From 7c3b4df594b6c51c1fc95e6fd9f949bdddff34b5 Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Mon, 14 Feb 2022 19:59:19 +0200 Subject: [PATCH] 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: Maxim Mikityanskiy Reviewed-by: Tariq Toukan Signed-off-by: Saeed Mahameed --- .../ethernet/mellanox/mlx5/core/en/params.c | 34 +++++++++++++++---- 1 file changed, 27 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c index 0bd8698f7226..0f258e7a65e0 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c @@ -392,16 +392,23 @@ 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, - struct mlx5e_params *params, - struct mlx5e_xsk_param *xsk, - struct mlx5e_rq_frags_info *info) +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) { 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, ¶m->frags_info); + err = mlx5e_build_rq_frags_info(mdev, params, xsk, ¶m->frags_info); + if (err) + return err; ndsegs = param->frags_info.num_frags; } -- 2.20.1