@@ -579,6 +579,16 @@ struct dsa_switch_ops {
struct devlink_param_gset_ctx *ctx);
int (*devlink_param_set)(struct dsa_switch *ds, u32 id,
struct devlink_param_gset_ctx *ctx);
+
+ /*
+ * MTU change functionality. Switches can also adjust their MRU through
+ * this method. By MTU, one understands the SDU (L2 payload) length.
+ * If the switch needs to account for the DSA tag on the CPU port, this
+ * method needs to to do so privately.
+ */
+ int (*port_change_mtu)(struct dsa_switch *ds, int port,
+ int new_mtu);
+ int (*port_max_mtu)(struct dsa_switch *ds, int port);
};
#define DSA_DEVLINK_PARAM_DRIVER(_id, _name, _type, _cmodes) \
@@ -22,6 +22,7 @@ enum {
DSA_NOTIFIER_MDB_DEL,
DSA_NOTIFIER_VLAN_ADD,
DSA_NOTIFIER_VLAN_DEL,
+ DSA_NOTIFIER_MTU,
};
/* DSA_NOTIFIER_AGEING_TIME */
@@ -61,6 +62,14 @@ struct dsa_notifier_vlan_info {
int port;
};
+/* DSA_NOTIFIER_MTU */
+struct dsa_notifier_mtu_info {
+ bool propagate_upstream;
+ int sw_index;
+ int port;
+ int mtu;
+};
+
struct dsa_slave_priv {
/* Copy of CPU port xmit for faster access in slave transmit hot path */
struct sk_buff * (*xmit)(struct sk_buff *skb,
@@ -127,6 +136,8 @@ int dsa_port_vlan_filtering(struct dsa_port *dp, bool vlan_filtering,
struct switchdev_trans *trans);
int dsa_port_ageing_time(struct dsa_port *dp, clock_t ageing_clock,
struct switchdev_trans *trans);
+int dsa_port_mtu_change(struct dsa_port *dp, int new_mtu,
+ bool propagate_upstream);
int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
u16 vid);
int dsa_port_fdb_del(struct dsa_port *dp, const unsigned char *addr,
@@ -314,20 +314,6 @@ static const struct attribute_group dsa_group = {
.attrs = dsa_slave_attrs,
};
-static void dsa_master_set_mtu(struct net_device *dev, struct dsa_port *cpu_dp)
-{
- unsigned int mtu = ETH_DATA_LEN + cpu_dp->tag_ops->overhead;
- int err;
-
- rtnl_lock();
- if (mtu <= dev->max_mtu) {
- err = dev_set_mtu(dev, mtu);
- if (err)
- netdev_dbg(dev, "Unable to set MTU to include for DSA overheads\n");
- }
- rtnl_unlock();
-}
-
static void dsa_master_reset_mtu(struct net_device *dev)
{
int err;
@@ -344,7 +330,12 @@ int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
{
int ret;
- dsa_master_set_mtu(dev, cpu_dp);
+ rtnl_lock();
+ ret = dev_set_mtu(dev, ETH_DATA_LEN + cpu_dp->tag_ops->overhead);
+ rtnl_unlock();
+ if (ret)
+ netdev_warn(dev, "error %d setting MTU to include DSA overhead\n",
+ ret);
/* If we use a tagging format that doesn't have an ethertype
* field, make sure that all packets from this point on get
@@ -297,6 +297,19 @@ int dsa_port_mrouter(struct dsa_port *dp, bool mrouter,
return ds->ops->port_egress_floods(ds, port, true, mrouter);
}
+int dsa_port_mtu_change(struct dsa_port *dp, int new_mtu,
+ bool propagate_upstream)
+{
+ struct dsa_notifier_mtu_info info = {
+ .sw_index = dp->ds->index,
+ .propagate_upstream = propagate_upstream,
+ .port = dp->index,
+ .mtu = new_mtu,
+ };
+
+ return dsa_port_notify(dp, DSA_NOTIFIER_MTU, &info);
+}
+
int dsa_port_fdb_add(struct dsa_port *dp, const unsigned char *addr,
u16 vid)
{
@@ -1218,6 +1218,96 @@ static int dsa_slave_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
return dsa_port_vid_del(dp, vid);
}
+static int dsa_slave_change_mtu(struct net_device *dev, int new_mtu)
+{
+ struct net_device *master = dsa_slave_to_master(dev);
+ struct dsa_port *dp = dsa_slave_to_port(dev);
+ struct dsa_slave_priv *p = netdev_priv(dev);
+ struct dsa_switch *ds = p->dp->ds;
+ struct dsa_port *cpu_dp;
+ int port = p->dp->index;
+ int largest_mtu = 0;
+ int new_master_mtu;
+ int old_master_mtu;
+ int mtu_limit;
+ int cpu_mtu;
+ int err, i;
+
+ if (!ds->ops->port_change_mtu)
+ return -EOPNOTSUPP;
+
+ for (i = 0; i < ds->num_ports; i++) {
+ int slave_mtu;
+
+ if (!dsa_is_user_port(ds, i))
+ continue;
+
+ /* During probe, this function will be called for each slave
+ * device, while not all of them have been allocated. That's
+ * ok, it doesn't change what the maximum is, so ignore it.
