Re: [PATCH net-next v3 03/11] mlx4: Use 'void *' as the event param of mlx4_dispatch_event()

[Leon Romanovsky]

On Mon, Aug 21, 2023 at 03:12:17PM +0200, Petr Pavlu wrote:
> Function mlx4_dispatch_event() takes an 'unsigned long' as its event
> parameter. The actual value is none (MLX4_DEV_EVENT_CATASTROPHIC_ERROR),
> a pointer to mlx4_eqe (MLX4_DEV_EVENT_PORT_MGMT_CHANGE), or a 32-bit
> integer (remaining events).
> 
> In preparation to switch mlx4_en and mlx4_ib to be an auxiliary device,
> the mlx4_interface.event callback is replaced with a notifier and
> function mlx4_dispatch_event() gets updated to invoke
> atomic_notifier_call_chain(). This requires forwarding the input 'param'
> value from the former function to the latter. A problem is that the
> notifier call takes 'void *' as its 'param' value, compared to
> 'unsigned long' used by mlx4_dispatch_event(). Re-passing the value
> would need either punning it to 'void *' or passing down the address of
> the input 'param'. Both approaches create a number of unnecessary casts.
> 
> Change instead the input 'param' of mlx4_dispatch_event() from
> 'unsigned long' to 'void *'. A mlx4_eqe pointer can be passed directly,
> callers using an int value are adjusted to pass its address.
> 
> Signed-off-by: Petr Pavlu <petr.pavlu@xxxxxxxx>
> ---
>  drivers/infiniband/hw/mlx4/main.c            | 14 ++++++++++----
>  drivers/net/ethernet/mellanox/mlx4/catas.c   |  2 +-
>  drivers/net/ethernet/mellanox/mlx4/cmd.c     |  4 ++--
>  drivers/net/ethernet/mellanox/mlx4/en_main.c | 17 +++++++++++++++--
>  drivers/net/ethernet/mellanox/mlx4/eq.c      | 15 ++++++++-------
>  drivers/net/ethernet/mellanox/mlx4/intf.c    |  2 +-
>  drivers/net/ethernet/mellanox/mlx4/mlx4.h    |  2 +-
>  include/linux/mlx4/driver.h                  |  2 +-
>  8 files changed, 39 insertions(+), 19 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx>