On Mon, Apr 26, 2021 at 07:04:08PM +0200, Tobias Waldekranz wrote:
> Allow DSA drivers to support forward offloading from a bridge by:
>
> - Passing calls to .ndo_dfwd_{add,del}_station to the drivers.
>
> - Recording the subordinate device of offloaded skbs in the control
> buffer so that the tagger can take the appropriate action.
>
> Signed-off-by: Tobias Waldekranz <tobias@xxxxxxxxxxxxxx>
> ---
> include/net/dsa.h | 7 +++++++
> net/dsa/slave.c | 36 ++++++++++++++++++++++++++++++++++--
> 2 files changed, 41 insertions(+), 2 deletions(-)
>
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index 1f9ba9889034..77d4df819299 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -119,6 +119,7 @@ struct dsa_netdevice_ops {
>
> struct dsa_skb_cb {
> struct sk_buff *clone;
> + struct net_device *sb_dev;
> };
>
> struct __dsa_skb_cb {
> @@ -828,6 +829,12 @@ struct dsa_switch_ops {
> const struct switchdev_obj_ring_role_mrp *mrp);
> int (*port_mrp_del_ring_role)(struct dsa_switch *ds, int port,
> const struct switchdev_obj_ring_role_mrp *mrp);
> +
> + /* L2 forward offloading */
> + void * (*dfwd_add_station)(struct dsa_switch *ds, int port,
> + struct net_device *sb_dev);
> + void (*dfwd_del_station)(struct dsa_switch *ds, int port,
> + struct net_device *sb_dev);
> };
>
> #define DSA_DEVLINK_PARAM_DRIVER(_id, _name, _type, _cmodes) \
> diff --git a/net/dsa/slave.c b/net/dsa/slave.c
> index 77b33bd161b8..3689ffa2dbb8 100644
> --- a/net/dsa/slave.c
> +++ b/net/dsa/slave.c
> @@ -657,6 +657,13 @@ static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev)
> return dsa_enqueue_skb(nskb, dev);
> }
>
> +static u16 dsa_slave_select_queue(struct net_device *dev, struct sk_buff *skb,
> + struct net_device *sb_dev)
> +{
> + DSA_SKB_CB(skb)->sb_dev = sb_dev;
> + return netdev_pick_tx(dev, skb, sb_dev);
> +}
> +
DSA_SKB_CB is going away:
https://patchwork.kernel.org/project/netdevbpf/patch/20210427042203.26258-5-yangbo.lu@xxxxxxx/
Let's either negotiate with Yangbo on keeping it, or make
.ndo_select_queue a bypass towards the tagger, where it can use its own
SKB_CB structure and be more flexible in general (I think I'm leaning
towards the latter).
