From: Majd Dibbiny <majd@mellanox.com>
Date: Thu, 22 Mar 2018 15:34:03 +0200
Subject: IB/mlx5: Enable ECN capable bits for UD RoCE v2 QPs
Patch-mainline: v4.17-rc1
Git-commit: ea8af0d2f2b5b16da4553205ddaf225e0a057e03
References: bsc#1046305 FATE#322943

When working with RC QPs, the FW sets the ECN capable bits for all
the RoCE v2 packets. On the other hand, for UD QPs, the driver needs
to set the the ECN capable bits in the Address Handler since the HW
generates each packet according to the Address Handler and not
the QP context.

If ECN is not enabled in NIC or switch, these bits are ignored.

Fixes: 2811ba51b049 ("IB/mlx5: Add RoCE fields to Address Vector")
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/mlx5/ah.c |   12 ++++++++++++
 1 file changed, 12 insertions(+)

--- a/drivers/infiniband/hw/mlx5/ah.c
+++ b/drivers/infiniband/hw/mlx5/ah.c
@@ -36,6 +36,9 @@ static struct ib_ah *create_ib_ah(struct
 				  struct mlx5_ib_ah *ah,
 				  struct rdma_ah_attr *ah_attr)
 {
+	enum ib_gid_type gid_type;
+	int err;
+
 	if (rdma_ah_get_ah_flags(ah_attr) & IB_AH_GRH) {
 		const struct ib_global_route *grh = rdma_ah_read_grh(ah_attr);
 
@@ -50,6 +53,12 @@ static struct ib_ah *create_ib_ah(struct
 	ah->av.stat_rate_sl = (rdma_ah_get_static_rate(ah_attr) << 4);
 
 	if (ah_attr->type == RDMA_AH_ATTR_TYPE_ROCE) {
+		err = mlx5_get_roce_gid_type(dev, ah_attr->port_num,
+					     ah_attr->grh.sgid_index,
+					     &gid_type);
+		if (err)
+			return ERR_PTR(err);
+
 		memcpy(ah->av.rmac, ah_attr->roce.dmac,
 		       sizeof(ah_attr->roce.dmac));
 		ah->av.udp_sport =
@@ -57,6 +66,9 @@ static struct ib_ah *create_ib_ah(struct
 					rdma_ah_get_port_num(ah_attr),
 					rdma_ah_read_grh(ah_attr)->sgid_index);
 		ah->av.stat_rate_sl |= (rdma_ah_get_sl(ah_attr) & 0x7) << 1;
+		if (gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP)
+#define MLX5_ECN_ENABLED BIT(1)
+			ah->av.tclass |= MLX5_ECN_ENABLED;
 	} else {
 		ah->av.rlid = cpu_to_be16(rdma_ah_get_dlid(ah_attr));
 		ah->av.fl_mlid = rdma_ah_get_path_bits(ah_attr) & 0x7f;