IB/mlx4: Fix SL to 802.1Q priority-bits mapping for IBoE

For IBoE, SLs 0-7 are mapped to Ethernet 802.1Q user priority bits
(pbits) which are part of the VLAN tag, SLs 8-15 are reserved.

Under Ethernet, the ConnectX firmware treats (decode/encode) the four
bit SL field in various constructs such as QPC / UD WQE / CQE as PPP0
and not as 0PPP. This correlates well to the fact that within the
vlan tag the pbits are located in bits 15-13 and not 12-14.

The current code wasn't consistent around that area - the
encoding was correct for the IBoE QPC.path.schedule_queue field,
but was wrong for IBoE CQEs and when MLX header was built.

These inconsistencies resulted in wrong SL <--> wire 802.1Q pbits
mapping, which is fixed by using SL <--> PPP0 all around the place.

Signed-off-by: Oren Duer <oren@mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

3 files changed, 8 insertions, 4 deletions

diff --git a/drivers/infiniband/hw/mlx4/ah.c b/drivers/infiniband/hw/mlx4/ah.c
index 4b8f9c49397e..a251becdaa98 100644
--- a/drivers/infiniband/hw/mlx4/ah.c
+++ b/drivers/infiniband/hw/mlx4/ah.c
@@ -126,7 +126,7 @@ static struct ib_ah *create_iboe_ah(struct ib_pd *pd, struct ib_ah_attr *ah_attr
                 ah->av.ib.dlid = cpu_to_be16(0xc000);
 
         memcpy(ah->av.eth.dgid, ah_attr->grh.dgid.raw, 16);
-        ah->av.eth.sl_tclass_flowlabel = cpu_to_be32(ah_attr->sl << 28);
+        ah->av.eth.sl_tclass_flowlabel = cpu_to_be32(ah_attr->sl << 29);
 
         return &ah->ibah;
 }
diff --git a/drivers/infiniband/hw/mlx4/cq.c b/drivers/infiniband/hw/mlx4/cq.c
index e8df155bc3b0..5ecf38d97269 100644
--- a/drivers/infiniband/hw/mlx4/cq.c
+++ b/drivers/infiniband/hw/mlx4/cq.c
@@ -715,13 +715,17 @@ repoll:
                 }
 
                 wc->slid           = be16_to_cpu(cqe->rlid);
-                wc->sl             = be16_to_cpu(cqe->sl_vid) >> 12;
                 g_mlpath_rqpn      = be32_to_cpu(cqe->g_mlpath_rqpn);
                 wc->src_qp         = g_mlpath_rqpn & 0xffffff;
                 wc->dlid_path_bits = (g_mlpath_rqpn >> 24) & 0x7f;
                 wc->wc_flags      |= g_mlpath_rqpn & 0x80000000 ? IB_WC_GRH : 0;
                 wc->pkey_index     = be32_to_cpu(cqe->immed_rss_invalid) & 0x7f;
                 wc->csum_ok        = mlx4_ib_ipoib_csum_ok(cqe->status, cqe->checksum);
+                if (rdma_port_get_link_layer(wc->qp->device,
+                                (*cur_qp)->port) == IB_LINK_LAYER_ETHERNET)
+                        wc->sl  = be16_to_cpu(cqe->sl_vid) >> 13;
+                else
+                        wc->sl  = be16_to_cpu(cqe->sl_vid) >> 12;
         }
 
         return 0;
diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index a16f0c8e6f3f..aa2aefa4236c 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -962,7 +962,7 @@ static int mlx4_set_path(struct mlx4_ib_dev *dev, const struct ib_ah_attr *ah,
 
         if (is_eth) {
                 path->sched_queue = MLX4_IB_DEFAULT_SCHED_QUEUE |
-                        ((port - 1) << 6) | ((ah->sl & 7) << 3) | ((ah->sl & 8) >> 1);
+                        ((port - 1) << 6) | ((ah->sl & 7) << 3);
 
                 if (!(ah->ah_flags & IB_AH_GRH))
                         return -1;
@@ -1437,7 +1437,7 @@ static int build_mlx_header(struct mlx4_ib_sqp *sqp, struct ib_send_wr *wr,
                         u16 pcp;
 
                         sqp->ud_header.vlan.type = cpu_to_be16(MLX4_IB_IBOE_ETHERTYPE);
-                        pcp = (be32_to_cpu(ah->av.ib.sl_tclass_flowlabel) >> 27 & 3) << 13;
+                        pcp = (be32_to_cpu(ah->av.ib.sl_tclass_flowlabel) >> 29) << 13;
                         sqp->ud_header.vlan.tag = cpu_to_be16(vlan | pcp);
                 }
         } else {