RDMA/core: Simplify rdma_addr_get_sgid() to not support RoCE

Now that all callers who care about RoCE addresses have been
converted to use rdma_read_gids() simplify rdma_addr_get_sgid()
to only support real GID addresses.

Callers should only use it for OPA and IB transports.

The now deleted implementation for RoCE has several bugs related to IPv6
support and incorrect/inconsistent 'GID' addresses compared to the CM
paths.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

include/rdma/ib_addr.h

@@ -197,34 +197,15 @@ static inline void rdma_gid2ip(struct sockaddr *out, const union ib_gid *gid)
 	}
 }
 
-static inline void iboe_addr_get_sgid(struct rdma_dev_addr *dev_addr,
-				      union ib_gid *gid)
-{
-	struct net_device *dev;
-	struct in_device *ip4;
-
-	dev = dev_get_by_index(&init_net, dev_addr->bound_dev_if);
-	if (dev) {
-		ip4 = in_dev_get(dev);
-		if (ip4 && ip4->ifa_list && ip4->ifa_list->ifa_address)
-			ipv6_addr_set_v4mapped(ip4->ifa_list->ifa_address,
-					       (struct in6_addr *)gid);
-
-		if (ip4)
-			in_dev_put(ip4);
-
-		dev_put(dev);
-	}
-}
-
+/*
+ * rdma_get/set_sgid/dgid() APIs are applicable to IB, and iWarp.
+ * They are not applicable to RoCE.
+ * RoCE GIDs are derived from the IP addresses.
+ */
 static inline void rdma_addr_get_sgid(struct rdma_dev_addr *dev_addr, union ib_gid *gid)
 {
-	if (dev_addr->transport == RDMA_TRANSPORT_IB &&
-	    dev_addr->dev_type != ARPHRD_INFINIBAND)
-		iboe_addr_get_sgid(dev_addr, gid);
-	else
-		memcpy(gid, dev_addr->src_dev_addr +
-		       rdma_addr_gid_offset(dev_addr), sizeof *gid);
+	memcpy(gid, dev_addr->src_dev_addr + rdma_addr_gid_offset(dev_addr),
+	       sizeof(*gid));
 }
 
 static inline void rdma_addr_set_sgid(struct rdma_dev_addr *dev_addr, union ib_gid *gid)