android_kernel_motorola_sm6225/drivers/net/virtio_net.c
Mark McLoughlin 3f2c31d903 virtio_net: VIRTIO_NET_F_MSG_RXBUF (imprive rcv buffer allocation)
If segmentation offload is enabled by the host, we currently allocate
maximum sized packet buffers and pass them to the host. This uses up
20 ring entries, allowing us to supply only 20 packet buffers to the
host with a 256 entry ring. This is a huge overhead when receiving
small packets, and is most keenly felt when receiving MTU sized
packets from off-host.

The VIRTIO_NET_F_MRG_RXBUF feature flag is set by hosts which support
using receive buffers which are smaller than the maximum packet size.
In order to transfer large packets to the guest, the host merges
together multiple receive buffers to form a larger logical buffer.
The number of merged buffers is returned to the guest via a field in
the virtio_net_hdr.

Make use of this support by supplying single page receive buffers to
the host. On receive, we extract the virtio_net_hdr, copy 128 bytes of
the payload to the skb's linear data buffer and adjust the fragment
offset to point to the remaining data. This ensures proper alignment
and allows us to not use any paged data for small packets. If the
payload occupies multiple pages, we simply append those pages as
fragments and free the associated skbs.

This scheme allows us to be efficient in our use of ring entries
while still supporting large packets. Benchmarking using netperf from
an external machine to a guest over a 10Gb/s network shows a 100%
improvement from ~1Gb/s to ~2Gb/s. With a local host->guest benchmark
with GSO disabled on the host side, throughput was seen to increase
from 700Mb/s to 1.7Gb/s.

Based on a patch from Herbert Xu.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (use netdev_priv)
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-16 22:41:34 -08:00

