net/mlx5e: Introduce SRIOV VF representors

net/mlx5e: Introduce SRIOV VF representors

Implement the relevant profile functions to create mlx5e driver instance
serving as VF representor. When SRIOV offloads mode is enabled, each VF
will have a representor netdevice instance on the host.

To do that, we also export set of shared service functions from en_main.c,
such that they can be used by both NIC and repsresentors netdevs.

The newly created representor netdevice has a basic set of net_device_ops
which are the same ndo functions as the NIC netdevice and an ndo of it's
own for phys port name.

The profiling infrastructure allow sharing code between the NIC and the
vport representor even though the representor has only a subset of the
NIC functionality.

The VF reps and the PF which is used in that mode to represent the uplink,
expose switchdev ops. Currently the only op supposed is attr get for the
port parent ID which here serves to identify net-devices belonging to the
same HW E-Switch. Other than that, no offloading is implemented and hence
switching functionality is achieved if one sets SW switching rules, e.g
using tc, bridge or ovs.

Port phys name (ndo_get_phys_port_name) is implemented to allow exporting
to user-space the VF vport number and along with the switchdev port parent
id (phys_switch_id) enable a udev base consistent naming scheme:

SUBSYSTEM=="net", ACTION=="add", ATTR{phys_switch_id}=="<phys_switch_id>", \
        ATTR{phys_port_name}!="", NAME="$PF_NIC$attr{phys_port_name}"

where phys_switch_id is exposed by the PF (and VF reps) and $PF_NIC is
the name of the PF netdevice.

Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>