, crit,
* highest, avg, reset
*/
#define PMBUS_MAX_SENSORS_PER_FAN 1 /* input */
#define PMBUS_MAX_SENSORS_PER_TEMP 9 /* input, min, max, lcrit,
* crit, lowest, highest, avg,
* reset
*/
#define PMBUS_MAX_INPUT_BOOLEANS 7 /* v: min_alarm, max_alarm,
lcrit_alarm, crit_alarm;
c: alarm, crit_alarm;
p: crit_alarm */
#define PMBUS_VOUT_BOOLEANS_PER_PAGE 4 /* min_alarm, max_alarm,
lcrit_alarm, crit_alarm */
#define PMBUS_IOUT_BOOLEANS_PER_PAGE 3 /* alarm, lcrit_alarm,
crit_alarm */
#define PMBUS_POUT_BOOLEANS_PER_PAGE 3 /* cap_alarm, alarm, crit_alarm
*/
#define PMBUS_MAX_BOOLEANS_PER_FAN 2 /* alarm, fault */
#define PMBUS_MAX_BOOLEANS_PER_TEMP 4 /* min_alarm, max_alarm,
lcrit_alarm, crit_alarm */
#define PMBUS_MAX_INPUT_LABELS 4 /* vin, vcap, iin, pin */
#define PMBUS_ATTR_ALLOC_SIZE 32
/*
* status, status_vout, status_iout, status_fans, status_fan34, and status_temp
@ -127,7 +98,6 @@ struct pmbus_data {
int max_attributes;
int num_attributes;
struct attribute **attributes;
struct attribute_group group;
struct pmbus_sensor *sensors;
@ -790,6 +760,22 @@ static ssize_t pmbus_show_label(struct device *dev,
return snprintf(buf, PAGE_SIZE, "%s\n", label->label);
}
static int pmbus_add_attribute(struct pmbus_data *data, struct attribute *attr)
{
if (data->num_attributes >= data->max_attributes - 1) {
data->max_attributes += PMBUS_ATTR_ALLOC_SIZE;
data->group.attrs = krealloc(data->group.attrs,
sizeof(struct attribute *) *
data->max_attributes, GFP_KERNEL);
if (data->group.attrs == NULL)
return -ENOMEM;
}
data->group.attrs[data->num_attributes++] = attr;
data->group.attrs[data->num_attributes] = NULL;
return 0;
}
static void pmbus_dev_attr_init(struct device_attribute *dev_attr,
const char *name,
umode_t mode,
@ -831,8 +817,6 @@ static int pmbus_add_boolean(struct pmbus_data *data,
struct pmbus_boolean *boolean;
struct sensor_device_attribute *a;
BUG_ON(data->num_attributes >= data->max_attributes);
boolean = devm_kzalloc(data->dev, sizeof(*boolean), GFP_KERNEL);
if (!boolean)
return -ENOMEM;
@ -845,9 +829,8 @@ static int pmbus_add_boolean(struct pmbus_data *data,
boolean->s2 = s2;
pmbus_attr_init(a, boolean->name, S_IRUGO, pmbus_show_boolean, NULL,
(reg << 8) | mask);
data->attributes[data->num_attributes++] = &a->dev_attr.attr;
return 0;
return pmbus_add_attribute(data, &a->dev_attr.attr);
}
static struct pmbus_sensor *pmbus_add_sensor(struct pmbus_data *data,
@ -859,8 +842,6 @@ static struct pmbus_sensor *pmbus_add_sensor(struct pmbus_data *data,
struct pmbus_sensor *sensor;
struct device_attribute *a;
BUG_ON(data->num_attributes >= data->max_attributes);
sensor = devm_kzalloc(data->dev, sizeof(*sensor), GFP_KERNEL);
if (!sensor)
return NULL;
@ -876,7 +857,9 @@ static struct pmbus_sensor *pmbus_add_sensor(struct pmbus_data *data,
readonly ? S_IRUGO : S_IRUGO | S_IWUSR,
pmbus_show_sensor, pmbus_set_sensor);
data->attributes[data->num_attributes++] = &a->attr;
if (pmbus_add_attribute(data, &a->attr))
return NULL;
sensor->next = data->sensors;
data->sensors = sensor;
@ -890,8 +873,6 @@ static int pmbus_add_label(struct pmbus_data *data,
struct pmbus_label *label;
struct device_attribute *a;
BUG_ON(data->num_attributes >= data->max_attributes);
label = devm_kzalloc(data->dev, sizeof(*label), GFP_KERNEL);
if (!label)
return -ENOMEM;
@ -906,62 +887,7 @@ static int pmbus_add_label(struct pmbus_data *data,
index);
pmbus_dev_attr_init(a, label->name, S_IRUGO, pmbus_show_label, NULL);
data->attributes[data->num_attributes++] = &a->attr;
return 0;
}
/*
* Determine maximum number of sensors, booleans, and labels.
