IB/mlx4: Add support for the port info class for RoCE ports

Report that driver supports IB_PMA_CLASS_CAP_EXT_WIDTH in respond for
IB_MGMT_CLASS_PERF_MGMT mad with IB_PMA_CLASS_PORT_INFO attr id.
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx4/mad.c

@@ -852,6 +852,15 @@ static void edit_counter(struct mlx4_counter *cnt, void *counters,
 	}
 }
 
+static int iboe_process_mad_port_info(void *out_mad)
+{
+	struct ib_class_port_info cpi = {};
+
+	cpi.capability_mask = IB_PMA_CLASS_CAP_EXT_WIDTH;
+	memcpy(out_mad, &cpi, sizeof(cpi));
+	return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY;
+}
+
 static int iboe_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
 			const struct ib_wc *in_wc, const struct ib_grh *in_grh,
 			const struct ib_mad *in_mad, struct ib_mad *out_mad)
@@ -864,6 +873,9 @@ static int iboe_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
 	if (in_mad->mad_hdr.mgmt_class != IB_MGMT_CLASS_PERF_MGMT)
 		return -EINVAL;
 
+	if (in_mad->mad_hdr.attr_id == IB_PMA_CLASS_PORT_INFO)
+		return iboe_process_mad_port_info((void *)(out_mad->data + 40));
+
 	memset(&counter_stats, 0, sizeof(counter_stats));
 	mutex_lock(&dev->counters_table[port_num - 1].mutex);
 	list_for_each_entry(tmp_counter,
@@ -919,7 +931,8 @@ int mlx4_ib_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
 		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 ||
-		      in_mad->mad_hdr.attr_id == IB_PMA_PORT_COUNTERS_EXT)))
+		      in_mad->mad_hdr.attr_id == IB_PMA_PORT_COUNTERS_EXT ||
+		      in_mad->mad_hdr.attr_id == IB_PMA_CLASS_PORT_INFO)))
 			return iboe_process_mad(ibdev, mad_flags, port_num, in_wc,
 						in_grh, in_mad, out_mad);