path: root/net/switchdev/switchdev.c

/*
 * 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>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#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>

/**
 *	switchdev_trans_item_enqueue - Enqueue data item to transaction queue
 *
 *	@trans: transaction
 *	@data: pointer to data being queued
 *	@destructor: data destructor
 *	@tritem: transaction item being queued
 *
 *	Enqeueue data item to transaction queue. tritem is typically placed in
 *	cointainter pointed at by data pointer. Destructor is called on
 *	transaction abort and after successful commit phase in case
 *	the caller did not dequeue the item before.
 */
void switchdev_trans_item_enqueue(struct switchdev_trans *trans,
				  void *data, void (*destructor)(void const *),
				  struct switchdev_trans_item *tritem)
{
	tritem->data = data;
	tritem->destructor = destructor;
	list_add_tail(&tritem->list, &trans->item_list);
}
EXPORT_SYMBOL_GPL(switchdev_trans_item_enqueue);

static struct switchdev_trans_item *
__switchdev_trans_item_dequeue(struct switchdev_trans *trans)
{
	struct switchdev_trans_item *tritem;

	if (list_empty(&trans->item_list))
		return NULL;
	tritem = list_first_entry(&trans->item_list,
				  struct switchdev_trans_item, list);
	list_del(&tritem->list);
	return tritem;
}

/**
 *	switchdev_trans_item_dequeue - Dequeue data item from transaction queue
 *
 *	@trans: transaction
 */
void *switchdev_trans_item_dequeue(struct switchdev_trans *trans)
{
	struct switchdev_trans_item *tritem;

	tritem = __switchdev_trans_item_dequeue(trans);
	BUG_ON(!tritem);
	return tritem->data;
}
EXPORT_SYMBOL_GPL(switchdev_trans_item_dequeue);

static void switchdev_trans_init(struct switchdev_trans *trans)
{
	INIT_LIST_HEAD(&trans->item_list);
}

static void switchdev_trans_items_destroy(struct switchdev_trans *trans)
{
	struct switchdev_trans_item *tritem;

	while ((tritem = __switchdev_trans_item_dequeue(trans)))
		tritem->destructor(tritem->data);
}

static void switchdev_trans_items_warn_destroy(struct net_device *dev,
					       struct switchdev_trans *trans)
{
	WARN(!list_empty(&trans->item_list), "%s: transaction item queue is not empty.\n",
	     dev->name);
	switchdev_trans_items_destroy(trans);
}

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<