[deliverable/linux.git] / drivers / net / virtio_net.c

/* A simple network driver using virtio.
 *
 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
 *
 * 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.
 *
 * This program is distributed in the hope that 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
//#define DEBUG
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/module.h>
#include <linux/virtio.h>
#include <linux/virtio_net.h>
#include <linux/scatterlist.h>

static int napi_weight = 128;
module_param(napi_weight, int, 0444);

static int csum = 1, gso = 1;
module_param(csum, bool, 0444);
module_param(gso, bool, 0444);

/* FIXME: MTU in config. */
#define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)

struct virtnet_info
{
	struct virtio_device *vdev;
	struct virtqueue *rvq, *svq;
	struct net_device *dev;
	struct napi_struct napi;

	/* The skb we couldn't send because buffers were full. */
	struct sk_buff *last_xmit_skb;

	struct timer_list xmit_free_timer;

	/* Number of input buffers, and max we've ever had. */
	unsigned int num, max;

	/* For cleaning up after transmission. */
	struct tasklet_struct tasklet;

	/* Receive & send queues. */
	struct sk_buff_head recv;
	struct sk_buff_head send;
};

static inline struct virtio_net_hdr *skb_vnet_hdr(struct sk_buff *skb)
{
	return (struct virtio_net_hdr *)skb->cb;
}

static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
{
	sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
}

static void skb_xmit_done(struct virtqueue *svq)
{
	struct virtnet_info *vi = svq->vdev->priv;

	/* Suppress further interrupts. */
	svq->vq_ops->disable_cb(svq);

	/* We were waiting for more output buffers. */
	netif_wake_queue(vi->dev);

	/* Make sure we re-xmit last_xmit_skb: if there are no more packets
	 * queued, start_xmit won't be called. */
	tasklet_schedule(&vi->tasklet);
}

static void receive_skb(struct net_device *dev, struct sk_buff *skb,
			unsigned len)
{
	struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);

	if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
		pr_debug("%s: short packet %i\n", dev->name, len);
		dev->stats.rx_length_errors++;
		goto drop;
	}
	len -= sizeof(struct virtio_net_hdr);
	BUG_ON(len > MAX_PACKET_LEN);

	skb_trim(skb, len);

	dev->stats.rx_bytes += skb->len;
	dev->stats.rx_packets++;

	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
		pr_debug("Needs csum!\n");
		if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
			goto frame_err;
	}

	skb->protocol = eth_type_trans(skb, dev);
	pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
		 ntohs(skb->protocol), skb->len, skb->pkt_type);

	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
		pr_debug("GSO!\n");
		switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
		case VIRTIO_NET_HDR_GSO_TCPV4:
			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
			break;
		case VIRTIO_NET_HDR_GSO_UDP:
			skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
			break;
		case VIRTIO_NET_HDR_GSO_TCPV6:
			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
			break;
		default:
			if (net_ratelimit())
				printk(KERN_WARNING "%s: bad gso type %u.\n",
				       dev->name, hdr->gso_type);
			goto frame_err;
		}

		if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
			skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;

		skb_shinfo(skb)->gso_size = hdr->gso_size;
		if (skb_shinfo(skb)->gso_size == 0) {
			if (net_ratelimit())
				printk(KERN_WARNING "%s: zero gso size.\n",
				       dev->name);
			goto frame_err;
		}

		/* Header must be checked, and gso_segs computed. */
		skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
		skb_shinfo(skb)->gso_segs = 0;
	}

	netif_receive_skb(skb);
	return;

frame_err:
	dev->stats.rx_frame_errors++;
drop:
	dev_kfree_skb(skb);
}

static void try_fill_recv(struct virtnet_info *vi)
{
	struct sk_buff *skb;
	struct scatterlist sg[2+MAX_SKB_FRAGS];
	int num, err;

	sg_init_table(sg, 2+MAX_SKB_FRAGS);
	for (;;) {
		skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
		if (unlikely(!skb))
			break;

		skb_put(skb, MAX_PACKET_LEN);
		vnet_hdr_to_sg(sg, skb);
		num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
		skb_queue_head(&vi->recv, skb);

		err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
		if (err) {
			skb_unlink(skb, &vi->recv);
			kfree_skb(skb);
			break;
		}
		vi->num++;
	}
	if (unlikely(vi->num > vi->max))
		vi->max = vi->num;
	vi->rvq->vq_ops->kick(vi->rvq);
}

static void skb_recv_done(struct virtqueue *rvq)
{
	struct virtnet_info *vi = rvq->vdev->priv;
	/* Schedule NAPI, Suppress further interrupts if successful. */
	if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
		rvq->vq_ops->disable_cb(rvq);
		__netif_rx_schedule(vi->dev, &vi->napi);
	}
}

static int virtnet_poll(struct napi_struct *napi, int budget)
{
	struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
	struct sk_buff *skb = NULL;
	unsigned int len, received = 0;

again:
	while (received < budget &&
	       (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
		__skb_unlink(skb, &vi->recv);
		receive_skb(vi->dev, skb, len);
		vi->num--;
		received++;
	}

