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>

1 files changed, 51 insertions, 55 deletions

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 3bbf07352433..7ed9f13067b5 100644
--- 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;
 }
 
 /*