xdp/mlx5: setup xdp_rxq_info

The mlx5 driver have a special drop-RQ queue (one per interface) that
simply drops all incoming traffic. It helps driver keep other HW
objects (flow steering) alive upon down/up operations.  It is
temporarily pointed by flow steering objects during the interface
setup, and when interface is down. It lacks many fields that are set
in a regular RQ (for example its state is never switched to
MLX5_RQC_STATE_RDY). (Thanks to Tariq Toukan for explanation).

The XDP RX-queue info for this drop-RQ marked as unused, which
allow us to use the same takedown/free code path as other RX-queues.

Driver hook points for xdp_rxq_info:
 * reg   : mlx5e_alloc_rq()
 * unused: mlx5e_alloc_drop_rq()
 * unreg : mlx5e_free_rq()

Tested on actual hardware with samples/bpf program

Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Matan Barak <matanb@mellanox.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 543060c305a073c0457cc31ae7318f425a0e7c49..5299310f2481d9a276a559cf32b58046d557f880 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -46,6 +46,7 @@
 #include <linux/mlx5/transobj.h>
 #include <linux/rhashtable.h>
 #include <net/switchdev.h>
+#include <net/xdp.h>
 #include "wq.h"
 #include "mlx5_core.h"
 #include "en_stats.h"
@@ -571,6 +572,9 @@ struct mlx5e_rq {
        u32                    rqn;
        struct mlx5_core_dev  *mdev;
        struct mlx5_core_mkey  umr_mkey;
+
+       /* XDP read-mostly */
+       struct xdp_rxq_info    xdp_rxq;
 } ____cacheline_aligned_in_smp;
 
 struct mlx5e_channel {

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 3aa1c90e7c86582013d8d19c3daee2386f7cc051..539bd1d24396dcff2284d6db1f6911e4fecd300f 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -582,6 +582,9 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c,
                goto err_rq_wq_destroy;
        }
 
+       if (xdp_rxq_info_reg(&rq->xdp_rxq, rq->netdev, rq->ix) < 0)
+               goto err_rq_wq_destroy;
+
        rq->buff.map_dir = rq->xdp_prog ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE;
        rq->buff.headroom = params->rq_headroom;
 
@@ -687,6 +690,7 @@ err_destroy_umr_mkey:
 err_rq_wq_destroy:
        if (rq->xdp_prog)
                bpf_prog_put(rq->xdp_prog);
+       xdp_rxq_info_unreg(&rq->xdp_rxq);
        mlx5_wq_destroy(&rq->wq_ctrl);
 
        return err;
@@ -699,6 +703,8 @@ static void mlx5e_free_rq(struct mlx5e_rq *rq)
        if (rq->xdp_prog)
                bpf_prog_put(rq->xdp_prog);
 
+       xdp_rxq_info_unreg(&rq->xdp_rxq);
+
        switch (rq->wq_type) {
        case MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ:
                mlx5e_rq_free_mpwqe_info(rq);
@@ -2766,6 +2772,9 @@ static int mlx5e_alloc_drop_rq(struct mlx5_core_dev *mdev,
        if (err)
                return err;
 
+       /* Mark as unused given "Drop-RQ" packets never reach XDP */
+       xdp_rxq_info_unused(&rq->xdp_rxq);
+
        rq->mdev = mdev;
 
        return 0;

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 5b499c7a698f0f0143f624111e400dda6966f9e1..7b38480811d42e718f5c3fedc4616ceba1052644 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -812,6 +812,7 @@ static inline int mlx5e_xdp_handle(struct mlx5e_rq *rq,
        xdp_set_data_meta_invalid(&xdp);
        xdp.data_end = xdp.data + *len;
        xdp.data_hard_start = va;
+       xdp.rxq = &rq->xdp_rxq;
 
        act = bpf_prog_run_xdp(prog, &xdp);
        switch (act) {