[GitHub/mt8127/android_kernel_alcatel_ttab.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>

/* 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;

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

	/* 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 *rvq)
{
	struct virtnet_info *vi = rvq->vdev->priv;

	/* In case we were waiting for output buffers. */
	netif_wake_queue(vi->dev);
}

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);
	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);
	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;
	}

	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
		pr_debug("GSO!\n");
		switch (hdr->gso_type) {
		case VIRTIO_NET_HDR_GSO_TCPV4:
			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
			break;
		case VIRTIO_NET_HDR_GSO_TCPV4_ECN:
			skb_shinfo(skb)->gso_type = SKB_GSO_TCP_ECN;
			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;
		}

		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[1+MAX_SKB_FRAGS];
	int num, err;

	sg_init_table(sg, 1+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))
		    && netif_rx_reschedule(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 += len;
		vi->dev->stats.tx_packets++;
		kfree_skb(skb);
	}
}

static int start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct virtnet_info *vi = netdev_priv(dev);
	int num, err;
	struct scatterlist sg[1+MAX_SKB_FRAGS];
	struct virtio_net_hdr *hdr;
	const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
	DECLARE_MAC_BUF(mac);

	sg_init_table(sg, 1+MAX_SKB_FRAGS);

	pr_debug("%s: xmit %p %s\n", dev->name, skb, print_mac(mac, dest));

	free_old_xmit_skbs(vi);

	/* 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->gso_size = skb_shinfo(skb)->gso_size;
		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
			hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4_ECN;
		else 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();
	} else {
		hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
		hdr->gso_size = 0;
	}

	vnet_hdr_to_sg(sg, skb);
	num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
	__skb_queue_head(&vi->send, skb);
	err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
	if (err) {
		pr_debug("%s: virtio not prepared to send\n", dev->name);
		skb_unlink(skb, &vi->send);
		netif_stop_queue(dev);
		return NETDEV_TX_BUSY;
	}
	vi->svq->vq_ops->kick(vi->svq);

	return 0;
}

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

	try_fill_recv(vi);

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

	napi_enable(&vi->napi);
	return 0;
}

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

	napi_disable(&vi->napi);

	/* networking core has neutered skb_xmit_done/skb_recv_done, so don't
	 * worry about races vs. get(). */
	vi->rvq->vq_ops->shutdown(vi->rvq);
	while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
		kfree_skb(skb);
		vi->num--;
	}
	vi->svq->vq_ops->shutdown(vi->svq);
	while ((skb = __skb_dequeue(&vi->send)) != NULL)
		kfree_skb(skb);

	BUG_ON(vi->num != 0);
	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. */
	ether_setup(dev);
	dev->open = virtnet_open;
	dev->stop = virtnet_close;
	dev->hard_start_xmit = start_xmit;
	dev->features = NETIF_F_HIGHDMA;
	SET_NETDEV_DEV(dev, &vdev->dev);

	/* Do we support "hardware" checksums? */
	if (vdev->config->feature(vdev, VIRTIO_NET_F_NO_CSUM)) {
		/* This opens up the world of extra features. */
		dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
		if (vdev->config->feature(vdev, VIRTIO_NET_F_TSO4))
			dev->features |= NETIF_F_TSO;
		if (vdev->config->feature(vdev, VIRTIO_NET_F_UFO))
			dev->features |= NETIF_F_UFO;
		if (vdev->config->feature(vdev, VIRTIO_NET_F_TSO4_ECN))
			dev->features |= NETIF_F_TSO_ECN;
		if (vdev->config->feature(vdev, VIRTIO_NET_F_TSO6))
			dev->features |= NETIF_F_TSO6;
	}

	/* Configuration may specify what MAC to use.  Otherwise random. */
	if (vdev->config->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, 16);
	vi->dev = dev;
	vi->vdev = vdev;

	/* 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);

	err = register_netdev(dev);
	if (err) {
		pr_debug("virtio_net: registering device failed\n");
		goto free_send;
	}
	pr_debug("virtnet: registered device %s\n", dev->name);
	vdev->priv = vi;
	return 0;

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;

