OpenCloudOS-Kernel/drivers/net/rionet.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * rionet - Ethernet driver over RapidIO messaging services
 *
 * Copyright 2005 MontaVista Software, Inc.
 * Matt Porter <mporter@kernel.crashing.org>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
#include <linux/rio.h>
#include <linux/rio_drv.h>
#include <linux/slab.h>
#include <linux/rio_ids.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/crc32.h>
#include <linux/ethtool.h>
#include <linux/reboot.h>

#define DRV_NAME        "rionet"
#define DRV_VERSION     "0.3"
#define DRV_AUTHOR      "Matt Porter <mporter@kernel.crashing.org>"
#define DRV_DESC        "Ethernet over RapidIO"

MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION(DRV_DESC);
MODULE_LICENSE("GPL");

#define RIONET_DEFAULT_MSGLEVEL \
			(NETIF_MSG_DRV          | \
			 NETIF_MSG_LINK         | \
			 NETIF_MSG_RX_ERR       | \
			 NETIF_MSG_TX_ERR)

#define RIONET_DOORBELL_JOIN	0x1000
#define RIONET_DOORBELL_LEAVE	0x1001

#define RIONET_MAILBOX		0

#define RIONET_TX_RING_SIZE	CONFIG_RIONET_TX_SIZE
#define RIONET_RX_RING_SIZE	CONFIG_RIONET_RX_SIZE
#define RIONET_MAX_NETS		8
#define RIONET_MSG_SIZE         RIO_MAX_MSG_SIZE
#define RIONET_MAX_MTU          (RIONET_MSG_SIZE - ETH_HLEN)

struct rionet_private {
	struct rio_mport *mport;
	struct sk_buff *rx_skb[RIONET_RX_RING_SIZE];
	struct sk_buff *tx_skb[RIONET_TX_RING_SIZE];
	int rx_slot;
	int tx_slot;
	int tx_cnt;
	int ack_slot;
	spinlock_t lock;
	spinlock_t tx_lock;
	u32 msg_enable;
	bool open;
};

struct rionet_peer {
	struct list_head node;
	struct rio_dev *rdev;
	struct resource *res;
};

struct rionet_net {
	struct net_device *ndev;
	struct list_head peers;
	spinlock_t lock;	/* net info access lock */
	struct rio_dev **active;
	int nact;	/* number of active peers */
};

static struct rionet_net nets[RIONET_MAX_NETS];

#define is_rionet_capable(src_ops, dst_ops)			\
			((src_ops & RIO_SRC_OPS_DATA_MSG) &&	\
			 (dst_ops & RIO_DST_OPS_DATA_MSG) &&	\
			 (src_ops & RIO_SRC_OPS_DOORBELL) &&	\
			 (dst_ops & RIO_DST_OPS_DOORBELL))
#define dev_rionet_capable(dev) \
	is_rionet_capable(dev->src_ops, dev->dst_ops)

#define RIONET_MAC_MATCH(x)	(!memcmp((x), "\00\01\00\01", 4))
#define RIONET_GET_DESTID(x)	((*((u8 *)x + 4) << 8) | *((u8 *)x + 5))

static int rionet_rx_clean(struct net_device *ndev)
{
	int i;
	int error = 0;
	struct rionet_private *rnet = netdev_priv(ndev);
	void *data;

	i = rnet->rx_slot;

	do {
		if (!rnet->rx_skb[i])
			continue;

		if (!(data = rio_get_inb_message(rnet->mport, RIONET_MAILBOX)))
			break;

		rnet->rx_skb[i]->data = data;
		skb_put(rnet->rx_skb[i], RIO_MAX_MSG_SIZE);
		rnet->rx_skb[i]->protocol =
		    eth_type_trans(rnet->rx_skb[i], ndev);
		error = netif_rx(rnet->rx_skb[i]);

		if (error == NET_RX_DROP) {
			ndev->stats.rx_dropped++;
		} else {
			ndev->stats.rx_packets++;
			ndev->stats.rx_bytes += RIO_MAX_MSG_SIZE;
		}

