hv_netvsc: rearrange start_xmit

Rearrange the transmit routine to eliminate goto's and unnecessary
boolean variables. Use standard functions to test for vlan tag.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 3bbf073..7ed9f13 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -357,11 +357,8 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
        struct rndis_message *rndis_msg;
        struct rndis_packet *rndis_pkt;
        u32 rndis_msg_size;
-       bool isvlan;
-       bool linear = false;
        struct rndis_per_packet_info *ppi;
        struct ndis_tcp_ip_checksum_info *csum_info;
-       struct ndis_tcp_lso_info *lso_info;
        int  hdr_offset;
        u32 net_trans_info;
        u32 hash;
@@ -376,22 +373,23 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
         * more pages we try linearizing it.
         */
 
-check_size:
        skb_length = skb->len;
        num_data_pgs = netvsc_get_slots(skb) + 2;
-       if (num_data_pgs > MAX_PAGE_BUFFER_COUNT && linear) {
-               net_alert_ratelimited("packet too big: %u pages (%u bytes)\n",
-                                     num_data_pgs, skb->len);
-               ret = -EFAULT;
-               goto drop;
-       } else if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
+
+       if (unlikely(num_data_pgs > MAX_PAGE_BUFFER_COUNT)) {
                if (skb_linearize(skb)) {
                        net_alert_ratelimited("failed to linearize skb\n");
                        ret = -ENOMEM;
                        goto drop;
                }
-               linear = true;
-               goto check_size;
+
+               num_data_pgs = netvsc_get_slots(skb) + 2;
+               if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
+                       net_alert_ratelimited("packet too big: %u pages (%u bytes)\n",
+                                             num_data_pgs, skb->len);
+                       ret = -EFAULT;
+                       goto drop;
+               }
        }
 
        /*
@@ -418,8 +416,6 @@ check_size:
 
        memset(rndis_msg, 0, RNDIS_AND_PPI_SIZE);
 
-       isvlan = skb->vlan_tci & VLAN_TAG_PRESENT;
-
        /* Add the rndis header */
        rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
        rndis_msg->msg_len = packet->total_data_buflen;
@@ -438,7 +434,7 @@ check_size:
                *(u32 *)((void *)ppi + ppi->ppi_offset) = hash;
        }
 
-       if (isvlan) {
+       if (skb_vlan_tag_present(skb)) {
                struct ndis_pkt_8021q_info *vlan;
 
                rndis_msg_size += NDIS_VLAN_PPI_SIZE;
@@ -459,8 +455,37 @@ check_size:
         * Setup the sendside checksum offload only if this is not a
         * GSO packet.
         */
-       if (skb_is_gso(skb))
-               goto do_lso;
+       if (skb_is_gso(skb)) {
+               struct ndis_tcp_lso_info *lso_info;
+
+               rndis_msg_size += NDIS_LSO_PPI_SIZE;
+               ppi = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
+                                   TCP_LARGESEND_PKTINFO);
+
+               lso_info = (struct ndis_tcp_lso_info *)((void *)ppi +
+                                                       ppi->ppi_offset);
+
+               lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
+               if (net_trans_info & (INFO_IPV4 << 16)) {
+                       lso_info->lso_v2_transmit.ip_version =
+                               NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
+                       ip_hdr(skb)->tot_len = 0;
+                       ip_hdr(skb)->check = 0;
+                       tcp_hdr(skb)->check =
+                               ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
+                                                  ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
+               } else {
+                       lso_info->lso_v2_transmit.ip_version =
+                               NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
+                       ipv6_hdr(skb)->payload_len = 0;
+                       tcp_hdr(skb)->check =
+                               ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+                                                &ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
+               }
+               lso_info->lso_v2_transmit.tcp_header_offset = hdr_offset;
+               lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
+               goto do_send;
+       }
 
        if ((skb->ip_summed == CHECKSUM_NONE) ||
            (skb->ip_summed == CHECKSUM_UNNECESSARY))
@@ -507,35 +532,6 @@ check_size:
 
                csum_info->transmit.udp_checksum = 0;
        }
-       goto do_send;
-
-do_lso:
-       rndis_msg_size += NDIS_LSO_PPI_SIZE;
-       ppi = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
-                           TCP_LARGESEND_PKTINFO);
-
-       lso_info = (struct ndis_tcp_lso_info *)((void *)ppi +
-                       ppi->ppi_offset);
-
-       lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
-       if (net_trans_info & (INFO_IPV4 << 16)) {
-               lso_info->lso_v2_transmit.ip_version =
-                       NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
-               ip_hdr(skb)->tot_len = 0;
-               ip_hdr(skb)->check = 0;
-               tcp_hdr(skb)->check =
-               ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
-                                  ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
-       } else {
-               lso_info->lso_v2_transmit.ip_version =
-                       NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
-               ipv6_hdr(skb)->payload_len = 0;
-               tcp_hdr(skb)->check =
-               ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
-                               &ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
-       }
-       lso_info->lso_v2_transmit.tcp_header_offset = hdr_offset;
-       lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
 
 do_send:
        /* Start filling in the page buffers with the rndis hdr */
@@ -548,21 +544,21 @@ do_send:
        skb_tx_timestamp(skb);
        ret = netvsc_send(net_device_ctx->device_ctx, packet,
                          rndis_msg, &pb, skb);
-
-drop:
-       if (ret == 0) {
+       if (likely(ret == 0)) {
                u64_stats_update_begin(&tx_stats->syncp);
                tx_stats->packets++;
                tx_stats->bytes += skb_length;
                u64_stats_update_end(&tx_stats->syncp);
-       } else {
-               if (ret != -EAGAIN) {
-                       dev_kfree_skb_any(skb);
-                       net->stats.tx_dropped++;
-               }
+               return NETDEV_TX_OK;
        }
+       if (ret == -EAGAIN)
+               return NETDEV_TX_BUSY;
+
+drop:
+       dev_kfree_skb_any(skb);
+       net->stats.tx_dropped++;
 
-       return (ret == -EAGAIN) ? NETDEV_TX_BUSY : NETDEV_TX_OK;
+       return NETDEV_TX_OK;
 }
 
 /*