Re: [Bridge] [PATCH v3 net-next 08/14] net: bridge: mst: Add helper to check if MST is enabled

[Nikolay Aleksandrov]

On 14/03/2022 11:52, Tobias Waldekranz wrote:
> This is useful for switchdev drivers that might want to refuse to join
> a bridge where MST is enabled, if the hardware can't support it.
> 
> Signed-off-by: Tobias Waldekranz <tob...@waldekranz.com>
> ---
>  include/linux/if_bridge.h | 5 +++++
>  net/bridge/br_mst.c       | 9 +++++++++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
> index 46e6327fef06..5dbab0a280a6 100644
> --- a/include/linux/if_bridge.h
> +++ b/include/linux/if_bridge.h
> @@ -119,6 +119,7 @@ int br_vlan_get_info(const struct net_device *dev, u16 
> vid,
>                    struct bridge_vlan_info *p_vinfo);
>  int br_vlan_get_info_rcu(const struct net_device *dev, u16 vid,
>                        struct bridge_vlan_info *p_vinfo);
> +bool br_mst_enabled(struct net_device *dev);
>  int br_mst_get_info(struct net_device *dev, u16 msti, unsigned long *vids);
>  #else
>  static inline bool br_vlan_enabled(const struct net_device *dev)
> @@ -152,6 +153,10 @@ static inline int br_vlan_get_info_rcu(const struct 
> net_device *dev, u16 vid,
>  {
>       return -EINVAL;
>  }
> +static inline bool br_mst_enabled(struct net_device *dev)
> +{
> +     return false;
> +}
>  static inline int br_mst_get_info(struct net_device *dev, u16 msti,
>                                 unsigned long *vids)
>  {
> diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
> index eb18dbd5838f..e5ab2ce451c2 100644
> --- a/net/bridge/br_mst.c
> +++ b/net/bridge/br_mst.c
> @@ -13,6 +13,15 @@
>  
>  DEFINE_STATIC_KEY_FALSE(br_mst_used);
>  
> +bool br_mst_enabled(struct net_device *dev)

const dev

> +{
> +     if (!netif_is_bridge_master(dev))
> +             return false;
> +
> +     return br_opt_get(netdev_priv(dev), BROPT_MST_ENABLED);
> +}
> +EXPORT_SYMBOL(br_mst_enabled);

EXPORT_SYMBOL_GPL

> +
>  int br_mst_get_info(struct net_device *dev, u16 msti, unsigned long *vids)
>  {
>       struct net_bridge_vlan_group *vg;