	} while ((i = (i + 1) % RIONET_RX_RING_SIZE) != rnet->rx_slot);

	return i;
}

static void rionet_rx_fill(struct net_device *ndev, int end)
{
	int i;
	struct rionet_private *rnet = netdev_priv(ndev);

	i = rnet->rx_slot;
	do {
		rnet->rx_skb[i] = dev_alloc_skb(RIO_MAX_MSG_SIZE);

		if (!rnet->rx_skb[i])
			break;

		rio_add_inb_buffer(rnet->mport, RIONET_MAILBOX,
				   rnet->rx_skb[i]->data);
	} while ((i = (i + 1) % RIONET_RX_RING_SIZE) != end);

	rnet->rx_slot = i;
}

static int rionet_queue_tx_msg(struct sk_buff *skb, struct net_device *ndev,
			       struct rio_dev *rdev)
{
	struct rionet_private *rnet = netdev_priv(ndev);

	rio_add_outb_message(rnet->mport, rdev, 0, skb->data, skb->len);
	rnet->tx_skb[rnet->tx_slot] = skb;

	ndev->stats.tx_packets++;
	ndev->stats.tx_bytes += skb->len;

	if (++rnet->tx_cnt == RIONET_TX_RING_SIZE)
		netif_stop_queue(ndev);

	++rnet->tx_slot;
	rnet->tx_slot &= (RIONET_TX_RING_SIZE - 1);

	if (netif_msg_tx_queued(rnet))
		printk(KERN_INFO "%s: queued skb len %8.8x\n", DRV_NAME,
		       skb->len);

	return 0;
}

static int rionet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
	int i;
	struct rionet_private *rnet = netdev_priv(ndev);
	struct ethhdr *eth = (struct ethhdr *)skb->data;
	u16 destid;
	unsigned long flags;
	int add_num = 1;

	spin_lock_irqsave(&rnet->tx_lock, flags);

	if (is_multicast_ether_addr(eth->h_dest))
		add_num = nets[rnet->mport->id].nact;

	if ((rnet->tx_cnt + add_num) > RIONET_TX_RING_SIZE) {
		netif_stop_queue(ndev);
		spin_unlock_irqrestore(&rnet->tx_lock, flags);
		printk(KERN_ERR "%s: BUG! Tx Ring full when queue awake!\n",
		       ndev->name);
		return NETDEV_TX_BUSY;
	}

	if (is_multicast_ether_addr(eth->h_dest)) {
		int count = 0;

		for (i = 0; i < RIO_MAX_ROUTE_ENTRIES(rnet->mport->sys_size);
				i++)
			if (nets[rnet->mport->id].active[i]) {
				rionet_queue_tx_msg(skb, ndev,
					nets[rnet->mport->id].active[i]);
				if (count)
					refcount_inc(&skb->users);
				count++;
			}
	} else if (RIONET_MAC_MATCH(eth->h_dest)) {
		destid = RIONET_GET_DESTID(eth->h_dest);
		if (nets[rnet->mport->id].active[destid])
			rionet_queue_tx_msg(skb, ndev,
					nets[rnet->mport->id].active[destid]);
		else {
			/*
			 * If the target device was removed from the list of
			 * active peers but we still have TX packets targeting
			 * it just report sending a packet to the target
			 * (without actual packet transfer).
			 */
			ndev->stats.tx_packets++;
			ndev->stats.tx_bytes += skb->len;
			dev_kfree_skb_any(skb);
		}
	}

	spin_unlock_irqrestore(&rnet->tx_lock, flags);

	return NETDEV_TX_OK;
}

static void rionet_dbell_event(struct rio_mport *mport, void *dev_id, u16 sid, u16 tid,
			       u16 info)
{
	struct net_device *ndev = dev_id;
	struct rionet_private *rnet = netdev_priv(ndev);
	struct rionet_peer *peer;
	unsigned char netid = rnet->mport->id;

	if (netif_msg_intr(rnet))
		printk(KERN_INFO "%s: doorbell sid %4.4x tid %4.4x info %4.4x",
		       DRV_NAME, sid, tid, info);
	if (info == RIONET_DOORBELL_JOIN) {
		if (!nets[netid].active[sid]) {
			spin_lock(&nets[netid].lock);
			list_for_each_entry(peer, &nets[netid].peers, node) {
				if (peer->rdev->destid == sid) {
					nets[netid].active[sid] = peer->rdev;
					nets[netid].nact++;
				}
			}
			spin_unlock(&nets[netid].lock);

