Re: [PATCH net-next 2/5] net: hns3: support ndo_select_queue()

[huangguangbin (A)]

On 2022/9/6 21:15, Paolo Abeni wrote:
> On Mon, 2022-09-05 at 16:15 +0800, Guangbin Huang wrote:
> > To support tx packets to select queue according to its dscp field after
> > setting dscp and tc map relationship, this patch implements
> > ndo_select_queue() to set skb->priority according to the user's setting
> > dscp and priority map relationship.
> >
> > Signed-off-by: Guangbin Huang <huangguangbin2@xxxxxxxxxx>
> > ---
> >   .../net/ethernet/hisilicon/hns3/hns3_enet.c   | 46 +++++++++++++++++++
> >   1 file changed, 46 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > index 481a300819ad..82f83e3f8162 100644
> > --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
> > @@ -2963,6 +2963,51 @@ static int hns3_nic_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
> >   	return h->ae_algo->ops->set_vf_mac(h, vf_id, mac);
> >   }
> >   
> > +#define HNS3_INVALID_DSCP		0xff
> > +#define HNS3_DSCP_SHIFT			2
> > +
> > +static u8 hns3_get_skb_dscp(struct sk_buff *skb)
> > +{
> > +	__be16 protocol = skb->protocol;
> > +	u8 dscp = HNS3_INVALID_DSCP;
> > +
> > +	if (protocol == htons(ETH_P_8021Q))
> > +		protocol = vlan_get_protocol(skb);
> > +
> > +	if (protocol == htons(ETH_P_IP))
> > +		dscp = ipv4_get_dsfield(ip_hdr(skb)) >> HNS3_DSCP_SHIFT;
> > +	else if (protocol == htons(ETH_P_IPV6))
> > +		dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> HNS3_DSCP_SHIFT;
> > +
> > +	return dscp;
> > +}
> > +
> > +static u16 hns3_nic_select_queue(struct net_device *netdev,
> > +				 struct sk_buff *skb,
> > +				 struct net_device *sb_dev)
> > +{
> > +	struct hnae3_handle *h = hns3_get_handle(netdev);
> > +	u8 dscp, priority;
> > +	int ret;
> > +
> > +	if (h->kinfo.tc_map_mode != HNAE3_TC_MAP_MODE_DSCP ||
> > +	    !h->ae_algo->ops->get_dscp_prio)
> > +		goto out;
> > +
> > +	dscp = hns3_get_skb_dscp(skb);
> > +	if (unlikely(dscp == HNS3_INVALID_DSCP))
> > +		goto out;
> > +
> > +	ret = h->ae_algo->ops->get_dscp_prio(h, dscp, NULL, &priority);
>
> This introduces an additional, unneeded indirect call in the fast path,
> you could consider replacing the above with a direct call to
> hclge_get_dscp_prio() - again taking care of the CONFIG_HNS3_DCB
> dependency.
>
> Cheers,
>
> Paolo
>
> .
Ok.