net/mlx5e: Permit XDP with non-linear legacy RQ

Now that legacy RQ implements XDP in the non-linear mode, stop blocking
this configuration. Allow non-linear mode only for programs aware of
multi buffer.

XDP performance with linear mode RQ hasn't changed.

Baseline (MTU 1500, TX MPWQE, legacy RQ, single core):
 60-byte packets, XDP_DROP: 11.25 Mpps
 60-byte packets, XDP_TX: 9.0 Mpps
 60-byte packets, XDP_PASS: 668 kpps

Multi buffer (MTU 9000, TX MPWQE, legacy RQ, single core):
 60-byte packets, XDP_DROP: 10.1 Mpps
 60-byte packets, XDP_TX: 6.6 Mpps
 60-byte packets, XDP_PASS: 658 kpps
 8900-byte packets, XDP_DROP: 769 kpps (100% of sent packets)
 8900-byte packets, XDP_TX: 674 kpps (100% of sent packets)
 8900-byte packets, XDP_PASS: 637 kpps

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 95cec28..3256d2c 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3953,6 +3953,31 @@ static bool mlx5e_xsk_validate_mtu(struct net_device *netdev,
        return true;
 }
 
+static bool mlx5e_params_validate_xdp(struct net_device *netdev, struct mlx5e_params *params)
+{
+       bool is_linear;
+
+       /* No XSK params: AF_XDP can't be enabled yet at the point of setting
+        * the XDP program.
+        */
+       is_linear = mlx5e_rx_is_linear_skb(params, NULL);
+
+       if (!is_linear && params->rq_wq_type != MLX5_WQ_TYPE_CYCLIC) {
+               netdev_warn(netdev, "XDP is not allowed with striding RQ and MTU(%d) > %d\n",
+                           params->sw_mtu,
+                           mlx5e_xdp_max_mtu(params, NULL));
+               return false;
+       }
+       if (!is_linear && !params->xdp_prog->aux->xdp_has_frags) {
+               netdev_warn(netdev, "MTU(%d) > %d, too big for an XDP program not aware of multi buffer\n",
+                           params->sw_mtu,
+                           mlx5e_xdp_max_mtu(params, NULL));
+               return false;
+       }
+
+       return true;
+}
+
 int mlx5e_change_mtu(struct net_device *netdev, int new_mtu,
                     mlx5e_fp_preactivate preactivate)
 {
@@ -3972,10 +3997,7 @@ int mlx5e_change_mtu(struct net_device *netdev, int new_mtu,
        if (err)
                goto out;
 
-       if (params->xdp_prog &&
-           !mlx5e_rx_is_linear_skb(&new_params, NULL)) {
-               netdev_err(netdev, "MTU(%d) > %d is not allowed while XDP enabled\n",
-                          new_mtu, mlx5e_xdp_max_mtu(params, NULL));
+       if (new_params.xdp_prog && !mlx5e_params_validate_xdp(netdev, &new_params)) {
                err = -EINVAL;
                goto out;
        }
@@ -4458,15 +4480,8 @@ static int mlx5e_xdp_allowed(struct mlx5e_priv *priv, struct bpf_prog *prog)
        new_params = priv->channels.params;
        new_params.xdp_prog = prog;
 
-       /* No XSK params: AF_XDP can't be enabled yet at the point of setting
-        * the XDP program.
-        */
-       if (!mlx5e_rx_is_linear_skb(&new_params, NULL)) {
-               netdev_warn(netdev, "XDP is not allowed with MTU(%d) > %d\n",
-                           new_params.sw_mtu,
-                           mlx5e_xdp_max_mtu(&new_params, NULL));
+       if (!mlx5e_params_validate_xdp(netdev, &new_params))
                return -EINVAL;
-       }
 
        return 0;
 }