virtio_net: factor out xdp handler for readability

At this point the do_xdp_prog is mostly if/else branches handling
the different modes of virtio_net. So remove it and handle running
the program in the per mode handlers.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index bc814c079506dccf6c983fdd5c22264a5f83ffa6..68221655740e07f6bcbff4c110bdced0a9279fa5 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -398,52 +398,6 @@ static bool virtnet_xdp_xmit(struct virtnet_info *vi,
        return true;
 }
 
-static u32 do_xdp_prog(struct virtnet_info *vi,
-                      struct receive_queue *rq,
-                      struct bpf_prog *xdp_prog,
-                      void *data, int len)
-{
-       int hdr_padded_len;
-       struct xdp_buff xdp;
-       void *buf;
-       unsigned int qp;
-       u32 act;
-
-       if (vi->mergeable_rx_bufs) {
-               hdr_padded_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
-               xdp.data = data + hdr_padded_len;
-               xdp.data_end = xdp.data + (len - vi->hdr_len);
-               buf = data;
-       } else { /* small buffers */
-               struct sk_buff *skb = data;
-
-               xdp.data = skb->data;
-               xdp.data_end = xdp.data + len;
-               buf = skb->data;
-       }
-
-       act = bpf_prog_run_xdp(xdp_prog, &xdp);
-       switch (act) {
-       case XDP_PASS:
-               return XDP_PASS;
-       case XDP_TX:
-               qp = vi->curr_queue_pairs -
-                       vi->xdp_queue_pairs +
-                       smp_processor_id();
-               xdp.data = buf;
-               if (unlikely(!virtnet_xdp_xmit(vi, rq, &vi->sq[qp], &xdp,
-                                              data)))
-                       trace_xdp_exception(vi->dev, xdp_prog, act);
-               return XDP_TX;
-       default:
-               bpf_warn_invalid_xdp_action(act);
-       case XDP_ABORTED:
-               trace_xdp_exception(vi->dev, xdp_prog, act);
-       case XDP_DROP:
-               return XDP_DROP;
-       }
-}
-
 static struct sk_buff *receive_small(struct net_device *dev,
                                     struct virtnet_info *vi,
                                     struct receive_queue *rq,
@@ -459,19 +413,34 @@ static struct sk_buff *receive_small(struct net_device *dev,
        xdp_prog = rcu_dereference(rq->xdp_prog);
        if (xdp_prog) {
                struct virtio_net_hdr_mrg_rxbuf *hdr = buf;
+               struct xdp_buff xdp;
+               unsigned int qp;
                u32 act;
 
                if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
                        goto err_xdp;
-               act = do_xdp_prog(vi, rq, xdp_prog, skb, len);
+
+               xdp.data = skb->data;
+               xdp.data_end = xdp.data + len;
+               act = bpf_prog_run_xdp(xdp_prog, &xdp);
+
                switch (act) {
                case XDP_PASS:
                        break;
                case XDP_TX:
+                       qp = vi->curr_queue_pairs -
+                               vi->xdp_queue_pairs +
+                               smp_processor_id();
+                       if (unlikely(!virtnet_xdp_xmit(vi, rq, &vi->sq[qp],
+                                                      &xdp, skb)))
+                               trace_xdp_exception(vi->dev, xdp_prog, act);
                        rcu_read_unlock();
                        goto xdp_xmit;
-               case XDP_DROP:
                default:
+                       bpf_warn_invalid_xdp_action(act);
+               case XDP_ABORTED:
+                       trace_xdp_exception(vi->dev, xdp_prog, act);
+               case XDP_DROP:
                        goto err_xdp;
                }
        }
@@ -589,6 +558,9 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
        xdp_prog = rcu_dereference(rq->xdp_prog);
        if (xdp_prog) {
                struct page *xdp_page;
+               struct xdp_buff xdp;
+               unsigned int qp;
+               void *data;
                u32 act;
 
                /* This happens when rx buffer size is underestimated */
@@ -611,8 +583,11 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
                if (unlikely(hdr->hdr.gso_type))
                        goto err_xdp;
 
-               act = do_xdp_prog(vi, rq, xdp_prog,
-                                 page_address(xdp_page) + offset, len);
+               data = page_address(xdp_page) + offset;
+               xdp.data = data + vi->hdr_len;
+               xdp.data_end = xdp.data + (len - vi->hdr_len);
+               act = bpf_prog_run_xdp(xdp_prog, &xdp);
+
                switch (act) {
                case XDP_PASS:
                        /* We can only create skb based on xdp_page. */
@@ -626,13 +601,22 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
                        }
                        break;
                case XDP_TX:
+                       qp = vi->curr_queue_pairs -
+                               vi->xdp_queue_pairs +
+                               smp_processor_id();
+                       if (unlikely(!virtnet_xdp_xmit(vi, rq, &vi->sq[qp],
+                                                      &xdp, data)))
+                               trace_xdp_exception(vi->dev, xdp_prog, act);
                        ewma_pkt_len_add(&rq->mrg_avg_pkt_len, len);
                        if (unlikely(xdp_page != page))
                                goto err_xdp;
                        rcu_read_unlock();
                        goto xdp_xmit;
-               case XDP_DROP:
                default:
+                       bpf_warn_invalid_xdp_action(act);
+               case XDP_ABORTED:
+                       trace_xdp_exception(vi->dev, xdp_prog, act);
+               case XDP_DROP:
                        if (unlikely(xdp_page != page))
                                __free_pages(xdp_page, 0);
                        ewma_pkt_len_add(&rq->mrg_avg_pkt_len, len);