RDMA/mlx5: Set local port to one when accessing counters

When accessing Ports Performance Counters Register (PPCNT),
local port must be one if it is Function-Per-Port HCA that
HCA_CAP.num_ports is 1.

The offending patch can change the local port to other values
when accessing PPCNT after enabling switchdev mode. The following
syndrome will be printed:

 # cat /sys/class/infiniband/rdmap4s0f0/ports/2/counters/*
 # dmesg
 mlx5_core 0000:04:00.0: mlx5_cmd_check:756:(pid 12450): ACCESS_REG(0x805) op_mod(0x1) failed, status bad parameter(0x3), syndrome (0x1e5585)

Fix it by setting local port to one for Function-Per-Port HCA.

Fixes: 210b1f7 ("IB/mlx5: When not in dual port RoCE mode, use provided port as native")
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Chris Mi <cmi@nvidia.com>
Link: https://lore.kernel.org/r/6c5086c295c76211169e58dbd610fb0402360bab.1661763459.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/mlx5/mad.c

@@ -166,6 +166,12 @@ static int process_pma_cmd(struct mlx5_ib_dev *dev, u32 port_num,
 		mdev = dev->mdev;
 		mdev_port_num = 1;
 	}
+	if (MLX5_CAP_GEN(dev->mdev, num_ports) == 1) {
+		/* set local port to one for Function-Per-Port HCA. */
+		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 = {};