net: dsa: support VLAN filtering switchdev attr

When a user explicitly requests VLAN filtering with something like:

    # echo 1 > /sys/class/net/<bridge>/bridge/vlan_filtering

Switchdev propagates a SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING port
attribute.

Add support for it in the DSA layer with a new port_vlan_filtering
function to let drivers toggle 802.1Q filtering on user demand.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 23 insertions, 0 deletions

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 3dd54867174a..26c0a3fa009a 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -305,6 +305,8 @@ struct dsa_switch_driver {
         /*
          * VLAN support
          */
+        int     (*port_vlan_filtering)(struct dsa_switch *ds, int port,
+                                       bool vlan_filtering);
         int     (*port_vlan_prepare)(struct dsa_switch *ds, int port,
                                      const struct switchdev_obj_port_vlan *vlan,
                                      struct switchdev_trans *trans);
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index cde29239b60d..27bf03d11670 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -317,6 +317,24 @@ static int dsa_slave_stp_update(struct net_device *dev, u8 state)
         return ret;
 }
 
+static int dsa_slave_vlan_filtering(struct net_device *dev,
+                                    const struct switchdev_attr *attr,
+                                    struct switchdev_trans *trans)
+{
+        struct dsa_slave_priv *p = netdev_priv(dev);
+        struct dsa_switch *ds = p->parent;
+
+        /* bridge skips -EOPNOTSUPP, so skip the prepare phase */
+        if (switchdev_trans_ph_prepare(trans))
+                return 0;
+
+        if (ds->drv->port_vlan_filtering)
+                return ds->drv->port_vlan_filtering(ds, p->port,
+                                                    attr->u.vlan_filtering);
+
+        return 0;
+}
+
 static int dsa_slave_port_attr_set(struct net_device *dev,
                                    const struct switchdev_attr *attr,
                                    struct switchdev_trans *trans)
@@ -333,6 +351,9 @@ static int dsa_slave_port_attr_set(struct net_device *dev,
                         ret = ds->drv->port_stp_update(ds, p->port,
                                                        attr->u.stp_state);
                 break;
+        case SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING:
+                ret = dsa_slave_vlan_filtering(dev, attr, trans);
+                break;
         default:
                 ret = -EOPNOTSUPP;
                 break;