net: dsa: support switchdev ageing time attr

Add a new function for DSA drivers to handle the switchdev
SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME attribute.

The ageing time is passed as milliseconds.

Also because we can have multiple logical bridges on top of a physical
switch and ageing time are switch-wide, call the driver function with
the fastest ageing time in use on the chip instead of the requested one.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 41 insertions, 0 deletions

diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 7236eb26dc97..fc9196745225 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -333,6 +333,44 @@ static int dsa_slave_vlan_filtering(struct net_device *dev,
         return 0;
 }
 
+static int dsa_fastest_ageing_time(struct dsa_switch *ds,
+                                   unsigned int ageing_time)
+{
+        int i;
+
+        for (i = 0; i < DSA_MAX_PORTS; ++i) {
+                struct dsa_port *dp = &ds->ports[i];
+
+                if (dp && dp->ageing_time && dp->ageing_time < ageing_time)
+                        ageing_time = dp->ageing_time;
+        }
+
+        return ageing_time;
+}
+
+static int dsa_slave_ageing_time(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;
+        unsigned long ageing_jiffies = clock_t_to_jiffies(attr->u.ageing_time);
+        unsigned int ageing_time = jiffies_to_msecs(ageing_jiffies);
+
+        /* bridge skips -EOPNOTSUPP, so skip the prepare phase */
+        if (switchdev_trans_ph_prepare(trans))
+                return 0;
+
+        /* Keep the fastest ageing time in case of multiple bridges */
+        ds->ports[p->port].ageing_time = ageing_time;
+        ageing_time = dsa_fastest_ageing_time(ds, ageing_time);
+
+        if (ds->drv->set_ageing_time)
+                return ds->drv->set_ageing_time(ds, ageing_time);
+
+        return 0;
+}
+
 static int dsa_slave_port_attr_set(struct net_device *dev,
                                    const struct switchdev_attr *attr,
                                    struct switchdev_trans *trans)
@@ -346,6 +384,9 @@ static int dsa_slave_port_attr_set(struct net_device *dev,
         case SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING:
                 ret = dsa_slave_vlan_filtering(dev, attr, trans);
                 break;
+        case SWITCHDEV_ATTR_ID_BRIDGE_AGEING_TIME:
+                ret = dsa_slave_ageing_time(dev, attr, trans);
+                break;
         default:
                 ret = -EOPNOTSUPP;
                 break;