OFED: A few channges from Linux 5.0

The main point of these changes is the last commit adding a couple of
helper functions used in ROCE drivers.

This contains changes from the following Linux commits:

a70c07397fd8 RDMA: Introduce and use GID attr helper to read RoCE L2 fields
8f9748602491 IB/cm: Reduce dependency on gid attribute ndev check
adb4a57a7a1d RDMA/cma: Use rdma_read_gid_attr_ndev_rcu to access netdev
b4fb4cc5ba83 RDMA/cma: Fix unbalanced cm_id reference count during address resolve
d5665a21250e RDMA/core: Add hash functions to calculate RoCEv2 flowlabel and UDP source port

Tested by:	Wafa Hamzah <[email protected]> (mlx5_ib)
Tested by:	John Baldwin <[email protected]> (iw_cxgbe)
Sponsored by:	Chelsio Communications

sys/dev/bnxt/bnxt_re/ib_verbs.c

@@ -517,8 +517,10 @@ int bnxt_re_add_gid(const struct ib_gid_attr *attr, void **context)
 	struct bnxt_re_gid_ctx *ctx, **ctx_tbl;
 	struct bnxt_re_dev *rdev = to_bnxt_re_dev(attr->device, ibdev);
 	struct bnxt_qplib_sgid_tbl *sgid_tbl = &rdev->qplib_res.sgid_tbl;
-	if ((attr->ndev) && is_vlan_dev(attr->ndev))
-		vlan_id = vlan_dev_vlan_id(attr->ndev);
+
+	rc = rdma_read_gid_l2_fields(attr, &vlan_id, NULL);
+	if (rc)
+		return rc;
 
 	rc = bnxt_qplib_add_sgid(sgid_tbl, &attr->gid,
 				 rdev->dev_addr,
@@ -936,13 +938,11 @@ static int bnxt_re_get_ah_info(struct bnxt_re_dev *rdev,
 	ah_info->sgid = gattr->gid;
 
 	/* Get vlan tag */
-	if (gattr->ndev) {
-		if (is_vlan_dev(gattr->ndev))
-			ah_info->vlan_tag = vlan_dev_vlan_id(gattr->ndev);
-	}
+	rc = rdma_read_gid_l2_fields(gattr, &ah_info->vlan_tag, NULL);
+	if (rc)
+		return rc;
 
 	/* Get network header type for this GID */
-
 	ib_ntype = rdma_gid_attr_network_type(gattr);
 	ntype = _to_bnxt_re_nw_type(ib_ntype);
 	ah_info->nw_type = ntype;
@@ -2649,8 +2649,11 @@ int bnxt_re_modify_qp(struct ib_qp *ib_qp, struct ib_qp_attr *qp_attr,
 		sgid_attr = grh->sgid_attr;
 		gid_ptr = &sgid_attr->gid;
 		if (sgid_attr->ndev) {
-			memcpy(qp->qplib_qp.smac, rdev->dev_addr,
-			       ETH_ALEN);
+			rc = rdma_read_gid_l2_fields(sgid_attr, NULL,
+						     &qp->qplib_qp.smac[0]);
+			if (rc)
+				return rc;
+
 			nw_type = rdma_gid_attr_network_type(sgid_attr);
 			dev_dbg(rdev_to_dev(rdev),
 				 "Connection using the nw_type %d\n", nw_type);

sys/dev/mlx4/mlx4_ib/mlx4_ib_ah.c

@@ -95,9 +95,11 @@ static int create_iboe_ah(struct ib_ah *ib_ah, struct rdma_ah_attr *ah_attr)
 	memcpy(ah->av.eth.mac, ah_attr->roce.dmac, ETH_ALEN);
 	eth_zero_addr(ah->av.eth.s_mac);
 	gid_attr = ah_attr->grh.sgid_attr;
-	vlan_tag = rdma_vlan_dev_vlan_id(gid_attr->ndev);
-	memcpy(ah->av.eth.s_mac, if_getlladdr(gid_attr->ndev), ETH_ALEN);
-
+	ret = rdma_read_gid_l2_fields(gid_attr, &vlan_tag,
+				      &ah->av.eth.s_mac[0]);
+	if (ret)
+		return ret;
+	
 	if (vlan_tag < 0x1000)
 		vlan_tag |= (rdma_ah_get_sl(ah_attr) & 7) << 13;
 	ah->av.eth.port_pd = cpu_to_be32(to_mpd(pd)->pdn |

