Re: [PATCH v3 5/5] net: ethernet: ti: cpsw: add ethtool channels support

[Mugunthan V N]

On Tuesday 16 August 2016 04:55 AM, Ivan Khoronzhuk wrote:
> These ops allow to control number of channels driver is allowed to
> work with at cpdma level. The maximum number of channels is 8 for
> rx and 8 for tx. In dual_emac mode the h/w channels are shared
> between two interfaces and changing number on one interface changes
> number of channels on another.
> 
> How many channels are supported and enabled:
> $ ethtool -l ethX
> 
> Change number of channels (up to 8)
> $ ethtool -L ethX rx 6 tx 6
> 
> Per-channel statistic:
> $ ethtool -S ethX
> 
> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
> ---
>  drivers/net/ethernet/ti/cpsw.c | 180 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 176 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
> index 6dcbd8a..f02e577 100644
> --- a/drivers/net/ethernet/ti/cpsw.c
> +++ b/drivers/net/ethernet/ti/cpsw.c
> @@ -735,6 +735,11 @@ static void cpsw_rx_handler(void *token, int len, int status)
>  	}
>  
>  requeue:
> +	if (netif_dormant(ndev)) {
> +		dev_kfree_skb_any(new_skb);
> +		return;
> +	}
> +
>  	ch = cpsw->rxch[skb_get_queue_mapping(new_skb)];
>  	ret = cpdma_chan_submit(ch, new_skb, new_skb->data,
>  				skb_tailroom(new_skb), 0);
> @@ -1267,9 +1272,8 @@ static void cpsw_init_host_port(struct cpsw_priv *priv)
>  	}
>  }
>  
> -static int cpsw_fill_rx_channels(struct net_device *ndev)
> +static int cpsw_fill_rx_channels(struct cpsw_priv *priv)

This change can be moved to patch 1/5 where the function definition is
added at first.