	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 struct virtio_driver virtio_net = {
	.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
	27	/* FIXME: MTU in config. */
	28	#define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
	29
	30	struct virtnet_info
	31	{
	32	struct virtio_device *vdev;
	33	struct virtqueue rvq, svq;
	34	struct net_device *dev;
	35	struct napi_struct napi;
	36
	37	/* Number of input buffers, and max we've ever had. */
	38	unsigned int num, max;
	39
	40	/* Receive & send queues. */
	41	struct sk_buff_head recv;
	42	struct sk_buff_head send;
	43	};
	44
	45	static inline struct virtio_net_hdr skb_vnet_hdr(struct sk_buff skb)
	46	{
	47	return (struct virtio_net_hdr *)skb->cb;
	48	}
	49
	50	static inline void vnet_hdr_to_sg(struct scatterlist sg, struct sk_buff skb)
	51	{
	52	sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
	53	}
	54
18445c4d	55	static void skb_xmit_done(struct virtqueue *rvq)
296f96fc RR	56	{
	57	struct virtnet_info *vi = rvq->vdev->priv;
	58
	59	/* In case we were waiting for output buffers. */
	60	netif_wake_queue(vi->dev);
296f96fc RR	61	}
	62
	63	static void receive_skb(struct net_device dev, struct sk_buff skb,
	64	unsigned len)
	65	{
	66	struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
	67
	68	if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
	69	pr_debug("%s: short packet %i\n", dev->name, len);
	70	dev->stats.rx_length_errors++;
	71	goto drop;
	72	}
	73	len -= sizeof(struct virtio_net_hdr);
	74	BUG_ON(len > MAX_PACKET_LEN);
	75
	76	skb_trim(skb, len);
	77	skb->protocol = eth_type_trans(skb, dev);
	78	pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
	79	ntohs(skb->protocol), skb->len, skb->pkt_type);
	80	dev->stats.rx_bytes += skb->len;
	81	dev->stats.rx_packets++;
	82
	83	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
	84	pr_debug("Needs csum!\n");
f35d9d8a	85	if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
296f96fc	86	goto frame_err;
296f96fc RR	87	}
	88
	89	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
	90	pr_debug("GSO!\n");
	91	switch (hdr->gso_type) {
	92	case VIRTIO_NET_HDR_GSO_TCPV4:
	93	skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
	94	break;
	95	case VIRTIO_NET_HDR_GSO_TCPV4_ECN:
	96	skb_shinfo(skb)->gso_type = SKB_GSO_TCP_ECN;
	97	break;
	98	case VIRTIO_NET_HDR_GSO_UDP:
	99	skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
	100	break;
	101	case VIRTIO_NET_HDR_GSO_TCPV6:
	102	skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
	103	break;
	104	default:
	105	if (net_ratelimit())
	106	printk(KERN_WARNING "%s: bad gso type %u.\n",
	107	dev->name, hdr->gso_type);
	108	goto frame_err;
	109	}
	110
	111	skb_shinfo(skb)->gso_size = hdr->gso_size;
	112	if (skb_shinfo(skb)->gso_size == 0) {
	113	if (net_ratelimit())
	114	printk(KERN_WARNING "%s: zero gso size.\n",
	115	dev->name);
	116	goto frame_err;
	117	}
	118
	119	/* Header must be checked, and gso_segs computed. */
	120	skb_shinfo(skb)->gso_type \|= SKB_GSO_DODGY;
	121	skb_shinfo(skb)->gso_segs = 0;
	122	}
	123
	124	netif_receive_skb(skb);
	125	return;
	126
	127	frame_err:
	128	dev->stats.rx_frame_errors++;
	129	drop:
	130	dev_kfree_skb(skb);
	131	}
	132
	133	static void try_fill_recv(struct virtnet_info *vi)
	134	{
	135	struct sk_buff *skb;
	136	struct scatterlist sg[1+MAX_SKB_FRAGS];
	137	int num, err;
	138
4d125de3	139	sg_init_table(sg, 1+MAX_SKB_FRAGS);
296f96fc RR	140	for (;;) {
	141	skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
	142	if (unlikely(!skb))
	143	break;
	144
	145	skb_put(skb, MAX_PACKET_LEN);
	146	vnet_hdr_to_sg(sg, skb);
	147	num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
	148	skb_queue_head(&vi->recv, skb);
	149
	150	err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
	151	if (err) {
	152	skb_unlink(skb, &vi->recv);
	153	kfree_skb(skb);
	154	break;
	155	}
	156	vi->num++;
	157	}
	158	if (unlikely(vi->num > vi->max))
	159	vi->max = vi->num;
	160	vi->rvq->vq_ops->kick(vi->rvq);
	161	}
	162
18445c4d	163	static void skb_recv_done(struct virtqueue *rvq)
296f96fc RR	164	{
296f96fc RR	165	struct virtnet_info *vi = rvq->vdev->priv;
