drivers/net/ethernet/intel/i40e/i40e_configfs.c - kernel/msm-4.19 - Gitiles

 /*******************************************************************************
  *
  * Intel Ethernet Controller XL710 Family Linux Driver
  * Copyright(c) 2013 - 2015 Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License along
  * with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  * The full GNU General Public License is included in this distribution in
  * the file called "COPYING".
  *
  * Contact Information:
  * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  *
  ******************************************************************************/

 #include <linux/configfs.h>
 #include "i40e.h"

 #if IS_ENABLED(CONFIG_I40E_CONFIGFS_FS)

 /**
  * configfs structure for i40e
  *
  * This file adds code for configfs support for the i40e driver.  This sets
  * up a filesystem under /sys/kernel/config in which configuration changes
  * can be made for the driver's netdevs.
  *
  * The initialization in this code creates the "i40e" entry in the configfs
  * system.  After that, the user needs to use mkdir to create configurations
  * for specific netdev ports; for example "mkdir eth3".  This code will verify
  * that such a netdev exists and that it is owned by i40e.
  *
  **/

 struct i40e_cfgfs_vsi {
 	struct config_item item;
 	struct i40e_vsi *vsi;
 };

 static inline struct i40e_cfgfs_vsi *to_i40e_cfgfs_vsi(struct config_item *item)
 {
 	return item ? container_of(item, struct i40e_cfgfs_vsi, item) : NULL;
 }

 static struct configfs_attribute i40e_cfgfs_vsi_attr_min_bw = {
 	.ca_owner = THIS_MODULE,
 	.ca_name = "min_bw",
 	.ca_mode = S_IRUGO | S_IWUSR,
 };

 static struct configfs_attribute i40e_cfgfs_vsi_attr_max_bw = {
 	.ca_owner = THIS_MODULE,
 	.ca_name = "max_bw",
 	.ca_mode = S_IRUGO | S_IWUSR,
 };

 static struct configfs_attribute i40e_cfgfs_vsi_attr_commit = {
 	.ca_owner = THIS_MODULE,
 	.ca_name = "commit",
 	.ca_mode = S_IRUGO | S_IWUSR,
 };

 static struct configfs_attribute i40e_cfgfs_vsi_attr_port_count = {
 	.ca_owner = THIS_MODULE,
 	.ca_name = "ports",
 	.ca_mode = S_IRUGO | S_IWUSR,
 };

 static struct configfs_attribute i40e_cfgfs_vsi_attr_part_count = {
 	.ca_owner = THIS_MODULE,
 	.ca_name = "partitions",
 	.ca_mode = S_IRUGO | S_IWUSR,
 };

 static struct configfs_attribute *i40e_cfgfs_vsi_attrs[] = {
 	&i40e_cfgfs_vsi_attr_min_bw,
 	&i40e_cfgfs_vsi_attr_max_bw,
 	&i40e_cfgfs_vsi_attr_commit,
 	&i40e_cfgfs_vsi_attr_port_count,
 	&i40e_cfgfs_vsi_attr_part_count,
 	NULL,
 };

 /**
  * i40e_cfgfs_vsi_attr_show - Show a VSI's NPAR BW partition info
  * @item: A pointer back to the configfs item created on driver load
  * @attr: A pointer to this item's configuration attribute
  * @page: A pointer to the output buffer
  **/
 static ssize_t i40e_cfgfs_vsi_attr_show(struct config_item *item,
 					struct configfs_attribute *attr,
 					char *page)
 {
 	struct i40e_cfgfs_vsi *i40e_cfgfs_vsi = to_i40e_cfgfs_vsi(item);
 	struct i40e_pf *pf = i40e_cfgfs_vsi->vsi->back;
 	ssize_t count;

 	if (i40e_cfgfs_vsi->vsi != pf->vsi[pf->lan_vsi])
 		return 0;

 	if (strncmp(attr->ca_name, "min_bw", 6) == 0)
 		count = sprintf(page, "%s %s %d%%\n",
 				i40e_cfgfs_vsi->vsi->netdev->name,
 				(pf->npar_min_bw & I40E_ALT_BW_RELATIVE_MASK) ?
 				"Relative Min BW" : "Absolute Min BW",
 				pf->npar_min_bw & I40E_ALT_BW_VALUE_MASK);
 	else if (strncmp(attr->ca_name, "max_bw", 6) == 0)
 		count = sprintf(page, "%s %s %d%%\n",
 				i40e_cfgfs_vsi->vsi->netdev->name,
 				(pf->npar_max_bw & I40E_ALT_BW_RELATIVE_MASK) ?
 				"Relative Max BW" : "Absolute Max BW",
 				pf->npar_max_bw & I40E_ALT_BW_VALUE_MASK);
 	else if (strncmp(attr->ca_name, "ports", 5) == 0)
 		count = sprintf(page, "%d\n",
 				pf->hw.num_ports);
 	else if (strncmp(attr->ca_name, "partitions", 10) == 0)
 		count = sprintf(page, "%d\n",
 				pf->hw.num_partitions);
 	else
 		return 0;

 	return count;
 }

 /**
  * i40e_cfgfs_vsi_attr_store - Show a VSI's NPAR BW partition info
  * @item: A pointer back to the configfs item created on driver load
  * @attr: A pointer to this item's configuration attribute
  * @page: A pointer to the user input buffer holding the user input values
  **/
 static ssize_t i40e_cfgfs_vsi_attr_store(struct config_item *item,
 					 struct configfs_attribute *attr,
 					 const char *page, size_t count)
 {
 	struct i40e_cfgfs_vsi *i40e_cfgfs_vsi = to_i40e_cfgfs_vsi(item);
 	struct i40e_pf *pf = i40e_cfgfs_vsi->vsi->back;
 	char *p = (char *)page;
 	int rc;
 	unsigned long tmp;

 	if (i40e_cfgfs_vsi->vsi != pf->vsi[pf->lan_vsi])
 		return 0;

 	if (!p || (*p && (*p == '\n')))
 		return -EINVAL;

 	rc = kstrtoul(p, 10, &tmp);
 	if (rc)
 		return rc;
 	if (tmp > 100)
 		return -ERANGE;

 	if (strncmp(attr->ca_name, "min_bw", 6) == 0) {
 		if (tmp > (pf->npar_max_bw & I40E_ALT_BW_VALUE_MASK))
 			return -ERANGE;
 		/* Preserve the valid and relative BW bits - the rest is
 		 * don't care.
 		 */
 		pf->npar_min_bw &= (I40E_ALT_BW_RELATIVE_MASK |
 				    I40E_ALT_BW_VALID_MASK);
 		pf->npar_min_bw |= (tmp & I40E_ALT_BW_VALUE_MASK);
 		i40e_set_npar_bw_setting(pf);
 	} else if (strncmp(attr->ca_name, "max_bw", 6) == 0) {
 		if (tmp < 1 ||
 		    tmp < (pf->npar_min_bw & I40E_ALT_BW_VALUE_MASK))
 			return -ERANGE;
 		/* Preserve the valid and relative BW bits - the rest is
 		 * don't care.
 		 */
 		pf->npar_max_bw &= (I40E_ALT_BW_RELATIVE_MASK |
 				    I40E_ALT_BW_VALID_MASK);
 		pf->npar_max_bw |= (tmp & I40E_ALT_BW_VALUE_MASK);
 		i40e_set_npar_bw_setting(pf);
 	} else if (strncmp(attr->ca_name, "commit", 6) == 0 && tmp == 1) {
 		if (i40e_commit_npar_bw_setting(pf))
 			return -EIO;
 	}

 	return count;
 }

 /**
  * i40e_cfgfs_vsi_release - Free up the configuration item memory
  * @item: A pointer back to the configfs item created on driver load
  **/
 static void i40e_cfgfs_vsi_release(struct config_item *item)
 {
 	kfree(to_i40e_cfgfs_vsi(item));
 }

 static struct configfs_item_operations i40e_cfgfs_vsi_item_ops = {
 	.release		= i40e_cfgfs_vsi_release,
 	.show_attribute		= i40e_cfgfs_vsi_attr_show,
 	.store_attribute	= i40e_cfgfs_vsi_attr_store,
 };

 static struct config_item_type i40e_cfgfs_vsi_type = {
 	.ct_item_ops	= &i40e_cfgfs_vsi_item_ops,
 	.ct_attrs	= i40e_cfgfs_vsi_attrs,
 	.ct_owner	= THIS_MODULE,
 };

 struct i40e_cfgfs_group {
 	struct config_group group;
 };

