net/mlx5e: Introduce abstraction of RSS context

Bring all fields that define and maintain RSS behavior together
into a new structure.
Align all usages with this new structure. Keep it hidden within
rx_res.c.
This helps supporting multiple RSS contexts in downstream patch.

Use dynamic allocations for the RSS context.
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

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

@@ -53,7 +53,7 @@ int mlx5e_rx_res_xsk_deactivate(struct mlx5e_rx_res *res, unsigned int ix);
 struct mlx5e_rss_params_traffic_type
 mlx5e_rx_res_rss_get_current_tt_config(struct mlx5e_rx_res *res, enum mlx5_traffic_types tt);
 void mlx5e_rx_res_rss_set_indir_uniform(struct mlx5e_rx_res *res, unsigned int nch);
-void mlx5e_rx_res_rss_get_rxfh(struct mlx5e_rx_res *res, u32 *indir, u8 *key, u8 *hfunc);
+int mlx5e_rx_res_rss_get_rxfh(struct mlx5e_rx_res *res, u32 *indir, u8 *key, u8 *hfunc);
 int mlx5e_rx_res_rss_set_rxfh(struct mlx5e_rx_res *res, const u32 *indir,
 			      const u8 *key, const u8 *hfunc);
 u8 mlx5e_rx_res_rss_get_hash_fields(struct mlx5e_rx_res *res, enum mlx5_traffic_types tt);

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

@@ -1198,12 +1198,12 @@ int mlx5e_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key,
 		   u8 *hfunc)
 {
 	struct mlx5e_priv *priv = netdev_priv(netdev);
+	int err;
 
 	mutex_lock(&priv->state_lock);
-	mlx5e_rx_res_rss_get_rxfh(priv->rx_res, indir, key, hfunc);
+	err = mlx5e_rx_res_rss_get_rxfh(priv->rx_res, indir, key, hfunc);
 	mutex_unlock(&priv->state_lock);
-
-	return 0;
+	return err;
 }
 
 int mlx5e_set_rxfh(struct net_device *dev, const u32 *indir,