Subject: [PATCH 50/58] net/mlx5e: RX, Verify MPWQE stride size is in range

From: Moshe Shemesh <[email-masked]>
Date: Fri, 2 Nov 2018 06:10:49 +0200

[ Upstream commit e1c15b62b7015119d3e5915cd2ae3b89d59c2576 ]

Add check of MPWQE stride size is within range supported by HW. In case
calculated MPWQE stride size exceed range, linear SKB can't be used and
we should use non linear MPWQE instead.

Fixes: 619a8f2a42f1 ("net/mlx5e: Use linear SKB in Striding RQ")
Signed-off-by: Moshe Shemesh <[email-masked]>
Reviewed-by: Tariq Toukan <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index fddb6001e3a7..7365899c3ac9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -128,6 +128,8 @@ static bool mlx5e_rx_is_linear_skb(struct mlx5_core_dev *mdev,
 	return !params->lro_en && frag_sz <= PAGE_SIZE;
 }
 
+#define MLX5_MAX_MPWQE_LOG_WQE_STRIDE_SZ ((BIT(__mlx5_bit_sz(wq, log_wqe_stride_size)) - 1) + \
+					  MLX5_MPWQE_LOG_STRIDE_SZ_BASE)
 static bool mlx5e_rx_mpwqe_is_linear_skb(struct mlx5_core_dev *mdev,
 					 struct mlx5e_params *params)
 {
@@ -138,6 +140,9 @@ static bool mlx5e_rx_mpwqe_is_linear_skb(struct mlx5_core_dev *mdev,
 	if (!mlx5e_rx_is_linear_skb(mdev, params))
 		return false;
 
+	if (order_base_2(frag_sz) > MLX5_MAX_MPWQE_LOG_WQE_STRIDE_SZ)
+		return false;
+
 	if (MLX5_CAP_GEN(mdev, ext_stride_num_range))
 		return true;
 
-- 
2.20.1