Patch "IB/mlx5: Set correct SL in completion for RoCE" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

IB/mlx5: Set correct SL in completion for RoCE

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ib-mlx5-set-correct-sl-in-completion-for-roce.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Moni Shoua <[email protected]>
Date: Thu, 20 Apr 2017 13:26:54 +0300
Subject: IB/mlx5: Set correct SL in completion for RoCE

From: Moni Shoua <[email protected]>

[ Upstream commit 12f8fedef2ec94c783f929126b20440a01512c14 ]

There is a difference when parsing a completion entry between Ethernet and IB ports. When link layer is Ethernet the bits describe the type of L3 header in the packet. In the case when link layer is Ethernet and VLAN header is present the value of SL is equal to the 3 UP bits in the VLAN header. If VLAN header is not present then the SL is undefined and consumer of the completion should check if IB_WC_WITH_VLAN is set.

While that, this patch also fills the vlan_id field in the completion if present.

---
 drivers/infiniband/hw/mlx5/cq.c |   19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

@@ -172,6 +172,8 @@ static void handle_responder(struct ib_w
 	struct mlx5_ib_srq *srq;
 	struct mlx5_ib_wq *wq;
 	u16 wqe_ctr;
+	u8  roce_packet_type;
+	bool vlan_present;
 	u8 g;
 
 	if (qp->ibqp.srq || qp->ibqp.xrcd) {

@@ -223,7 +225,6 @@ static void handle_responder(struct ib_w
 		break;
 	}
 	wc->slid	   = be16_to_cpu(cqe->slid);
-	wc->sl		   = (be32_to_cpu(cqe->flags_rqpn) >> 24) & 0xf;
 	wc->src_qp	   = be32_to_cpu(cqe->flags_rqpn) & 0xffffff;
 	wc->dlid_path_bits = cqe->ml_path;
 	g = (be32_to_cpu(cqe->flags_rqpn) >> 28) & 3;

@@ -237,10 +238,22 @@ static void handle_responder(struct ib_w
 		wc->pkey_index = 0;
 	}
 
-	if (ll != IB_LINK_LAYER_ETHERNET)
+	if (ll != IB_LINK_LAYER_ETHERNET) {
+		wc->sl = (be32_to_cpu(cqe->flags_rqpn) >> 24) & 0xf;
 		return;
+	}
+
+	vlan_present = cqe->l4_l3_hdr_type & 0x1;
+	roce_packet_type   = (be32_to_cpu(cqe->flags_rqpn) >> 24) & 0x3;
+	if (vlan_present) {
+		wc->vlan_id = (be16_to_cpu(cqe->vlan_info)) & 0xfff;
+		wc->sl = (be16_to_cpu(cqe->vlan_info) >> 13) & 0x7;
+		wc->wc_flags |= IB_WC_WITH_VLAN;
+	} else {
+		wc->sl = 0;
+	}
 
-	switch (wc->sl & 0x3) {
+	switch (roce_packet_type) {
 	case MLX5_CQE_ROCE_L3_HEADER_TYPE_GRH:
 		wc->network_hdr_type = RDMA_NETWORK_IB;
 		break;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/ib-mlx5-set-correct-sl-in-completion-for-roce.patch queue-4.9/ib-rxe-don-t-clamp-residual-length-to-mtu.patch