net/switchdev/switchdev.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * net/switchdev/switchdev.c - Switch device API
  * Copyright (c) 2014-2015 Jiri Pirko <jiri@resnulli.us>
  * Copyright (c) 2014-2015 Scott Feldman <sfeldma@gmail.com>
  */

 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/init.h>
 #include <linux/mutex.h>
 #include <linux/notifier.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/if_bridge.h>
 #include <linux/list.h>
 #include <linux/workqueue.h>
 #include <linux/if_vlan.h>
 #include <linux/rtnetlink.h>
 #include <net/switchdev.h>

 static LIST_HEAD(deferred);
 static DEFINE_SPINLOCK(deferred_lock);

 typedef void switchdev_deferred_func_t(struct net_device *dev,
 				       const void *data);

 struct switchdev_deferred_item {
 	struct list_head list;
 	struct net_device *dev;
 	switchdev_deferred_func_t *func;
 	unsigned long data[0];
 };

 static struct switchdev_deferred_item *switchdev_deferred_dequeue(void)
 {
 	struct switchdev_deferred_item *dfitem;

 	spin_lock_bh(&deferred_lock);
 	if (list_empty(&deferred)) {
 		dfitem = NULL;
 		goto unlock;
 	}
 	dfitem = list_first_entry(&deferred,
 				  struct switchdev_deferred_item, list);
 	list_del(&dfitem->list);
 unlock:
 	spin_unlock_bh(&deferred_lock);
 	return dfitem;
 }

 /**
  *	switchdev_deferred_process - Process ops in deferred queue
  *
  *	Called to flush the ops currently queued in deferred ops queue.
  *	rtnl_lock must be held.
  */
 void switchdev_deferred_process(void)
 {
 	struct switchdev_deferred_item *dfitem;

 	ASSERT_RTNL();

 	while ((dfitem = switchdev_deferred_dequeue())) {
 		dfitem->func(dfitem->dev, dfitem->data);
 		dev_put(dfitem->dev);
 		kfree(dfitem);
 	}
 }
 EXPORT_SYMBOL_GPL(switchdev_deferred_process);

 static void switchdev_deferred_process_work(struct work_struct *work)
 {
 	rtnl_lock();
 	switchdev_deferred_process();
 	rtnl_unlock();
 }

 static DECLARE_WORK(deferred_process_work, switchdev_deferred_process_work);

 static int switchdev_deferred_enqueue(struct net_device *dev,
 				      const void *data, size_t data_len,
 				      switchdev_deferred_func_t *func)
 {
 	struct switchdev_deferred_item *dfitem;

 	dfitem = kmalloc(sizeof(*dfitem) + data_len, GFP_ATOMIC);
 	if (!dfitem)
 		return -ENOMEM;
 	dfitem->dev = dev;
 	dfitem->func = func;
 	memcpy(dfitem->data, data, data_len);
 	dev_hold(dev);
 	spin_lock_bh(&deferred_lock);
 	list_add_tail(&dfitem->list, &deferred);
 	spin_unlock_bh(&deferred_lock);
 	schedule_work(&deferred_process_work);
 	return 0;
 }

 static int switchdev_port_attr_notify(enum switchdev_notifier_type nt,
 				      struct net_device *dev,
 				      const struct switchdev_attr *attr,
 				      struct switchdev_trans *trans)
 {
 	int err;
 	int rc;

 	struct switchdev_notifier_port_attr_info attr_info = {
 		.attr = attr,
 		.trans = trans,
 		.handled = false,
 	};

 	rc = call_switchdev_blocking_notifiers(nt, dev,
 					       &attr_info.info, NULL);
 	err = notifier_to_errno(rc);
 	if (err) {
 		WARN_ON(!attr_info.handled);
 		return err;
 	}

 	if (!attr_info.handled)
 		return -EOPNOTSUPP;

 	return 0;
 }

 static int switchdev_port_attr_set_now(struct net_device *dev,
 				       const struct switchdev_attr *attr)
 {
 	struct switchdev_trans trans;
 	int err;

 	/* Phase I: prepare for attr set. Driver/device should fail
 	 * here if there are going to be issues in the commit phase,
 	 * such as lack of resources or support.  The driver/device
 	 * should reserve resources needed for the commit phase here,
 	 * but should not commit the attr.
 	 */

 	trans.ph_prepare = true;
 	err = switchdev_port_attr_notify(SWITCHDEV_PORT_ATTR_SET, dev, attr,
 					 &trans);
 	if (err)
 		return err;

