enic: add MBOX PF handlers for VF register and capability

Implement PF-side mailbox message processing for SR-IOV V2
admin channel communication.

When the PF receives messages from VFs, the dispatch routes
them to type-specific handlers:
  - VF_CAPABILITY_REQUEST: reply with protocol version 1
  - VF_REGISTER_REQUEST: send the register reply, mark the
    VF registered on success, then send PF_LINK_STATE_NOTIF
    reflecting the PF's current carrier state
  - VF_UNREGISTER_REQUEST: mark VF unregistered, send reply
  - PF_LINK_STATE_ACK: log errors from VF acknowledgment

Per-VF state (struct enic_vf_state) is tracked via enic->vf_state
which will be allocated when SRIOV V2 is enabled.

Remove the CONFIG_PCI_IOV guard from num_vfs in struct enic. The
PF handlers reference enic->num_vfs for VF ID bounds checking in
enic_mbox.c, which is compiled unconditionally. The field must be
visible regardless of CONFIG_PCI_IOV to avoid build failures.

Add enic_mbox_send_link_state() helper for PF-initiated link
state notifications.

Signed-off-by: Satish Kharat <satishkh@cisco.com>
Link: https://patch.msgid.link/20260812-enic-sriov-v2-admin-channel-v2-v13-7-b3809e448aba@cisco.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions