[PATCH RFC v2 16/33] mlx4: add XDP frame size and adjust max XDP MTU

Jesper Dangaard Brouer
2020-04-08T11:52:06Z

The mlx4 drivers size of memory backing the RX packet is stored in
frag_stride. For XDP mode this will be PAGE_SIZE (normally 4096).
For normal mode frag_stride is 2048.

Also adjust MLX4_EN_MAX_XDP_MTU to take tailroom into account.

Cc: Tariq Toukan <tariqt@mellanox.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
---
drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 3 ++-
drivers/net/ethernet/mellanox/mlx4/en_rx.c | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index 43dcbd8214c6..5bd3cd37d50f 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -51,7 +51,8 @@
#include "en_port.h"

#define MLX4_EN_MAX_XDP_MTU ((int)(PAGE_SIZE - ETH_HLEN - (2 * VLAN_HLEN) - \
- XDP_PACKET_HEADROOM))
+ XDP_PACKET_HEADROOM - \
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info))))

int mlx4_en_setup_tc(struct net_device *dev, u8 up)
{
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index db3552f2d087..231f08c0276c 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -683,6 +683,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
rcu_read_lock();
xdp_prog = rcu_dereference(ring->xdp_prog);
xdp.rxq = &ring->xdp_rxq;
+ xdp.frame_sz = priv->frag_info[0].frag_stride;
doorbell_pending = 0;

/* We assume a 1:1 mapping between CQEs and Rx descriptors, so Rx