net/mlx5e: RX, Add checks for calculated Striding RQ attributes

Striding RQ attributes below are mutually dependent. An unaware
change to one might take the others out of the valid range derived
by the HW caps:
- The MPWQE size in bytes
- The number of strides in a MPWQE
- The stride size

Add checks to verify they are valid and comply to the HW spec
and SW assumptions/requirements.
This is not a fix, no particular issue exists today.
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

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

@@ -90,30 +90,39 @@ bool mlx5e_rx_is_linear_skb(struct mlx5e_params *params,
 	return !params->lro_en && linear_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)
-bool mlx5e_rx_mpwqe_is_linear_skb(struct mlx5_core_dev *mdev,
-				  struct mlx5e_params *params,
-				  struct mlx5e_xsk_param *xsk)
+bool mlx5e_verify_rx_mpwqe_strides(struct mlx5_core_dev *mdev,
+				   u8 log_stride_sz, u8 log_num_strides)
 {
-	u32 linear_frag_sz = mlx5e_rx_get_linear_frag_sz(params, xsk);
-	s8 signed_log_num_strides_param;
-	u8 log_num_strides;
+	if (log_stride_sz + log_num_strides != MLX5_MPWRQ_LOG_WQE_SZ)
+		return false;
 
-	if (!mlx5e_rx_is_linear_skb(params, xsk))
+	if (log_stride_sz < MLX5_MPWQE_LOG_STRIDE_SZ_BASE ||
+	    log_stride_sz > MLX5_MPWQE_LOG_STRIDE_SZ_MAX)
 		return false;
 
-	if (order_base_2(linear_frag_sz) > MLX5_MAX_MPWQE_LOG_WQE_STRIDE_SZ)
+	if (log_num_strides > MLX5_MPWQE_LOG_NUM_STRIDES_MAX)
 		return false;
 
 	if (MLX5_CAP_GEN(mdev, ext_stride_num_range))
-		return true;
+		return log_num_strides >= MLX5_MPWQE_LOG_NUM_STRIDES_EXT_BASE;
+
+	return log_num_strides >= MLX5_MPWQE_LOG_NUM_STRIDES_BASE;
+}
+
+bool mlx5e_rx_mpwqe_is_linear_skb(struct mlx5_core_dev *mdev,
+				  struct mlx5e_params *params,
+				  struct mlx5e_xsk_param *xsk)
+{
+	s8 log_num_strides;
+	u8 log_stride_sz;
+
+	if (!mlx5e_rx_is_linear_skb(params, xsk))
+		return false;
 
-	log_num_strides = MLX5_MPWRQ_LOG_WQE_SZ - order_base_2(linear_frag_sz);
-	signed_log_num_strides_param =
-		(s8)log_num_strides - MLX5_MPWQE_LOG_NUM_STRIDES_BASE;
+	log_stride_sz = order_base_2(mlx5e_rx_get_linear_frag_sz(params, xsk));
+	log_num_strides = MLX5_MPWRQ_LOG_WQE_SZ - log_stride_sz;
 
-	return signed_log_num_strides_param >= 0;
+	return mlx5e_verify_rx_mpwqe_strides(mdev, log_stride_sz, log_num_strides);
 }
 
 u8 mlx5e_mpwqe_get_log_rq_size(struct mlx5e_params *params,
@@ -462,7 +471,7 @@ static void mlx5e_build_rx_cq_param(struct mlx5_core_dev *mdev,
 	param->cq_period_mode = params->rx_cq_moderation.cq_period_mode;
 }
 
-void mlx5e_build_rq_param(struct mlx5_core_dev *mdev,
+int mlx5e_build_rq_param(struct mlx5_core_dev *mdev,
 			 struct mlx5e_params *params,
 			 struct mlx5e_xsk_param *xsk,
 			 u16 q_counter,
@@ -473,15 +482,25 @@ void mlx5e_build_rq_param(struct mlx5_core_dev *mdev,
 	int ndsegs = 1;
 
 	switch (params->rq_wq_type) {
-	case MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ:
+	case MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ: {
+		u8 log_wqe_num_of_strides = mlx5e_mpwqe_get_log_num_strides(mdev, params, xsk);
+		u8 log_wqe_stride_size = mlx5e_mpwqe_get_log_stride_size(mdev, params, xsk);
+
+		if (!mlx5e_verify_rx_mpwqe_strides(mdev, log_wqe_stride_size,
+						   log_wqe_num_of_strides)) {
+			mlx5_core_err(mdev,
+				      "Bad RX MPWQE params: log_stride_size %u, log_num_strides %u\n",
+				      log_wqe_stride_size, log_wqe_num_of_strides);
+			return -EINVAL;
+		}
+
 		MLX5_SET(wq, wq, log_wqe_num_of_strides,
-			 mlx5e_mpwqe_get_log_num_strides(mdev, params, xsk) -
-			 MLX5_MPWQE_LOG_NUM_STRIDES_BASE);
+			 log_wqe_num_of_strides - MLX5_MPWQE_LOG_NUM_STRIDES_BASE);
 		MLX5_SET(wq, wq, log_wqe_stride_size,
-			 mlx5e_mpwqe_get_log_stride_size(mdev, params, xsk) -
-			 MLX5_MPWQE_LOG_STRIDE_SZ_BASE);
+			 log_wqe_stride_size - MLX5_MPWQE_LOG_STRIDE_SZ_BASE);
 		MLX5_SET(wq, wq, log_wq_sz, mlx5e_mpwqe_get_log_rq_size(params, xsk));
 		break;
+	}
 	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);
@@ -499,6 +518,8 @@ void mlx5e_build_rq_param(struct mlx5_core_dev *mdev,
 
 	param->wq.buf_numa_node = dev_to_node(mlx5_core_dma_dev(mdev));
 	mlx5e_build_rx_cq_param(mdev, params, xsk, &param->cqp);
+
+	return 0;
 }
 
 void mlx5e_build_drop_rq_param(struct mlx5_core_dev *mdev,
@@ -643,14 +664,17 @@ void mlx5e_build_xdpsq_param(struct mlx5_core_dev *mdev,
 	mlx5e_build_tx_cq_param(mdev, params, &param->cqp);
 }
 