	/* FIXME: If we oom and completely run out of inbufs, we need
	 * to start a timer trying to fill more. */
	if (vi->num < vi->max / 2)
		try_fill_recv(vi);

	/* Out of packets? */
	if (received < budget) {
		netif_rx_complete(vi->dev, napi);
		if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
		    && napi_schedule_prep(napi)) {
			vi->rvq->vq_ops->disable_cb(vi->rvq);
			__netif_rx_schedule(vi->dev, napi);
			goto again;
		}
	}

	return received;
}

static void free_old_xmit_skbs(struct virtnet_info *vi)
{
	struct sk_buff *skb;
	unsigned int len;

	while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
		pr_debug("Sent skb %p\n", skb);
		__skb_unlink(skb, &vi->send);
		vi->dev->stats.tx_bytes += skb->len;
		vi->dev->stats.tx_packets++;
		kfree_skb(skb);
	}
}

static void xmit_free(unsigned long data)
{
	struct virtnet_info *vi = (void *)data;

	netif_tx_lock(vi->dev);

	free_old_xmit_skbs(vi);

	if (!skb_queue_empty(&vi->send))
		mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));

	netif_tx_unlock(vi->dev);
}

static int xmit_skb(struct virtnet_info *vi, struct sk_buff *skb)
{
	int num, err;
	struct scatterlist sg[2+MAX_SKB_FRAGS];
	struct virtio_net_hdr *hdr;
	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;

	sg_init_table(sg, 2+MAX_SKB_FRAGS);

	pr_debug("%s: xmit %p " MAC_FMT "\n", vi->dev->name, skb,
		 dest[0], dest[1], dest[2],
		 dest[3], dest[4], dest[5]);

	/* Encode metadata header at front. */
	hdr = skb_vnet_hdr(skb);
	if (skb->ip_summed == CHECKSUM_PARTIAL) {
		hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
		hdr->csum_start = skb->csum_start - skb_headroom(skb);
		hdr->csum_offset = skb->csum_offset;
	} else {
		hdr->flags = 0;
		hdr->csum_offset = hdr->csum_start = 0;
	}

	if (skb_is_gso(skb)) {
		hdr->hdr_len = skb_transport_header(skb) - skb->data;
		hdr->gso_size = skb_shinfo(skb)->gso_size;
		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
		else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
		else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
			hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
		else
			BUG();
		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
			hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
	} else {
		hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
		hdr->gso_size = hdr->hdr_len = 0;
	}

	vnet_hdr_to_sg(sg, skb);
	num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;

	err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
	if (!err)
		mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));

	return err;
}

static void xmit_tasklet(unsigned long data)
{
	struct virtnet_info *vi = (void *)data;

	netif_tx_lock_bh(vi->dev);
	if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
		vi->svq->vq_ops->kick(vi->svq);
		vi->last_xmit_skb = NULL;
	}
	netif_tx_unlock_bh(vi->dev);
}

static int start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);

again:
	/* Free up any pending old buffers before queueing new ones. */
	free_old_xmit_skbs(vi);

	/* If we has a buffer left over from last time, send it now. */
	if (unlikely(vi->last_xmit_skb)) {
		if (xmit_skb(vi, vi->last_xmit_skb) != 0) {
			/* Drop this skb: we only queue one. */
			vi->dev->stats.tx_dropped++;
			kfree_skb(skb);
			skb = NULL;
			goto stop_queue;
		}
		vi->last_xmit_skb = NULL;
	}

	/* Put new one in send queue and do transmit */
	if (likely(skb)) {
		__skb_queue_head(&vi->send, skb);
		if (xmit_skb(vi, skb) != 0) {
			vi->last_xmit_skb = skb;
			skb = NULL;
			goto stop_queue;
		}
	}
done:
	vi->svq->vq_ops->kick(vi->svq);
	return NETDEV_TX_OK;

stop_queue:
	pr_debug("%s: virtio not prepared to send\n", dev->name);
	netif_stop_queue(dev);

