IB/mlx4: Fix possible vl/sl field mismatch in LRH header in QP1 packets

In MLX qp packets, the LRH (built by the driver) has both a VL field
and an SL field. When building a QP1 packet, the VL field should
reflect the SLtoVL mapping and not arbitrarily contain zero (as is
done now). This bug causes credit problems in IB switches at
high rates of QP1 packets.

The fix is to cache the SL to VL mapping in the driver, and look up
the VL mapped to the SL provided in the send request when sending
QP1 packets.

For FW versions which support generating a port_management_config_change
event with subtype sl-to-vl-table-change, the driver uses that event
to update its sl-to-vl mapping cache.  Otherwise, the driver snoops
incoming SMP mads to update the cache.

There remains the case where the FW is running in secure-host mode
(so no QP0 packets are delivered to the driver), and the FW does not
generate the sl2vl mapping change event. To support this case, the
driver updates (via querying the FW) its sl2vl mapping cache when
running in secure-host mode when it receives either a Port Up event
or a client-reregister event (where the port is still up, but there
may have been an opensm failover).
OpenSM modifies the sl2vl mapping before Port Up and Client-reregister
events occur, so if there is a mapping change the driver's cache will
be properly updated.

Fixes: 225c7b1feef1 ("IB/mlx4: Add a driver Mellanox ConnectX InfiniBand adapters")
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/mlx4/mlx4_ib.h b/drivers/infiniband/hw/mlx4/mlx4_ib.h
index 7c5832ede4bd..8db7cb1a3716 100644
--- a/drivers/infiniband/hw/mlx4/mlx4_ib.h
+++ b/drivers/infiniband/hw/mlx4/mlx4_ib.h
@@ -570,6 +570,7 @@ struct mlx4_ib_dev {
 	struct ib_mad_agent    *send_agent[MLX4_MAX_PORTS][2];
 	struct ib_ah	       *sm_ah[MLX4_MAX_PORTS];
 	spinlock_t		sm_lock;
+	atomic64_t		sl2vl[MLX4_MAX_PORTS];
 	struct mlx4_ib_sriov	sriov;
 
 	struct mutex		cap_mask_mutex;
@@ -600,6 +601,7 @@ struct ib_event_work {
 	struct work_struct	work;
 	struct mlx4_ib_dev	*ib_dev;
 	struct mlx4_eqe		ib_eqe;
+	int			port;
 };
 
 struct mlx4_ib_qp_tunnel_init_attr {
@@ -883,4 +885,9 @@ int mlx4_ib_rereg_user_mr(struct ib_mr *mr, int flags,
 int mlx4_ib_gid_index_to_real_index(struct mlx4_ib_dev *ibdev,
 				    u8 port_num, int index);
 
+void mlx4_sched_ib_sl2vl_update_work(struct mlx4_ib_dev *ibdev,
+				     int port);
+
+void mlx4_ib_sl2vl_update(struct mlx4_ib_dev *mdev, int port);
+
 #endif /* MLX4_IB_H */