net/mlx5: SF, Handle function changed event

net/mlx5: SF, Handle function changed event

When host is powered off, firmware does not send vhca_state event
for every probed host SF on the DPU because it may have deployed
thousands of SFs to the host. Instead it sends a function changed
event. Currently, only VFs handle this event. This commit extends
support to SFs.

When DPU user deactivates[1] SFs, mlx5 expects vhca_state event
and leaves the SF in dangling state[2].

When DPU user deletes[3] SFs, mlx5 also expects vhca_state event
and destroys the SF resources[4].

Fix it by changing SF to the right state and freeing SF resources
when the function changed event is received.

When this event is received, driver checks all SF states.
 - If state is in_use, change it to active.
 - If state is teardown_request, change it to allocated.

And SF hardware table entry is freed if it is pending for delete.

[1]
 # devlink port function set en3f0c1pf0sf0 state inactive

[2]
 # devlink port function set en3f0c1pf0sf0 state active
 Error: mlx5_core: SF is inactivated but it is still attached.
 kernel answers: Device or resource busy

[3]
 # devlink port show
 pci/0000:03:00.0/229376: type eth netdev en3f0c1pf0sf0 \
	flavour pcisf controller 1 pfnum 0 sfnum 0 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state active opstate attached \
	roce enable trust off max_uc_macs 4096 max_io_eqs 8
 # devlink port del en3f0c1pf0sf0

[4]
 # devlink port add pci/0000:03:00.0 flavour pcisf pfnum 0 sfnum 0 \
	controller 1
 Error: mlx5_core: SF already exist. Choose different sfnum.
 kernel answers: File exists

Fixes: 6a3273217469 ("net/mlx5: SF, Port function state change support")
Signed-off-by: Chris Mi <cmi@nvidia.com>
Reviewed-by: Shay Drori <shayd@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260729071622.2423270-1-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>