A devlink port may be for a controller consist of PCI device.
A devlink instance holds ports of two types of controllers.
(1) controller discovered on same system where eswitch resides
This is the case where PCI PF/VF of a controller and devlink eswitch
instance both are located on a single system.
(2) controller located on external host system.
This is the case where a controller is located in one system and its
devlink eswitch ports are located in a different system.

When a devlink eswitch instance serves the devlink ports of both
controllers together, PCI PF/VF numbers may overlap.
Due to this a unique phys_port_name cannot be constructed.

For example in below such system controller-0 and controller-1, each has
PCI PF pf0 whose eswitch ports can be present in controller-0.
These results in phys_port_name as "pf0" for both.
Similar problem exists for VFs and upcoming Sub functions.

An example view of two controller systems:

             ---------------------------------------------------------
             |                                                       |
             |           --------- ---------         ------- ------- |
-----------  |           | vf(s) | | sf(s) |         |vf(s)| |sf(s)| |
| server  |  | -------   ----/---- ---/----- ------- ---/--- ---/--- |
| pci rc  |=== | pf0 |______/________/       | pf1 |___/_______/     |
| connect |  | -------                       -------                 |
-----------  |     | controller_num=1 (no eswitch)                   |
             ------|--------------------------------------------------
             (internal wire)
                   |
             ---------------------------------------------------------
             | devlink eswitch ports and reps                        |
             | ----------------------------------------------------- |
             | |ctrl-0 | ctrl-0 | ctrl-0 | ctrl-0 | ctrl-0 |ctrl-0 | |
             | |pf0    | pf0vfN | pf0sfN | pf1    | pf1vfN |pf1sfN | |
             | ----------------------------------------------------- |
             | |ctrl-1 | ctrl-1 | ctrl-1 | ctrl-1 | ctrl-1 |ctrl-1 | |
             | |pf1    | pf1vfN | pf1sfN | pf1    | pf1vfN |pf0sfN | |
             | ----------------------------------------------------- |
             |                                                       |
             |                                                       |
             |           --------- ---------         ------- ------- |
             |           | vf(s) | | sf(s) |         |vf(s)| |sf(s)| |
             | -------   ----/---- ---/----- ------- ---/--- ---/--- |
             | | pf0 |______/________/       | pf1 |___/_______/     |
             | -------                       -------                 |
             |                                                       |
             |  local controller_num=0 (eswitch)                     |
             ---------------------------------------------------------

An example devlink port for external controller with controller
number = 1 for a VF 1 of PF 0:

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev ens2f0pf0vf1 flavour pcivf controller 1 pfnum 0 vfnum 1 external true splittable false
  function:
    hw_addr 00:00:00:00:00:00

$ devlink port show pci/0000:06:00.0/2 -jp
{
    "port": {
        "pci/0000:06:00.0/2": {
            "type": "eth",
            "netdev": "ens2f0pf0vf1",
            "flavour": "pcivf",
            "controller": 1,
            "pfnum": 0,
            "vfnum": 1,
            "external": true,
            "splittable": false,
            "function": {
                "hw_addr": "00:00:00:00:00:00"
            }
        }
    }
}
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>