diff options
| author |   Eric Dumazet <edumazet@google.com> | 2014-10-05 12:35:11 +0300 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2014-10-06 01:04:15 -0400 |
| commit | 6a4e81211f475561ed87c613216f981fbef8b7fc (patch) | |
| tree | ced59807448f488d408e5fe28a89b563357676bb | |
| parent | net/mlx4_en: Align tx path structures to cache lines (diff) | |
| download | linux-dev-6a4e81211f475561ed87c613216f981fbef8b7fc.tar.xz linux-dev-6a4e81211f475561ed87c613216f981fbef8b7fc.zip | |
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>
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/en_tx.c | 17 | ||||
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 3 |
2 files changed, 12 insertions, 8 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index eaf23eb7266a..322cda32ef80 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -195,7 +195,8 @@ int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv, 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 @@ static void mlx4_bf_copy(void __iomem *dst, const void *src, 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 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 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 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 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 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 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 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) 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 b7bde95e05fe..ab34461e628c 100644 --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h @@ -279,7 +279,8 @@ struct mlx4_en_tx_ring { 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; |