Subject: Re: [PATCH net-next 04/10] net/mlx5e: Prepare IPsec packet reformat code for tunnel mode

From: Simon Horman <[email-masked]>
Date: Tue, 11 Apr 2023 18:00:00 +0200

On Mon, Apr 10, 2023 at 09:19:06AM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <[email-masked]>
> 
> Refactor setup_pkt_reformat() function to accommodate future extension
> to support tunnel mode.
> 
> Signed-off-by: Leon Romanovsky <[email-masked]>

...

> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c
> index 060be020ca64..980583fb1e52 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c
> @@ -836,40 +836,78 @@ static int setup_modify_header(struct mlx5_core_dev *mdev, u32 val, u8 dir,
>  	return 0;
>  }
>  
> +static int
> +setup_pkt_transport_reformat(struct mlx5_accel_esp_xfrm_attrs *attrs,
> +			     struct mlx5_pkt_reformat_params *reformat_params)
> +{
> +	u8 *reformatbf;
> +	__be32 spi;
> +
> +	switch (attrs->dir) {
> +	case XFRM_DEV_OFFLOAD_IN:
> +		reformat_params->type = MLX5_REFORMAT_TYPE_DEL_ESP_TRANSPORT;
> +		break;
> +	case XFRM_DEV_OFFLOAD_OUT:
> +		if (attrs->family == AF_INET)
> +			reformat_params->type =
> +				MLX5_REFORMAT_TYPE_ADD_ESP_TRANSPORT_OVER_IPV4;
> +		else
> +			reformat_params->type =
> +				MLX5_REFORMAT_TYPE_ADD_ESP_TRANSPORT_OVER_IPV6;

Maybe this is nicer? Maybe not.

		reformat_params->type = attrs->family == AF_INET ?
			MLX5_REFORMAT_TYPE_ADD_ESP_TRANSPORT_OVER_IPV4 :
			MLX5_REFORMAT_TYPE_ADD_ESP_TRANSPORT_OVER_IPV6;

> +
> +		reformatbf = kzalloc(16, GFP_KERNEL);

I know you are just moving code around.
But 16 is doing a lot of work in this function.
Could it be a #define ?

> +		if (!reformatbf)
> +			return -ENOMEM;
> +
> +		/* convert to network format */
> +		spi = htonl(attrs->spi);
> +		memcpy(reformatbf, &spi, 4);

This seems to be a lot of work to copy a word.
But anyway, maybe:

		memcpy(reformatbf, &spi, sizeof(spi));

> +
> +		reformat_params->param_0 = attrs->authsize;
> +		reformat_params->size = 16;
> +		reformat_params->data = reformatbf;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +

...