From ea3349a03519dcd4f32d949cd80ab995623dc5ac Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Wed, 7 Dec 2016 15:53:13 -0800 Subject: [PATCH] mlx4: xdp: Reserve headroom for receiving packet when XDP prog is active Reserve XDP_PACKET_HEADROOM for packet and enable bpf_xdp_adjust_head() support. This patch only affects the code path when XDP is active. After testing, the tx_dropped counter is incremented if the xdp_prog sends more than wire MTU. Signed-off-by: Martin KaFai Lau Acked-by: Saeed Mahameed Signed-off-by: David S. Miller --- .../net/ethernet/mellanox/mlx4/en_netdev.c | 8 ++----- drivers/net/ethernet/mellanox/mlx4/en_rx.c | 24 ++++++++++++++----- drivers/net/ethernet/mellanox/mlx4/en_tx.c | 9 +++---- drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 3 ++- 4 files changed, 27 insertions(+), 17 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c index c97d25b06444..bcd955339058 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c @@ -51,7 +51,8 @@ #include "mlx4_en.h" #include "en_port.h" -#define MLX4_EN_MAX_XDP_MTU ((int)(PAGE_SIZE - ETH_HLEN - (2 * VLAN_HLEN))) +#define MLX4_EN_MAX_XDP_MTU ((int)(PAGE_SIZE - ETH_HLEN - (2 * VLAN_HLEN) - \ + XDP_PACKET_HEADROOM)) int mlx4_en_setup_tc(struct net_device *dev, u8 up) { @@ -2700,11 +2701,6 @@ static int mlx4_xdp_set(struct net_device *dev, struct bpf_prog *prog) int err; int i; - if (prog && prog->xdp_adjust_head) { - en_err(priv, "Does not support bpf_xdp_adjust_head()\n"); - return -EOPNOTSUPP; - } - xdp_ring_num = prog ? priv->rx_ring_num : 0; /* No need to reconfigure buffers when simply swapping the diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index 23e9d04d1ef4..3c37e216bbf3 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -96,7 +96,6 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv, struct mlx4_en_rx_alloc page_alloc[MLX4_EN_MAX_RX_FRAGS]; const struct mlx4_en_frag_info *frag_info; struct page *page; - dma_addr_t dma; int i; for (i = 0; i < priv->num_frags; i++) { @@ -115,9 +114,10 @@ static int mlx4_en_alloc_frags(struct mlx4_en_priv *priv, for (i = 0; i < priv->num_frags; i++) { frags[i] = ring_alloc[i]; - dma = ring_alloc[i].dma + ring_alloc[i].page_offset; + frags[i].page_offset += priv->frag_info[i].rx_headroom; + rx_desc->data[i].addr = cpu_to_be64(frags[i].dma + + frags[i].page_offset); ring_alloc[i] = page_alloc[i]; - rx_desc->data[i].addr = cpu_to_be64(dma); } return 0; @@ -250,7 +250,8 @@ static int mlx4_en_prepare_rx_desc(struct mlx4_en_priv *priv, if (ring->page_cache.index > 0) { frags[0] = ring->page_cache.buf[--ring->page_cache.index]; - rx_desc->data[0].addr = cpu_to_be64(frags[0].dma); + rx_desc->data[0].addr = cpu_to_be64(frags[0].dma + + frags[0].page_offset); return 0; } @@ -889,6 +890,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud if (xdp_prog) { struct xdp_buff xdp; dma_addr_t dma; + void *orig_data; u32 act; dma = be64_to_cpu(rx_desc->data[0].addr); @@ -896,11 +898,19 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud priv->frag_info[0].frag_size, DMA_FROM_DEVICE); - xdp.data = page_address(frags[0].page) + - frags[0].page_offset; + xdp.data_hard_start = page_address(frags[0].page); + xdp.data = xdp.data_hard_start + frags[0].page_offset; xdp.data_end = xdp.data + length; + orig_data = xdp.data; act = bpf_prog_run_xdp(xdp_prog, &xdp); + + if (xdp.data != orig_data) { + length = xdp.data_end - xdp.data; + frags[0].page_offset = xdp.data - + xdp.data_hard_start; + } + switch (act) { case XDP_PASS: break; @@ -1180,6 +1190,7 @@ void mlx4_en_calc_rx_buf(struct net_device *dev) */ priv->frag_info[0].frag_stride = PAGE_SIZE; priv->frag_info[0].dma_dir = PCI_DMA_BIDIRECTIONAL; + priv->frag_info[0].rx_headroom = XDP_PACKET_HEADROOM; i = 1; } else { int buf_size = 0; @@ -1194,6 +1205,7 @@ void mlx4_en_calc_rx_buf(struct net_device *dev) ALIGN(priv->frag_info[i].frag_size, SMP_CACHE_BYTES); priv->frag_info[i].dma_dir = PCI_DMA_FROMDEVICE; + priv->frag_info[i].rx_headroom = 0; buf_size += priv->frag_info[i].frag_size; i++; } diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index 4b597dca5c52..5886ad78058f 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -354,7 +354,7 @@ u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv, struct mlx4_en_rx_alloc frame = { .page = tx_info->page, .dma = tx_info->map0_dma, - .page_offset = 0, + .page_offset = XDP_PACKET_HEADROOM, .page_size = PAGE_SIZE, }; @@ -1132,7 +1132,7 @@ netdev_tx_t mlx4_en_xmit_frame(struct mlx4_en_rx_ring *rx_ring, tx_info->page = frame->page; frame->page = NULL; tx_info->map0_dma = dma; - tx_info->map0_byte_count = length; + tx_info->map0_byte_count = PAGE_SIZE; tx_info->nr_txbb = nr_txbb; tx_info->nr_bytes = max_t(unsigned int, length, ETH_ZLEN); tx_info->data_offset = (void *)data - (void *)tx_desc; @@ -1141,9 +1141,10 @@ netdev_tx_t mlx4_en_xmit_frame(struct mlx4_en_rx_ring *rx_ring, tx_info->linear = 1; tx_info->inl = 0; - dma_sync_single_for_device(priv->ddev, dma, length, PCI_DMA_TODEVICE); + dma_sync_single_range_for_device(priv->ddev, dma, frame->page_offset, + length, PCI_DMA_TODEVICE); - data->addr = cpu_to_be64(dma); + data->addr = cpu_to_be64(dma + frame->page_offset); data->lkey = ring->mr_key; dma_wmb(); data->byte_count = cpu_to_be32(length); diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h index 20a936428f4a..ba1c6cd0cc79 100644 --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h @@ -475,7 +475,8 @@ struct mlx4_en_frag_info { u16 frag_prefix_size; u32 frag_stride; enum dma_data_direction dma_dir; - int order; + u16 order; + u16 rx_headroom; }; #ifdef CONFIG_MLX4_EN_DCB -- 2.20.1