net/mlx4_en: Avoid calling bswap in tx fast path
- doorbell_qpn is stored in the cpu_to_be32() way to avoid bswap() in fast
path.
- mdev->mr.key stored in ring->mr_key to also avoid bswap() and access to
cold cache line.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index eaf23eb..322cda3 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -195,7 +195,8 @@
memset(ring->buf, 0, ring->buf_size);
ring->qp_state = MLX4_QP_STATE_RST;
- ring->doorbell_qpn = ring->qp.qpn << 8;
+ ring->doorbell_qpn = cpu_to_be32(ring->qp.qpn << 8);
+ ring->mr_key = cpu_to_be32(mdev->mr.key);
mlx4_en_fill_qp_context(priv, ring->size, ring->stride, 1, 0, ring->qpn,
ring->cqn, user_prio, &ring->context);
@@ -654,7 +655,6 @@
netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct mlx4_en_priv *priv = netdev_priv(dev);
- struct mlx4_en_dev *mdev = priv->mdev;
struct device *ddev = priv->ddev;
struct mlx4_en_tx_ring *ring;
struct mlx4_en_tx_desc *tx_desc;
@@ -769,7 +769,7 @@
goto tx_drop_unmap;
data->addr = cpu_to_be64(dma);
- data->lkey = cpu_to_be32(mdev->mr.key);
+ data->lkey = ring->mr_key;
wmb();
data->byte_count = cpu_to_be32(skb_frag_size(frag));
--data;
@@ -787,7 +787,7 @@
goto tx_drop_unmap;
data->addr = cpu_to_be64(dma);
- data->lkey = cpu_to_be32(mdev->mr.key);
+ data->lkey = ring->mr_key;
wmb();
data->byte_count = cpu_to_be32(byte_count);
}
@@ -879,9 +879,12 @@
send_doorbell = !skb->xmit_more || netif_xmit_stopped(ring->tx_queue);
+ real_size = (real_size / 16) & 0x3f;
+
if (ring->bf_enabled && desc_size <= MAX_BF && !bounce &&
!vlan_tx_tag_present(skb) && send_doorbell) {
- tx_desc->ctrl.bf_qpn |= cpu_to_be32(ring->doorbell_qpn);
+ tx_desc->ctrl.bf_qpn = ring->doorbell_qpn |
+ cpu_to_be32(real_size);
op_own |= htonl((bf_index & 0xffff) << 8);
/* Ensure new descriptor hits memory
@@ -911,8 +914,8 @@
tx_desc->ctrl.owner_opcode = op_own;
if (send_doorbell) {
wmb();
- iowrite32be(ring->doorbell_qpn,
- ring->bf.uar->map + MLX4_SEND_DOORBELL);
+ iowrite32(ring->doorbell_qpn,
+ ring->bf.uar->map + MLX4_SEND_DOORBELL);
} else {
ring->xmit_more++;
}
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index b7bde95..ab34461 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -279,7 +279,8 @@
u16 stride;
u16 cqn; /* index of port CQ associated with this ring */
u32 buf_size;
- u32 doorbell_qpn;
+ __be32 doorbell_qpn;
+ __be32 mr_key;
void *buf;
struct mlx4_en_tx_info *tx_info;
u8 *bounce_buf;