net/mlx5e: Support XDP over Striding RQ

Add XDP support over Striding RQ.
Now that linear SKB is supported over Striding RQ,
we can support XDP by setting stride size to PAGE_SIZE
and headroom to XDP_PACKET_HEADROOM.

Upon a MPWQE free, do not release pages that are being
XDP xmit, they will be released upon completions.

Striding RQ is capable of a higher packet-rate than
conventional RQ.
A performance gain is expected for all cases that had
a HW packet-rate bottleneck. This is the case whenever
using many flows that distribute to many cores.

Performance testing:
ConnectX-5, 24 rings, default MTU.
CQE compression ON (to reduce completions BW in PCI).

XDP_DROP packet rate:
--------------------------------------------------
| pkt size | XDP rate   | 100GbE linerate | pct% |
--------------------------------------------------
|   64byte | 126.2 Mpps |      148.0 Mpps |  85% |
|  128byte |  80.0 Mpps |       84.8 Mpps |  94% |
|  256byte |  42.7 Mpps |       42.7 Mpps | 100% |
|  512byte |  23.4 Mpps |       23.4 Mpps | 100% |
--------------------------------------------------

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index a6ca54393bb6ea8509ccc6bf5860ad8960cca6a9..7997d7c159db2fe599175df20770c29fc6d20c80 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -457,6 +457,7 @@ struct mlx5e_mpw_info {
        struct mlx5e_umr_dma_info umr;
        u16 consumed_strides;
        u16 skbs_frags[MLX5_MPWRQ_PAGES_PER_WQE];
+       DECLARE_BITMAP(xdp_xmit_bitmap, MLX5_MPWRQ_PAGES_PER_WQE);
 };
 
 /* a single cache unit is capable to serve one napi call (for non-striding rq)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index bba2fa0aa15f5a067a4320c0458b82934032248e..b03a2327356afe14e10d93c98146ed3146115618 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -200,7 +200,8 @@ bool mlx5e_striding_rq_possible(struct mlx5_core_dev *mdev,
                                struct mlx5e_params *params)
 {
        return mlx5e_check_fragmented_striding_rq_cap(mdev) &&
-               !params->xdp_prog && !MLX5_IPSEC_DEV(mdev);
+               !MLX5_IPSEC_DEV(mdev) &&
+               !(params->xdp_prog && !mlx5e_rx_mpwqe_is_linear_skb(mdev, params));
 }
 
 void mlx5e_set_rq_type(struct mlx5_core_dev *mdev, struct mlx5e_params *params)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index a827571deb858733dd304e10df691d966beb3a16..1da79cab1838b0e7e6a26f711df0fab9fdf551ca 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -349,13 +349,16 @@ mlx5e_copy_skb_header_mpwqe(struct device *pdev,
 
 void mlx5e_free_rx_mpwqe(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi)
 {
+       const bool no_xdp_xmit =
+               bitmap_empty(wi->xdp_xmit_bitmap, MLX5_MPWRQ_PAGES_PER_WQE);
        int pg_strides = mlx5e_mpwqe_strides_per_page(rq);
-       struct mlx5e_dma_info *dma_info = &wi->umr.dma_info[0];
+       struct mlx5e_dma_info *dma_info = wi->umr.dma_info;
        int i;
 
-       for (i = 0; i < MLX5_MPWRQ_PAGES_PER_WQE; i++, dma_info++) {
-               page_ref_sub(dma_info->page, pg_strides - wi->skbs_frags[i]);
-               mlx5e_page_release(rq, dma_info, true);
+       for (i = 0; i < MLX5_MPWRQ_PAGES_PER_WQE; i++) {
+               page_ref_sub(dma_info[i].page, pg_strides - wi->skbs_frags[i]);
+               if (no_xdp_xmit || !test_bit(i, wi->xdp_xmit_bitmap))
+                       mlx5e_page_release(rq, &dma_info[i], true);
        }
 }
 
@@ -404,6 +407,7 @@ static int mlx5e_alloc_rx_mpwqe(struct mlx5e_rq *rq, u16 ix)
        }
 
        memset(wi->skbs_frags, 0, sizeof(*wi->skbs_frags) * MLX5_MPWRQ_PAGES_PER_WQE);
+       bitmap_zero(wi->xdp_xmit_bitmap, MLX5_MPWRQ_PAGES_PER_WQE);
        wi->consumed_strides = 0;
 
        rq->mpwqe.umr_in_progress = true;
@@ -1028,18 +1032,30 @@ mlx5e_skb_from_cqe_mpwrq_linear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi,
 {
        struct mlx5e_dma_info *di = &wi->umr.dma_info[page_idx];
        u16 rx_headroom = rq->buff.headroom;
+       u32 cqe_bcnt32 = cqe_bcnt;
        struct sk_buff *skb;
        void *va, *data;
        u32 frag_size;
+       bool consumed;
 
        va             = page_address(di->page) + head_offset;
        data           = va + rx_headroom;
-       frag_size      = MLX5_SKB_FRAG_SZ(rx_headroom + cqe_bcnt);
+       frag_size      = MLX5_SKB_FRAG_SZ(rx_headroom + cqe_bcnt32);
 
        dma_sync_single_range_for_cpu(rq->pdev, di->addr, head_offset,
                                      frag_size, DMA_FROM_DEVICE);
        prefetch(data);
-       skb = mlx5e_build_linear_skb(rq, va, frag_size, rx_headroom, cqe_bcnt);
+
+       rcu_read_lock();
+       consumed = mlx5e_xdp_handle(rq, di, va, &rx_headroom, &cqe_bcnt32);
+       rcu_read_unlock();
+       if (consumed) {
+               if (__test_and_clear_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags))
+                       __set_bit(page_idx, wi->xdp_xmit_bitmap); /* non-atomic */
+               return NULL; /* page/packet was consumed by XDP */
+       }
+
+       skb = mlx5e_build_linear_skb(rq, va, frag_size, rx_headroom, cqe_bcnt32);
        if (unlikely(!skb))
                return NULL;
 
@@ -1078,7 +1094,7 @@ void mlx5e_handle_rx_cqe_mpwrq(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe)
 
        skb = rq->mpwqe.skb_from_cqe_mpwrq(rq, wi, cqe_bcnt, head_offset,
                                           page_idx);
-       if (unlikely(!skb))
+       if (!skb)
                goto mpwrq_cqe_out;
 
        mlx5e_complete_rx_cqe(rq, cqe, cqe_bcnt, skb);