	/* Activate callback for using skbs: if this returns false it
	 * means some were used in the meantime. */
	if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
		vi->svq->vq_ops->disable_cb(vi->svq);
		netif_start_queue(dev);
		goto again;
	}
	goto done;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void virtnet_netpoll(struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);

	napi_schedule(&vi->napi);
}
#endif

static int virtnet_open(struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);

	napi_enable(&vi->napi);

	/* If all buffers were filled by other side before we napi_enabled, we
	 * won't get another interrupt, so process any outstanding packets
	 * now.  virtnet_poll wants re-enable the queue, so we disable here.
	 * We synchronize against interrupts via NAPI_STATE_SCHED */
	if (netif_rx_schedule_prep(dev, &vi->napi)) {
		vi->rvq->vq_ops->disable_cb(vi->rvq);
		__netif_rx_schedule(dev, &vi->napi);
	}
	return 0;
}

static int virtnet_close(struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);

	napi_disable(&vi->napi);

	return 0;
}

static int virtnet_probe(struct virtio_device *vdev)
{
	int err;
	struct net_device *dev;
	struct virtnet_info *vi;

	/* Allocate ourselves a network device with room for our info */
	dev = alloc_etherdev(sizeof(struct virtnet_info));
	if (!dev)
		return -ENOMEM;

	/* Set up network device as normal. */
	dev->open = virtnet_open;
	dev->stop = virtnet_close;
	dev->hard_start_xmit = start_xmit;
	dev->features = NETIF_F_HIGHDMA;
#ifdef CONFIG_NET_POLL_CONTROLLER
	dev->poll_controller = virtnet_netpoll;
#endif
	SET_NETDEV_DEV(dev, &vdev->dev);

	/* Do we support "hardware" checksums? */
	if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
		/* This opens up the world of extra features. */
		dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
			dev->features |= NETIF_F_TSO | NETIF_F_UFO
				| NETIF_F_TSO_ECN | NETIF_F_TSO6;
		}
		/* Individual feature bits: what can host handle? */
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
			dev->features |= NETIF_F_TSO;
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
			dev->features |= NETIF_F_TSO6;
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
			dev->features |= NETIF_F_TSO_ECN;
		if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
			dev->features |= NETIF_F_UFO;
	}

	/* Configuration may specify what MAC to use.  Otherwise random. */
	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
		vdev->config->get(vdev,
				  offsetof(struct virtio_net_config, mac),
				  dev->dev_addr, dev->addr_len);
	} else
		random_ether_addr(dev->dev_addr);

	/* Set up our device-specific information */
	vi = netdev_priv(dev);
	netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
	vi->dev = dev;
	vi->vdev = vdev;
	vdev->priv = vi;

	/* We expect two virtqueues, receive then send. */
	vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
	if (IS_ERR(vi->rvq)) {
		err = PTR_ERR(vi->rvq);
		goto free;
	}

	vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done);
	if (IS_ERR(vi->svq)) {
		err = PTR_ERR(vi->svq);
		goto free_recv;
	}

	/* Initialize our empty receive and send queues. */
	skb_queue_head_init(&vi->recv);
	skb_queue_head_init(&vi->send);

	tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);

	setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);

	err = register_netdev(dev);
	if (err) {
		pr_debug("virtio_net: registering device failed\n");
		goto free_send;
	}

	/* Last of all, set up some receive buffers. */
	try_fill_recv(vi);

	/* If we didn't even get one input buffer, we're useless. */
	if (vi->num == 0) {
		err = -ENOMEM;
		goto unregister;
	}

	pr_debug("virtnet: registered device %s\n", dev->name);
	return 0;

unregister:
	unregister_netdev(dev);
free_send:
	vdev->config->del_vq(vi->svq);
free_recv:
	vdev->config->del_vq(vi->rvq);
free:
	free_netdev(dev);
	return err;
}

static void virtnet_remove(struct virtio_device *vdev)
{
	struct virtnet_info *vi = vdev->priv;
	struct sk_buff *skb;

	/* Stop all the virtqueues. */
	vdev->config->reset(vdev);

	del_timer_sync(&vi->xmit_free_timer);

	/* Free our skbs in send and recv queues, if any. */
	while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
		kfree_skb(skb);
		vi->num--;
	}
	__skb_queue_purge(&vi->send);