			rio_mport_send_doorbell(mport, sid,
						RIONET_DOORBELL_JOIN);
		}
	} else if (info == RIONET_DOORBELL_LEAVE) {
		spin_lock(&nets[netid].lock);
		if (nets[netid].active[sid]) {
			nets[netid].active[sid] = NULL;
			nets[netid].nact--;
		}
		spin_unlock(&nets[netid].lock);
	} else {
		if (netif_msg_intr(rnet))
			printk(KERN_WARNING "%s: unhandled doorbell\n",
			       DRV_NAME);
	}
}

static void rionet_inb_msg_event(struct rio_mport *mport, void *dev_id, int mbox, int slot)
{
	int n;
	struct net_device *ndev = dev_id;
	struct rionet_private *rnet = netdev_priv(ndev);

	if (netif_msg_intr(rnet))
		printk(KERN_INFO "%s: inbound message event, mbox %d slot %d\n",
		       DRV_NAME, mbox, slot);

	spin_lock(&rnet->lock);
	if ((n = rionet_rx_clean(ndev)) != rnet->rx_slot)
		rionet_rx_fill(ndev, n);
	spin_unlock(&rnet->lock);
}

static void rionet_outb_msg_event(struct rio_mport *mport, void *dev_id, int mbox, int slot)
{
	struct net_device *ndev = dev_id;
	struct rionet_private *rnet = netdev_priv(ndev);

	spin_lock(&rnet->tx_lock);

	if (netif_msg_intr(rnet))
		printk(KERN_INFO
		       "%s: outbound message event, mbox %d slot %d\n",
		       DRV_NAME, mbox, slot);

	while (rnet->tx_cnt && (rnet->ack_slot != slot)) {
		/* dma unmap single */
		dev_kfree_skb_irq(rnet->tx_skb[rnet->ack_slot]);
		rnet->tx_skb[rnet->ack_slot] = NULL;
		++rnet->ack_slot;
		rnet->ack_slot &= (RIONET_TX_RING_SIZE - 1);
		rnet->tx_cnt--;
	}

	if (rnet->tx_cnt < RIONET_TX_RING_SIZE)
		netif_wake_queue(ndev);

	spin_unlock(&rnet->tx_lock);
}

static int rionet_open(struct net_device *ndev)
{
	int i, rc = 0;
	struct rionet_peer *peer;
	struct rionet_private *rnet = netdev_priv(ndev);
	unsigned char netid = rnet->mport->id;
	unsigned long flags;

	if (netif_msg_ifup(rnet))
		printk(KERN_INFO "%s: open\n", DRV_NAME);

	if ((rc = rio_request_inb_dbell(rnet->mport,
					(void *)ndev,
					RIONET_DOORBELL_JOIN,
					RIONET_DOORBELL_LEAVE,
					rionet_dbell_event)) < 0)
		goto out;

	if ((rc = rio_request_inb_mbox(rnet->mport,
				       (void *)ndev,
				       RIONET_MAILBOX,
				       RIONET_RX_RING_SIZE,
				       rionet_inb_msg_event)) < 0)
		goto out;

	if ((rc = rio_request_outb_mbox(rnet->mport,
					(void *)ndev,
					RIONET_MAILBOX,
					RIONET_TX_RING_SIZE,
					rionet_outb_msg_event)) < 0)
		goto out;

	/* Initialize inbound message ring */
	for (i = 0; i < RIONET_RX_RING_SIZE; i++)
		rnet->rx_skb[i] = NULL;
	rnet->rx_slot = 0;
	rionet_rx_fill(ndev, 0);

	rnet->tx_slot = 0;
	rnet->tx_cnt = 0;
	rnet->ack_slot = 0;

	netif_carrier_on(ndev);
	netif_start_queue(ndev);

	spin_lock_irqsave(&nets[netid].lock, flags);
	list_for_each_entry(peer, &nets[netid].peers, node) {
		/* Send a join message */
		rio_send_doorbell(peer->rdev, RIONET_DOORBELL_JOIN);
	}
	spin_unlock_irqrestore(&nets[netid].lock, flags);
	rnet->open = true;

