mlx4_en: dont change mac_header on xmit

A driver xmit function is not allowed to change skb without special
care.

mlx4_en_xmit() should not call skb_reset_mac_header() and instead should
use skb->data to access ethernet header.

This removes a dumb test : if (ethh && ethh->h_dest)

Also remove this slow mlx4_en_mac_to_u64() call, we can use
get_unaligned() to get faster code.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 7 insertions, 13 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index ff3250586584..2fd51405a509 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -601,8 +601,6 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
         struct skb_frag_struct *frag;
         struct mlx4_en_tx_info *tx_info;
         struct ethhdr *ethh;
-        u64 mac;
-        u32 mac_l, mac_h;
         int tx_ind = 0;
         int nr_txbb;
         int desc_size;
@@ -687,16 +685,9 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
         }
 
         /* Copy dst mac address to wqe */
-        skb_reset_mac_header(skb);
-        ethh = eth_hdr(skb);
-        if (ethh && ethh->h_dest) {
-                mac = mlx4_en_mac_to_u64(ethh->h_dest);
-                mac_h = (u32) ((mac & 0xffff00000000ULL) >> 16);
-                mac_l = (u32) (mac & 0xffffffff);
-                tx_desc->ctrl.srcrb_flags |= cpu_to_be32(mac_h);
-                tx_desc->ctrl.imm = cpu_to_be32(mac_l);
-        }
-
+        ethh = (struct ethhdr *)skb->data;
+        tx_desc->ctrl.srcrb_flags16[0] = get_unaligned((u16 *)ethh->h_dest);
+        tx_desc->ctrl.imm = get_unaligned((u32 *)(ethh->h_dest + 2));
         /* Handle LSO (TSO) packets */
         if (lso_header_size) {
                 /* Mark opcode as LSO */
diff --git a/include/linux/mlx4/qp.h b/include/linux/mlx4/qp.h
index bee8fa231276..091f9e7dc8b9 100644
--- a/include/linux/mlx4/qp.h
+++ b/include/linux/mlx4/qp.h
@@ -212,7 +212,10 @@ struct mlx4_wqe_ctrl_seg {
          * [1]   SE (solicited event)
          * [0]   FL (force loopback)
          */
-        __be32                  srcrb_flags;
+        union {
+                __be32                  srcrb_flags;
+                __be16                  srcrb_flags16[2];
+        };
         /*
          * imm is immediate data for send/RDMA write w/ immediate;
          * also invalidation key for send with invalidate; input