net/mlx4_en: Refactor the XDP forwarding rings scheme

Separately manage the two types of TX rings: regular ones, and XDP.
Upon an XDP set, do not borrow regular TX rings and convert them
into XDP ones, but allocate new ones, unless we hit the max number
of rings.
Which means that in systems with smaller #cores we will not consume
the current TX rings for XDP, while we are still in the num TX limit.

XDP TX rings counters are not shown in ethtool statistics.
Instead, XDP counters will be added to the respective RX rings
in a downstream patch.

This has no performance implications.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 83c914a79f14..6e0693659f85 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -207,8 +207,10 @@ enum {
  */
 
 enum cq_type {
+	/* keep tx types first */
 	TX,
 	TX_XDP,
+#define MLX4_EN_NUM_TX_TYPES (TX_XDP + 1)
 	RX,
 };
 
@@ -373,7 +375,7 @@ struct mlx4_en_cq {
 
 struct mlx4_en_port_profile {
 	u32 flags;
-	u32 tx_ring_num;
+	u32 tx_ring_num[MLX4_EN_NUM_TX_TYPES];
 	u32 rx_ring_num;
 	u32 tx_ring_size;
 	u32 rx_ring_size;
@@ -570,17 +572,16 @@ struct mlx4_en_priv {
 	u32 flags;
 	u8 num_tx_rings_p_up;
 	u32 tx_work_limit;
-	u32 tx_ring_num;
+	u32 tx_ring_num[MLX4_EN_NUM_TX_TYPES];
 	u32 rx_ring_num;
 	u32 rx_skb_size;
 	struct mlx4_en_frag_info frag_info[MLX4_EN_MAX_RX_FRAGS];
 	u16 num_frags;
 	u16 log_rx_info;
-	int xdp_ring_num;
 
-	struct mlx4_en_tx_ring **tx_ring;
+	struct mlx4_en_tx_ring **tx_ring[MLX4_EN_NUM_TX_TYPES];
 	struct mlx4_en_rx_ring *rx_ring[MAX_RX_RINGS];
-	struct mlx4_en_cq **tx_cq;
+	struct mlx4_en_cq **tx_cq[MLX4_EN_NUM_TX_TYPES];
 	struct mlx4_en_cq *rx_cq[MAX_RX_RINGS];
 	struct mlx4_qp drop_qp;
 	struct work_struct rx_mode_task;