Re: [PATCH net-next] net: ethernet: ti: cpsw: replace unnecessarily macroses on functions

[Ivan Khoronzhuk]

On Fri, Jul 27, 2018 at 12:21:07PM -0700, Joe Perches wrote:
> On Fri, 2018-07-27 at 22:13 +0300, Ivan Khoronzhuk wrote:
> > Replace ugly macroses on functions.
>
> Careful, see below.
>
> > diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
> []
> > @@ -565,40 +565,40 @@ static const struct cpsw_stats cpsw_gstrings_ch_stats[] = {
> >  				(func)(slave++, ##arg);			\
> >  	} while (0)
> >
> > -#define cpsw_dual_emac_src_port_detect(cpsw, status, ndev, skb)		\
> > -	do {								\
> > -		if (!cpsw->data.dual_emac)				\
> > -			break;						\
> > -		if (CPDMA_RX_SOURCE_PORT(status) == 1) {		\
> > -			ndev = cpsw->slaves[0].ndev;			\
> > -			skb->dev = ndev;				\
> > -		} else if (CPDMA_RX_SOURCE_PORT(status) == 2) {		\
> > -			ndev = cpsw->slaves[1].ndev;			\
> > -			skb->dev = ndev;				\
> > -		}							\
> > -	} while (0)
> > -#define cpsw_add_mcast(cpsw, priv, addr)				\
> > -	do {								\
> > -		if (cpsw->data.dual_emac) {				\
> > -			struct cpsw_slave *slave = cpsw->slaves +	\
> > -						priv->emac_port;	\
> > -			int slave_port = cpsw_get_slave_port(		\
> > -						slave->slave_num);	\
> > -			cpsw_ale_add_mcast(cpsw->ale, addr,		\
> > -				1 << slave_port | ALE_PORT_HOST,	\
> > -				ALE_VLAN, slave->port_vlan, 0);		\
> > -		} else {						\
> > -			cpsw_ale_add_mcast(cpsw->ale, addr,		\
> > -				ALE_ALL_PORTS,				\
> > -				0, 0, 0);				\
> > -		}							\
> > -	} while (0)
> > -
> >  static inline int cpsw_get_slave_port(u32 slave_num)
> >  {
> >  	return slave_num + 1;
> >  }
> >
> > +static inline void cpsw_src_port_detect(struct cpsw_common *cpsw, int status,
> > +					struct sk_buff *skb)
> > +{
> > +	if (!cpsw->data.dual_emac)
> > +		return;
> > +
> > +	if (CPDMA_RX_SOURCE_PORT(status) == 1)
> > +		skb->dev = cpsw->slaves[0].ndev;
> > +	else if (CPDMA_RX_SOURCE_PORT(status) == 2)
> > +		skb->dev = cpsw->slaves[1].ndev;
> > +}
>
> perhaps better as a switch/case
not better, it's shorter.

> > +
> > +static void cpsw_add_mcast(struct cpsw_priv *priv, u8 *addr)
> > +{
> > +	struct cpsw_common *cpsw = priv->cpsw;
> > +
> > +	if (cpsw->data.dual_emac) {
> > +		struct cpsw_slave *slave = cpsw->slaves + priv->emac_port;
> > +		int slave_port = cpsw_get_slave_port(slave->slave_num);
> > +
> > +		cpsw_ale_add_mcast(cpsw->ale, addr,
> > +				   1 << slave_port | ALE_PORT_HOST,
> > +				   ALE_VLAN, slave->port_vlan, 0);
> > +		return;
> > +	}
> > +
> > +	cpsw_ale_add_mcast(cpsw->ale, addr, ALE_ALL_PORTS, 0, 0, 0);
> > +}
> > +
> >  static void cpsw_set_promiscious(struct net_device *ndev, bool enable)
> >  {
> >  	struct cpsw_common *cpsw = ndev_to_cpsw(ndev);
> > @@ -706,7 +706,7 @@ static void cpsw_ndo_set_rx_mode(struct net_device *ndev)
> >
> >  		/* program multicast address list into ALE register */
> >  		netdev_for_each_mc_addr(ha, ndev) {
> > -			cpsw_add_mcast(cpsw, priv, (u8 *)ha->addr);
> > +			cpsw_add_mcast(priv, (u8 *)ha->addr);
> >  		}
> >  	}
> >  }
> > @@ -801,7 +801,8 @@ static void cpsw_rx_handler(void *token, int len, int status)
> >  	int			ret = 0;
> >  	struct cpsw_common	*cpsw = ndev_to_cpsw(ndev);
> >
> > -	cpsw_dual_emac_src_port_detect(cpsw, status, ndev, skb);
> > +	cpsw_src_port_detect(cpsw, status, skb);
> > +	ndev = skb->dev;
>
> This is not the same code as the new function
> is not guaranteed to succeed or set skb->dev.
Guaranteed by above skb->dev is initialized already.
The function reflects previous macro.

Even more, seems that here is duplication of ndev=skb->dev;
It should be removed at init ), even if it 100% is optimized by complier.
So guaranteed a little more then needed ), will send v2 with removed
ndev = skb->dev at init if no objection.

> >  	if (unlikely(status < 0) || unlikely(!netif_running(ndev))) {
> >  		/* In dual emac mode check for all interfaces */

--
Regards,
Ivan Khoronzhuk