net: mlx4: Add support for XDP_REDIRECT

Signed-off-by: Joshua Roys <roysjosh@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -669,6 +669,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 	struct bpf_prog *xdp_prog;
 	int cq_ring = cq->ring;
 	bool doorbell_pending;
+	bool xdp_redir_flush;
 	struct mlx4_cqe *cqe;
 	struct xdp_buff xdp;
 	int polled = 0;
@@ -682,6 +683,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 	xdp_prog = rcu_dereference_bh(ring->xdp_prog);
 	xdp_init_buff(&xdp, priv->frag_info[0].frag_stride, &ring->xdp_rxq);
 	doorbell_pending = false;
+	xdp_redir_flush = false;
 
 	/* We assume a 1:1 mapping between CQEs and Rx descriptors, so Rx
 	 * descriptor offset can be deduced from the CQE index instead of
@@ -790,6 +792,14 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			switch (act) {
 			case XDP_PASS:
 				break;
+			case XDP_REDIRECT:
+				if (xdp_do_redirect(dev, &xdp, xdp_prog) >= 0) {
+					xdp_redir_flush = true;
+					frags[0].page = NULL;
+					goto next;
+				}
+				trace_xdp_exception(dev, xdp_prog, act);
+				goto xdp_drop_no_cnt;
 			case XDP_TX:
 				if (likely(!mlx4_en_xmit_frame(ring, frags, priv,
 							length, cq_ring,
@@ -897,6 +907,9 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 			break;
 	}
 
+	if (xdp_redir_flush)
+		xdp_do_flush();
+
 	if (likely(polled)) {
 		if (doorbell_pending) {
 			priv->tx_cq[TX_XDP][cq_ring]->xdp_busy = true;