Re: [PATCH net-next v3 6/7] net: stmmac: support fp parameter of tc-taprio

[Vladimir Oltean <olteanv@gmail.com>]

On Mon, Aug 19, 2024 at 03:25:19PM +0800, Furong Xu wrote:
> tc-taprio can select whether traffic classes are express or preemptible.
> 
> 0) tc qdisc add dev eth1 parent root handle 100 taprio \
>         num_tc 4 \
>         map 0 1 2 3 2 2 2 2 2 2 2 2 2 2 2 3 \
>         queues 1@0 1@1 1@2 1@3 \
>         base-time 1000000000 \
>         sched-entry S 03 10000000 \
>         sched-entry S 0e 10000000 \
>         flags 0x2 fp P E E E
> 
> 1) After some traffic tests, MAC merge layer statistics are all good.
> 
> Local device:
> [ {
>         "ifname": "eth1",
>         "pmac-enabled": true,
>         "tx-enabled": true,
>         "tx-active": true,
>         "tx-min-frag-size": 60,
>         "rx-min-frag-size": 60,
>         "verify-enabled": true,
>         "verify-time": 100,
>         "max-verify-time": 128,
>         "verify-status": "SUCCEEDED",
>         "statistics": {
>             "MACMergeFrameAssErrorCount": 0,
>             "MACMergeFrameSmdErrorCount": 0,
>             "MACMergeFrameAssOkCount": 0,
>             "MACMergeFragCountRx": 0,
>             "MACMergeFragCountTx": 17837,
>             "MACMergeHoldCount": 18639
>         }
>     } ]
> 
> Remote device:
> [ {
>         "ifname": "end1",
>         "pmac-enabled": true,
>         "tx-enabled": true,
>         "tx-active": true,
>         "tx-min-frag-size": 60,
>         "rx-min-frag-size": 60,
>         "verify-enabled": true,
>         "verify-time": 100,
>         "max-verify-time": 128,
>         "verify-status": "SUCCEEDED",
>         "statistics": {
>             "MACMergeFrameAssErrorCount": 0,
>             "MACMergeFrameSmdErrorCount": 0,
>             "MACMergeFrameAssOkCount": 17189,
>             "MACMergeFragCountRx": 17837,
>             "MACMergeFragCountTx": 0,
>             "MACMergeHoldCount": 0
>         }
>     } ]
> 
> Tested on DWMAC CORE 5.10a
> 
> Signed-off-by: Furong Xu <0x1207@gmail.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c | 17 ++++++-----------
>  1 file changed, 6 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> index a967c6f01e4e..05b870b35947 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
> @@ -933,7 +933,6 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
>  	u32 size, wid = priv->dma_cap.estwid, dep = priv->dma_cap.estdep;
>  	struct timespec64 time, current_time, qopt_time;
>  	ktime_t current_time_ns;
> -	bool fpe = false;
>  	int i, ret = 0;
>  	u64 ctr;
>  
> @@ -1018,16 +1017,12 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
>  
>  		switch (qopt->entries[i].command) {
>  		case TC_TAPRIO_CMD_SET_GATES:
> -			if (fpe)
> -				return -EINVAL;
>  			break;
>  		case TC_TAPRIO_CMD_SET_AND_HOLD:
>  			gates |= BIT(0);
> -			fpe = true;
>  			break;
>  		case TC_TAPRIO_CMD_SET_AND_RELEASE:
>  			gates &= ~BIT(0);
> -			fpe = true;
>  			break;
>  		default:
>  			return -EOPNOTSUPP;
> @@ -1058,7 +1053,7 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
>  
>  	tc_taprio_map_maxsdu_txq(priv, qopt);
>  
> -	if (fpe && !priv->dma_cap.fpesel) {
> +	if (qopt->mqprio.preemptible_tcs && !priv->dma_cap.fpesel) {
>  		mutex_unlock(&priv->est_lock);
>  		return -EOPNOTSUPP;
>  	}

This condition is dealt with by the core, now.

	if (have_preemption && !ethtool_dev_mm_supported(dev)) {
		NL_SET_ERR_MSG(extack, "Device does not support preemption");
		return -EOPNOTSUPP;
	}

where ethtool_dev_mm_supported() is implemented by issuing a get_mm()
command and seeing what it returns. There's a check for priv->dma_cap.fpesel
there already.

> @@ -1071,6 +1066,9 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
>  		goto disable;
>  	}
>  
> +	stmmac_fpe_set_preemptible_tcs(priv, priv->dev, qopt->mqprio.extack,
> +				       qopt->mqprio.preemptible_tcs);
> +
>  	netdev_info(priv->dev, "configured EST\n");
>  
>  	return 0;
> @@ -1089,11 +1087,8 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
>  		mutex_unlock(&priv->est_lock);
>  	}
>  
> -	stmmac_fpe_configure(priv, priv->ioaddr,
> -			     &priv->fpe_cfg,
> -			     priv->plat->tx_queues_to_use,
> -			     priv->plat->rx_queues_to_use,
> -			     false, false);
> +	stmmac_fpe_set_preemptible_tcs(priv, priv->dev, qopt->mqprio.extack, 0);
> +
>  	netdev_info(priv->dev, "disabled FPE\n");
>  
>  	return ret;
> -- 
> 2.34.1
>