Re: [PATCH net-next v1 4/5] net/mlx5: Register separate reload devlink ops for multiport device

[Jakub Kicinski <kuba@kernel.org>]

On Wed, 29 Sep 2021 15:00:45 +0300 Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@nvidia.com>
> 
> Mulitport slave device doesn't support devlink reload, so instead of
> complicating initialization flow with devlink_reload_enable() which
> will be removed in next patch, set specialized devlink ops callbacks
> for reload operations.
> 
> This fixes an error when reload counters exposed (and equal zero) for
> the mode that is not supported at all.
> 
> Fixes: d89ddaae1766 ("net/mlx5: Disable devlink reload for multi port slave device")
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
> ---
>  drivers/net/ethernet/mellanox/mlx5/core/devlink.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
> index 47c9f7f5bb79..e85eca6976a9 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
> @@ -309,14 +309,17 @@ static struct devlink_ops mlx5_devlink_ops = {
>  #endif
>  	.flash_update = mlx5_devlink_flash_update,
>  	.info_get = mlx5_devlink_info_get,
> +	.trap_init = mlx5_devlink_trap_init,
> +	.trap_fini = mlx5_devlink_trap_fini,
> +	.trap_action_set = mlx5_devlink_trap_action_set,
> +};
> +
> +static struct devlink_ops mlx5_devlink_reload = {
>  	.reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT) |
>  			  BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE),
>  	.reload_limits = BIT(DEVLINK_RELOAD_LIMIT_NO_RESET),
>  	.reload_down = mlx5_devlink_reload_down,
>  	.reload_up = mlx5_devlink_reload_up,
> -	.trap_init = mlx5_devlink_trap_init,
> -	.trap_fini = mlx5_devlink_trap_fini,
> -	.trap_action_set = mlx5_devlink_trap_action_set,
>  };
>  
>  void mlx5_devlink_trap_report(struct mlx5_core_dev *dev, int trap_id, struct sk_buff *skb,
> @@ -791,6 +794,7 @@ static void mlx5_devlink_traps_unregister(struct devlink *devlink)
>  
>  int mlx5_devlink_register(struct devlink *devlink)
>  {
> +	struct mlx5_core_dev *dev = devlink_priv(devlink);
>  	int err;
>  
>  	err = devlink_params_register(devlink, mlx5_devlink_params,
> @@ -808,6 +812,9 @@ int mlx5_devlink_register(struct devlink *devlink)
>  	if (err)
>  		goto traps_reg_err;
>  
> +	if (!mlx5_core_is_mp_slave(dev))
> +		devlink_set_ops(devlink, &mlx5_devlink_reload);

Does this work? Where do you make a copy of the ops? 🤔 You can't modify
the driver-global ops, to state the obvious.