	BUG_ON(vi->num != 0);

	vdev->config->del_vq(vi->svq);
	vdev->config->del_vq(vi->rvq);
	unregister_netdev(vi->dev);
	free_netdev(vi->dev);
}

static struct virtio_device_id id_table[] = {
	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
	{ 0 },
};

static unsigned int features[] = {
	VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
	VIRTIO_NET_F_HOST_ECN,
};

static struct virtio_driver virtio_net = {
	.feature_table = features,
	.feature_table_size = ARRAY_SIZE(features),
	.driver.name =	KBUILD_MODNAME,
	.driver.owner =	THIS_MODULE,
	.id_table =	id_table,
	.probe =	virtnet_probe,
	.remove =	__devexit_p(virtnet_remove),
};

static int __init init(void)
{
	return register_virtio_driver(&virtio_net);
}

static void __exit fini(void)
{
	unregister_virtio_driver(&virtio_net);
}
module_init(init);
module_exit(fini);

MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION("Virtio network driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
296f96fc RR	1	/* A simple network driver using virtio.
	2	*
	3	* Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	18	*/
	19	//#define DEBUG
	20	#include <linux/netdevice.h>
	21	#include <linux/etherdevice.h>
	22	#include <linux/module.h>
	23	#include <linux/virtio.h>
	24	#include <linux/virtio_net.h>
	25	#include <linux/scatterlist.h>
	26
6c0cd7c0 DL	27	static int napi_weight = 128;
	28	module_param(napi_weight, int, 0444);
	29
34a48579 RR	30	static int csum = 1, gso = 1;
	31	module_param(csum, bool, 0444);
	32	module_param(gso, bool, 0444);
	33
296f96fc RR	34	/* FIXME: MTU in config. */
	35	#define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
	36
	37	struct virtnet_info
	38	{
	39	struct virtio_device *vdev;
	40	struct virtqueue rvq, svq;
	41	struct net_device *dev;
	42	struct napi_struct napi;
	43
99ffc696 RR	44	/* The skb we couldn't send because buffers were full. */
	45	struct sk_buff *last_xmit_skb;
	46
14c998f0 MM	47	struct timer_list xmit_free_timer;
14c998f0 MM	48
296f96fc RR	49	/* Number of input buffers, and max we've ever had. */
	50	unsigned int num, max;
	51
11a3a154 RR	52	/* For cleaning up after transmission. */
	53	struct tasklet_struct tasklet;
	54
296f96fc RR	55	/* Receive & send queues. */
	56	struct sk_buff_head recv;
	57	struct sk_buff_head send;
	58	};
	59
	60	static inline struct virtio_net_hdr skb_vnet_hdr(struct sk_buff skb)
	61	{
	62	return (struct virtio_net_hdr *)skb->cb;
	63	}
	64
	65	static inline void vnet_hdr_to_sg(struct scatterlist sg, struct sk_buff skb)
	66	{
	67	sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
	68	}
	69
2cb9c6ba	70	static void skb_xmit_done(struct virtqueue *svq)
296f96fc	71	{
2cb9c6ba	72	struct virtnet_info *vi = svq->vdev->priv;
296f96fc	73
2cb9c6ba RR	74	/* Suppress further interrupts. */
2cb9c6ba RR	75	svq->vq_ops->disable_cb(svq);
11a3a154	76
2cb9c6ba	77	/* We were waiting for more output buffers. */
296f96fc	78	netif_wake_queue(vi->dev);
11a3a154 RR	79
	80	/* Make sure we re-xmit last_xmit_skb: if there are no more packets
	81	* queued, start_xmit won't be called. */
	82	tasklet_schedule(&vi->tasklet);
296f96fc RR	83	}
	84
	85	static void receive_skb(struct net_device dev, struct sk_buff skb,
	86	unsigned len)
	87	{
	88	struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
	89
	90	if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
	91	pr_debug("%s: short packet %i\n", dev->name, len);
	92	dev->stats.rx_length_errors++;
	93	goto drop;
	94	}
	95	len -= sizeof(struct virtio_net_hdr);
	96	BUG_ON(len > MAX_PACKET_LEN);
	97
	98	skb_trim(skb, len);
23cde76d	99
296f96fc RR	100	dev->stats.rx_bytes += skb->len;
	101	dev->stats.rx_packets++;
	102
	103	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
	104	pr_debug("Needs csum!\n");
f35d9d8a	105	if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
296f96fc	106	goto frame_err;
296f96fc RR	107	}
296f96fc RR	108
23cde76d MM	109	skb->protocol = eth_type_trans(skb, dev);
	110	pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
	111	ntohs(skb->protocol), skb->len, skb->pkt_type);
	112
296f96fc RR	113	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
296f96fc RR	114	pr_debug("GSO!\n");
34a48579	115	switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
296f96fc RR	116	case VIRTIO_NET_HDR_GSO_TCPV4:
	117	skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
	118	break;
296f96fc RR	119	case VIRTIO_NET_HDR_GSO_UDP:
	120	skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
	121	break;
	122	case VIRTIO_NET_HDR_GSO_TCPV6:
	123	skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
	124	break;
	125	default:
	126	if (net_ratelimit())
	127	printk(KERN_WARNING "%s: bad gso type %u.\n",
	128	dev->name, hdr->gso_type);
	129	goto frame_err;
	130	}
	131
34a48579 RR	132	if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
	133	skb_shinfo(skb)->gso_type \|= SKB_GSO_TCP_ECN;
	134
296f96fc RR	135	skb_shinfo(skb)->gso_size = hdr->gso_size;
	136	if (skb_shinfo(skb)->gso_size == 0) {
	137	if (net_ratelimit())
	138	printk(KERN_WARNING "%s: zero gso size.\n",
	139	dev->name);
	140	goto frame_err;
	141	}
	142
	143	/* Header must be checked, and gso_segs computed. */
	144	skb_shinfo(skb)->gso_type \|= SKB_GSO_DODGY;
	145	skb_shinfo(skb)->gso_segs = 0;
	146	}
	147
	148	netif_receive_skb(skb);
	149	return;
	150
	151	frame_err:
	152	dev->stats.rx_frame_errors++;
	153	drop:
	154	dev_kfree_skb(skb);
	155	}
	156
	157	static void try_fill_recv(struct virtnet_info *vi)
	158	{
	159	struct sk_buff *skb;
05271685	160	struct scatterlist sg[2+MAX_SKB_FRAGS];
296f96fc RR	161	int num, err;
296f96fc RR	162
05271685	163	sg_init_table(sg, 2+MAX_SKB_FRAGS);
296f96fc RR	164	for (;;) {
	165	skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
	166	if (unlikely(!skb))
	167	break;
	168
	169	skb_put(skb, MAX_PACKET_LEN);
	170	vnet_hdr_to_sg(sg, skb);
	171	num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
	172	skb_queue_head(&vi->recv, skb);
	173
	174	err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
	175	if (err) {
	176	skb_unlink(skb, &vi->recv);
	177	kfree_skb(skb);
	178	break;
	179	}
	180	vi->num++;
	181	}
	182	if (unlikely(vi->num > vi->max))
	183	vi->max = vi->num;
	184	vi->rvq->vq_ops->kick(vi->rvq);
	185	}
	186
18445c4d	187	static void skb_recv_done(struct virtqueue *rvq)
296f96fc RR	188	{
296f96fc RR	189	struct virtnet_info *vi = rvq->vdev->priv;
18445c4d RR	190	/* Schedule NAPI, Suppress further interrupts if successful. */
	191	if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
	192	rvq->vq_ops->disable_cb(rvq);
	193	__netif_rx_schedule(vi->dev, &vi->napi);
	194	}
296f96fc RR	195	}
	196
	197	static int virtnet_poll(struct napi_struct *napi, int budget)
	198	{
	199	struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
	200	struct sk_buff *skb = NULL;
	201	unsigned int len, received = 0;
	202
	203	again:
	204	while (received < budget &&
	205	(skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
	206	__skb_unlink(skb, &vi->recv);
	207	receive_skb(vi->dev, skb, len);
	208	vi->num--;
	209	received++;
	210	}
	211
	212	/* FIXME: If we oom and completely run out of inbufs, we need
	213	* to start a timer trying to fill more. */
	214	if (vi->num < vi->max / 2)
	215	try_fill_recv(vi);
	216
8329d98e RR	217	/* Out of packets? */
8329d98e RR	218	if (received < budget) {
296f96fc	219	netif_rx_complete(vi->dev, napi);
18445c4d	220	if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
4265f161 CB	221	&& napi_schedule_prep(napi)) {
	222	vi->rvq->vq_ops->disable_cb(vi->rvq);
	223	__netif_rx_schedule(vi->dev, napi);
296f96fc	224	goto again;
4265f161	225	}
296f96fc RR	226	}
	227
	228	return received;