 /**
  * to_i40e_cfgfs_group - Get the group pointer from the config item
  * @item: A pointer back to the configfs item created on driver load
  **/
 static inline struct i40e_cfgfs_group *
 to_i40e_cfgfs_group(struct config_item *item)
 {
 	return item ? container_of(to_config_group(item),
 				   struct i40e_cfgfs_group, group) : NULL;
 }

 /**
  * i40e_cfgfs_group_make_item - Create the configfs item with group container
  * @group: A pointer to our configfs group
  * @name: A pointer to the nume of the device we're looking for
  **/
 static struct config_item *
 i40e_cfgfs_group_make_item(struct config_group *group, const char *name)
 {
 	struct i40e_cfgfs_vsi *i40e_cfgfs_vsi;
 	struct net_device *netdev;
 	struct i40e_netdev_priv *np;

 	read_lock(&dev_base_lock);
 	netdev = first_net_device(&init_net);
 	while (netdev) {
 		if (strncmp(netdev->name, name, sizeof(netdev->name)) == 0)
 			break;
 		netdev = next_net_device(netdev);
 	}
 	read_unlock(&dev_base_lock);

 	if (!netdev)
 		return ERR_PTR(-ENODEV);

 	/* is this netdev owned by i40e? */
 	if (netdev->netdev_ops->ndo_open != i40e_open)
 		return ERR_PTR(-EACCES);

 	i40e_cfgfs_vsi = kzalloc(sizeof(*i40e_cfgfs_vsi), GFP_KERNEL);
 	if (!i40e_cfgfs_vsi)
 		return ERR_PTR(-ENOMEM);

 	np = netdev_priv(netdev);
 	i40e_cfgfs_vsi->vsi = np->vsi;
 	config_item_init_type_name(&i40e_cfgfs_vsi->item, name,
 				   &i40e_cfgfs_vsi_type);

 	return &i40e_cfgfs_vsi->item;
 }

 static struct configfs_attribute i40e_cfgfs_group_attr_description = {
 	.ca_owner = THIS_MODULE,
 	.ca_name = "description",
 	.ca_mode = S_IRUGO,
 };

 static struct configfs_attribute *i40e_cfgfs_group_attrs[] = {
 	&i40e_cfgfs_group_attr_description,
 	NULL,
 };

 static ssize_t i40e_cfgfs_group_attr_show(struct config_item *item,
 					  struct configfs_attribute *attr,
 					  char *page)
 {
 	return sprintf(page,
 "i40e\n"
 "\n"
 "This subsystem allows the modification of network port configurations.\n"
 "To start, use the name of the network port to be configured in a 'mkdir'\n"
 "command, e.g. 'mkdir eth3'.\n");
 }

 static void i40e_cfgfs_group_release(struct config_item *item)
 {
 	kfree(to_i40e_cfgfs_group(item));
 }

 static struct configfs_item_operations i40e_cfgfs_group_item_ops = {
 	.release	= i40e_cfgfs_group_release,
 	.show_attribute	= i40e_cfgfs_group_attr_show,
 };

 /* Note that, since no extra work is required on ->drop_item(),
  * no ->drop_item() is provided.
  */
 static struct configfs_group_operations i40e_cfgfs_group_ops = {
 	.make_item	= i40e_cfgfs_group_make_item,
 };

 static struct config_item_type i40e_cfgfs_group_type = {
 	.ct_item_ops	= &i40e_cfgfs_group_item_ops,
 	.ct_group_ops	= &i40e_cfgfs_group_ops,
 	.ct_attrs	= i40e_cfgfs_group_attrs,
 	.ct_owner	= THIS_MODULE,
 };

 static struct configfs_subsystem i40e_cfgfs_group_subsys = {
 	.su_group = {
 		.cg_item = {
 			.ci_namebuf = "i40e",
 			.ci_type = &i40e_cfgfs_group_type,
 		},
 	},
 };

 /**
  * i40e_configfs_init - Initialize configfs support for our driver
  **/
 int i40e_configfs_init(void)
 {
 	int ret;
 	struct configfs_subsystem *subsys;

 	subsys = &i40e_cfgfs_group_subsys;

 	config_group_init(&subsys->su_group);
 	mutex_init(&subsys->su_mutex);
 	ret = configfs_register_subsystem(subsys);
 	if (ret) {
 		pr_err("Error %d while registering configfs subsystem %s\n",
 		       ret, subsys->su_group.cg_item.ci_namebuf);
 		return ret;
 	}

 	return 0;
 }

 /**
  * i40e_configfs_init - Bail out - unregister configfs subsystem and release
  **/
 void i40e_configfs_exit(void)
 {
 	configfs_unregister_subsystem(&i40e_cfgfs_group_subsys);
 }
 #endif /* IS_ENABLED(CONFIG_I40E_CONFIGFS_FS) */
	/*******************************************************************************
	*
	* Intel Ethernet Controller XL710 Family Linux Driver
	* Copyright(c) 2013 - 2015 Intel Corporation.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License along
	* with this program. If not, see <http://www.gnu.org/licenses/>.
	*
	* The full GNU General Public License is included in this distribution in
	* the file called "COPYING".
	*
	* Contact Information:
	* e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
	* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
	*
	******************************************************************************/

