[PATCH net-next 14/15] net/mlx5e: Add param helper to calculate max page size

[Tariq Toukan]

From: Dragos Tatulea <dtatulea@xxxxxxxxxx>

This function will be necessary to determine the upper limit of
rx-page-size.

Signed-off-by: Dragos Tatulea <dtatulea@xxxxxxxxxx>
Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/params.c | 12 ++++++++++++
 drivers/net/ethernet/mellanox/mlx5/core/en/params.h |  1 +
 2 files changed, 13 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
index 304b46ecc8df..26bb31c56e45 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
@@ -501,6 +501,18 @@ u16 mlx5e_get_rq_headroom(struct mlx5_core_dev *mdev,
 	return 0;
 }
 
+u32 mlx5e_mpwrq_max_page_size(struct mlx5_core_dev *mdev)
+{
+	if (mlx5_core_is_ecpf(mdev))
+		return PAGE_SIZE;
+
+	/* Two MTTs are needed to form an octword. Driver is using a
+	 * single page per MTT for simplicity. Hence the limit of having
+	 * at least 2 pages per WQE.
+	 */
+	return BIT(MLX5_MPWRQ_MAX_LOG_WQE_SZ - 1);
+}
+
 u16 mlx5e_calc_sq_stop_room(struct mlx5_core_dev *mdev, struct mlx5e_params *params)
 {
 	bool is_mpwqe = MLX5E_GET_PFLAG(params, MLX5E_PFLAG_SKB_TX_MPWQE);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/params.h b/drivers/net/ethernet/mellanox/mlx5/core/en/params.h
index 5b6d528bce9b..9b1a2aed17c3 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/params.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/params.h
@@ -121,6 +121,7 @@ u8 mlx5e_mpwqe_get_min_wqe_bulk(unsigned int wq_sz);
 u16 mlx5e_get_rq_headroom(struct mlx5_core_dev *mdev,
 			  struct mlx5e_params *params,
 			  struct mlx5e_rq_opt_param *rqo);
+u32 mlx5e_mpwrq_max_page_size(struct mlx5_core_dev *mdev);
 
 /* Build queue parameters */
 
-- 
2.44.0