 	/* Phase II: commit attr set.  This cannot fail as a fault
 	 * of driver/device.  If it does, it's a bug in the driver/device
 	 * because the driver said everythings was OK in phase I.
 	 */

 	trans.ph_prepare = false;
 	err = switchdev_port_attr_notify(SWITCHDEV_PORT_ATTR_SET, dev, attr,
 					 &trans);
 	WARN(err, "%s: Commit of attribute (id=%d) failed.\n",
 	     dev->name, attr->id);

 	return err;
 }

 static void switchdev_port_attr_set_deferred(struct net_device *dev,
 					     const void *data)
 {
 	const struct switchdev_attr *attr = data;
 	int err;

 	err = switchdev_port_attr_set_now(dev, attr);
 	if (err && err != -EOPNOTSUPP)
 		netdev_err(dev, "failed (err=%d) to set attribute (id=%d)\n",
 			   err, attr->id);
 	if (attr->complete)
 		attr->complete(dev, err, attr->complete_priv);
 }

 static int switchdev_port_attr_set_defer(struct net_device *dev,
 					 const struct switchdev_attr *attr)
 {
 	return switchdev_deferred_enqueue(dev, attr, sizeof(*attr),
 					  switchdev_port_attr_set_deferred);
 }

 /**
  *	switchdev_port_attr_set - Set port attribute
  *
  *	@dev: port device
  *	@attr: attribute to set
  *
  *	Use a 2-phase prepare-commit transaction model to ensure
  *	system is not left in a partially updated state due to
  *	failure from driver/device.
  *
  *	rtnl_lock must be held and must not be in atomic section,
  *	in case SWITCHDEV_F_DEFER flag is not set.
  */
 int switchdev_port_attr_set(struct net_device *dev,
 			    const struct switchdev_attr *attr)
 {
 	if (attr->flags & SWITCHDEV_F_DEFER)
 		return switchdev_port_attr_set_defer(dev, attr);
 	ASSERT_RTNL();
 	return switchdev_port_attr_set_now(dev, attr);
 }
 EXPORT_SYMBOL_GPL(switchdev_port_attr_set);

 static size_t switchdev_obj_size(const struct switchdev_obj *obj)
 {
 	switch (obj->id) {
 	case SWITCHDEV_OBJ_ID_PORT_VLAN:
 		return sizeof(struct switchdev_obj_port_vlan);
 	case SWITCHDEV_OBJ_ID_PORT_MDB:
 		return sizeof(struct switchdev_obj_port_mdb);
 	case SWITCHDEV_OBJ_ID_HOST_MDB:
 		return sizeof(struct switchdev_obj_port_mdb);
 	default:
 		BUG();
 	}
 	return 0;
 }

 static int switchdev_port_obj_notify(enum switchdev_notifier_type nt,
 				     struct net_device *dev,
 				     const struct switchdev_obj *obj,
 				     struct switchdev_trans *trans,
 				     struct netlink_ext_ack *extack)
 {
 	int rc;
 	int err;

 	struct switchdev_notifier_port_obj_info obj_info = {
 		.obj = obj,
 		.trans = trans,
 		.handled = false,
 	};

 	rc = call_switchdev_blocking_notifiers(nt, dev, &obj_info.info, extack);
 	err = notifier_to_errno(rc);
 	if (err) {
 		WARN_ON(!obj_info.handled);
 		return err;
 	}
 	if (!obj_info.handled)
 		return -EOPNOTSUPP;
 	return 0;
 }

 static int switchdev_port_obj_add_now(struct net_device *dev,
 				      const struct switchdev_obj *obj,
 				      struct netlink_ext_ack *extack)
 {
 	struct switchdev_trans trans;
 	int err;

 	ASSERT_RTNL();

 	/* Phase I: prepare for obj add. Driver/device should fail
 	 * here if there are going to be issues in the commit phase,
 	 * such as lack of resources or support.  The driver/device
 	 * should reserve resources needed for the commit phase here,
 	 * but should not commit the obj.
 	 */

 	trans.ph_prepare = true;
 	err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
 					dev, obj, &trans, extack);
 	if (err)
 		return err;

 	/* Phase II: commit obj add.  This cannot fail as a fault
 	 * of driver/device.  If it does, it's a bug in the driver/device
 	 * because the driver said everythings was OK in phase I.
 	 */

 	trans.ph_prepare = false;
 	err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
 					dev, obj, &trans, extack);
 	WARN(err, "%s: Commit of object (id=%d) failed.\n", dev->name, obj->id);

 	return err;
 }

 static void switchdev_port_obj_add_deferred(struct net_device *dev,
 					    const void *data)
 {
 	const struct switchdev_obj *obj = data;
 	int err;

 	err = switchdev_port_obj_add_now(dev, obj, NULL);
 	if (err && err != -EOPNOTSUPP)
 		netdev_err(dev, "failed (err=%d) to add object (id=%d)\n",
 			   err, obj->id);
 	if (obj->complete)
 		obj->complete(dev, err, obj->complete_priv);
 }

 static int switchdev_port_obj_add_defer(struct net_device *dev,
 					const struct switchdev_obj *obj)
 {
 	return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
 					  switchdev_port_obj_add_deferred);
 }