	#include <linux/configfs.h>
	#include "i40e.h"

	#if IS_ENABLED(CONFIG_I40E_CONFIGFS_FS)

	/**
	* configfs structure for i40e
	*
	* This file adds code for configfs support for the i40e driver. This sets
	* up a filesystem under /sys/kernel/config in which configuration changes
	* can be made for the driver's netdevs.
	*
	* The initialization in this code creates the "i40e" entry in the configfs
	* system. After that, the user needs to use mkdir to create configurations
	* for specific netdev ports; for example "mkdir eth3". This code will verify
	* that such a netdev exists and that it is owned by i40e.
	*
	**/

	struct i40e_cfgfs_vsi {
	struct config_item item;
	struct i40e_vsi *vsi;
	};

	static inline struct i40e_cfgfs_vsi to_i40e_cfgfs_vsi(struct config_item item)
	{
	return item ? container_of(item, struct i40e_cfgfs_vsi, item) : NULL;
	}

	static struct configfs_attribute i40e_cfgfs_vsi_attr_min_bw = {
	.ca_owner = THIS_MODULE,
	.ca_name = "min_bw",
	.ca_mode = S_IRUGO \| S_IWUSR,
	};

	static struct configfs_attribute i40e_cfgfs_vsi_attr_max_bw = {
	.ca_owner = THIS_MODULE,
	.ca_name = "max_bw",
	.ca_mode = S_IRUGO \| S_IWUSR,
	};

	static struct configfs_attribute i40e_cfgfs_vsi_attr_commit = {
	.ca_owner = THIS_MODULE,
	.ca_name = "commit",
	.ca_mode = S_IRUGO \| S_IWUSR,
	};

	static struct configfs_attribute i40e_cfgfs_vsi_attr_port_count = {
	.ca_owner = THIS_MODULE,
	.ca_name = "ports",
	.ca_mode = S_IRUGO \| S_IWUSR,
	};

	static struct configfs_attribute i40e_cfgfs_vsi_attr_part_count = {
	.ca_owner = THIS_MODULE,
	.ca_name = "partitions",
	.ca_mode = S_IRUGO \| S_IWUSR,
	};

	static struct configfs_attribute *i40e_cfgfs_vsi_attrs[] = {
	&i40e_cfgfs_vsi_attr_min_bw,
	&i40e_cfgfs_vsi_attr_max_bw,
	&i40e_cfgfs_vsi_attr_commit,
	&i40e_cfgfs_vsi_attr_port_count,
	&i40e_cfgfs_vsi_attr_part_count,
	NULL,
	};

	/**
	* i40e_cfgfs_vsi_attr_show - Show a VSI's NPAR BW partition info
	* @item: A pointer back to the configfs item created on driver load
	* @attr: A pointer to this item's configuration attribute
	* @page: A pointer to the output buffer
	**/
	static ssize_t i40e_cfgfs_vsi_attr_show(struct config_item *item,
	struct configfs_attribute *attr,
	char *page)
	{
	struct i40e_cfgfs_vsi *i40e_cfgfs_vsi = to_i40e_cfgfs_vsi(item);
	struct i40e_pf *pf = i40e_cfgfs_vsi->vsi->back;
	ssize_t count;

	if (i40e_cfgfs_vsi->vsi != pf->vsi[pf->lan_vsi])
	return 0;

