net/mlx5e: Overcome slow response for first macsec ASO WQE

[ Upstream commit 7e3fce82d945cf6e7f99034b113ff2d250d7524d ]

First ASO WQE poll causes a cache miss in hardware hence the resut is
delayed. It causes to the situation where such WQE is polled earlier
than it is needed.

Add logic to retry ASO CQ polling operation.

Fixes: 739cfa34518e ("net/mlx5: Make ASO poll CQ usable in atomic context") 
Signed-off-by: Emeel Hakim <ehakim@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c
index 0c23340bfcc75c30f1fbc925dd01a61e0e074853..0f8f3ce35537d7ee65df2f378f33432da81801fd 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.c
@@ -1412,6 +1412,7 @@ static int macsec_aso_query(struct mlx5_core_dev *mdev, struct mlx5e_macsec *mac
        struct mlx5e_macsec_aso *aso;
        struct mlx5_aso_wqe *aso_wqe;
        struct mlx5_aso *maso;
+       unsigned long expires;
        int err;
 
        aso = &macsec->aso;
@@ -1425,7 +1426,13 @@ static int macsec_aso_query(struct mlx5_core_dev *mdev, struct mlx5e_macsec *mac
        macsec_aso_build_wqe_ctrl_seg(aso, &aso_wqe->aso_ctrl, NULL);
 
        mlx5_aso_post_wqe(maso, false, &aso_wqe->ctrl);
-       err = mlx5_aso_poll_cq(maso, false);
+       expires = jiffies + msecs_to_jiffies(10);
+       do {
+               err = mlx5_aso_poll_cq(maso, false);
+               if (err)
+                       usleep_range(2, 10);
+       } while (err && time_is_after_jiffies(expires));
+
        if (err)
                goto err_out;