[net 5/7] net/mlx5e: Overcome slow response for first macsec ASO WQE

[Saeed Mahameed <saeed@kernel.org>]

From: Emeel Hakim <ehakim@nvidia.com>

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>
---
 .../net/ethernet/mellanox/mlx5/core/en_accel/macsec.c    | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

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 8af53178e40d..33b3620ea45c 100644
--- 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;
 
-- 
2.39.2