On 02/19/2013 03:56 PM, Rusty Russell wrote:
> It's a bit cleaner to hand multiple sgs, rather than one big one.
>
> Signed-off-by: Rusty Russell <ru...@rustcorp.com.au>
> ---
> drivers/net/virtio_net.c | 50
> ++++++++++++++++++++++------------------------
> 1 file changed, 24 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 8ca69c0..63ac5c1 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -39,7 +39,6 @@ module_param(gso, bool, 0444);
> #define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
> #define GOOD_COPY_LEN 128
>
> -#define VIRTNET_SEND_COMMAND_SG_MAX 2
> #define VIRTNET_DRIVER_VERSION "1.0.0"
>
> struct virtnet_stats {
> @@ -831,32 +830,32 @@ static void virtnet_netpoll(struct net_device *dev)
> * never fail unless improperly formated.
> */
> static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
> - struct scatterlist *data, int out, int in)
> + struct scatterlist *out,
> + struct scatterlist *in)
> {
> - struct scatterlist *s, sg[VIRTNET_SEND_COMMAND_SG_MAX + 2];
> + struct scatterlist *sgs[4], hdr, stat;
> struct virtio_net_ctrl_hdr ctrl;
> virtio_net_ctrl_ack status = ~0;
> - unsigned int tmp;
> - int i;
> + unsigned out_num = 0, in_num = 0, tmp;
>
> /* Caller should know better */
> - BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ||
> - (out + in > VIRTNET_SEND_COMMAND_SG_MAX));
> -
> - out++; /* Add header */
> - in++; /* Add return status */
> + BUG_ON(!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ));
>
> - ctrl.class = class;
> - ctrl.cmd = cmd;
The class and cmd assignment of ctrl header is forgotten?
Thanks,
Wanlong Gao
> + /* Add header */
> + sg_init_one(&hdr, &ctrl, sizeof(ctrl));
> + sgs[out_num++] = &hdr;
>
> - sg_init_table(sg, out + in);
> + if (out)
> + sgs[out_num++] = out;
> + if (in)
> + sgs[out_num + in_num++] = in;
>
> - sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
> - for_each_sg(data, s, out + in - 2, i)
> - sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
> - sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
> + /* Add return status. */
> + sg_init_one(&stat, &status, sizeof(status));
> + sgs[out_num + in_num++] = &hdr;
>
> - BUG_ON(virtqueue_add_buf(vi->cvq, sg, out, in, vi, GFP_ATOMIC) < 0);
> + BUG_ON(virtqueue_add_sgs(vi->cvq, sgs, out_num, in_num, vi, GFP_ATOMIC)
> + < 0);
>
> virtqueue_kick(vi->cvq);
>
> @@ -874,8 +873,7 @@ static void virtnet_ack_link_announce(struct virtnet_info
> *vi)
> {
> rtnl_lock();
> if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_ANNOUNCE,
> - VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL,
> - 0, 0))
> + VIRTIO_NET_CTRL_ANNOUNCE_ACK, NULL, NULL))
> dev_warn(&vi->dev->dev, "Failed to ack link announce.\n");
> rtnl_unlock();
> }
> @@ -893,7 +891,7 @@ static int virtnet_set_queues(struct virtnet_info *vi,
> u16 queue_pairs)
> sg_init_one(&sg, &s, sizeof(s));
>
> if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
> - VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, 1, 0)){
> + VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &sg, NULL)) {
> dev_warn(&dev->dev, "Fail to set num of queue pairs to %d\n",
> queue_pairs);
> return -EINVAL;
> @@ -940,7 +938,7 @@ static void virtnet_set_rx_mode(struct net_device *dev)
>
> if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
> VIRTIO_NET_CTRL_RX_PROMISC,
> - sg, 1, 0))
> + sg, NULL))
> dev_warn(&dev->dev, "Failed to %sable promisc mode.\n",
> promisc ? "en" : "dis");
>
> @@ -948,7 +946,7 @@ static void virtnet_set_rx_mode(struct net_device *dev)
>
> if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
> VIRTIO_NET_CTRL_RX_ALLMULTI,
> - sg, 1, 0))
> + sg, NULL))
> dev_warn(&dev->dev, "Failed to %sable allmulti mode.\n",
> allmulti ? "en" : "dis");
>
> @@ -987,7 +985,7 @@ static void virtnet_set_rx_mode(struct net_device *dev)
>
> if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
> VIRTIO_NET_CTRL_MAC_TABLE_SET,
> - sg, 2, 0))
> + sg, NULL))
> dev_warn(&dev->dev, "Failed to set MAC fitler table.\n");
>
> kfree(buf);
> @@ -1001,7 +999,7 @@ static int virtnet_vlan_rx_add_vid(struct net_device
> *dev, u16 vid)
> sg_init_one(&sg, &vid, sizeof(vid));
>
> if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
> - VIRTIO_NET_CTRL_VLAN_ADD, &sg, 1, 0))
> + VIRTIO_NET_CTRL_VLAN_ADD, &sg, NULL))
> dev_warn(&dev->dev, "Failed to add VLAN ID %d.\n", vid);
> return 0;
> }
> @@ -1014,7 +1012,7 @@ static int virtnet_vlan_rx_kill_vid(struct net_device
> *dev, u16 vid)
> sg_init_one(&sg, &vid, sizeof(vid));
>
> if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
> - VIRTIO_NET_CTRL_VLAN_DEL, &sg, 1, 0))
> + VIRTIO_NET_CTRL_VLAN_DEL, &sg, NULL))
> dev_warn(&dev->dev, "Failed to kill VLAN ID %d.\n", vid);
> return 0;
> }
>
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