18445c4d RR	166	/* Schedule NAPI, Suppress further interrupts if successful. */
	167	if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
	168	rvq->vq_ops->disable_cb(rvq);
	169	__netif_rx_schedule(vi->dev, &vi->napi);
	170	}
296f96fc RR	171	}
	172
	173	static int virtnet_poll(struct napi_struct *napi, int budget)
	174	{
	175	struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
	176	struct sk_buff *skb = NULL;
	177	unsigned int len, received = 0;
	178
	179	again:
	180	while (received < budget &&
	181	(skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
	182	__skb_unlink(skb, &vi->recv);
	183	receive_skb(vi->dev, skb, len);
	184	vi->num--;
	185	received++;
	186	}
	187
	188	/* FIXME: If we oom and completely run out of inbufs, we need
	189	* to start a timer trying to fill more. */
	190	if (vi->num < vi->max / 2)
	191	try_fill_recv(vi);
	192
8329d98e RR	193	/* Out of packets? */
8329d98e RR	194	if (received < budget) {
296f96fc	195	netif_rx_complete(vi->dev, napi);
18445c4d	196	if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
296f96fc RR	197	&& netif_rx_reschedule(vi->dev, napi))
	198	goto again;
	199	}
	200
	201	return received;
	202	}
	203
	204	static void free_old_xmit_skbs(struct virtnet_info *vi)
	205	{
	206	struct sk_buff *skb;
	207	unsigned int len;
	208
	209	while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
	210	pr_debug("Sent skb %p\n", skb);
	211	__skb_unlink(skb, &vi->send);
	212	vi->dev->stats.tx_bytes += len;
	213	vi->dev->stats.tx_packets++;
	214	kfree_skb(skb);
	215	}
	216	}
	217
	218	static int start_xmit(struct sk_buff skb, struct net_device dev)
	219	{
	220	struct virtnet_info *vi = netdev_priv(dev);
	221	int num, err;
	222	struct scatterlist sg[1+MAX_SKB_FRAGS];
	223	struct virtio_net_hdr *hdr;
	224	const unsigned char dest = ((struct ethhdr )skb->data)->h_dest;
	225	DECLARE_MAC_BUF(mac);
	226
4d125de3 RR	227	sg_init_table(sg, 1+MAX_SKB_FRAGS);
4d125de3 RR	228
296f96fc RR	229	pr_debug("%s: xmit %p %s\n", dev->name, skb, print_mac(mac, dest));
	230
	231	free_old_xmit_skbs(vi);
	232
	233	/* Encode metadata header at front. */
	234	hdr = skb_vnet_hdr(skb);
	235	if (skb->ip_summed == CHECKSUM_PARTIAL) {
	236	hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
	237	hdr->csum_start = skb->csum_start - skb_headroom(skb);
	238	hdr->csum_offset = skb->csum_offset;
	239	} else {
	240	hdr->flags = 0;
	241	hdr->csum_offset = hdr->csum_start = 0;
	242	}
	243
	244	if (skb_is_gso(skb)) {
	245	hdr->gso_size = skb_shinfo(skb)->gso_size;
	246	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
	247	hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4_ECN;
	248	else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
	249	hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
	250	else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
	251	hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
	252	else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
	253	hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
	254	else
	255	BUG();
	256	} else {
	257	hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
	258	hdr->gso_size = 0;
	259	}
	260
	261	vnet_hdr_to_sg(sg, skb);
	262	num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
	263	__skb_queue_head(&vi->send, skb);
	264	err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
	265	if (err) {
	266	pr_debug("%s: virtio not prepared to send\n", dev->name);
	267	skb_unlink(skb, &vi->send);
	268	netif_stop_queue(dev);
	269	return NETDEV_TX_BUSY;
	270	}
	271	vi->svq->vq_ops->kick(vi->svq);
	272
	273	return 0;
	274	}
	275
	276	static int virtnet_open(struct net_device *dev)
	277	{
	278	struct virtnet_info *vi = netdev_priv(dev);
	279
	280	try_fill_recv(vi);
	281
	282	/* If we didn't even get one input buffer, we're useless. */
	283	if (vi->num == 0)
	284	return -ENOMEM;
	285
	286	napi_enable(&vi->napi);
	287	return 0;
	288	}
	289
	290	static int virtnet_close(struct net_device *dev)
	291	{
	292	struct virtnet_info *vi = netdev_priv(dev);
293	struct sk_buff *skb;
294
295	napi_disable(&vi->napi);
296
297	/* networking core has neutered skb_xmit_done/skb_recv_done, so don't
