Re: [PATCH net-next v2 07/12] net: dsa: Add ability to program multicast filter for CPU port

[Vivien Didelot]

Hi Florian,

On Tue, 29 Jan 2019 16:55:43 -0800, Florian Fainelli <f.faine...@gmail.com> 
wrote:

> +static int dsa_slave_sync_unsync_mdb_addr(struct net_device *dev,
> +                                       const unsigned char *addr, bool add)
> +{
> +     struct switchdev_obj_port_mdb mdb = {
> +             .obj = {
> +                     .id = SWITCHDEV_OBJ_ID_HOST_MDB,
> +                     .flags = SWITCHDEV_F_DEFER,
> +             },
> +             .vid = 0,
> +     };
> +     int ret = -EOPNOTSUPP;

Assignment unneeded here.

> +
> +     ether_addr_copy(mdb.addr, addr);
> +     if (add)
> +             ret = switchdev_port_obj_add(dev, &mdb.obj, NULL);
> +     else
> +             ret = switchdev_port_obj_del(dev, &mdb.obj);
> +
> +     return ret;
> +}
> +
> +static int dsa_slave_sync_mdb_addr(struct net_device *dev,
> +                                const unsigned char *addr)
> +{
> +     return dsa_slave_sync_unsync_mdb_addr(dev, addr, true);
> +}
> +
> +static int dsa_slave_unsync_mdb_addr(struct net_device *dev,
> +                                  const unsigned char *addr)
> +{
> +     return dsa_slave_sync_unsync_mdb_addr(dev, addr, false);
> +}

This wrapper isn't necessary IMO. I'd go with something like:

static int dsa_slave_sync(struct net_device *dev, const unsigned char *addr)
{
        struct switchdev_obj_port_mdb mdb = {
                .obj.id = SWITCHDEV_OBJ_ID_HOST_MDB,
                .obj.flags = SWITCHDEV_F_DEFER,
        };

        ether_addr_copy(mdb.addr, addr);

        return switchdev_port_obj_add(dev, &mdb.obj, NULL);
}

static int dsa_slave_unsync(struct net_device *dev, const unsigned char *addr)
{
        struct switchdev_obj_port_mdb mdb = {
                .obj.id = SWITCHDEV_OBJ_ID_HOST_MDB,
                .obj.flags = SWITCHDEV_F_DEFER,
        };

        ether_addr_copy(mdb.addr, addr);

        return switchdev_port_obj_del(dev, &mdb.obj);
}

We may eventually wrap this cryptic netdevery in:

static int dsa_slave_mc_sync(struct net_device *dev)
{
        return __hw_addr_sync_dev(&dev->mc, dev, dsa_slave_sync, 
dsa_slave_unsync);
}

static void dsa_slave_mc_unsync(struct net_device *dev)
{
        __hw_addr_unsync_dev(&dev->mc, dev, dsa_slave_sync);
}

> +
>  static int dsa_slave_open(struct net_device *dev)
>  {
>       struct net_device *master = dsa_slave_to_master(dev);
> @@ -126,6 +159,8 @@ static int dsa_slave_close(struct net_device *dev)
>  
>       dev_mc_unsync(master, dev);
>       dev_uc_unsync(master, dev);
> +     __hw_addr_unsync_dev(&dev->mc, dev, dsa_slave_unsync_mdb_addr);
> +
>       if (dev->flags & IFF_ALLMULTI)
>               dev_set_allmulti(master, -1);
>       if (dev->flags & IFF_PROMISC)
> @@ -150,7 +185,17 @@ static void dsa_slave_change_rx_flags(struct net_device 
> *dev, int change)
>  static void dsa_slave_set_rx_mode(struct net_device *dev)
>  {
>       struct net_device *master = dsa_slave_to_master(dev);
> +     struct dsa_port *dp = dsa_slave_to_port(dev);
>  
> +     /* If the port is bridged, the bridge takes care of sending
> +      * SWITCHDEV_OBJ_ID_HOST_MDB to program the host's MC filter
> +      */
> +     if (netdev_mc_empty(dev) || dp->bridge_dev)
> +             goto out;
> +
> +     __hw_addr_sync_dev(&dev->mc, dev, dsa_slave_sync_mdb_addr,
> +                        dsa_slave_unsync_mdb_addr);

And check the returned error code.

> +out:
>       dev_mc_sync(master, dev);
>       dev_uc_sync(master, dev);
>  }


Thanks,

        Vivien