      out:
	return rc;
}

static int rionet_close(struct net_device *ndev)
{
	struct rionet_private *rnet = netdev_priv(ndev);
	struct rionet_peer *peer;
	unsigned char netid = rnet->mport->id;
	unsigned long flags;
	int i;

	if (netif_msg_ifup(rnet))
		printk(KERN_INFO "%s: close %s\n", DRV_NAME, ndev->name);

	netif_stop_queue(ndev);
	netif_carrier_off(ndev);
	rnet->open = false;

	for (i = 0; i < RIONET_RX_RING_SIZE; i++)
		kfree_skb(rnet->rx_skb[i]);

	spin_lock_irqsave(&nets[netid].lock, flags);
	list_for_each_entry(peer, &nets[netid].peers, node) {
		if (nets[netid].active[peer->rdev->destid]) {
			rio_send_doorbell(peer->rdev, RIONET_DOORBELL_LEAVE);
			nets[netid].active[peer->rdev->destid] = NULL;
		}
		if (peer->res)
			rio_release_outb_dbell(peer->rdev, peer->res);
	}
	spin_unlock_irqrestore(&nets[netid].lock, flags);

	rio_release_inb_dbell(rnet->mport, RIONET_DOORBELL_JOIN,
			      RIONET_DOORBELL_LEAVE);
	rio_release_inb_mbox(rnet->mport, RIONET_MAILBOX);
	rio_release_outb_mbox(rnet->mport, RIONET_MAILBOX);

	return 0;
}

static void rionet_remove_dev(struct device *dev, struct subsys_interface *sif)
{
	struct rio_dev *rdev = to_rio_dev(dev);
	unsigned char netid = rdev->net->hport->id;
	struct rionet_peer *peer;
	int state, found = 0;
	unsigned long flags;

	if (!dev_rionet_capable(rdev))
		return;

	spin_lock_irqsave(&nets[netid].lock, flags);
	list_for_each_entry(peer, &nets[netid].peers, node) {
		if (peer->rdev == rdev) {
			list_del(&peer->node);
			if (nets[netid].active[rdev->destid]) {
				state = atomic_read(&rdev->state);
				if (state != RIO_DEVICE_GONE &&
				    state != RIO_DEVICE_INITIALIZING) {
					rio_send_doorbell(rdev,
							RIONET_DOORBELL_LEAVE);
				}
				nets[netid].active[rdev->destid] = NULL;
				nets[netid].nact--;
			}
			found = 1;
			break;
		}
	}
	spin_unlock_irqrestore(&nets[netid].lock, flags);

	if (found) {
		if (peer->res)
			rio_release_outb_dbell(rdev, peer->res);
		kfree(peer);
	}
}

static void rionet_get_drvinfo(struct net_device *ndev,
			       struct ethtool_drvinfo *info)
{
	struct rionet_private *rnet = netdev_priv(ndev);

	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
	strlcpy(info->fw_version, "n/a", sizeof(info->fw_version));
	strlcpy(info->bus_info, rnet->mport->name, sizeof(info->bus_info));
}

static u32 rionet_get_msglevel(struct net_device *ndev)
{
	struct rionet_private *rnet = netdev_priv(ndev);

	return rnet->msg_enable;
}

static void rionet_set_msglevel(struct net_device *ndev, u32 value)
{
	struct rionet_private *rnet = netdev_priv(ndev);

	rnet->msg_enable = value;
}

static const struct ethtool_ops rionet_ethtool_ops = {
	.get_drvinfo = rionet_get_drvinfo,
	.get_msglevel = rionet_get_msglevel,
	.set_msglevel = rionet_set_msglevel,
	.get_link = ethtool_op_get_link,
};

static const struct net_device_ops rionet_netdev_ops = {
	.ndo_open		= rionet_open,
	.ndo_stop		= rionet_close,
	.ndo_start_xmit		= rionet_start_xmit,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_set_mac_address	= eth_mac_addr,
};

static int rionet_setup_netdev(struct rio_mport *mport, struct net_device *ndev)
{
	int rc = 0;
	struct rionet_private *rnet;
	u16 device_id;
	const size_t rionet_active_bytes = sizeof(void *) *
				RIO_MAX_ROUTE_ENTRIES(mport->sys_size);

	nets[mport->id].active = (struct rio_dev **)__get_free_pages(GFP_KERNEL,
						get_order(rionet_active_bytes));
	if (!nets[mport->id].active) {
		rc = -ENOMEM;
		goto out;
	}
	memset((void *)nets[mport->id].active, 0, rionet_active_bytes);