298	* worry about races vs. get(). */
299	vi->rvq->vq_ops->shutdown(vi->rvq);
300	while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
301	kfree_skb(skb);
302	vi->num--;
303	}
304	vi->svq->vq_ops->shutdown(vi->svq);
305	while ((skb = __skb_dequeue(&vi->send)) != NULL)
306	kfree_skb(skb);
307
308	BUG_ON(vi->num != 0);
309	return 0;
310	}
311
312	static int virtnet_probe(struct virtio_device *vdev)
313	{
314	int err;
296f96fc RR	315	struct net_device *dev;
296f96fc RR	316	struct virtnet_info *vi;
296f96fc RR	317
	318	/* Allocate ourselves a network device with room for our info */
	319	dev = alloc_etherdev(sizeof(struct virtnet_info));
	320	if (!dev)
	321	return -ENOMEM;
	322
	323	/* Set up network device as normal. */
	324	ether_setup(dev);
	325	dev->open = virtnet_open;
	326	dev->stop = virtnet_close;
	327	dev->hard_start_xmit = start_xmit;
	328	dev->features = NETIF_F_HIGHDMA;
	329	SET_NETDEV_DEV(dev, &vdev->dev);
	330
	331	/* Do we support "hardware" checksums? */
a586d4f6	332	if (vdev->config->feature(vdev, VIRTIO_NET_F_NO_CSUM)) {
296f96fc RR	333	/* This opens up the world of extra features. */
296f96fc RR	334	dev->features \|= NETIF_F_HW_CSUM\|NETIF_F_SG\|NETIF_F_FRAGLIST;
a586d4f6	335	if (vdev->config->feature(vdev, VIRTIO_NET_F_TSO4))
296f96fc	336	dev->features \|= NETIF_F_TSO;
a586d4f6	337	if (vdev->config->feature(vdev, VIRTIO_NET_F_UFO))
296f96fc	338	dev->features \|= NETIF_F_UFO;
a586d4f6	339	if (vdev->config->feature(vdev, VIRTIO_NET_F_TSO4_ECN))
296f96fc	340	dev->features \|= NETIF_F_TSO_ECN;
a586d4f6	341	if (vdev->config->feature(vdev, VIRTIO_NET_F_TSO6))
296f96fc RR	342	dev->features \|= NETIF_F_TSO6;
	343	}
	344
	345	/* Configuration may specify what MAC to use. Otherwise random. */
a586d4f6 RR	346	if (vdev->config->feature(vdev, VIRTIO_NET_F_MAC)) {
	347	vdev->config->get(vdev,
	348	offsetof(struct virtio_net_config, mac),
	349	dev->dev_addr, dev->addr_len);
296f96fc RR	350	} else
	351	random_ether_addr(dev->dev_addr);
	352
	353	/* Set up our device-specific information */
	354	vi = netdev_priv(dev);
	355	netif_napi_add(dev, &vi->napi, virtnet_poll, 16);
	356	vi->dev = dev;
	357	vi->vdev = vdev;
	358
	359	/* We expect two virtqueues, receive then send. */
a586d4f6	360	vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
296f96fc RR	361	if (IS_ERR(vi->rvq)) {
	362	err = PTR_ERR(vi->rvq);
	363	goto free;
	364	}
	365
a586d4f6	366	vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done);
296f96fc RR	367	if (IS_ERR(vi->svq)) {
	368	err = PTR_ERR(vi->svq);
	369	goto free_recv;
	370	}
	371
	372	/* Initialize our empty receive and send queues. */
	373	skb_queue_head_init(&vi->recv);
	374	skb_queue_head_init(&vi->send);
	375
	376	err = register_netdev(dev);
	377	if (err) {
	378	pr_debug("virtio_net: registering device failed\n");
	379	goto free_send;
	380	}
	381	pr_debug("virtnet: registered device %s\n", dev->name);
	382	vdev->priv = vi;
	383	return 0;
	384
	385	free_send:
	386	vdev->config->del_vq(vi->svq);
	387	free_recv:
	388	vdev->config->del_vq(vi->rvq);
	389	free:
	390	free_netdev(dev);
	391	return err;
	392	}
	393
	394	static void virtnet_remove(struct virtio_device *vdev)
	395	{
74b2553f RR	396	struct virtnet_info *vi = vdev->priv;
	397
	398	vdev->config->del_vq(vi->svq);
	399	vdev->config->del_vq(vi->rvq);
	400	unregister_netdev(vi->dev);
	401	free_netdev(vi->dev);
296f96fc RR	402	}
	403
	404	static struct virtio_device_id id_table[] = {
	405	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
	406	{ 0 },
	407	};
	408
	409	static struct virtio_driver virtio_net = {
	410	.driver.name = KBUILD_MODNAME,
	411	.driver.owner = THIS_MODULE,
	412	.id_table = id_table,
	413	.probe = virtnet_probe,
	414	.remove = __devexit_p(virtnet_remove),
	415	};
	416
	417	static int __init init(void)
	418	{
	419	return register_virtio_driver(&virtio_net);
	420	}
	421
	422	static void __exit fini(void)
	423	{
	424	unregister_virtio_driver(&virtio_net);
	425	}
	426	module_init(init);
	427	module_exit(fini);
	428
	429	MODULE_DEVICE_TABLE(virtio, id_table);
	430	MODULE_DESCRIPTION("Virtio network driver");
	431	MODULE_LICENSE("GPL");