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

From: Leon Romanovsky <[email-masked]>
Date: Tue, 11 Apr 2023 19:37:29 +0300

On Tue, Apr 11, 2023 at 06:00:00PM +0200, Simon Horman wrote:
> 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 ?

I didn't like it because of the line above, IMHO it is too long and has
too many indirection.

> 			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 ?

I'll change

> 
> > +		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));

Will do.

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