	/* Set up private area */
	rnet = netdev_priv(ndev);
	rnet->mport = mport;
	rnet->open = false;

	/* Set the default MAC address */
	device_id = rio_local_get_device_id(mport);
	ndev->dev_addr[0] = 0x00;
	ndev->dev_addr[1] = 0x01;
	ndev->dev_addr[2] = 0x00;
	ndev->dev_addr[3] = 0x01;
	ndev->dev_addr[4] = device_id >> 8;
	ndev->dev_addr[5] = device_id & 0xff;

	ndev->netdev_ops = &rionet_netdev_ops;
	ndev->mtu = RIONET_MAX_MTU;
	/* MTU range: 68 - 4082 */
	ndev->min_mtu = ETH_MIN_MTU;
	ndev->max_mtu = RIONET_MAX_MTU;
	ndev->features = NETIF_F_LLTX;
	SET_NETDEV_DEV(ndev, &mport->dev);
	ndev->ethtool_ops = &rionet_ethtool_ops;

	spin_lock_init(&rnet->lock);
	spin_lock_init(&rnet->tx_lock);

	rnet->msg_enable = RIONET_DEFAULT_MSGLEVEL;

	rc = register_netdev(ndev);
	if (rc != 0) {
		free_pages((unsigned long)nets[mport->id].active,
			   get_order(rionet_active_bytes));
		goto out;
	}

	printk(KERN_INFO "%s: %s %s Version %s, MAC %pM, %s\n",
	       ndev->name,
	       DRV_NAME,
	       DRV_DESC,
	       DRV_VERSION,
	       ndev->dev_addr,
	       mport->name);

      out:
	return rc;
}

static int rionet_add_dev(struct device *dev, struct subsys_interface *sif)
{
	int rc = -ENODEV;
	u32 lsrc_ops, ldst_ops;
	struct rionet_peer *peer;
	struct net_device *ndev = NULL;
	struct rio_dev *rdev = to_rio_dev(dev);
	unsigned char netid = rdev->net->hport->id;

	if (netid >= RIONET_MAX_NETS)
		return rc;

	/*
	 * If first time through this net, make sure local device is rionet
	 * capable and setup netdev (this step will be skipped in later probes
	 * on the same net).
	 */
	if (!nets[netid].ndev) {
		rio_local_read_config_32(rdev->net->hport, RIO_SRC_OPS_CAR,
					 &lsrc_ops);
		rio_local_read_config_32(rdev->net->hport, RIO_DST_OPS_CAR,
					 &ldst_ops);
		if (!is_rionet_capable(lsrc_ops, ldst_ops)) {
			printk(KERN_ERR
			       "%s: local device %s is not network capable\n",
			       DRV_NAME, rdev->net->hport->name);
			goto out;
		}

		/* Allocate our net_device structure */
		ndev = alloc_etherdev(sizeof(struct rionet_private));
		if (ndev == NULL) {
			rc = -ENOMEM;
			goto out;
		}

		rc = rionet_setup_netdev(rdev->net->hport, ndev);
		if (rc) {
			printk(KERN_ERR "%s: failed to setup netdev (rc=%d)\n",
			       DRV_NAME, rc);
			free_netdev(ndev);
			goto out;
		}

		INIT_LIST_HEAD(&nets[netid].peers);
		spin_lock_init(&nets[netid].lock);
		nets[netid].nact = 0;
		nets[netid].ndev = ndev;
	}

