IB/mlx4: Fix use of flow-counters for process_mad

For IB links, reading HCA flow counters through iboe_process_mad() should
be used when mlx4_ib_process_mad() is invoked only for VFs PMA queries and
exactly nothing else.

Fixes: 7193a141eb74 ('IB/mlx4: Set VF to read from QP counters')
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c
index 9a810e3..68b3dfa 100644 (file)
--- a/drivers/infiniband/hw/mlx4/mad.c
+++ b/drivers/infiniband/hw/mlx4/mad.c
@@ -860,22 +860,31 @@ int mlx4_ib_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
        struct mlx4_ib_dev *dev = to_mdev(ibdev);
        const struct ib_mad *in_mad = (const struct ib_mad *)in;
        struct ib_mad *out_mad = (struct ib_mad *)out;
+       enum rdma_link_layer link = rdma_port_get_link_layer(ibdev, port_num);
 
        if (WARN_ON_ONCE(in_mad_size != sizeof(*in_mad) ||
                         *out_mad_size != sizeof(*out_mad)))
                return IB_MAD_RESULT_FAILURE;
 
-       switch (rdma_port_get_link_layer(ibdev, port_num)) {
-       case IB_LINK_LAYER_INFINIBAND:
-               if (!mlx4_is_slave(dev->dev))
-                       return ib_process_mad(ibdev, mad_flags, port_num, in_wc,
-                                             in_grh, in_mad, out_mad);
-       case IB_LINK_LAYER_ETHERNET:
-               return iboe_process_mad(ibdev, mad_flags, port_num, in_wc,
-                                         in_grh, in_mad, out_mad);
-       default:
-               return -EINVAL;
+       /* iboe_process_mad() which uses the HCA flow-counters to implement IB PMA
+        * queries, should be called only by VFs and for that specific purpose
+        */
+       if (link == IB_LINK_LAYER_INFINIBAND) {
+               if (mlx4_is_slave(dev->dev) &&
+                   in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_PERF_MGMT &&
+                   in_mad->mad_hdr.attr_id == IB_PMA_PORT_COUNTERS)
+                       return iboe_process_mad(ibdev, mad_flags, port_num, in_wc,
+                                               in_grh, in_mad, out_mad);
+
+               return ib_process_mad(ibdev, mad_flags, port_num, in_wc,
+                                     in_grh, in_mad, out_mad);
        }
+
+       if (link == IB_LINK_LAYER_ETHERNET)
+               return iboe_process_mad(ibdev, mad_flags, port_num, in_wc,
+                                       in_grh, in_mad, out_mad);
+
+       return -EINVAL;
 }
 
 static void send_handler(struct ib_mad_agent *agent,