>  {
> -	struct cpsw_priv *priv = netdev_priv(ndev);
>  	struct cpsw_common *cpsw = priv->cpsw;
>  	struct sk_buff *skb;
>  	int ch, i, ret;
> @@ -1279,7 +1283,7 @@ static int cpsw_fill_rx_channels(struct net_device *ndev)
>  
>  		ch_buf_num = cpdma_chan_get_rx_buf_num(cpsw->rxch[ch]);
>  		for (i = 0; i < ch_buf_num; i++) {
> -			skb = __netdev_alloc_skb_ip_align(ndev,
> +			skb = __netdev_alloc_skb_ip_align(priv->ndev,
>  							  cpsw->rx_packet_max,
>  							  GFP_KERNEL);
>  			if (!skb) {
> @@ -1397,7 +1401,7 @@ static int cpsw_ndo_open(struct net_device *ndev)
>  			enable_irq(cpsw->irqs_table[0]);
>  		}
>  
> -		ret = cpsw_fill_rx_channels(ndev);
> +		ret = cpsw_fill_rx_channels(priv);
>  		if (ret < 0)
>  			goto err_cleanup;
>  
> @@ -2060,6 +2064,172 @@ static void cpsw_ethtool_op_complete(struct net_device *ndev)
>  		cpsw_err(priv, drv, "ethtool complete failed %d\n", ret);
>  }
>  
> +static void cpsw_get_channels(struct net_device *ndev,
> +			      struct ethtool_channels *ch)
> +{
> +	struct cpsw_common *cpsw = ndev_to_cpsw(ndev);
> +
> +	ch->max_combined = 0;
> +	ch->max_rx = CPSW_MAX_QUEUES;
> +	ch->max_tx = CPSW_MAX_QUEUES;
> +	ch->max_other = 0;
> +	ch->other_count = 0;
> +	ch->rx_count = cpsw->rx_ch_num;
> +	ch->tx_count = cpsw->tx_ch_num;
> +	ch->combined_count = 0;
> +}
> +
> +static int cpsw_check_ch_settings(struct cpsw_common *cpsw,
> +				  struct ethtool_channels *ch)
> +{
> +	if (ch->combined_count)
> +		return -EINVAL;
> +
> +	/* verify we have at least one channel in each direction */
> +	if (!ch->rx_count || !ch->tx_count)
> +		return -EINVAL;
> +
> +	if (ch->rx_count > cpsw->data.channels ||
> +	    ch->tx_count > cpsw->data.channels)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static int cpsw_update_channels_res(struct cpsw_priv *priv, int ch_num, int rx)
> +{
> +	int (*poll)(struct napi_struct *, int);
> +	struct cpsw_common *cpsw = priv->cpsw;
> +	void (*handler)(void *, int, int);
> +	struct cpdma_chan **chan;
> +	int ret, *ch;
> +
> +	if (rx) {
> +		ch = &cpsw->rx_ch_num;
> +		chan = cpsw->rxch;
> +		handler = cpsw_rx_handler;
> +		poll = cpsw_rx_poll;
> +	} else {
> +		ch = &cpsw->tx_ch_num;
> +		chan = cpsw->txch;
> +		handler = cpsw_tx_handler;
> +		poll = cpsw_tx_poll;
> +	}
> +
> +	while (*ch < ch_num) {
> +		chan[*ch] = cpdma_chan_create(cpsw->dma, *ch, handler, rx);
> +
> +		if (IS_ERR(chan[*ch]))
> +			return PTR_ERR(chan[*ch]);
> +
> +		if (!chan[*ch])
> +			return -EINVAL;
> +
> +		cpsw_info(priv, ifup, "created new %d %s channel\n", *ch,
> +			  (rx ? "rx" : "tx"));
> +		(*ch)++;
> +	}
> +
> +	while (*ch > ch_num) {
> +		(*ch)--;
> +
> +		ret = cpdma_chan_destroy(chan[*ch]);
> +		if (ret)
> +			return ret;
> +
> +		cpsw_info(priv, ifup, "destroyed %d %s channel\n", *ch,
> +			  (rx ? "rx" : "tx"));
> +	}
> +
> +	return 0;
> +}
> +
> +static int cpsw_update_channels(struct cpsw_priv *priv,
> +				struct ethtool_channels *ch)
> +{
> +	int ret;
> +
> +	ret = cpsw_update_channels_res(priv, ch->rx_count, 1);
> +	if (ret)
> +		return ret;
> +
> +	ret = cpsw_update_channels_res(priv, ch->tx_count, 0);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int cpsw_set_channels(struct net_device *ndev,
> +			     struct ethtool_channels *chs)
> +{
> +	struct cpsw_priv *priv = netdev_priv(ndev);
> +	struct cpsw_common *cpsw = priv->cpsw;
> +	struct cpsw_slave *slave;
> +	int i, ret;
> +
> +	ret = cpsw_check_ch_settings(cpsw, chs);
> +	if (ret < 0)
> +		return ret;
> +
> +	cpsw_intr_disable(cpsw);
> +
> +	for (i = cpsw->data.slaves, slave = cpsw->slaves; i; i--, slave++) {
> +		if (!(slave->ndev && netif_running(slave->ndev)))
> +			continue;
> +
> +		netif_tx_stop_all_queues(slave->ndev);
> +		netif_dormant_on(slave->ndev);
> +	}
> +
> +	cpdma_ctlr_stop(cpsw->dma);
> +	ret = cpsw_update_channels(priv, chs);
> +	if (ret)
> +		goto err;
> +
> +	for (i = cpsw->data.slaves, slave = cpsw->slaves; i; i--, slave++) {
> +		if (!(slave->ndev && netif_running(slave->ndev)))
> +			continue;
> +
> +		/* inform stack about new count of queues */
> +		ret = netif_set_real_num_tx_queues(slave->ndev,
> +						   cpsw->tx_ch_num);
> +		if (ret) {
> +			dev_err(priv->dev, "cannot set real number of tx queues\n");
> +			goto err;
> +		}
> +
> +		ret = netif_set_real_num_rx_queues(slave->ndev,
> +						   cpsw->rx_ch_num);
> +		if (ret) {
> +			dev_err(priv->dev, "cannot set real number of rx queues\n");
> +			goto err;
> +		}
> +
> +		netif_dormant_off(slave->ndev);
> +	}
> +
> +	if (cpsw_common_res_usage_state(cpsw)) {
> +		if (cpsw_fill_rx_channels(priv))
> +			goto err;
> +
> +		cpdma_ctlr_start(cpsw->dma);
> +		cpsw_intr_enable(cpsw);
> +	}
> +
> +	for (i = cpsw->data.slaves, slave = cpsw->slaves; i; i--, slave++) {
> +		if (!(slave->ndev && netif_running(slave->ndev)))
> +			continue;
> +		netif_tx_start_all_queues(slave->ndev);
> +	}
> +
> +	return 0;
> +err:
> +	dev_err(priv->dev, "cannot update channels number, closing device\n");
> +	dev_close(ndev);
> +	return ret;
> +}
> +
>  static const struct ethtool_ops cpsw_ethtool_ops = {
>  	.get_drvinfo	= cpsw_get_drvinfo,
>  	.get_msglevel	= cpsw_get_msglevel,
> @@ -2081,6 +2251,8 @@ static const struct ethtool_ops cpsw_ethtool_ops = {
>  	.get_regs	= cpsw_get_regs,
>  	.begin		= cpsw_ethtool_op_begin,
>  	.complete	= cpsw_ethtool_op_complete,
> +	.get_channels	= cpsw_get_channels,
> +	.set_channels	= cpsw_set_channels,
>  };
>  
>  static void cpsw_slave_init(struct cpsw_slave *slave, struct cpsw_common *cpsw,
>