806 lines
20 KiB
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/ethtool.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)
#define GOOD_COPY_LEN 128
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;
/* If we need to free in a timer, this is it. */
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;
bool free_in_tasklet;
/* I like... big packets and I cannot lie! */
bool big_packets;
/* Host will merge rx buffers for big packets (shake it! shake it!) */
bool mergeable_rx_bufs;
/* Receive & send queues. */
struct sk_buff_head recv;
struct sk_buff_head send;
/* Chain pages by the private ptr. */
struct page *pages;
};
static inline void *skb_vnet_hdr(struct sk_buff *skb)
{
return (struct virtio_net_hdr *)skb->cb;
}
static void give_a_page(struct virtnet_info *vi, struct page *page)
{
page->private = (unsigned long)vi->pages;
vi->pages = page;
}
static void trim_pages(struct virtnet_info *vi, struct sk_buff *skb)
{
unsigned int i;
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
give_a_page(vi, skb_shinfo(skb)->frags[i].page);
skb_shinfo(skb)->nr_frags = 0;
skb->data_len = 0;
}
static struct page *get_a_page(struct virtnet_info *vi, gfp_t gfp_mask)
{
struct page *p = vi->pages;
if (p)
vi->pages = (struct page *)p->private;
else
p = alloc_page(gfp_mask);
return p;
}
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 probably 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 virtnet_info *vi = netdev_priv(dev);
struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
int err;
int i;
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;
}
if (vi->mergeable_rx_bufs) {
struct virtio_net_hdr_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
unsigned int copy;
char *p = page_address(skb_shinfo(skb)->frags[0].page);
if (len > PAGE_SIZE)
len = PAGE_SIZE;
len -= sizeof(struct virtio_net_hdr_mrg_rxbuf);
memcpy(hdr, p, sizeof(*mhdr));
p += sizeof(*mhdr);
copy = len;
if (copy > skb_tailroom(skb))
copy = skb_tailroom(skb);
memcpy(skb_put(skb, copy), p, copy);
len -= copy;
if (!len) {
give_a_page(vi, skb_shinfo(skb)->frags[0].page);
skb_shinfo(skb)->nr_frags--;
} else {
skb_shinfo(skb)->frags[0].page_offset +=
sizeof(*mhdr) + copy;
skb_shinfo(skb)->frags[0].size = len;
skb->data_len += len;
skb->len += len;
}
while (--mhdr->num_buffers) {
struct sk_buff *nskb;
i = skb_shinfo(skb)->nr_frags;
if (i >= MAX_SKB_FRAGS) {
pr_debug("%s: packet too long %d\n", dev->name,
len);
dev->stats.rx_length_errors++;
goto drop;
}
nskb = vi->rvq->vq_ops->get_buf(vi->rvq, &len);
if (!nskb) {
pr_debug("%s: rx error: %d buffers missing\n",
dev->name, mhdr->num_buffers);
dev->stats.rx_length_errors++;
goto drop;
}
__skb_unlink(nskb, &vi->recv);
vi->num--;
skb_shinfo(skb)->frags[i] = skb_shinfo(nskb)->frags[0];
skb_shinfo(nskb)->nr_frags = 0;
kfree_skb(nskb);
if (len > PAGE_SIZE)
len = PAGE_SIZE;
skb_shinfo(skb)->frags[i].size = len;
skb_shinfo(skb)->nr_frags++;
skb->data_len += len;
skb->len += len;
}
} else {
len -= sizeof(struct virtio_net_hdr);
if (len <= MAX_PACKET_LEN)
trim_pages(vi, skb);
err = pskb_trim(skb, len);
if (err) {
pr_debug("%s: pskb_trim failed %i %d\n", dev->name,
len, err);
dev->stats.rx_dropped++;
goto drop;
}
}
skb->truesize += skb->data_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_maxbufs(struct virtnet_info *vi)
{
struct sk_buff *skb;
struct scatterlist sg[2+MAX_SKB_FRAGS];
int num, err, i;
sg_init_table(sg, 2+MAX_SKB_FRAGS);
for (;;) {
struct virtio_net_hdr *hdr;
skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
if (unlikely(!skb))
break;
skb_put(skb, MAX_PACKET_LEN);
hdr = skb_vnet_hdr(skb);
sg_init_one(sg, hdr, sizeof(*hdr));
if (vi->big_packets) {
for (i = 0; i < MAX_SKB_FRAGS; i++) {
skb_frag_t *f = &skb_shinfo(skb)->frags[i];
f->page = get_a_page(vi, GFP_ATOMIC);
if (!f->page)
break;
f->page_offset = 0;
f->size = PAGE_SIZE;
skb->data_len += PAGE_SIZE;
skb->len += PAGE_SIZE;
skb_shinfo(skb)->nr_frags++;
}
}
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);
trim_pages(vi, skb);
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 try_fill_recv(struct virtnet_info *vi)
{
struct sk_buff *skb;
struct scatterlist sg[1];
int err;
if (!vi->mergeable_rx_bufs) {
try_fill_recv_maxbufs(vi);
return;
}
for (;;) {
skb_frag_t *f;
skb = netdev_alloc_skb(vi->dev, GOOD_COPY_LEN + NET_IP_ALIGN);
if (unlikely(!skb))
break;
skb_reserve(skb, NET_IP_ALIGN);
f = &skb_shinfo(skb)->frags[0];
f->page = get_a_page(vi, GFP_ATOMIC);
if (!f->page) {
kfree_skb(skb);
break;
}
f->page_offset = 0;
f->size = PAGE_SIZE;
skb_shinfo(skb)->nr_frags++;
sg_init_one(sg, page_address(f->page), PAGE_SIZE);
skb_queue_head(&vi->recv, skb);
err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, 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);
}
}
/* If the virtio transport doesn't always notify us when all in-flight packets
* are consumed, we fall back to using this function on a timer to free them. */
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_mrg_rxbuf *mhdr = skb_vnet_hdr(skb);
struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
sg_init_table(sg, 2+MAX_SKB_FRAGS);
pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
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;
}
mhdr->num_buffers = 0;
/* Encode metadata header at front. */
if (vi->mergeable_rx_bufs)
sg_init_one(sg, mhdr, sizeof(*mhdr));
else
sg_init_one(sg, hdr, sizeof(*hdr));
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 && !vi->free_in_tasklet)
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;
}
if (vi->free_in_tasklet)
free_old_xmit_skbs(vi);
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) &&
xmit_skb(vi, vi->last_xmit_skb) != 0)
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;
}
if (skb) {
/* Drop this skb: we only queue one. */
vi->dev->stats.tx_dropped++;
kfree_skb(skb);
}
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_set_tx_csum(struct net_device *dev, u32 data)
{
struct virtnet_info *vi = netdev_priv(dev);
struct virtio_device *vdev = vi->vdev;
if (data && !virtio_has_feature(vdev, VIRTIO_NET_F_CSUM))
return -ENOSYS;
return ethtool_op_set_tx_hw_csum(dev, data);
}
static struct ethtool_ops virtnet_ethtool_ops = {
.set_tx_csum = virtnet_set_tx_csum,
.set_sg = ethtool_op_set_sg,
.set_tso = ethtool_op_set_tso,
};
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_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
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;
vi->pages = NULL;
/* If they give us a callback when all buffers are done, we don't need
* the timer. */
vi->free_in_tasklet = virtio_has_feature(vdev,VIRTIO_F_NOTIFY_ON_EMPTY);
/* If we can receive ANY GSO packets, we must allocate large ones. */
if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4)
|| virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6)
|| virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_ECN))
vi->big_packets = true;
if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
vi->mergeable_rx_bufs = true;
/* 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);
if (!vi->free_in_tasklet)
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);
if (!vi->free_in_tasklet)
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);
while (vi->pages)
__free_pages(get_a_page(vi, GFP_KERNEL), 0);
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_GUEST_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, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */
VIRTIO_NET_F_MRG_RXBUF,
VIRTIO_F_NOTIFY_ON_EMPTY,
};
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");