-void mlx5e_build_channel_param(struct mlx5_core_dev *mdev,
+int mlx5e_build_channel_param(struct mlx5_core_dev *mdev,
 			      struct mlx5e_params *params,
 			      u16 q_counter,
 			      struct mlx5e_channel_param *cparam)
 {
 	u8 icosq_log_wq_sz, async_icosq_log_wq_sz;
+	int err;
 
-	mlx5e_build_rq_param(mdev, params, NULL, q_counter, &cparam->rq);
+	err = mlx5e_build_rq_param(mdev, params, NULL, q_counter, &cparam->rq);
+	if (err)
+		return err;
 
 	icosq_log_wq_sz = mlx5e_build_icosq_log_wq_sz(params, &cparam->rq);
 	async_icosq_log_wq_sz = mlx5e_build_async_icosq_log_wq_sz(mdev);
@@ -659,4 +683,6 @@ void mlx5e_build_channel_param(struct mlx5_core_dev *mdev,
 	mlx5e_build_xdpsq_param(mdev, params, &cparam->xdp_sq);
 	mlx5e_build_icosq_param(mdev, icosq_log_wq_sz, &cparam->icosq);
 	mlx5e_build_async_icosq_param(mdev, async_icosq_log_wq_sz, &cparam->async_icosq);
+
+	return 0;
 }

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

@@ -96,6 +96,8 @@ void mlx5e_build_rq_params(struct mlx5_core_dev *mdev, struct mlx5e_params *para
 void mlx5e_set_rq_type(struct mlx5_core_dev *mdev, struct mlx5e_params *params);
 void mlx5e_init_rq_type_params(struct mlx5_core_dev *mdev, struct mlx5e_params *params);
 
+bool mlx5e_verify_rx_mpwqe_strides(struct mlx5_core_dev *mdev,
+				   u8 log_stride_sz, u8 log_num_strides);
 u16 mlx5e_get_linear_rq_headroom(struct mlx5e_params *params,
 				 struct mlx5e_xsk_param *xsk);
 u32 mlx5e_rx_get_min_frag_sz(struct mlx5e_params *params,
@@ -122,7 +124,7 @@ u16 mlx5e_get_rq_headroom(struct mlx5_core_dev *mdev,
 /* Build queue parameters */
 
 void mlx5e_build_create_cq_param(struct mlx5e_create_cq_param *ccp, struct mlx5e_channel *c);
-void mlx5e_build_rq_param(struct mlx5_core_dev *mdev,
+int mlx5e_build_rq_param(struct mlx5_core_dev *mdev,
 			 struct mlx5e_params *params,
 			 struct mlx5e_xsk_param *xsk,
 			 u16 q_counter,
@@ -141,7 +143,7 @@ void mlx5e_build_tx_cq_param(struct mlx5_core_dev *mdev,
 void mlx5e_build_xdpsq_param(struct mlx5_core_dev *mdev,
 			     struct mlx5e_params *params,
 			     struct mlx5e_sq_param *param);
-void mlx5e_build_channel_param(struct mlx5_core_dev *mdev,
+int mlx5e_build_channel_param(struct mlx5_core_dev *mdev,
 			      struct mlx5e_params *params,
 			      u16 q_counter,
 			      struct mlx5e_channel_param *cparam);

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

@@ -2086,7 +2086,10 @@ int mlx5e_open_channels(struct mlx5e_priv *priv,
 	if (!chs->c || !cparam)
 		goto err_free;
 
-	mlx5e_build_channel_param(priv->mdev, &chs->params, priv->q_counter, cparam);
+	err = mlx5e_build_channel_param(priv->mdev, &chs->params, priv->q_counter, cparam);
+	if (err)
+		goto err_free;
+
 	for (i = 0; i < chs->num; i++) {
 		struct xsk_buff_pool *xsk_pool = NULL;
 

include/linux/mlx5/device.h

@@ -911,8 +911,11 @@ static inline u16 get_cqe_flow_tag(struct mlx5_cqe64 *cqe)
 	return be32_to_cpu(cqe->sop_drop_qpn) & 0xFFF;
 }
 
-#define MLX5_MPWQE_LOG_NUM_STRIDES_BASE	(9)
-#define MLX5_MPWQE_LOG_STRIDE_SZ_BASE	(6)
+#define MLX5_MPWQE_LOG_NUM_STRIDES_EXT_BASE	3
+#define MLX5_MPWQE_LOG_NUM_STRIDES_BASE		9
+#define MLX5_MPWQE_LOG_NUM_STRIDES_MAX		16
+#define MLX5_MPWQE_LOG_STRIDE_SZ_BASE		6
+#define MLX5_MPWQE_LOG_STRIDE_SZ_MAX		13
 
 struct mpwrq_cqe_bc {
 	__be16	filler_consumed_strides;