	229	}
	230
	231	static void free_old_xmit_skbs(struct virtnet_info *vi)
	232	{
	233	struct sk_buff *skb;
	234	unsigned int len;
	235
	236	while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
	237	pr_debug("Sent skb %p\n", skb);
	238	__skb_unlink(skb, &vi->send);
655aa31f	239	vi->dev->stats.tx_bytes += skb->len;
296f96fc RR	240	vi->dev->stats.tx_packets++;
	241	kfree_skb(skb);
	242	}
	243	}
	244
14c998f0 MM	245	static void xmit_free(unsigned long data)
	246	{
	247	struct virtnet_info vi = (void )data;
	248
	249	netif_tx_lock(vi->dev);
	250
	251	free_old_xmit_skbs(vi);
	252
	253	if (!skb_queue_empty(&vi->send))
	254	mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
	255
	256	netif_tx_unlock(vi->dev);
	257	}
	258
99ffc696	259	static int xmit_skb(struct virtnet_info vi, struct sk_buff skb)
296f96fc	260	{
14c998f0	261	int num, err;
05271685	262	struct scatterlist sg[2+MAX_SKB_FRAGS];
296f96fc RR	263	struct virtio_net_hdr *hdr;
296f96fc RR	264	const unsigned char dest = ((struct ethhdr )skb->data)->h_dest;
296f96fc	265
05271685	266	sg_init_table(sg, 2+MAX_SKB_FRAGS);
4d125de3	267
99ffc696	268	pr_debug("%s: xmit %p " MAC_FMT "\n", vi->dev->name, skb,
21f644f3 DM	269	dest[0], dest[1], dest[2],
21f644f3 DM	270	dest[3], dest[4], dest[5]);
296f96fc	271
296f96fc RR	272	/* Encode metadata header at front. */
	273	hdr = skb_vnet_hdr(skb);
	274	if (skb->ip_summed == CHECKSUM_PARTIAL) {
	275	hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
	276	hdr->csum_start = skb->csum_start - skb_headroom(skb);
	277	hdr->csum_offset = skb->csum_offset;
	278	} else {
	279	hdr->flags = 0;
	280	hdr->csum_offset = hdr->csum_start = 0;
	281	}
	282
	283	if (skb_is_gso(skb)) {
50c8ea80	284	hdr->hdr_len = skb_transport_header(skb) - skb->data;
296f96fc	285	hdr->gso_size = skb_shinfo(skb)->gso_size;
34a48579	286	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
296f96fc RR	287	hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
	288	else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
	289	hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
	290	else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
	291	hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
	292	else
	293	BUG();
34a48579 RR	294	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
34a48579 RR	295	hdr->gso_type \|= VIRTIO_NET_HDR_GSO_ECN;
296f96fc RR	296	} else {
296f96fc RR	297	hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
50c8ea80	298	hdr->gso_size = hdr->hdr_len = 0;
296f96fc RR	299	}
	300
	301	vnet_hdr_to_sg(sg, skb);
	302	num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
99ffc696	303
14c998f0 MM	304	err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
	305	if (!err)
	306	mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
	307
	308	return err;
99ffc696 RR	309	}
99ffc696 RR	310
11a3a154 RR	311	static void xmit_tasklet(unsigned long data)
	312	{
	313	struct virtnet_info vi = (void )data;
	314
	315	netif_tx_lock_bh(vi->dev);
	316	if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
	317	vi->svq->vq_ops->kick(vi->svq);
	318	vi->last_xmit_skb = NULL;
	319	}
	320	netif_tx_unlock_bh(vi->dev);
	321	}
	322
99ffc696 RR	323	static int start_xmit(struct sk_buff skb, struct net_device dev)
	324	{
	325	struct virtnet_info *vi = netdev_priv(dev);
2cb9c6ba RR	326
	327	again:
	328	/* Free up any pending old buffers before queueing new ones. */
	329	free_old_xmit_skbs(vi);
99ffc696 RR	330
99ffc696 RR	331	/* If we has a buffer left over from last time, send it now. */
7eb2e251	332	if (unlikely(vi->last_xmit_skb)) {
99ffc696 RR	333	if (xmit_skb(vi, vi->last_xmit_skb) != 0) {
	334	/* Drop this skb: we only queue one. */
	335	vi->dev->stats.tx_dropped++;
	336	kfree_skb(skb);
7eb2e251	337	skb = NULL;
99ffc696	338	goto stop_queue;
2cb9c6ba	339	}