* To keep things simple, only make a rough high estimate.
*/
static void pmbus_find_max_attr(struct i2c_client *client,
struct pmbus_data *data)
{
const struct pmbus_driver_info *info = data->info;
int page, max_sensors, max_booleans, max_labels;
max_sensors = PMBUS_MAX_INPUT_SENSORS;
max_booleans = PMBUS_MAX_INPUT_BOOLEANS;
max_labels = PMBUS_MAX_INPUT_LABELS;
for (page = 0; page < info->pages; page++) {
if (info->func[page] & PMBUS_HAVE_VOUT) {
max_sensors += PMBUS_VOUT_SENSORS_PER_PAGE;
max_booleans += PMBUS_VOUT_BOOLEANS_PER_PAGE;
max_labels++;
}
if (info->func[page] & PMBUS_HAVE_IOUT) {
max_sensors += PMBUS_IOUT_SENSORS_PER_PAGE;
max_booleans += PMBUS_IOUT_BOOLEANS_PER_PAGE;
max_labels++;
}
if (info->func[page] & PMBUS_HAVE_POUT) {
max_sensors += PMBUS_POUT_SENSORS_PER_PAGE;
max_booleans += PMBUS_POUT_BOOLEANS_PER_PAGE;
max_labels++;
}
if (info->func[page] & PMBUS_HAVE_FAN12) {
max_sensors += 2 * PMBUS_MAX_SENSORS_PER_FAN;
max_booleans += 2 * PMBUS_MAX_BOOLEANS_PER_FAN;
}
if (info->func[page] & PMBUS_HAVE_FAN34) {
max_sensors += 2 * PMBUS_MAX_SENSORS_PER_FAN;
max_booleans += 2 * PMBUS_MAX_BOOLEANS_PER_FAN;
}
if (info->func[page] & PMBUS_HAVE_TEMP) {
max_sensors += PMBUS_MAX_SENSORS_PER_TEMP;
max_booleans += PMBUS_MAX_BOOLEANS_PER_TEMP;
}
if (info->func[page] & PMBUS_HAVE_TEMP2) {
max_sensors += PMBUS_MAX_SENSORS_PER_TEMP;
max_booleans += PMBUS_MAX_BOOLEANS_PER_TEMP;
}
if (info->func[page] & PMBUS_HAVE_TEMP3) {
max_sensors += PMBUS_MAX_SENSORS_PER_TEMP;
max_booleans += PMBUS_MAX_BOOLEANS_PER_TEMP;
}
}
data->max_attributes = max_sensors + max_booleans + max_labels;
return pmbus_add_attribute(data, &a->attr);
}
/*
@ -1709,8 +1635,6 @@ static int pmbus_identify_common(struct i2c_client *client,
}
}
/* Determine maximum number of sensors, booleans, and labels */
pmbus_find_max_attr(client, data);
pmbus_clear_fault_page(client, 0);
return 0;
}
@ -1770,14 +1694,9 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
return ret;
}
data->attributes = devm_kzalloc(dev, sizeof(struct attribute *)
* data->max_attributes, GFP_KERNEL);
if (!data->attributes)
return -ENOMEM;
ret = pmbus_find_attributes(client, data);
if (ret)
return ret;
goto out_kfree;
/*
* If there are no attributes, something is wrong.
@ -1785,15 +1704,15 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
*/
if (!data->num_attributes) {
dev_err(dev, "No attributes found\n");
return -ENODEV;
ret = -ENODEV;
goto out_kfree;
}
/* Register sysfs hooks */
data->group.attrs = data->attributes;
ret = sysfs_create_group(&dev->kobj, &data->group);
if (ret) {
dev_err(dev, "Failed to create sysfs entries\n");
return ret;
goto out_kfree;
}
data->hwmon_dev = hwmon_device_register(dev);
if (IS_ERR(data->hwmon_dev)) {
@ -1805,6 +1724,8 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
out_hwmon_device_register:
sysfs_remove_group(&dev->kobj, &data->group);
out_kfree:
kfree(data->group.attrs);
return ret;
}
EXPORT_SYMBOL_GPL(pmbus_do_probe);
@ -1814,6 +1735,7 @@ int pmbus_do_remove(struct i2c_client *client)
struct pmbus_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &data->group);
kfree(data->group.attrs);
return 0;
}
EXPORT_SYMBOL_GPL(pmbus_do_remove);