Commit 85cfb3a8 authored by Guenter Roeck's avatar Guenter Roeck
Browse files

hwmon: (pmbus) Use krealloc to allocate attribute memory 



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: default avatarGuenter Roeck <linux@roeck-us.net>
parent e1e081a7

drivers/hwmon/pmbus/pmbus_core.c

+31 −109
Original line number Diff line number Diff line
@@ -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);

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