Re: [PATCH v5 net-next 08/15] net: bridge: mst: Add helper to check if MST is enabled

[Vladimir Oltean <olteanv@gmail.com>]

On Wed, Mar 16, 2022 at 04:08:50PM +0100, 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 <tobias@waldekranz.com>
> ---

Reviewed-by: Vladimir Oltean <olteanv@gmail.com>

>  include/linux/if_bridge.h | 6 ++++++
>  net/bridge/br_mst.c       | 9 +++++++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
> index 1cf0cc46d90d..4efd5540279a 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(const struct net_device *dev);
>  int br_mst_get_info(const struct net_device *dev, u16 msti, unsigned long *vids);
>  #else
>  static inline bool br_vlan_enabled(const struct net_device *dev)
> @@ -153,6 +154,11 @@ static inline int br_vlan_get_info_rcu(const struct net_device *dev, u16 vid,
>  	return -EINVAL;
>  }
>  
> +static inline bool br_mst_enabled(const struct net_device *dev)
> +{
> +	return false;
> +}
> +
>  static inline int br_mst_get_info(const struct net_device *dev, u16 msti,
>  				  unsigned long *vids)
>  {
> diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
> index 00b36e629224..830a5746479f 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(const struct net_device *dev)
> +{
> +	if (!netif_is_bridge_master(dev))
> +		return false;
> +
> +	return br_opt_get(netdev_priv(dev), BROPT_MST_ENABLED);
> +}
> +EXPORT_SYMBOL_GPL(br_mst_enabled);
> +
>  int br_mst_get_info(const struct net_device *dev, u16 msti, unsigned long *vids)
>  {
>  	const struct net_bridge_vlan_group *vg;
> -- 
> 2.25.1
>