sys/dev/mlx4/mlx4_ib/mlx4_ib_qp.c

@@ -1780,8 +1780,10 @@ static int __mlx4_ib_modify_qp(struct ib_qp *ibqp,
 
 		if (is_eth) {
 			gid_attr = attr->ah_attr.grh.sgid_attr;
-			vlan = rdma_vlan_dev_vlan_id(gid_attr->ndev);
-			memcpy(smac, if_getlladdr(gid_attr->ndev), ETH_ALEN);
+			err = rdma_read_gid_l2_fields(gid_attr, &vlan,
+						      &smac[0]);
+			if (err)
+				goto out;
 		}
 
 		if (mlx4_set_path(dev, attr, attr_mask, qp, &context->pri_path,

sys/dev/mlx5/mlx5_ib/mlx5_ib_main.c

@@ -368,12 +368,16 @@ static void ib_gid_to_mlx5_roce_addr(const union ib_gid *gid,
 	void *mlx5_addr_mac	= MLX5_ADDR_OF(roce_addr_layout, mlx5_addr,
 					       source_mac_47_32);
 	u16 vlan_id;
+	int ret;
 
 	if (!gid)
 		return;
-	ether_addr_copy(mlx5_addr_mac, if_getlladdr(attr->ndev));
 
-	vlan_id = rdma_vlan_dev_vlan_id(attr->ndev);
+
+	ret = rdma_read_gid_l2_fields(attr, &vlan_id, mlx5_addr_mac);
+	if (ret != 0)
+		return;
+
 	if (vlan_id != 0xffff) {
 		MLX5_SET_RA(mlx5_addr, vlan_valid, 1);
 		MLX5_SET_RA(mlx5_addr, vlan_id, vlan_id);

sys/ofed/drivers/infiniband/core/ib_addr.c

@@ -45,6 +45,7 @@
 #include <net/route/nhop.h>
 #include <net/netevent.h>
 #include <rdma/ib_addr.h>
+#include <rdma/ib_cache.h>
 #include <rdma/ib_sa.h>
 #include <rdma/ib.h>
 

sys/ofed/drivers/infiniband/core/ib_cache.c

@@ -38,6 +38,7 @@
 #include <sys/cdefs.h>
 #include <linux/module.h>
 #include <linux/errno.h>
+#include <linux/etherdevice.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 #include <linux/netdevice.h>
@@ -1297,6 +1298,37 @@ if_t rdma_read_gid_attr_ndev_rcu(const struct ib_gid_attr *attr)
 	read_unlock_irqrestore(&table->rwlock, flags);
 	return ndev;
 }
+EXPORT_SYMBOL(rdma_read_gid_attr_ndev_rcu);
+
+/**
+ * rdma_read_gid_l2_fields - Read the vlan ID and source MAC address
+ *			     of a GID entry.
+ *
+ * @attr:	GID attribute pointer whose L2 fields to be read
+ * @vlan_id:	Pointer to vlan id to fill up if the GID entry has
+ *		vlan id. It is optional.
+ * @smac:	Pointer to smac to fill up for a GID entry. It is optional.
+ *
+ * rdma_read_gid_l2_fields() returns 0 on success and returns vlan id
+ * (if gid entry has vlan) and source MAC, or returns error.
+ */
+int rdma_read_gid_l2_fields(const struct ib_gid_attr *attr,
+			    u16 *vlan_id, u8 *smac)
+{
+	if_t ndev;
+
+	ndev = attr->ndev;
+	if (!ndev)
+		return -EINVAL;
+
+	if (smac)
+		ether_addr_copy(smac, if_getlladdr(ndev));
+	if (vlan_id) {
+		*vlan_id = rdma_vlan_dev_vlan_id(ndev);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(rdma_read_gid_l2_fields);
 
 static int config_non_roce_gid_cache(struct ib_device *device,
 				     u8 port, int gid_tbl_len)

sys/ofed/drivers/infiniband/core/ib_cm.c

@@ -1985,11 +1985,12 @@ static int cm_req_handler(struct cm_work *work)
 	grh = rdma_ah_read_grh(&cm_id_priv->av.ah_attr);
 	gid_attr = grh->sgid_attr;
 