 /**
  *	switchdev_port_obj_add - Add port object
  *
  *	@dev: port device
  *	@id: object ID
  *	@obj: object to add
  *
  *	Use a 2-phase prepare-commit transaction model to ensure
  *	system is not left in a partially updated state due to
  *	failure from driver/device.
  *
  *	rtnl_lock must be held and must not be in atomic section,
  *	in case SWITCHDEV_F_DEFER flag is not set.
  */
 int switchdev_port_obj_add(struct net_device *dev,
 			   const struct switchdev_obj *obj,
 			   struct netlink_ext_ack *extack)
 {
 	if (obj->flags & SWITCHDEV_F_DEFER)
 		return switchdev_port_obj_add_defer(dev, obj);
 	ASSERT_RTNL();
 	return switchdev_port_obj_add_now(dev, obj, extack);
 }
 EXPORT_SYMBOL_GPL(switchdev_port_obj_add);

 static int switchdev_port_obj_del_now(struct net_device *dev,
 				      const struct switchdev_obj *obj)
 {
 	return switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_DEL,
 					 dev, obj, NULL, NULL);
 }

 static void switchdev_port_obj_del_deferred(struct net_device *dev,
 					    const void *data)
 {
 	const struct switchdev_obj *obj = data;
 	int err;

 	err = switchdev_port_obj_del_now(dev, obj);
 	if (err && err != -EOPNOTSUPP)
 		netdev_err(dev, "failed (err=%d) to del object (id=%d)\n",
 			   err, obj->id);
 	if (obj->complete)
 		obj->complete(dev, err, obj->complete_priv);
 }

 static int switchdev_port_obj_del_defer(struct net_device *dev,
 					const struct switchdev_obj *obj)
 {
 	return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
 					  switchdev_port_obj_del_deferred);
 }

 /**
  *	switchdev_port_obj_del - Delete port object
  *
  *	@dev: port device
  *	@id: object ID
  *	@obj: object to delete
  *
  *	rtnl_lock must be held and must not be in atomic section,
  *	in case SWITCHDEV_F_DEFER flag is not set.
  */
 int switchdev_port_obj_del(struct net_device *dev,
 			   const struct switchdev_obj *obj)
 {
 	if (obj->flags & SWITCHDEV_F_DEFER)
 		return switchdev_port_obj_del_defer(dev, obj);
 	ASSERT_RTNL();
 	return switchdev_port_obj_del_now(dev, obj);
 }
 EXPORT_SYMBOL_GPL(switchdev_port_obj_del);

 static ATOMIC_NOTIFIER_HEAD(switchdev_notif_chain);
 static BLOCKING_NOTIFIER_HEAD(switchdev_blocking_notif_chain);

 /**
  *	register_switchdev_notifier - Register notifier
  *	@nb: notifier_block
  *
  *	Register switch device notifier.
  */
 int register_switchdev_notifier(struct notifier_block *nb)
 {
 	return atomic_notifier_chain_register(&switchdev_notif_chain, nb);
 }
 EXPORT_SYMBOL_GPL(register_switchdev_notifier);

 /**
  *	unregister_switchdev_notifier - Unregister notifier
  *	@nb: notifier_block
  *
  *	Unregister switch device notifier.
  */
 int unregister_switchdev_notifier(struct notifier_block *nb)
 {
 	return atomic_notifier_chain_unregister(&switchdev_notif_chain, nb);
 }
 EXPORT_SYMBOL_GPL(unregister_switchdev_notifier);

 /**
  *	call_switchdev_notifiers - Call notifiers
  *	@val: value passed unmodified to notifier function
  *	@dev: port device
  *	@info: notifier information data
  *
  *	Call all network notifier blocks.
  */
 int call_switchdev_notifiers(unsigned long val, struct net_device *dev,
 			     struct switchdev_notifier_info *info,
 			     struct netlink_ext_ack *extack)
 {
 	info->dev = dev;
 	info->extack = extack;
 	return atomic_notifier_call_chain(&switchdev_notif_chain, val, info);
 }
 EXPORT_SYMBOL_GPL(call_switchdev_notifiers);

 int register_switchdev_blocking_notifier(struct notifier_block *nb)
 {
 	struct blocking_notifier_head *chain = &switchdev_blocking_notif_chain;

 	return blocking_notifier_chain_register(chain, nb);
 }
 EXPORT_SYMBOL_GPL(register_switchdev_blocking_notifier);

 int unregister_switchdev_blocking_notifier(struct notifier_block *nb)
 {
 	struct blocking_notifier_head *chain = &switchdev_blocking_notif_chain;

 	return blocking_notifier_chain_unregister(chain, nb);
 }
 EXPORT_SYMBOL_GPL(unregister_switchdev_blocking_notifier);

 int call_switchdev_blocking_notifiers(unsigned long val, struct net_device *dev,
 				      struct switchdev_notifier_info *info,
 				      struct netlink_ext_ack *extack)
 {
 	info->dev = dev;
 	info->extack = extack;
 	return blocking_notifier_call_chain(&switchdev_blocking_notif_chain,
 					    val, info);
 }
 EXPORT_SYMBOL_GPL(call_switchdev_blocking_notifiers);

 static int __switchdev_handle_port_obj_add(struct net_device *dev,
 			struct switchdev_notifier_port_obj_info *port_obj_info,
 			bool (*check_cb)(const struct net_device *dev),
 			int (*add_cb)(struct net_device *dev,
 				      const struct switchdev_obj *obj,
 				      struct switchdev_trans *trans,
 				      struct netlink_ext_ack *extack))
 {
 	struct netlink_ext_ack *extack;
 	struct net_device *lower_dev;
 	struct list_head *iter;
 	int err = -EOPNOTSUPP;

 	extack = switchdev_notifier_info_to_extack(&port_obj_info->info);

 	if (check_cb(dev)) {
 		err = add_cb(dev, port_obj_info->obj, port_obj_info->trans,
 			     extack);
 		if (err != -EOPNOTSUPP)
 			port_obj_info->handled = true;
 		return err;
 	}