	if (strncmp(attr->ca_name, "min_bw", 6) == 0)
	count = sprintf(page, "%s %s %d%%\n",
	i40e_cfgfs_vsi->vsi->netdev->name,
	(pf->npar_min_bw & I40E_ALT_BW_RELATIVE_MASK) ?
	"Relative Min BW" : "Absolute Min BW",
	pf->npar_min_bw & I40E_ALT_BW_VALUE_MASK);
	else if (strncmp(attr->ca_name, "max_bw", 6) == 0)
	count = sprintf(page, "%s %s %d%%\n",
	i40e_cfgfs_vsi->vsi->netdev->name,
	(pf->npar_max_bw & I40E_ALT_BW_RELATIVE_MASK) ?
	"Relative Max BW" : "Absolute Max BW",
	pf->npar_max_bw & I40E_ALT_BW_VALUE_MASK);
	else if (strncmp(attr->ca_name, "ports", 5) == 0)
	count = sprintf(page, "%d\n",
	pf->hw.num_ports);
	else if (strncmp(attr->ca_name, "partitions", 10) == 0)
	count = sprintf(page, "%d\n",
	pf->hw.num_partitions);
	else
	return 0;

	return count;
	}

	/**
	* i40e_cfgfs_vsi_attr_store - Show a VSI's NPAR BW partition info
	* @item: A pointer back to the configfs item created on driver load
	* @attr: A pointer to this item's configuration attribute
	* @page: A pointer to the user input buffer holding the user input values
	**/
	static ssize_t i40e_cfgfs_vsi_attr_store(struct config_item *item,
	struct configfs_attribute *attr,
	const char *page, size_t count)
	{
	struct i40e_cfgfs_vsi *i40e_cfgfs_vsi = to_i40e_cfgfs_vsi(item);
	struct i40e_pf *pf = i40e_cfgfs_vsi->vsi->back;
	char p = (char )page;
	int rc;
	unsigned long tmp;

	if (i40e_cfgfs_vsi->vsi != pf->vsi[pf->lan_vsi])
	return 0;

	if (!p \|\| (p && (p == '\n')))
	return -EINVAL;

	rc = kstrtoul(p, 10, &tmp);
	if (rc)
	return rc;
	if (tmp > 100)
	return -ERANGE;

	if (strncmp(attr->ca_name, "min_bw", 6) == 0) {
	if (tmp > (pf->npar_max_bw & I40E_ALT_BW_VALUE_MASK))
	return -ERANGE;
	/* Preserve the valid and relative BW bits - the rest is
	* don't care.
	*/
	pf->npar_min_bw &= (I40E_ALT_BW_RELATIVE_MASK \|
	I40E_ALT_BW_VALID_MASK);
	pf->npar_min_bw \|= (tmp & I40E_ALT_BW_VALUE_MASK);
	i40e_set_npar_bw_setting(pf);
	} else if (strncmp(attr->ca_name, "max_bw", 6) == 0) {
	if (tmp < 1 \|\|
	tmp < (pf->npar_min_bw & I40E_ALT_BW_VALUE_MASK))
	return -ERANGE;
	/* Preserve the valid and relative BW bits - the rest is
	* don't care.
	*/
	pf->npar_max_bw &= (I40E_ALT_BW_RELATIVE_MASK \|
	I40E_ALT_BW_VALID_MASK);
	pf->npar_max_bw \|= (tmp & I40E_ALT_BW_VALUE_MASK);
	i40e_set_npar_bw_setting(pf);
	} else if (strncmp(attr->ca_name, "commit", 6) == 0 && tmp == 1) {
	if (i40e_commit_npar_bw_setting(pf))
	return -EIO;
	}

	return count;
	}

	/**
	* i40e_cfgfs_vsi_release - Free up the configuration item memory
	* @item: A pointer back to the configfs item created on driver load
	**/
	static void i40e_cfgfs_vsi_release(struct config_item *item)
	{
	kfree(to_i40e_cfgfs_vsi(item));
	}

	static struct configfs_item_operations i40e_cfgfs_vsi_item_ops = {
	.release = i40e_cfgfs_vsi_release,
	.show_attribute = i40e_cfgfs_vsi_attr_show,
	.store_attribute = i40e_cfgfs_vsi_attr_store,
	};

	static struct config_item_type i40e_cfgfs_vsi_type = {
	.ct_item_ops = &i40e_cfgfs_vsi_item_ops,
	.ct_attrs = i40e_cfgfs_vsi_attrs,
	.ct_owner = THIS_MODULE,
	};

	struct i40e_cfgfs_group {
	struct config_group group;
	};

	/**
	* to_i40e_cfgfs_group - Get the group pointer from the config item
	* @item: A pointer back to the configfs item created on driver load
	**/
	static inline struct i40e_cfgfs_group *
	to_i40e_cfgfs_group(struct config_item *item)
	{
	return item ? container_of(to_config_group(item),
	struct i40e_cfgfs_group, group) : NULL;
	}

