RDMA/hns: Get udp sport num dynamically instead of using a fixed value

The UDP source port number in RoCE v2 is used to create entropy for
network routers (ECMP), load balancers and 802.3ad link aggregation
switching that are not aware of RoCE IB headers. Considering that the IB
core has achieved a new interface to get a hashed value of it, the fixed
value of it in QPC and UD WQE in hns driver could be fixed and the port
number is to be set dynamically now.

For QPC of RC, the value could be hashed from flow_lable if the user pass
it in or from remote qpn and local qpn. For WQE of UD, it is set according
to fl or as a random value.

Link: https://lore.kernel.org/r/1598002289-8611-1-git-send-email-liweihang@huawei.comSigned-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/hns/hns_roce_ah.c

@@ -39,6 +39,22 @@
 #define HNS_ROCE_VLAN_SL_BIT_MASK	7
 #define HNS_ROCE_VLAN_SL_SHIFT		13
 
+static inline u16 get_ah_udp_sport(const struct rdma_ah_attr *ah_attr)
+{
+	u32 fl = ah_attr->grh.flow_label;
+	u16 sport;
+
+	if (!fl)
+		sport = get_random_u32() %
+			(IB_ROCE_UDP_ENCAP_VALID_PORT_MAX + 1 -
+			 IB_ROCE_UDP_ENCAP_VALID_PORT_MIN) +
+			IB_ROCE_UDP_ENCAP_VALID_PORT_MIN;
+	else
+		sport = rdma_flow_label_to_udp_sport(fl);
+
+	return sport;
+}
+
 int hns_roce_create_ah(struct ib_ah *ibah, struct rdma_ah_init_attr *init_attr,
 		       struct ib_udata *udata)
 {
@@ -79,6 +95,8 @@ int hns_roce_create_ah(struct ib_ah *ibah, struct rdma_ah_init_attr *init_attr,
 
 	memcpy(ah->av.dgid, grh->dgid.raw, HNS_ROCE_GID_SIZE);
 	ah->av.sl = rdma_ah_get_sl(ah_attr);
+	ah->av.flowlabel = grh->flow_label;
+	ah->av.udp_sport = get_ah_udp_sport(ah_attr);
 
 	return 0;
 }

drivers/infiniband/hw/hns/hns_roce_device.h

@@ -537,17 +537,18 @@ struct hns_roce_raq_table {
 };
 
 struct hns_roce_av {
-	u8          port;
-	u8          gid_index;
-	u8          stat_rate;
-	u8          hop_limit;
-	u32         flowlabel;
-	u8          sl;
-	u8          tclass;
-	u8          dgid[HNS_ROCE_GID_SIZE];
-	u8          mac[ETH_ALEN];
-	u16         vlan_id;
-	bool	    vlan_en;
+	u8 port;
+	u8 gid_index;
+	u8 stat_rate;
+	u8 hop_limit;
+	u32 flowlabel;
+	u16 udp_sport;
+	u8 sl;
+	u8 tclass;
+	u8 dgid[HNS_ROCE_GID_SIZE];
+	u8 mac[ETH_ALEN];
+	u16 vlan_id;
+	bool vlan_en;
 };
 
 struct hns_roce_ah {

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -369,7 +369,7 @@ static inline int set_ud_wqe(struct hns_roce_qp *qp,
 		       curr_idx & (qp->sge.sge_cnt - 1));
 
 	roce_set_field(ud_sq_wqe->byte_24, V2_UD_SEND_WQE_BYTE_24_UDPSPN_M,
-		       V2_UD_SEND_WQE_BYTE_24_UDPSPN_S, 0);
+		       V2_UD_SEND_WQE_BYTE_24_UDPSPN_S, ah->av.udp_sport);
 	ud_sq_wqe->qkey = cpu_to_le32(ud_wr(wr)->remote_qkey & 0x80000000 ?
 			  qp->qkey : ud_wr(wr)->remote_qkey);
 	roce_set_field(ud_sq_wqe->byte_32, V2_UD_SEND_WQE_BYTE_32_DQPN_M,
@@ -4165,6 +4165,14 @@ static int modify_qp_rtr_to_rts(struct ib_qp *ibqp,
 	return 0;
 }
 
+static inline u16 get_udp_sport(u32 fl, u32 lqpn, u32 rqpn)
+{
+	if (!fl)
+		fl = rdma_calc_flow_label(lqpn, rqpn);
+
+	return rdma_flow_label_to_udp_sport(fl);
+}
+
 static int hns_roce_v2_set_path(struct ib_qp *ibqp,
 				const struct ib_qp_attr *attr,
 				int attr_mask,
@@ -4228,7 +4236,8 @@ static int hns_roce_v2_set_path(struct ib_qp *ibqp,
 
 	roce_set_field(context->byte_52_udpspn_dmac, V2_QPC_BYTE_52_UDPSPN_M,
 		       V2_QPC_BYTE_52_UDPSPN_S,
-		       is_udp ? 0x12b7 : 0);
+		       is_udp ? get_udp_sport(grh->flow_label, ibqp->qp_num,
+					      attr->dest_qp_num) : 0);
 
 	roce_set_field(qpc_mask->byte_52_udpspn_dmac, V2_QPC_BYTE_52_UDPSPN_M,
 		       V2_QPC_BYTE_52_UDPSPN_S, 0);

include/rdma/ib_verbs.h

@@ -4706,6 +4706,7 @@ bool rdma_dev_access_netns(const struct ib_device *device,
 			   const struct net *net);
 
 #define IB_ROCE_UDP_ENCAP_VALID_PORT_MIN (0xC000)
+#define IB_ROCE_UDP_ENCAP_VALID_PORT_MAX (0xFFFF)
 #define IB_GRH_FLOWLABEL_MASK (0x000FFFFF)
 
 /**