 	/* Switch ports might be stacked under e.g. a LAG. Ignore the
 	 * unsupported devices, another driver might be able to handle them. But
 	 * propagate to the callers any hard errors.
 	 *
 	 * If the driver does its own bookkeeping of stacked ports, it's not
 	 * necessary to go through this helper.
 	 */
 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
 		if (netif_is_bridge_master(lower_dev))
 			continue;

 		err = __switchdev_handle_port_obj_add(lower_dev, port_obj_info,
 						      check_cb, add_cb);
 		if (err && err != -EOPNOTSUPP)
 			return err;
 	}

 	return err;
 }

 int switchdev_handle_port_obj_add(struct net_device *dev,
 			struct switchdev_notifier_port_obj_info *port_obj_info,
 			bool (*check_cb)(const struct net_device *dev),
 			int (*add_cb)(struct net_device *dev,
 				      const struct switchdev_obj *obj,
 				      struct switchdev_trans *trans,
 				      struct netlink_ext_ack *extack))
 {
 	int err;

 	err = __switchdev_handle_port_obj_add(dev, port_obj_info, check_cb,
 					      add_cb);
 	if (err == -EOPNOTSUPP)
 		err = 0;
 	return err;
 }
 EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_add);

 static int __switchdev_handle_port_obj_del(struct net_device *dev,
 			struct switchdev_notifier_port_obj_info *port_obj_info,
 			bool (*check_cb)(const struct net_device *dev),
 			int (*del_cb)(struct net_device *dev,
 				      const struct switchdev_obj *obj))
 {
 	struct net_device *lower_dev;
 	struct list_head *iter;
 	int err = -EOPNOTSUPP;

 	if (check_cb(dev)) {
 		err = del_cb(dev, port_obj_info->obj);
 		if (err != -EOPNOTSUPP)
 			port_obj_info->handled = true;
 		return err;
 	}

 	/* Switch ports might be stacked under e.g. a LAG. Ignore the
 	 * unsupported devices, another driver might be able to handle them. But
 	 * propagate to the callers any hard errors.
 	 *
 	 * If the driver does its own bookkeeping of stacked ports, it's not
 	 * necessary to go through this helper.
 	 */
 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
 		if (netif_is_bridge_master(lower_dev))
 			continue;

 		err = __switchdev_handle_port_obj_del(lower_dev, port_obj_info,
 						      check_cb, del_cb);
 		if (err && err != -EOPNOTSUPP)
 			return err;
 	}

 	return err;
 }

 int switchdev_handle_port_obj_del(struct net_device *dev,
 			struct switchdev_notifier_port_obj_info *port_obj_info,
 			bool (*check_cb)(const struct net_device *dev),
 			int (*del_cb)(struct net_device *dev,
 				      const struct switchdev_obj *obj))
 {
 	int err;

 	err = __switchdev_handle_port_obj_del(dev, port_obj_info, check_cb,
 					      del_cb);
 	if (err == -EOPNOTSUPP)
 		err = 0;
 	return err;
 }
 EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_del);

 static int __switchdev_handle_port_attr_set(struct net_device *dev,
 			struct switchdev_notifier_port_attr_info *port_attr_info,
 			bool (*check_cb)(const struct net_device *dev),
 			int (*set_cb)(struct net_device *dev,
 				      const struct switchdev_attr *attr,
 				      struct switchdev_trans *trans))
 {
 	struct net_device *lower_dev;
 	struct list_head *iter;
 	int err = -EOPNOTSUPP;

 	if (check_cb(dev)) {
 		err = set_cb(dev, port_attr_info->attr, port_attr_info->trans);
 		if (err != -EOPNOTSUPP)
 			port_attr_info->handled = true;
 		return err;
 	}

 	/* Switch ports might be stacked under e.g. a LAG. Ignore the
 	 * unsupported devices, another driver might be able to handle them. But
 	 * propagate to the callers any hard errors.
 	 *
 	 * If the driver does its own bookkeeping of stacked ports, it's not
 	 * necessary to go through this helper.
 	 */
 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
 		if (netif_is_bridge_master(lower_dev))
 			continue;

 		err = __switchdev_handle_port_attr_set(lower_dev, port_attr_info,
 						       check_cb, set_cb);
 		if (err && err != -EOPNOTSUPP)
 			return err;
 	}

 	return err;
 }

 int switchdev_handle_port_attr_set(struct net_device *dev,
 			struct switchdev_notifier_port_attr_info *port_attr_info,
 			bool (*check_cb)(const struct net_device *dev),
 			int (*set_cb)(struct net_device *dev,
 				      const struct switchdev_attr *attr,
 				      struct switchdev_trans *trans))
 {
 	int err;

 	err = __switchdev_handle_port_attr_set(dev, port_attr_info, check_cb,
 					       set_cb);
 	if (err == -EOPNOTSUPP)
 		err = 0;
 	return err;
 }
 EXPORT_SYMBOL_GPL(switchdev_handle_port_attr_set);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* net/switchdev/switchdev.c - Switch device API
	* Copyright (c) 2014-2015 Jiri Pirko <jiri@resnulli.us>
	* Copyright (c) 2014-2015 Scott Feldman <sfeldma@gmail.com>
	*/