99ffc696 RR	340	vi->last_xmit_skb = NULL;
99ffc696 RR	341	}
2cb9c6ba	342
99ffc696	343	/* Put new one in send queue and do transmit */
7eb2e251 RR	344	if (likely(skb)) {
	345	__skb_queue_head(&vi->send, skb);
	346	if (xmit_skb(vi, skb) != 0) {
	347	vi->last_xmit_skb = skb;
	348	skb = NULL;
	349	goto stop_queue;
	350	}
296f96fc	351	}
99ffc696	352	done:
296f96fc	353	vi->svq->vq_ops->kick(vi->svq);
99ffc696 RR	354	return NETDEV_TX_OK;
	355
	356	stop_queue:
	357	pr_debug("%s: virtio not prepared to send\n", dev->name);
	358	netif_stop_queue(dev);
	359
	360	/* Activate callback for using skbs: if this returns false it
	361	* means some were used in the meantime. */
	362	if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
	363	vi->svq->vq_ops->disable_cb(vi->svq);
	364	netif_start_queue(dev);
	365	goto again;
	366	}
	367	goto done;
296f96fc RR	368	}
296f96fc RR	369
da74e89d AS	370	#ifdef CONFIG_NET_POLL_CONTROLLER
	371	static void virtnet_netpoll(struct net_device *dev)
	372	{
	373	struct virtnet_info *vi = netdev_priv(dev);
	374
	375	napi_schedule(&vi->napi);
	376	}
	377	#endif
	378
296f96fc RR	379	static int virtnet_open(struct net_device *dev)
	380	{
	381	struct virtnet_info *vi = netdev_priv(dev);
	382
296f96fc	383	napi_enable(&vi->napi);
a48bd8f6 RR	384
	385	/* If all buffers were filled by other side before we napi_enabled, we
	386	* won't get another interrupt, so process any outstanding packets
370076d9 CB	387	* now. virtnet_poll wants re-enable the queue, so we disable here.
	388	* We synchronize against interrupts via NAPI_STATE_SCHED */
	389	if (netif_rx_schedule_prep(dev, &vi->napi)) {
	390	vi->rvq->vq_ops->disable_cb(vi->rvq);
	391	__netif_rx_schedule(dev, &vi->napi);
	392	}
296f96fc RR	393	return 0;
	394	}
	395
	396	static int virtnet_close(struct net_device *dev)
	397	{
	398	struct virtnet_info *vi = netdev_priv(dev);
296f96fc RR	399
	400	napi_disable(&vi->napi);
	401
296f96fc RR	402	return 0;
	403	}
	404
	405	static int virtnet_probe(struct virtio_device *vdev)
	406	{
	407	int err;
296f96fc RR	408	struct net_device *dev;
296f96fc RR	409	struct virtnet_info *vi;
296f96fc RR	410
	411	/* Allocate ourselves a network device with room for our info */
	412	dev = alloc_etherdev(sizeof(struct virtnet_info));
	413	if (!dev)
	414	return -ENOMEM;
	415
	416	/* Set up network device as normal. */
296f96fc RR	417	dev->open = virtnet_open;
	418	dev->stop = virtnet_close;
	419	dev->hard_start_xmit = start_xmit;
	420	dev->features = NETIF_F_HIGHDMA;
da74e89d AS	421	#ifdef CONFIG_NET_POLL_CONTROLLER
	422	dev->poll_controller = virtnet_netpoll;
	423	#endif
296f96fc RR	424	SET_NETDEV_DEV(dev, &vdev->dev);
	425
	426	/* Do we support "hardware" checksums? */
c45a6816	427	if (csum && virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) {
296f96fc RR	428	/* This opens up the world of extra features. */
296f96fc RR	429	dev->features \|= NETIF_F_HW_CSUM\|NETIF_F_SG\|NETIF_F_FRAGLIST;
c45a6816	430	if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
34a48579 RR	431	dev->features \|= NETIF_F_TSO \| NETIF_F_UFO
	432	\| NETIF_F_TSO_ECN \| NETIF_F_TSO6;
	433	}
5539ae96	434	/* Individual feature bits: what can host handle? */
c45a6816	435	if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
5539ae96	436	dev->features \|= NETIF_F_TSO;
c45a6816	437	if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO6))
5539ae96	438	dev->features \|= NETIF_F_TSO6;
c45a6816	439	if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_ECN))
5539ae96	440	dev->features \|= NETIF_F_TSO_ECN;
c45a6816	441	if (gso && virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UFO))
5539ae96	442	dev->features \|= NETIF_F_UFO;
296f96fc RR	443	}
	444
	445	/* Configuration may specify what MAC to use. Otherwise random. */
c45a6816	446	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
