From 9e8c0395a7e87a8f0eb008297df25ffdf3e0e5b3 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 8 Mar 2017 08:17:15 -0800 Subject: [PATCH] mlx4: do not access rx_desc from mlx4_en_process_rx_cq() Instead of fetching dma address from rx_desc->data[0].addr, prefer using frags[0].dma + frags[0].page_offset to avoid a potential cache line miss. Signed-off-by: Eric Dumazet Acked-by: Tariq Toukan Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx4/en_rx.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index d3a425fa46b3..b62fa265890e 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -528,7 +528,6 @@ fail: static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv, - struct mlx4_en_rx_desc *rx_desc, struct mlx4_en_rx_alloc *frags, unsigned int length) { @@ -703,7 +702,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud struct mlx4_cqe *cqe; struct mlx4_en_rx_ring *ring = priv->rx_ring[cq->ring]; struct mlx4_en_rx_alloc *frags; - struct mlx4_en_rx_desc *rx_desc; struct bpf_prog *xdp_prog; int doorbell_pending; struct sk_buff *skb; @@ -738,7 +736,6 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud cq->mcq.cons_index & cq->size)) { frags = ring->rx_info + (index << priv->log_rx_info); - rx_desc = ring->buf + (index << ring->log_stride); /* * make sure we read the CQE after we read the ownership bit @@ -767,7 +764,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud /* Get pointer to first fragment since we haven't * skb yet and cast it to ethhdr struct */ - dma = be64_to_cpu(rx_desc->data[0].addr); + dma = frags[0].dma + frags[0].page_offset; dma_sync_single_for_cpu(priv->ddev, dma, sizeof(*ethh), DMA_FROM_DEVICE); ethh = (struct ethhdr *)(page_address(frags[0].page) + @@ -806,7 +803,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud void *orig_data; u32 act; - dma = be64_to_cpu(rx_desc->data[0].addr); + dma = frags[0].dma + frags[0].page_offset; dma_sync_single_for_cpu(priv->ddev, dma, priv->frag_info[0].frag_size, DMA_FROM_DEVICE); @@ -946,7 +943,7 @@ xdp_drop_no_cnt: } /* GRO not possible, complete processing here */ - skb = mlx4_en_rx_skb(priv, rx_desc, frags, length); + skb = mlx4_en_rx_skb(priv, frags, length); if (unlikely(!skb)) { ring->dropped++; goto next;