	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/init.h>
	#include <linux/mutex.h>
	#include <linux/notifier.h>
	#include <linux/netdevice.h>
	#include <linux/etherdevice.h>
	#include <linux/if_bridge.h>
	#include <linux/list.h>
	#include <linux/workqueue.h>
	#include <linux/if_vlan.h>
	#include <linux/rtnetlink.h>
	#include <net/switchdev.h>

	static LIST_HEAD(deferred);
	static DEFINE_SPINLOCK(deferred_lock);

	typedef void switchdev_deferred_func_t(struct net_device *dev,
	const void *data);

	struct switchdev_deferred_item {
	struct list_head list;
	struct net_device *dev;
	switchdev_deferred_func_t *func;
	unsigned long data[0];
	};

	static struct switchdev_deferred_item *switchdev_deferred_dequeue(void)
	{
	struct switchdev_deferred_item *dfitem;

	spin_lock_bh(&deferred_lock);
	if (list_empty(&deferred)) {
	dfitem = NULL;
	goto unlock;
	}
	dfitem = list_first_entry(&deferred,
	struct switchdev_deferred_item, list);
	list_del(&dfitem->list);
	unlock:
	spin_unlock_bh(&deferred_lock);
	return dfitem;
	}

	/**
	* switchdev_deferred_process - Process ops in deferred queue
	*
	* Called to flush the ops currently queued in deferred ops queue.
	* rtnl_lock must be held.
	*/
	void switchdev_deferred_process(void)
	{
	struct switchdev_deferred_item *dfitem;

	ASSERT_RTNL();

	while ((dfitem = switchdev_deferred_dequeue())) {
	dfitem->func(dfitem->dev, dfitem->data);
	dev_put(dfitem->dev);
	kfree(dfitem);
	}
	}
	EXPORT_SYMBOL_GPL(switchdev_deferred_process);

	static void switchdev_deferred_process_work(struct work_struct *work)
	{
	rtnl_lock();
	switchdev_deferred_process();
	rtnl_unlock();
	}

	static DECLARE_WORK(deferred_process_work, switchdev_deferred_process_work);

	static int switchdev_deferred_enqueue(struct net_device *dev,
	const void *data, size_t data_len,
	switchdev_deferred_func_t *func)
	{
	struct switchdev_deferred_item *dfitem;

	dfitem = kmalloc(sizeof(*dfitem) + data_len, GFP_ATOMIC);
	if (!dfitem)
	return -ENOMEM;
	dfitem->dev = dev;
	dfitem->func = func;
	memcpy(dfitem->data, data, data_len);
	dev_hold(dev);
	spin_lock_bh(&deferred_lock);
	list_add_tail(&dfitem->list, &deferred);
	spin_unlock_bh(&deferred_lock);
	schedule_work(&deferred_process_work);
	return 0;
	}

	static int switchdev_port_attr_notify(enum switchdev_notifier_type nt,
	struct net_device *dev,
	const struct switchdev_attr *attr,
	struct switchdev_trans *trans)
	{
	int err;
	int rc;

	struct switchdev_notifier_port_attr_info attr_info = {
	.attr = attr,
	.trans = trans,
	.handled = false,
	};

	rc = call_switchdev_blocking_notifiers(nt, dev,
	&attr_info.info, NULL);
	err = notifier_to_errno(rc);
	if (err) {
	WARN_ON(!attr_info.handled);
	return err;
	}

	if (!attr_info.handled)
	return -EOPNOTSUPP;

	return 0;
	}

	static int switchdev_port_attr_set_now(struct net_device *dev,
	const struct switchdev_attr *attr)
	{
	struct switchdev_trans trans;
	int err;

	/* Phase I: prepare for attr set. Driver/device should fail
	* here if there are going to be issues in the commit phase,
	* such as lack of resources or support. The driver/device
	* should reserve resources needed for the commit phase here,
	* but should not commit the attr.
	*/

	trans.ph_prepare = true;
	err = switchdev_port_attr_notify(SWITCHDEV_PORT_ATTR_SET, dev, attr,
	&trans);
	if (err)
	return err;

