[dpdk-dev] [PATCH 5/5] net/mlx4: add loopback Tx from VF

[Moti Haimovsky <motih@mellanox.com>]

Added loopback functionality use when the chip is a VF in order to
enable packet transmission between VFs and between VFs and PF.

Signed-off-by: Moti Haimovsky <motih@mellanox.com>
---
 drivers/net/mlx4/mlx4_prm.h  |  2 +-
 drivers/net/mlx4/mlx4_rxtx.c | 28 ++++++++++++++++++++++------
 drivers/net/mlx4/mlx4_rxtx.h |  2 ++
 drivers/net/mlx4/mlx4_txq.c  |  2 ++
 4 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/drivers/net/mlx4/mlx4_prm.h b/drivers/net/mlx4/mlx4_prm.h
index 38e9a45..e328cff 100644
--- a/drivers/net/mlx4/mlx4_prm.h
+++ b/drivers/net/mlx4/mlx4_prm.h
@@ -168,7 +168,7 @@
 		  uint32_t srcrb_flags, uint32_t imm)
 {
 	seg->fence_size = fence_size;
-	seg->srcrb_flags = rte_cpu_to_be_32(srcrb_flags);
+	seg->srcrb_flags = srcrb_flags;
 	/*
 	 * The caller should prepare "imm" in advance based on WR opcode.
 	 * For IBV_WR_SEND_WITH_IMM and IBV_WR_RDMA_WRITE_WITH_IMM,
diff --git a/drivers/net/mlx4/mlx4_rxtx.c b/drivers/net/mlx4/mlx4_rxtx.c
index 3415f63..ed19c72 100644
--- a/drivers/net/mlx4/mlx4_rxtx.c
+++ b/drivers/net/mlx4/mlx4_rxtx.c
@@ -426,7 +426,11 @@
 	struct mlx4_wqe_data_seg *dseg;
 	struct mlx4_sq *sq = &txq->msq;
 	struct ibv_sge sge[wr->num_sge];
-	uint32_t srcrb_flags;
+	union {
+		uint32_t flags;
+		uint16_t flags16[2];
+	} srcrb;
+	uint32_t imm = 0;
 	uint8_t fence_size;
 	uint32_t head_idx = sq->head & sq->txbb_cnt_mask;
 	uint32_t owner_opcode;
@@ -466,10 +470,10 @@
 	/*  Request Tx completion. */
 	txq->elts_comp_cd -= nr_txbbs;
 	if (unlikely(txq->elts_comp_cd <= 0)) {
-		srcrb_flags = MLX4_WQE_CTRL_SOLICIT | MLX4_WQE_CTRL_CQ_UPDATE;
+		srcrb.flags = MLX4_WQE_CTRL_SOLICIT | MLX4_WQE_CTRL_CQ_UPDATE;
 		txq->elts_comp_cd = txq->elts_comp_cd_init;
 	} else {
-		srcrb_flags = MLX4_WQE_CTRL_SOLICIT;
+		srcrb.flags = MLX4_WQE_CTRL_SOLICIT;
 	}
 	fence_size = (wr->send_flags & IBV_SEND_FENCE ?
 		MLX4_WQE_CTRL_FENCE : 0) | ((wqe_real_size / 16) & 0x3f);
@@ -487,14 +491,26 @@
 			owner_opcode |= MLX4_WQE_CTRL_IIP_HDR_CSUM |
 					MLX4_WQE_CTRL_IL4_HDR_CSUM;
 			if (pkt->ol_flags & PKT_TX_OUTER_IP_CKSUM)
-				srcrb_flags |= MLX4_WQE_CTRL_IP_HDR_CSUM;
+				srcrb.flags |= MLX4_WQE_CTRL_IP_HDR_CSUM;
 		} else {
-			srcrb_flags |= MLX4_WQE_CTRL_IP_HDR_CSUM |
+			srcrb.flags |= MLX4_WQE_CTRL_IP_HDR_CSUM |
 				      MLX4_WQE_CTRL_TCP_UDP_CSUM;
 		}
 	}
+	/* convert flags to BE before adding the mac address (if at all)
+	 * to it
+	 */
+	srcrb.flags = rte_cpu_to_be_32(srcrb.flags);
+	/* Copy dst mac address to wqe. This allows loopback in eSwitch,
+	 * so that VFs and PF can communicate with each other
+	 */
+	if (txq->lb) {
+		srcrb.flags16[0] = *(rte_pktmbuf_mtod(pkt, uint16_t *));
+		imm = *(rte_pktmbuf_mtod_offset(pkt, uint32_t *,
+						sizeof(uint16_t)));
+	}
 	/* fill in ctrl info but ownership */
-	mlx4_set_ctrl_seg(ctrl, fence_size, srcrb_flags, 0);
+	mlx4_set_ctrl_seg(ctrl, fence_size, srcrb.flags, imm);
 	/* If we used a bounce buffer then copy wqe back into sq */
 	if (unlikely(bounce))
 		ctrl = mlx4_bounce_to_desc(txq, head_idx, wqe_size);
diff --git a/drivers/net/mlx4/mlx4_rxtx.h b/drivers/net/mlx4/mlx4_rxtx.h
index b4675b7..8e407f5 100644
--- a/drivers/net/mlx4/mlx4_rxtx.h
+++ b/drivers/net/mlx4/mlx4_rxtx.h
@@ -148,6 +148,8 @@ struct txq {
 	struct mlx4_cq mcq; /**< Info for directly manipulating the CQ. */
 	uint16_t tunnel_en:1;
 	/* When set TX offload for tunneled packets are supported. */
+	uint16_t lb:1;
+	/* Whether pkts should be looped-back by eswitch or not */
 	char *bounce_buf; /**< Side memory to be used when wqe wraps around */
 };
 
diff --git a/drivers/net/mlx4/mlx4_txq.c b/drivers/net/mlx4/mlx4_txq.c
index cecd5e8..296d72d 100644
--- a/drivers/net/mlx4/mlx4_txq.c
+++ b/drivers/net/mlx4/mlx4_txq.c
@@ -410,6 +410,8 @@ struct txq_mp2mr_mbuf_check_data {
 		      (void *)dev, strerror(rte_errno));
 		goto error;
 	}
+	/* If a VF device - need to loopback xmitted packets */
+	tmpl.lb = !!(priv->vf);
 	/* Clean up txq in case we're reinitializing it. */
 	DEBUG("%p: cleaning-up old txq just in case", (void *)txq);
 	mlx4_txq_cleanup(txq);
-- 
1.8.3.1