	/*
	 * If the remote device has mailbox/doorbell capabilities,
	 * add it to the peer list.
	 */
	if (dev_rionet_capable(rdev)) {
		struct rionet_private *rnet;
		unsigned long flags;

		rnet = netdev_priv(nets[netid].ndev);

		peer = kzalloc(sizeof(*peer), GFP_KERNEL);
		if (!peer) {
			rc = -ENOMEM;
			goto out;
		}
		peer->rdev = rdev;
		peer->res = rio_request_outb_dbell(peer->rdev,
						RIONET_DOORBELL_JOIN,
						RIONET_DOORBELL_LEAVE);
		if (!peer->res) {
			pr_err("%s: error requesting doorbells\n", DRV_NAME);
			kfree(peer);
			rc = -ENOMEM;
			goto out;
		}

		spin_lock_irqsave(&nets[netid].lock, flags);
		list_add_tail(&peer->node, &nets[netid].peers);
		spin_unlock_irqrestore(&nets[netid].lock, flags);
		pr_debug("%s: %s add peer %s\n",
			 DRV_NAME, __func__, rio_name(rdev));

		/* If netdev is already opened, send join request to new peer */
		if (rnet->open)
			rio_send_doorbell(peer->rdev, RIONET_DOORBELL_JOIN);
	}

	return 0;
out:
	return rc;
}

static int rionet_shutdown(struct notifier_block *nb, unsigned long code,
			   void *unused)
{
	struct rionet_peer *peer;
	unsigned long flags;
	int i;

	pr_debug("%s: %s\n", DRV_NAME, __func__);

	for (i = 0; i < RIONET_MAX_NETS; i++) {
		if (!nets[i].ndev)
			continue;

		spin_lock_irqsave(&nets[i].lock, flags);
		list_for_each_entry(peer, &nets[i].peers, node) {
			if (nets[i].active[peer->rdev->destid]) {
				rio_send_doorbell(peer->rdev,
						  RIONET_DOORBELL_LEAVE);
				nets[i].active[peer->rdev->destid] = NULL;
			}
		}
		spin_unlock_irqrestore(&nets[i].lock, flags);
	}

	return NOTIFY_DONE;
}

static void rionet_remove_mport(struct device *dev,
				struct class_interface *class_intf)
{
	struct rio_mport *mport = to_rio_mport(dev);
	struct net_device *ndev;
	int id = mport->id;

	pr_debug("%s %s\n", __func__, mport->name);

	WARN(nets[id].nact, "%s called when connected to %d peers\n",
	     __func__, nets[id].nact);
	WARN(!nets[id].ndev, "%s called for mport without NDEV\n",
	     __func__);

	if (nets[id].ndev) {
		ndev = nets[id].ndev;
		netif_stop_queue(ndev);
		unregister_netdev(ndev);

		free_pages((unsigned long)nets[id].active,
			   get_order(sizeof(void *) *
			   RIO_MAX_ROUTE_ENTRIES(mport->sys_size)));
		nets[id].active = NULL;
		free_netdev(ndev);
		nets[id].ndev = NULL;
	}
}

#ifdef MODULE
static struct rio_device_id rionet_id_table[] = {
	{RIO_DEVICE(RIO_ANY_ID, RIO_ANY_ID)},
	{ 0, }	/* terminate list */
};

MODULE_DEVICE_TABLE(rapidio, rionet_id_table);
#endif

static struct subsys_interface rionet_interface = {
	.name		= "rionet",
	.subsys		= &rio_bus_type,
	.add_dev	= rionet_add_dev,
	.remove_dev	= rionet_remove_dev,
};

static struct notifier_block rionet_notifier = {
	.notifier_call = rionet_shutdown,
};

/* the rio_mport_interface is used to handle local mport devices */
static struct class_interface rio_mport_interface __refdata = {
	.class = &rio_mport_class,
	.add_dev = NULL,
	.remove_dev = rionet_remove_mport,
};

static int __init rionet_init(void)
{
	int ret;

	ret = register_reboot_notifier(&rionet_notifier);
	if (ret) {
		pr_err("%s: failed to register reboot notifier (err=%d)\n",
		       DRV_NAME, ret);
		return ret;
	}

	ret = class_interface_register(&rio_mport_interface);
	if (ret) {
		pr_err("%s: class_interface_register error: %d\n",
		       DRV_NAME, ret);
		return ret;
	}

	return subsys_interface_register(&rionet_interface);
}

static void __exit rionet_exit(void)
{
	unregister_reboot_notifier(&rionet_notifier);
	subsys_interface_unregister(&rionet_interface);
	class_interface_unregister(&rio_mport_interface);
}

late_initcall(rionet_init);
module_exit(rionet_exit);