	/* Phase II: commit attr set. This cannot fail as a fault
	* of driver/device. If it does, it's a bug in the driver/device
	* because the driver said everythings was OK in phase I.
	*/

	trans.ph_prepare = false;
	err = switchdev_port_attr_notify(SWITCHDEV_PORT_ATTR_SET, dev, attr,
	&trans);
	WARN(err, "%s: Commit of attribute (id=%d) failed.\n",
	dev->name, attr->id);

	return err;
	}

	static void switchdev_port_attr_set_deferred(struct net_device *dev,
	const void *data)
	{
	const struct switchdev_attr *attr = data;
	int err;

	err = switchdev_port_attr_set_now(dev, attr);
	if (err && err != -EOPNOTSUPP)
	netdev_err(dev, "failed (err=%d) to set attribute (id=%d)\n",
	err, attr->id);
	if (attr->complete)
	attr->complete(dev, err, attr->complete_priv);
	}

	static int switchdev_port_attr_set_defer(struct net_device *dev,
	const struct switchdev_attr *attr)
	{
	return switchdev_deferred_enqueue(dev, attr, sizeof(*attr),
	switchdev_port_attr_set_deferred);
	}

	/**
	* switchdev_port_attr_set - Set port attribute
	*
	* @dev: port device
	* @attr: attribute to set
	*
	* Use a 2-phase prepare-commit transaction model to ensure
	* system is not left in a partially updated state due to
	* failure from driver/device.
	*
	* rtnl_lock must be held and must not be in atomic section,
	* in case SWITCHDEV_F_DEFER flag is not set.
	*/
	int switchdev_port_attr_set(struct net_device *dev,
	const struct switchdev_attr *attr)
	{
	if (attr->flags & SWITCHDEV_F_DEFER)
	return switchdev_port_attr_set_defer(dev, attr);
	ASSERT_RTNL();
	return switchdev_port_attr_set_now(dev, attr);
	}
	EXPORT_SYMBOL_GPL(switchdev_port_attr_set);

	static size_t switchdev_obj_size(const struct switchdev_obj *obj)
	{
	switch (obj->id) {
	case SWITCHDEV_OBJ_ID_PORT_VLAN:
	return sizeof(struct switchdev_obj_port_vlan);
	case SWITCHDEV_OBJ_ID_PORT_MDB:
	return sizeof(struct switchdev_obj_port_mdb);
	case SWITCHDEV_OBJ_ID_HOST_MDB:
	return sizeof(struct switchdev_obj_port_mdb);
	default:
	BUG();
	}
	return 0;
	}

	static int switchdev_port_obj_notify(enum switchdev_notifier_type nt,
	struct net_device *dev,
	const struct switchdev_obj *obj,
	struct switchdev_trans *trans,
	struct netlink_ext_ack *extack)
	{
	int rc;
	int err;

	struct switchdev_notifier_port_obj_info obj_info = {
	.obj = obj,
	.trans = trans,
	.handled = false,
	};

	rc = call_switchdev_blocking_notifiers(nt, dev, &obj_info.info, extack);
	err = notifier_to_errno(rc);
	if (err) {
	WARN_ON(!obj_info.handled);
	return err;
	}
	if (!obj_info.handled)
	return -EOPNOTSUPP;
	return 0;
	}

	static int switchdev_port_obj_add_now(struct net_device *dev,
	const struct switchdev_obj *obj,
	struct netlink_ext_ack *extack)
	{
	struct switchdev_trans trans;
	int err;

	ASSERT_RTNL();

	/* Phase I: prepare for obj add. Driver/device should fail
	* here if there are going to be issues in the commit phase,
	* such as lack of resources or support. The driver/device
	* should reserve resources needed for the commit phase here,
	* but should not commit the obj.
	*/

	trans.ph_prepare = true;
	err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
	dev, obj, &trans, extack);
	if (err)
	return err;

	/* Phase II: commit obj add. This cannot fail as a fault
	* of driver/device. If it does, it's a bug in the driver/device
	* because the driver said everythings was OK in phase I.
	*/

	trans.ph_prepare = false;
	err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
	dev, obj, &trans, extack);
	WARN(err, "%s: Commit of object (id=%d) failed.\n", dev->name, obj->id);

	return err;
	}

	static void switchdev_port_obj_add_deferred(struct net_device *dev,
	const void *data)
	{
	const struct switchdev_obj *obj = data;
	int err;

	err = switchdev_port_obj_add_now(dev, obj, NULL);
	if (err && err != -EOPNOTSUPP)
	netdev_err(dev, "failed (err=%d) to add object (id=%d)\n",
	err, obj->id);
	if (obj->complete)
	obj->complete(dev, err, obj->complete_priv);
	}

	static int switchdev_port_obj_add_defer(struct net_device *dev,
	const struct switchdev_obj *obj)
	{
	return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
	switchdev_port_obj_add_deferred);
	}