-	if (gid_attr && gid_attr->ndev) {
+	if (gid_attr &&
+	    rdma_protocol_roce(work->port->cm_dev->ib_device,
+			       work->port->port_num)) {
 		work->path[0].rec_type =
 			sa_conv_gid_to_pathrec_type(gid_attr->gid_type);
 	} else {
-		/* If no GID attribute or ndev is null, it is not RoCE. */
 		cm_path_set_rec_type(work->port->cm_dev->ib_device,
 				     work->port->port_num,
 				     &work->path[0],

sys/ofed/drivers/infiniband/core/ib_cma.c

@@ -1537,6 +1537,7 @@ static if_t
 roce_get_net_dev_by_cm_event(const struct ib_cm_event *ib_event)
 {
 	const struct ib_gid_attr *sgid_attr = NULL;
+	if_t ndev;
 
 	if (ib_event->event == IB_CM_REQ_RECEIVED)
 		sgid_attr = ib_event->param.req_rcvd.ppath_sgid_attr;
@@ -1545,8 +1546,15 @@ roce_get_net_dev_by_cm_event(const struct ib_cm_event *ib_event)
 
 	if (!sgid_attr)
 		return NULL;
-	dev_hold(sgid_attr->ndev);
-	return sgid_attr->ndev;
+
+	rcu_read_lock();
+	ndev = rdma_read_gid_attr_ndev_rcu(sgid_attr);
+	if (IS_ERR(ndev))
+		ndev = NULL;
+	else
+		dev_hold(ndev);
+	rcu_read_unlock();
+	return ndev;
 }
 
 static if_t cma_get_net_dev(const struct ib_cm_event *ib_event,
@@ -3095,6 +3103,7 @@ static int cma_resolve_loopback(struct rdma_id_private *id_priv)
 	rdma_addr_get_sgid(&id_priv->id.route.addr.dev_addr, &gid);
 	rdma_addr_set_dgid(&id_priv->id.route.addr.dev_addr, &gid);
 
+	atomic_inc(&id_priv->refcount);
 	cma_init_resolve_addr_work(work, id_priv);
 	queue_work(cma_wq, &work->work);
 	return 0;
@@ -3121,6 +3130,7 @@ static int cma_resolve_ib_addr(struct rdma_id_private *id_priv)
 	rdma_addr_set_dgid(&id_priv->id.route.addr.dev_addr, (union ib_gid *)
 		&(((struct sockaddr_ib *) &id_priv->id.route.addr.dst_addr)->sib_addr));
 
+	atomic_inc(&id_priv->refcount);
 	cma_init_resolve_addr_work(work, id_priv);
 	queue_work(cma_wq, &work->work);
 	return 0;

sys/ofed/include/rdma/ib_cache.h

@@ -56,6 +56,10 @@ const struct ib_gid_attr *rdma_find_gid_by_filter(
 		       void *),
 	void *context);
 
+int rdma_read_gid_l2_fields(const struct ib_gid_attr *attr,
+			    u16 *vlan_id, u8 *smac);
+if_t rdma_read_gid_attr_ndev_rcu(const struct ib_gid_attr *attr);
+
 /**
  * ib_get_cached_pkey - Returns a cached PKey table entry
  * @device: The device to query.

sys/ofed/include/rdma/ib_verbs.h

@@ -4179,4 +4179,48 @@ static inline __be16 ib_lid_be16(u32 lid)
 	WARN_ON_ONCE(lid & 0xFFFF0000);
 	return cpu_to_be16((u16)lid);
 }
+
+#define IB_ROCE_UDP_ENCAP_VALID_PORT_MIN (0xC000)
+#define IB_GRH_FLOWLABEL_MASK (0x000FFFFF)
+
+/**
+ * rdma_flow_label_to_udp_sport - generate a RoCE v2 UDP src port value based
+ *                               on the flow_label
+ *
+ * This function will convert the 20 bit flow_label input to a valid RoCE v2
+ * UDP src port 14 bit value. All RoCE V2 drivers should use this same
+ * convention.
+ */
+static inline u16 rdma_flow_label_to_udp_sport(u32 fl)
+{
+	u32 fl_low = fl & 0x03fff, fl_high = fl & 0xFC000;
+
+	fl_low ^= fl_high >> 14;
+	return (u16)(fl_low | IB_ROCE_UDP_ENCAP_VALID_PORT_MIN);
+}
+
+/**
+ * rdma_calc_flow_label - generate a RDMA symmetric flow label value based on
+ *                        local and remote qpn values
+ *
+ * This function folded the multiplication results of two qpns, 24 bit each,
+ * fields, and converts it to a 20 bit results.
+ *
+ * This function will create symmetric flow_label value based on the local
+ * and remote qpn values. this will allow both the requester and responder
+ * to calculate the same flow_label for a given connection.
+ *
+ * This helper function should be used by driver in case the upper layer
+ * provide a zero flow_label value. This is to improve entropy of RDMA
+ * traffic in the network.
+ */
+static inline u32 rdma_calc_flow_label(u32 lqpn, u32 rqpn)
+{
+	u64 v = (u64)lqpn * rqpn;
+
+	v ^= v >> 20;
+	v ^= v >> 40;
+
+	return (u32)(v & IB_GRH_FLOWLABEL_MASK);
+}
 #endif /* IB_VERBS_H */