IB/mlx5: Fixed reporting counters on 2nd port for Dual port RoCE

Currently during dual port IB device registration in below code flow,

ib_register_device()
  ib_device_register_sysfs()
    ib_setup_port_attrs()
      add_port()
        get_counter_table()
          get_perf_mad()
            process_mad()
              mlx5_ib_process_mad()

mlx5_ib_process_mad() fails on 2nd port when both the ports are not fully
setup at the device level (because 2nd port is unaffiliated).

As a result, get_perf_mad() registers different PMA counter group for 1st
and 2nd port, namely pma_counter_ext and pma_counter. However both ports
have the same capability and counter offsets.

Due to this when counters are read by the user via sysfs in below code
flow, counters are queried from wrong location from the device mainly from
PPCNT instead of VPORT counters.

show_pma_counter()
  get_perf_mad()
    process_mad()
      mlx5_ib_process_mad()
        process_pma_cmd()

This shows all zero counters for 2nd port.

To overcome this, process_pma_cmd() is invoked, and when unaffiliated port
is not yet setup during device registration phase, make the query on the
first port.  while at it, only process_pma_cmd() needs to work on the
native port number and underlying mdev, so shift the get, put calls to
where its needed inside process_pma_cmd().

Fixes: 212f2a87 ("IB/mlx5: Route MADs for dual port RoCE")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/mad.c

@@ -200,19 +200,33 @@ static void pma_cnt_assign(struct ib_pma_portcounters *pma_cnt,
 			     vl_15_dropped);
 }
 
-static int process_pma_cmd(struct mlx5_core_dev *mdev, u8 port_num,
+static int process_pma_cmd(struct mlx5_ib_dev *dev, u8 port_num,
 			   const struct ib_mad *in_mad, struct ib_mad *out_mad)
 {
-	int err;
+	struct mlx5_core_dev *mdev;
+	bool native_port = true;
+	u8 mdev_port_num;
 	void *out_cnt;
+	int err;
 
+	mdev = mlx5_ib_get_native_port_mdev(dev, port_num, &mdev_port_num);
+	if (!mdev) {
+		/* Fail to get the native port, likely due to 2nd port is still
+		 * unaffiliated. In such case default to 1st port and attached
+		 * PF device.
+		 */
+		native_port = false;
+		mdev = dev->mdev;
+		mdev_port_num = 1;
+	}
 	/* Declaring support of extended counters */
 	if (in_mad->mad_hdr.attr_id == IB_PMA_CLASS_PORT_INFO) {
 		struct ib_class_port_info cpi = {};
 
 		cpi.capability_mask = IB_PMA_CLASS_CAP_EXT_WIDTH;
 		memcpy((out_mad->data + 40), &cpi, sizeof(cpi));
-		return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY;
+		err = IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY;
+		goto done;
 	}
 
 	if (in_mad->mad_hdr.attr_id == IB_PMA_PORT_COUNTERS_EXT) {
@@ -221,11 +235,13 @@ static int process_pma_cmd(struct mlx5_core_dev *mdev, u8 port_num,
 		int sz = MLX5_ST_SZ_BYTES(query_vport_counter_out);
 
 		out_cnt = kvzalloc(sz, GFP_KERNEL);
-		if (!out_cnt)
-			return IB_MAD_RESULT_FAILURE;
+		if (!out_cnt) {
+			err = IB_MAD_RESULT_FAILURE;
+			goto done;
+		}
 
 		err = mlx5_core_query_vport_counter(mdev, 0, 0,
-						    port_num, out_cnt, sz);
+						    mdev_port_num, out_cnt, sz);
 		if (!err)
 			pma_cnt_ext_assign(pma_cnt_ext, out_cnt);
 	} else {
@@ -234,20 +250,23 @@ static int process_pma_cmd(struct mlx5_core_dev *mdev, u8 port_num,
 		int sz = MLX5_ST_SZ_BYTES(ppcnt_reg);
 
 		out_cnt = kvzalloc(sz, GFP_KERNEL);
-		if (!out_cnt)
-			return IB_MAD_RESULT_FAILURE;
+		if (!out_cnt) {
+			err = IB_MAD_RESULT_FAILURE;
+			goto done;
+		}
 
-		err = mlx5_core_query_ib_ppcnt(mdev, port_num,
+		err = mlx5_core_query_ib_ppcnt(mdev, mdev_port_num,
 					       out_cnt, sz);
 		if (!err)
 			pma_cnt_assign(pma_cnt, out_cnt);
-		}
-
+	}
 	kvfree(out_cnt);
-	if (err)
-		return IB_MAD_RESULT_FAILURE;
-
-	return IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY;
+	err = err ? IB_MAD_RESULT_FAILURE :
+		    IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_REPLY;
+done:
+	if (native_port)
+		mlx5_ib_put_native_port_mdev(dev, port_num);
+	return err;
 }
 
 int mlx5_ib_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
@@ -259,8 +278,6 @@ int mlx5_ib_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
 	struct mlx5_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;
-	struct mlx5_core_dev *mdev;
-	u8 mdev_port_num;
 	int ret;
 
 	if (WARN_ON_ONCE(in_mad_size != sizeof(*in_mad) ||
@@ -269,19 +286,14 @@ int mlx5_ib_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
 
 	memset(out_mad->data, 0, sizeof(out_mad->data));
 
-	mdev = mlx5_ib_get_native_port_mdev(dev, port_num, &mdev_port_num);
-	if (!mdev)
-		return IB_MAD_RESULT_FAILURE;
-
-	if (MLX5_CAP_GEN(mdev, vport_counters) &&
+	if (MLX5_CAP_GEN(dev->mdev, vport_counters) &&
 	    in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_PERF_MGMT &&
 	    in_mad->mad_hdr.method == IB_MGMT_METHOD_GET) {
-		ret = process_pma_cmd(mdev, mdev_port_num, in_mad, out_mad);
+		ret = process_pma_cmd(dev, port_num, in_mad, out_mad);
 	} else {
 		ret =  process_mad(ibdev, mad_flags, port_num, in_wc, in_grh,
 				   in_mad, out_mad);
 	}
-	mlx5_ib_put_native_port_mdev(dev, port_num);
 	return ret;
 }