	/**
	* switchdev_port_obj_add - Add port object
	*
	* @dev: port device
	* @id: object ID
	* @obj: object to add
	*
	* Use a 2-phase prepare-commit transaction model to ensure
	* system is not left in a partially updated state due to
	* failure from driver/device.
	*
	* rtnl_lock must be held and must not be in atomic section,
	* in case SWITCHDEV_F_DEFER flag is not set.
	*/
	int switchdev_port_obj_add(struct net_device *dev,
	const struct switchdev_obj *obj,
	struct netlink_ext_ack *extack)
	{
	if (obj->flags & SWITCHDEV_F_DEFER)
	return switchdev_port_obj_add_defer(dev, obj);
	ASSERT_RTNL();
	return switchdev_port_obj_add_now(dev, obj, extack);
	}
	EXPORT_SYMBOL_GPL(switchdev_port_obj_add);

	static int switchdev_port_obj_del_now(struct net_device *dev,
	const struct switchdev_obj *obj)
	{
	return switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_DEL,
	dev, obj, NULL, NULL);
	}

	static void switchdev_port_obj_del_deferred(struct net_device *dev,
	const void *data)
	{
	const struct switchdev_obj *obj = data;
	int err;

	err = switchdev_port_obj_del_now(dev, obj);
	if (err && err != -EOPNOTSUPP)
	netdev_err(dev, "failed (err=%d) to del object (id=%d)\n",
	err, obj->id);
	if (obj->complete)
	obj->complete(dev, err, obj->complete_priv);
	}

	static int switchdev_port_obj_del_defer(struct net_device *dev,
	const struct switchdev_obj *obj)
	{
	return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
	switchdev_port_obj_del_deferred);
	}

	/**
	* switchdev_port_obj_del - Delete port object
	*
	* @dev: port device
	* @id: object ID
	* @obj: object to delete
	*
	* rtnl_lock must be held and must not be in atomic section,
	* in case SWITCHDEV_F_DEFER flag is not set.
	*/
	int switchdev_port_obj_del(struct net_device *dev,
	const struct switchdev_obj *obj)
	{
	if (obj->flags & SWITCHDEV_F_DEFER)
	return switchdev_port_obj_del_defer(dev, obj);
	ASSERT_RTNL();
	return switchdev_port_obj_del_now(dev, obj);
	}
	EXPORT_SYMBOL_GPL(switchdev_port_obj_del);

	static ATOMIC_NOTIFIER_HEAD(switchdev_notif_chain);
	static BLOCKING_NOTIFIER_HEAD(switchdev_blocking_notif_chain);

	/**
	* register_switchdev_notifier - Register notifier
	* @nb: notifier_block
	*
	* Register switch device notifier.
	*/
	int register_switchdev_notifier(struct notifier_block *nb)
	{
	return atomic_notifier_chain_register(&switchdev_notif_chain, nb);
	}
	EXPORT_SYMBOL_GPL(register_switchdev_notifier);

	/**
	* unregister_switchdev_notifier - Unregister notifier
	* @nb: notifier_block
	*
	* Unregister switch device notifier.
	*/
	int unregister_switchdev_notifier(struct notifier_block *nb)
	{
	return atomic_notifier_chain_unregister(&switchdev_notif_chain, nb);
	}
	EXPORT_SYMBOL_GPL(unregister_switchdev_notifier);

	/**
	* call_switchdev_notifiers - Call notifiers
	* @val: value passed unmodified to notifier function
	* @dev: port device
	* @info: notifier information data
	*
	* Call all network notifier blocks.
	*/
	int call_switchdev_notifiers(unsigned long val, struct net_device *dev,
	struct switchdev_notifier_info *info,
	struct netlink_ext_ack *extack)
	{
	info->dev = dev;
	info->extack = extack;
	return atomic_notifier_call_chain(&switchdev_notif_chain, val, info);
	}
	EXPORT_SYMBOL_GPL(call_switchdev_notifiers);

	int register_switchdev_blocking_notifier(struct notifier_block *nb)
	{
	struct blocking_notifier_head *chain = &switchdev_blocking_notif_chain;

	return blocking_notifier_chain_register(chain, nb);
	}
	EXPORT_SYMBOL_GPL(register_switchdev_blocking_notifier);

	int unregister_switchdev_blocking_notifier(struct notifier_block *nb)
	{
	struct blocking_notifier_head *chain = &switchdev_blocking_notif_chain;

	return blocking_notifier_chain_unregister(chain, nb);
	}
	EXPORT_SYMBOL_GPL(unregister_switchdev_blocking_notifier);

	int call_switchdev_blocking_notifiers(unsigned long val, struct net_device *dev,
	struct switchdev_notifier_info *info,
	struct netlink_ext_ack *extack)
	{
	info->dev = dev;
	info->extack = extack;
	return blocking_notifier_call_chain(&switchdev_blocking_notif_chain,
	val, info);
	}
	EXPORT_SYMBOL_GPL(call_switchdev_blocking_notifiers);

	static int __switchdev_handle_port_obj_add(struct net_device *dev,
	struct switchdev_notifier_port_obj_info *port_obj_info,
	bool (check_cb)(const struct net_device dev),
	int (add_cb)(struct net_device dev,
	const struct switchdev_obj *obj,
	struct switchdev_trans *trans,
	struct netlink_ext_ack *extack))
	{
	struct netlink_ext_ack *extack;
	struct net_device *lower_dev;
	struct list_head *iter;
	int err = -EOPNOTSUPP;

	extack = switchdev_notifier_info_to_extack(&port_obj_info->info);

	if (check_cb(dev)) {
	err = add_cb(dev, port_obj_info->obj, port_obj_info->trans,
	extack);
	if (err != -EOPNOTSUPP)
	port_obj_info->handled = true;
	return err;
	}

