[PATCH net-next 5/5] net/mlx5e: do not create xdp_redirect for non-uplink rep

[Tariq Toukan <tariqt@nvidia.com>]

From: William Tu <witu@nvidia.com>

XDP and XDP socket require extra SQ/RQ/CQs. Most of these resources
are dynamically created: no XDP program loaded, no resources are
created. One exception is the SQ/CQ created for XDP_REDRIECT, used
for other netdev to forward packet to mlx5 for transmit. The patch
disables creation of SQ and CQ used for egress XDP_REDIRECT, by
checking whether ndo_xdp_xmit is set or not.

For netdev without XDP support such as non-uplink representor, this
saves around 0.35MB of memory, per representor netdevice per channel.

Signed-off-by: William Tu <witu@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../net/ethernet/mellanox/mlx5/core/en_main.c   | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 2f609b92d29b..59d7a0e28f24 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -2514,6 +2514,7 @@ static int mlx5e_open_queues(struct mlx5e_channel *c,
 			     struct mlx5e_params *params,
 			     struct mlx5e_channel_param *cparam)
 {
+	const struct net_device_ops *netdev_ops = c->netdev->netdev_ops;
 	struct dim_cq_moder icocq_moder = {0, 0};
 	struct mlx5e_create_cq_param ccp;
 	int err;
@@ -2534,10 +2535,12 @@ static int mlx5e_open_queues(struct mlx5e_channel *c,
 	if (err)
 		goto err_close_icosq_cq;
 
-	c->xdpsq = mlx5e_open_xdpredirect_sq(c, params, cparam, &ccp);
-	if (IS_ERR(c->xdpsq)) {
-		err = PTR_ERR(c->xdpsq);
-		goto err_close_tx_cqs;
+	if (netdev_ops->ndo_xdp_xmit) {
+		c->xdpsq = mlx5e_open_xdpredirect_sq(c, params, cparam, &ccp);
+		if (IS_ERR(c->xdpsq)) {
+			err = PTR_ERR(c->xdpsq);
+			goto err_close_tx_cqs;
+		}
 	}
 
 	err = mlx5e_open_cq(c->mdev, params->rx_cq_moderation, &cparam->rq.cqp, &ccp,
@@ -2601,7 +2604,8 @@ static int mlx5e_open_queues(struct mlx5e_channel *c,
 	mlx5e_close_cq(&c->rq.cq);
 
 err_close_xdpredirect_sq:
-	mlx5e_close_xdpredirect_sq(c->xdpsq);
+	if (c->xdpsq)
+		mlx5e_close_xdpredirect_sq(c->xdpsq);
 
 err_close_tx_cqs:
 	mlx5e_close_tx_cqs(c);
@@ -2629,7 +2633,8 @@ static void mlx5e_close_queues(struct mlx5e_channel *c)
 	if (c->xdp)
 		mlx5e_close_cq(&c->rq_xdpsq.cq);
 	mlx5e_close_cq(&c->rq.cq);
-	mlx5e_close_xdpredirect_sq(c->xdpsq);
+	if (c->xdpsq)
+		mlx5e_close_xdpredirect_sq(c->xdpsq);
 	mlx5e_close_tx_cqs(c);
 	mlx5e_close_cq(&c->icosq.cq);
 	mlx5e_close_cq(&c->async_icosq.cq);
-- 
2.44.0