RDMA/cma: Always set static rate to 0 for RoCE

Set static rate to 0 as it should be discovered by path query and
has no meaning for RoCE.
This also avoid of using the rtnl lock and ethtool API, which is
a bottleneck when try to setup many rdma-cm connections at the same
time, especially with multiple processes.

Fixes: 3c86aa7 ("RDMA/cm: Add RDMA CM support for IBoE devices")
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Link: https://lore.kernel.org/r/f72a4f8b667b803aee9fa794069f61afb5839ce4.1685960567.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: MarkZhang81

drivers/infiniband/core/cma.c

@@ -3295,7 +3295,7 @@ static int cma_resolve_iboe_route(struct rdma_id_private *id_priv)
 	route->path_rec->traffic_class = tos;
 	route->path_rec->mtu = iboe_get_mtu(ndev->mtu);
 	route->path_rec->rate_selector = IB_SA_EQ;
-	route->path_rec->rate = iboe_get_rate(ndev);
+	route->path_rec->rate = IB_RATE_PORT_CURRENT;
 	dev_put(ndev);
 	route->path_rec->packet_life_time_selector = IB_SA_EQ;
 	/* In case ACK timeout is set, use this value to calculate
@@ -4964,7 +4964,7 @@ static int cma_iboe_join_multicast(struct rdma_id_private *id_priv,
 	if (!ndev)
 		return -ENODEV;
 
-	ib.rec.rate = iboe_get_rate(ndev);
+	ib.rec.rate = IB_RATE_PORT_CURRENT;
 	ib.rec.hop_limit = 1;
 	ib.rec.mtu = iboe_get_mtu(ndev->mtu);
 

include/rdma/ib_addr.h

@@ -194,29 +194,6 @@ static inline enum ib_mtu iboe_get_mtu(int mtu)
 		return 0;
 }
 
-static inline int iboe_get_rate(struct net_device *dev)
-{
-	struct ethtool_link_ksettings cmd;
-	int err;
-
-	rtnl_lock();
-	err = __ethtool_get_link_ksettings(dev, &cmd);
-	rtnl_unlock();
-	if (err)
-		return IB_RATE_PORT_CURRENT;
-
-	if (cmd.base.speed >= 40000)
-		return IB_RATE_40_GBPS;
-	else if (cmd.base.speed >= 30000)
-		return IB_RATE_30_GBPS;
-	else if (cmd.base.speed >= 20000)
-		return IB_RATE_20_GBPS;
-	else if (cmd.base.speed >= 10000)
-		return IB_RATE_10_GBPS;
-	else
-		return IB_RATE_PORT_CURRENT;
-}
-
 static inline int rdma_link_local_addr(struct in6_addr *addr)
 {
 	if (addr->s6_addr32[0] == htonl(0xfe800000) &&