	/* Switch ports might be stacked under e.g. a LAG. Ignore the
	* unsupported devices, another driver might be able to handle them. But
	* propagate to the callers any hard errors.
	*
	* If the driver does its own bookkeeping of stacked ports, it's not
	* necessary to go through this helper.
	*/
	netdev_for_each_lower_dev(dev, lower_dev, iter) {
	if (netif_is_bridge_master(lower_dev))
	continue;

	err = __switchdev_handle_port_obj_add(lower_dev, port_obj_info,
	check_cb, add_cb);
	if (err && err != -EOPNOTSUPP)
	return err;
	}

	return err;
	}

	int switchdev_handle_port_obj_add(struct net_device *dev,
	struct switchdev_notifier_port_obj_info *port_obj_info,
	bool (check_cb)(const struct net_device dev),
	int (add_cb)(struct net_device dev,
	const struct switchdev_obj *obj,
	struct switchdev_trans *trans,
	struct netlink_ext_ack *extack))
	{
	int err;

	err = __switchdev_handle_port_obj_add(dev, port_obj_info, check_cb,
	add_cb);
	if (err == -EOPNOTSUPP)
	err = 0;
	return err;
	}
	EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_add);

	static int __switchdev_handle_port_obj_del(struct net_device *dev,
	struct switchdev_notifier_port_obj_info *port_obj_info,
	bool (check_cb)(const struct net_device dev),
	int (del_cb)(struct net_device dev,
	const struct switchdev_obj *obj))
	{
	struct net_device *lower_dev;
	struct list_head *iter;
	int err = -EOPNOTSUPP;

	if (check_cb(dev)) {
	err = del_cb(dev, port_obj_info->obj);
	if (err != -EOPNOTSUPP)
	port_obj_info->handled = true;
	return err;
	}

	/* Switch ports might be stacked under e.g. a LAG. Ignore the
	* unsupported devices, another driver might be able to handle them. But
	* propagate to the callers any hard errors.
	*
	* If the driver does its own bookkeeping of stacked ports, it's not
	* necessary to go through this helper.
	*/
	netdev_for_each_lower_dev(dev, lower_dev, iter) {
	if (netif_is_bridge_master(lower_dev))
	continue;

	err = __switchdev_handle_port_obj_del(lower_dev, port_obj_info,
	check_cb, del_cb);
	if (err && err != -EOPNOTSUPP)
	return err;
	}

	return err;
	}

	int switchdev_handle_port_obj_del(struct net_device *dev,
	struct switchdev_notifier_port_obj_info *port_obj_info,
	bool (check_cb)(const struct net_device dev),
	int (del_cb)(struct net_device dev,
	const struct switchdev_obj *obj))
	{
	int err;

	err = __switchdev_handle_port_obj_del(dev, port_obj_info, check_cb,
	del_cb);
	if (err == -EOPNOTSUPP)
	err = 0;
	return err;
	}
	EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_del);

	static int __switchdev_handle_port_attr_set(struct net_device *dev,
	struct switchdev_notifier_port_attr_info *port_attr_info,
	bool (check_cb)(const struct net_device dev),
	int (set_cb)(struct net_device dev,
	const struct switchdev_attr *attr,
	struct switchdev_trans *trans))
	{
	struct net_device *lower_dev;
	struct list_head *iter;
	int err = -EOPNOTSUPP;

	if (check_cb(dev)) {
	err = set_cb(dev, port_attr_info->attr, port_attr_info->trans);
	if (err != -EOPNOTSUPP)
	port_attr_info->handled = true;
	return err;
	}

	/* Switch ports might be stacked under e.g. a LAG. Ignore the
	* unsupported devices, another driver might be able to handle them. But
	* propagate to the callers any hard errors.
	*
	* If the driver does its own bookkeeping of stacked ports, it's not
	* necessary to go through this helper.
	*/
	netdev_for_each_lower_dev(dev, lower_dev, iter) {
	if (netif_is_bridge_master(lower_dev))
	continue;

	err = __switchdev_handle_port_attr_set(lower_dev, port_attr_info,
	check_cb, set_cb);
	if (err && err != -EOPNOTSUPP)
	return err;
	}

	return err;
	}

	int switchdev_handle_port_attr_set(struct net_device *dev,
	struct switchdev_notifier_port_attr_info *port_attr_info,
	bool (check_cb)(const struct net_device dev),
	int (set_cb)(struct net_device dev,
	const struct switchdev_attr *attr,
	struct switchdev_trans *trans))
	{
	int err;

	err = __switchdev_handle_port_attr_set(dev, port_attr_info, check_cb,
	set_cb);
	if (err == -EOPNOTSUPP)
	err = 0;
	return err;
	}
	EXPORT_SYMBOL_GPL(switchdev_handle_port_attr_set);