	/**
	* i40e_cfgfs_group_make_item - Create the configfs item with group container
	* @group: A pointer to our configfs group
	* @name: A pointer to the nume of the device we're looking for
	**/
	static struct config_item *
	i40e_cfgfs_group_make_item(struct config_group group, const char name)
	{
	struct i40e_cfgfs_vsi *i40e_cfgfs_vsi;
	struct net_device *netdev;
	struct i40e_netdev_priv *np;

	read_lock(&dev_base_lock);
	netdev = first_net_device(&init_net);
	while (netdev) {
	if (strncmp(netdev->name, name, sizeof(netdev->name)) == 0)
	break;
	netdev = next_net_device(netdev);
	}
	read_unlock(&dev_base_lock);

	if (!netdev)
	return ERR_PTR(-ENODEV);

	/* is this netdev owned by i40e? */
	if (netdev->netdev_ops->ndo_open != i40e_open)
	return ERR_PTR(-EACCES);

	i40e_cfgfs_vsi = kzalloc(sizeof(*i40e_cfgfs_vsi), GFP_KERNEL);
	if (!i40e_cfgfs_vsi)
	return ERR_PTR(-ENOMEM);

	np = netdev_priv(netdev);
	i40e_cfgfs_vsi->vsi = np->vsi;
	config_item_init_type_name(&i40e_cfgfs_vsi->item, name,
	&i40e_cfgfs_vsi_type);

	return &i40e_cfgfs_vsi->item;
	}

	static struct configfs_attribute i40e_cfgfs_group_attr_description = {
	.ca_owner = THIS_MODULE,
	.ca_name = "description",
	.ca_mode = S_IRUGO,
	};

	static struct configfs_attribute *i40e_cfgfs_group_attrs[] = {
	&i40e_cfgfs_group_attr_description,
	NULL,
	};

	static ssize_t i40e_cfgfs_group_attr_show(struct config_item *item,
	struct configfs_attribute *attr,
	char *page)
	{
	return sprintf(page,
	"i40e\n"
	"\n"
	"This subsystem allows the modification of network port configurations.\n"
	"To start, use the name of the network port to be configured in a 'mkdir'\n"
	"command, e.g. 'mkdir eth3'.\n");
	}

	static void i40e_cfgfs_group_release(struct config_item *item)
	{
	kfree(to_i40e_cfgfs_group(item));
	}

	static struct configfs_item_operations i40e_cfgfs_group_item_ops = {
	.release = i40e_cfgfs_group_release,
	.show_attribute = i40e_cfgfs_group_attr_show,
	};

	/* Note that, since no extra work is required on ->drop_item(),
	* no ->drop_item() is provided.
	*/
	static struct configfs_group_operations i40e_cfgfs_group_ops = {
	.make_item = i40e_cfgfs_group_make_item,
	};

	static struct config_item_type i40e_cfgfs_group_type = {
	.ct_item_ops = &i40e_cfgfs_group_item_ops,
	.ct_group_ops = &i40e_cfgfs_group_ops,
	.ct_attrs = i40e_cfgfs_group_attrs,
	.ct_owner = THIS_MODULE,
	};

	static struct configfs_subsystem i40e_cfgfs_group_subsys = {
	.su_group = {
	.cg_item = {
	.ci_namebuf = "i40e",
	.ci_type = &i40e_cfgfs_group_type,
	},
	},
	};

	/**
	* i40e_configfs_init - Initialize configfs support for our driver
	**/
	int i40e_configfs_init(void)
	{
	int ret;
	struct configfs_subsystem *subsys;

	subsys = &i40e_cfgfs_group_subsys;

	config_group_init(&subsys->su_group);
	mutex_init(&subsys->su_mutex);
	ret = configfs_register_subsystem(subsys);
	if (ret) {
	pr_err("Error %d while registering configfs subsystem %s\n",
	ret, subsys->su_group.cg_item.ci_namebuf);
	return ret;
	}

	return 0;
	}

	/**
	* i40e_configfs_init - Bail out - unregister configfs subsystem and release
	**/
	void i40e_configfs_exit(void)
	{
	configfs_unregister_subsystem(&i40e_cfgfs_group_subsys);
	}
	#endif /* IS_ENABLED(CONFIG_I40E_CONFIGFS_FS) */