a586d4f6 RR	447	vdev->config->get(vdev,
	448	offsetof(struct virtio_net_config, mac),
	449	dev->dev_addr, dev->addr_len);
296f96fc RR	450	} else
	451	random_ether_addr(dev->dev_addr);
	452
	453	/* Set up our device-specific information */
	454	vi = netdev_priv(dev);
6c0cd7c0	455	netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
296f96fc RR	456	vi->dev = dev;
296f96fc RR	457	vi->vdev = vdev;
d9d5dcc8	458	vdev->priv = vi;
296f96fc RR	459
296f96fc RR	460	/* We expect two virtqueues, receive then send. */
a586d4f6	461	vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
296f96fc RR	462	if (IS_ERR(vi->rvq)) {
	463	err = PTR_ERR(vi->rvq);
	464	goto free;
	465	}
	466
a586d4f6	467	vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done);
296f96fc RR	468	if (IS_ERR(vi->svq)) {
	469	err = PTR_ERR(vi->svq);
	470	goto free_recv;
	471	}
	472
	473	/* Initialize our empty receive and send queues. */
	474	skb_queue_head_init(&vi->recv);
	475	skb_queue_head_init(&vi->send);
	476
11a3a154 RR	477	tasklet_init(&vi->tasklet, xmit_tasklet, (unsigned long)vi);
11a3a154 RR	478
14c998f0 MM	479	setup_timer(&vi->xmit_free_timer, xmit_free, (unsigned long)vi);
14c998f0 MM	480
296f96fc RR	481	err = register_netdev(dev);
	482	if (err) {
	483	pr_debug("virtio_net: registering device failed\n");
	484	goto free_send;
	485	}
b3369c1f RR	486
	487	/* Last of all, set up some receive buffers. */
	488	try_fill_recv(vi);
	489
	490	/* If we didn't even get one input buffer, we're useless. */
	491	if (vi->num == 0) {
	492	err = -ENOMEM;
	493	goto unregister;
	494	}
	495
296f96fc	496	pr_debug("virtnet: registered device %s\n", dev->name);
296f96fc RR	497	return 0;
296f96fc RR	498
b3369c1f RR	499	unregister:
b3369c1f RR	500	unregister_netdev(dev);
296f96fc RR	501	free_send:
	502	vdev->config->del_vq(vi->svq);
	503	free_recv:
	504	vdev->config->del_vq(vi->rvq);
	505	free:
	506	free_netdev(dev);
	507	return err;
	508	}
	509
	510	static void virtnet_remove(struct virtio_device *vdev)
	511	{
74b2553f	512	struct virtnet_info *vi = vdev->priv;
b3369c1f RR	513	struct sk_buff *skb;
b3369c1f RR	514
6e5aa7ef RR	515	/* Stop all the virtqueues. */
	516	vdev->config->reset(vdev);
	517
14c998f0 MM	518	del_timer_sync(&vi->xmit_free_timer);
14c998f0 MM	519
b3369c1f	520	/* Free our skbs in send and recv queues, if any. */
b3369c1f RR	521	while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
	522	kfree_skb(skb);
	523	vi->num--;
	524	}
288369cc	525	__skb_queue_purge(&vi->send);
b3369c1f RR	526
b3369c1f RR	527	BUG_ON(vi->num != 0);
74b2553f RR	528
	529	vdev->config->del_vq(vi->svq);
	530	vdev->config->del_vq(vi->rvq);
	531	unregister_netdev(vi->dev);
	532	free_netdev(vi->dev);
296f96fc RR	533	}
	534
	535	static struct virtio_device_id id_table[] = {
	536	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
	537	{ 0 },
	538	};
	539
c45a6816 RR	540	static unsigned int features[] = {
	541	VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GSO, VIRTIO_NET_F_MAC,
	542	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,
	543	VIRTIO_NET_F_HOST_ECN,
	544	};
	545
296f96fc	546	static struct virtio_driver virtio_net = {
c45a6816 RR	547	.feature_table = features,
c45a6816 RR	548	.feature_table_size = ARRAY_SIZE(features),
296f96fc RR	549	.driver.name = KBUILD_MODNAME,
	550	.driver.owner = THIS_MODULE,
	551	.id_table = id_table,
	552	.probe = virtnet_probe,
	553	.remove = __devexit_p(virtnet_remove),
	554	};
	555
	556	static int __init init(void)
	557	{
	558	return register_virtio_driver(&virtio_net);
	559	}
	560
	561	static void __exit fini(void)
	562	{
	563	unregister_virtio_driver(&virtio_net);
	564	}
	565	module_init(init);
	566	module_exit(fini);
	567
	568	MODULE_DEVICE_TABLE(virtio, id_table);
	569	MODULE_DESCRIPTION("Virtio network driver");
	570	MODULE_LICENSE("GPL");