Re: [PATCH net-next] rtase: Add ndo_setup_tc support for CBS offload in traffic control setup

[Simon Horman <horms@kernel.org>]

On Fri, Mar 14, 2025 at 05:40:21PM +0800, Justin Lai wrote:
> Add support for ndo_setup_tc to enable CBS offload functionality as
> part of traffic control configuration for network devices.
> 
> Signed-off-by: Justin Lai <justinlai0215@realtek.com>

...

> diff --git a/drivers/net/ethernet/realtek/rtase/rtase_main.c b/drivers/net/ethernet/realtek/rtase/rtase_main.c
> index 2aacc1996796..2a61cd192026 100644
> --- a/drivers/net/ethernet/realtek/rtase/rtase_main.c
> +++ b/drivers/net/ethernet/realtek/rtase/rtase_main.c
> @@ -1661,6 +1661,54 @@ static void rtase_get_stats64(struct net_device *dev,
>  	stats->rx_length_errors = tp->stats.rx_length_errors;
>  }
>  
> +static void rtase_set_hw_cbs(const struct rtase_private *tp, u32 queue)
> +{
> +	u32 idle = tp->tx_qos[queue].idleslope * RTASE_1T_CLOCK;
> +	u32 val, i;
> +
> +	val = u32_encode_bits(idle / RTASE_1T_POWER, RTASE_IDLESLOPE_INT_MASK);
> +	idle %= RTASE_1T_POWER;
> +
> +	for (i = 1; i <= RTASE_IDLESLOPE_INT_SHIFT; i++) {
> +		idle *= 2;
> +		if ((idle / RTASE_1T_POWER) == 1)
> +			val |= BIT(RTASE_IDLESLOPE_INT_SHIFT - i);
> +
> +		idle %= RTASE_1T_POWER;
> +	}
> +
> +	rtase_w32(tp, RTASE_TXQCRDT_0 + queue * 4, val);
> +}
> +
> +static void rtase_setup_tc_cbs(struct rtase_private *tp,
> +			       const struct tc_cbs_qopt_offload *qopt)
> +{
> +	u32 queue = qopt->queue;

Hi Justin,

Does queue need to be checked somewhere to make sure it is in range?

> +
> +	tp->tx_qos[queue].hicredit = qopt->hicredit;
> +	tp->tx_qos[queue].locredit = qopt->locredit;
> +	tp->tx_qos[queue].idleslope = qopt->idleslope;
> +	tp->tx_qos[queue].sendslope = qopt->sendslope;

Does qopt->enable need to be honoured in order to allow
the offload to be both enabled and disabled?

> +
> +	rtase_set_hw_cbs(tp, queue);
> +}
> +
> +static int rtase_setup_tc(struct net_device *dev, enum tc_setup_type type,
> +			  void *type_data)
> +{
> +	struct rtase_private *tp = netdev_priv(dev);
> +
> +	switch (type) {
> +	case TC_SETUP_QDISC_CBS:
> +		rtase_setup_tc_cbs(tp, type_data);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
>  static netdev_features_t rtase_fix_features(struct net_device *dev,
>  					    netdev_features_t features)
>  {

...