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Message-ID: <bf9b90a5-63c7-ac9d-385f-cd0c60de7eee@blackwall.org>
Date:   Mon, 14 Mar 2022 12:42:18 +0200
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Subject: Re: [PATCH v3 net-next 07/14] net: bridge: mst: Add helper to map an
 MSTI to a VID set
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To:     Tobias Waldekranz <tobias@waldekranz.com>, davem@davemloft.net,
        kuba@kernel.org
Cc:     Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        Jiri Pirko <jiri@resnulli.us>,
        Ivan Vecera <ivecera@redhat.com>,
        Roopa Prabhu <roopa@nvidia.com>,
        Russell King <linux@armlinux.org.uk>,
        Ido Schimmel <idosch@nvidia.com>,
        Petr Machata <petrm@nvidia.com>,
        Cooper Lees <me@cooperlees.com>,
        Matt Johnston <matt@codeconstruct.com.au>,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        bridge@lists.linux-foundation.org
References: <20220314095231.3486931-1-tobias@waldekranz.com>
 <20220314095231.3486931-8-tobias@waldekranz.com>
From:   Nikolay Aleksandrov <razor@blackwall.org>
In-Reply-To: <20220314095231.3486931-8-tobias@waldekranz.com>
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Precedence: bulk

On 14/03/2022 11:52, Tobias Waldekranz wrote:
> br_mst_get_info answers the question: "On this bridge, which VIDs are
> mapped to the given MSTI?"
> 
> This is useful in switchdev drivers, which might have to fan-out
> operations, relating to an MSTI, per VLAN.
> 
> An example: When a port's MST state changes from forwarding to
> blocking, a driver may choose to flush the dynamic FDB entries on that
> port to get faster reconvergence of the network, but this should only
> be done in the VLANs that are managed by the MSTI in question.
> 
> Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
> ---
>  include/linux/if_bridge.h |  6 ++++++
>  net/bridge/br_mst.c       | 26 ++++++++++++++++++++++++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
> index 3aae023a9353..46e6327fef06 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);
> +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)
>  {
> @@ -151,6 +152,11 @@ static inline int br_vlan_get_info_rcu(const struct net_device *dev, u16 vid,
>  {
>  	return -EINVAL;
>  }
> +static inline int br_mst_get_info(struct net_device *dev, u16 msti,
> +				  unsigned long *vids)
> +{
> +	return -EINVAL;
> +}
>  #endif
>  
>  #if IS_ENABLED(CONFIG_BRIDGE)
> diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
> index 7d16926a3a31..eb18dbd5838f 100644
> --- a/net/bridge/br_mst.c
> +++ b/net/bridge/br_mst.c
> @@ -13,6 +13,32 @@
>  
>  DEFINE_STATIC_KEY_FALSE(br_mst_used);
>  
> +int br_mst_get_info(struct net_device *dev, u16 msti, unsigned long *vids)
> +{
> +	struct net_bridge_vlan_group *vg;
> +	struct net_bridge_vlan *v;
> +	struct net_bridge *br;

const dev, vg, v, br

> +
> +	ASSERT_RTNL();
> +
> +	if (!netif_is_bridge_master(dev))
> +		return -EINVAL;
> +
> +	br = netdev_priv(dev);
> +	if (!br_opt_get(br, BROPT_MST_ENABLED))
> +		return -EINVAL;
> +
> +	vg = br_vlan_group(br);
> +
> +	list_for_each_entry(v, &vg->vlan_list, vlist) {
> +		if (v->msti == msti)
> +			set_bit(v->vid, vids);

__set_bit()

> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(br_mst_get_info);

EXPORT_SYMBOL_GPL

> +
>  static void br_mst_vlan_set_state(struct net_bridge_port *p, struct net_bridge_vlan *v,
>  				  u8 state)
>  {