enic: SR-IOV V2 preparatory infrastructure

This is the first of four series adding SR-IOV V2 support to the enic
driver for Cisco VIC 14xx/15xx adapters.

The existing V1 SR-IOV implementation has VFs that interact directly
with the VIC firmware, leaving the PF driver with no visibility or
control over VF behavior. V2 introduces a PF-mediated model where VFs
communicate with the PF through a mailbox over a dedicated admin
channel. This brings enic in line with the standard Linux SR-IOV
model, enabling full PF management of VFs via ip link (MAC, VLAN,
link state, spoofchk, trust, and per-VF statistics).

This preparatory series adds detection and resource helper code with
no functional change to existing driver behavior:

  - Extend BAR resource discovery for admin channel resources
  - Register the V2 VF PCI device ID
  - Detect VF type (V1/V2/usNIC) from SR-IOV PCI capability
  - Make enic_dev_enable/disable ref-counted for shared use by data
    path and admin channel
  - Add type-aware resource allocation for admin WQ/RQ/CQ/INTR
  - Detect presence of admin channel resources at probe time

Tested on VIC 14xx and 15xx series adapters with V2 VFs under KVM
(sriov_numvfs, VF passthrough, ip link VF configuration, VF traffic).

Based in part on initial work by Christian Benvenuti.

---
Satish Kharat (6):
      enic: extend resource discovery for SR-IOV admin channel
      enic: add V2 SR-IOV VF device ID
      enic: detect SR-IOV VF type from PCI capability
      enic: make enic_dev_enable/disable ref-counted
      enic: add type-aware alloc for WQ, RQ, CQ and INTR resources
      enic: detect admin channel resources for SR-IOV

 drivers/net/ethernet/cisco/enic/enic.h          | 18 +++++++++++
 drivers/net/ethernet/cisco/enic/enic_dev.c      | 17 +++++++---
 drivers/net/ethernet/cisco/enic/enic_main.c     | 42 ++++++++++++++++++++++++-
 drivers/net/ethernet/cisco/enic/enic_res.c      | 10 ++++--
 drivers/net/ethernet/cisco/enic/vnic_cq.c       | 14 +++++++--
 drivers/net/ethernet/cisco/enic/vnic_cq.h       |  3 ++
 drivers/net/ethernet/cisco/enic/vnic_dev.c      | 10 ++++++
 drivers/net/ethernet/cisco/enic/vnic_intr.c     | 12 +++++--
 drivers/net/ethernet/cisco/enic/vnic_intr.h     |  2 ++
 drivers/net/ethernet/cisco/enic/vnic_resource.h |  4 +++
 drivers/net/ethernet/cisco/enic/vnic_rq.c       | 14 +++++++--
 drivers/net/ethernet/cisco/enic/vnic_rq.h       |  3 ++
 drivers/net/ethernet/cisco/enic/vnic_wq.c       | 14 +++++++--
 drivers/net/ethernet/cisco/enic/vnic_wq.h       |  3 ++
 14 files changed, 147 insertions(+), 19 deletions(-)
---
base-commit: b1c803d5c8167026791abfaed96fd3e6a1fcd750
change-id: 20260324-enic-sriov-v2-prep-2fe1eabc3dc1

Best regards,
-- 
Satish Kharat <satishkh@cisco.com>