Commit 7c3b4df5 authored by Maxim Mikityanskiy's avatar Maxim Mikityanskiy Committed by Saeed Mahameed
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net/mlx5e: Validate MTU when building non-linear legacy RQ fragments info 



mlx5e_build_rq_frags_info() assumes that MTU is not bigger than
PAGE_SIZE * MLX5E_MAX_RX_FRAGS, which is 16K for 4K pages. Currently,
the firmware limits MTU to 10K, so the assumption doesn't lead to a bug.

This commits adds an additional driver check for reliability, since the
firmware boundary might be changed.

The calculation is taken to a separate function with a comment
explaining it. It's a preparation for the following patches that
introcuce XDP multi buffer support.

Signed-off-by: default avatarMaxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: default avatarTariq Toukan <tariqt@nvidia.com>
Signed-off-by: default avatarSaeed Mahameed <saeedm@nvidia.com>
parent 1abea24a

drivers/net/ethernet/mellanox/mlx5/core/en/params.c

+27 −7
Original line number Diff line number Diff line
@@ -392,9 +392,15 @@ void mlx5e_build_create_cq_param(struct mlx5e_create_cq_param *ccp, struct mlx5e 
	};

}



static int mlx5e_max_nonlinear_mtu(int frag_size)

{

	/* Optimization for small packets: the last fragment is bigger than the others. */

	return (MLX5E_MAX_RX_FRAGS - 1) * frag_size + PAGE_SIZE;

}



#define DEFAULT_FRAG_SIZE (2048)



static void mlx5e_build_rq_frags_info(struct mlx5_core_dev *mdev,

static int mlx5e_build_rq_frags_info(struct mlx5_core_dev *mdev,

				     struct mlx5e_params *params,

				     struct mlx5e_xsk_param *xsk,

				     struct mlx5e_rq_frags_info *info)
@@ -402,6 +408,7 @@ static void mlx5e_build_rq_frags_info(struct mlx5_core_dev *mdev, 
	u32 byte_count = MLX5E_SW2HW_MTU(params, params->sw_mtu);

	int frag_size_max = DEFAULT_FRAG_SIZE;

	u32 buf_size = 0;

	int max_mtu;

	int i;



	if (mlx5_fpga_is_ipsec_device(mdev))
@@ -420,10 +427,18 @@ static void mlx5e_build_rq_frags_info(struct mlx5_core_dev *mdev, 
		goto out;

	}



	if (byte_count > PAGE_SIZE +

	    (MLX5E_MAX_RX_FRAGS - 1) * frag_size_max)

	max_mtu = mlx5e_max_nonlinear_mtu(frag_size_max);

	if (byte_count > max_mtu) {

		frag_size_max = PAGE_SIZE;



		max_mtu = mlx5e_max_nonlinear_mtu(frag_size_max);

		if (byte_count > max_mtu) {

			mlx5_core_err(mdev, "MTU %u is too big for non-linear legacy RQ (max %d)\n",

				      params->sw_mtu, max_mtu);

			return -EINVAL;

		}

	}



	i = 0;

	while (buf_size < byte_count) {

		int frag_size = byte_count - buf_size;
@@ -444,6 +459,8 @@ static void mlx5e_build_rq_frags_info(struct mlx5_core_dev *mdev, 
out:

	info->wqe_bulk = max_t(u8, info->wqe_bulk, 8);

	info->log_num_frags = order_base_2(info->num_frags);



	return 0;

}



static u8 mlx5e_get_rqwq_log_stride(u8 wq_type, int ndsegs)
@@ -540,6 +557,7 @@ int mlx5e_build_rq_param(struct mlx5_core_dev *mdev, 
	void *rqc = param->rqc;

	void *wq = MLX5_ADDR_OF(rqc, rqc, wq);

	int ndsegs = 1;

	int err;



	switch (params->rq_wq_type) {

	case MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ: {
@@ -579,7 +597,9 @@ int mlx5e_build_rq_param(struct mlx5_core_dev *mdev, 
	}

	default: /* MLX5_WQ_TYPE_CYCLIC */

		MLX5_SET(wq, wq, log_wq_sz, params->log_rq_mtu_frames);

		mlx5e_build_rq_frags_info(mdev, params, xsk, &param->frags_info);

		err = mlx5e_build_rq_frags_info(mdev, params, xsk, &param->frags_info);

		if (err)

			return err;

		ndsegs = param->frags_info.num_frags;

	}