+ */
+ if (!dsa_to_port(ds, i)->slave)
+ continue;
+
+ /* Pretend that we already applied the setting, which we
+ * actually haven't (still haven't done all integrity checks)
+ */
+ if (i == port)
+ slave_mtu = new_mtu;
+ else
+ slave_mtu = dsa_to_port(ds, i)->slave->mtu;
+
+ if (largest_mtu < slave_mtu)
+ largest_mtu = slave_mtu;
+ }
+
+ cpu_dp = dsa_to_port(ds, port)->cpu_dp;
+
+ mtu_limit = min_t(int, master->max_mtu, dev->max_mtu);
+ old_master_mtu = master->mtu;
+ new_master_mtu = largest_mtu + cpu_dp->tag_ops->overhead;
+ if (new_master_mtu > mtu_limit)
+ return -ERANGE;
+
+ /* If the master MTU isn't over limit, there's no need to check the CPU
+ * MTU, since that surely isn't either.
+ */
+ cpu_mtu = largest_mtu;
+
+ /* Start applying stuff */
+ if (new_master_mtu != old_master_mtu) {
+ err = dev_set_mtu(master, new_master_mtu);
+ if (err < 0)
+ goto out_master_failed;
+
+ /* We only need to propagate the MTU of the CPU port to
+ * upstream switches.
+ */
+ err = dsa_port_mtu_change(cpu_dp, cpu_mtu, true);
+ if (err)
+ goto out_cpu_failed;
+ }
+
+ err = dsa_port_mtu_change(dp, new_mtu, false);
+ if (err)
+ goto out_port_failed;
+
+ dev->mtu = new_mtu;
+
+ return 0;
+
+out_port_failed:
+ if (new_master_mtu != old_master_mtu)
+ dsa_port_mtu_change(cpu_dp, old_master_mtu -
+ cpu_dp->tag_ops->overhead,
+ true);
+out_cpu_failed:
+ if (new_master_mtu != old_master_mtu)
+ dev_set_mtu(master, old_master_mtu);
+out_master_failed:
+ return err;
+}
+
static const struct ethtool_ops dsa_slave_ethtool_ops = {
.get_drvinfo = dsa_slave_get_drvinfo,
.get_regs_len = dsa_slave_get_regs_len,
@@ -1295,6 +1385,7 @@ static const struct net_device_ops dsa_slave_netdev_ops = {
.ndo_vlan_rx_add_vid = dsa_slave_vlan_rx_add_vid,
.ndo_vlan_rx_kill_vid = dsa_slave_vlan_rx_kill_vid,
.ndo_get_devlink_port = dsa_slave_get_devlink_port,
+ .ndo_change_mtu = dsa_slave_change_mtu,
};
static struct device_type dsa_type = {
@@ -1465,7 +1556,10 @@ int dsa_slave_create(struct dsa_port *port)
slave_dev->priv_flags |= IFF_NO_QUEUE;
slave_dev->netdev_ops = &dsa_slave_netdev_ops;
slave_dev->min_mtu = 0;
- slave_dev->max_mtu = ETH_MAX_MTU;
+ if (ds->ops->port_max_mtu)
+ slave_dev->max_mtu = ds->ops->port_max_mtu(ds, port->index);
+ else
+ slave_dev->max_mtu = ETH_MAX_MTU;
SET_NETDEV_DEVTYPE(slave_dev, &dsa_type);
SET_NETDEV_DEV(slave_dev, port->ds->dev);
@@ -1483,6 +1577,15 @@ int dsa_slave_create(struct dsa_port *port)
p->xmit = cpu_dp->tag_ops->xmit;
port->slave = slave_dev;
+ rtnl_lock();
+ ret = dsa_slave_change_mtu(slave_dev, ETH_DATA_LEN);
+ rtnl_unlock();
+ if (ret && ret != -EOPNOTSUPP) {
+ dev_err(ds->dev, "error %d setting MTU on port %d\n",
+ ret, port->index);
+ goto out_free;
+ }
+
netif_carrier_off(slave_dev);
ret = dsa_slave_phy_setup(slave_dev);
@@ -52,6 +52,40 @@ static int dsa_switch_ageing_time(struct dsa_switch *ds,
return 0;
}
+static bool dsa_switch_mtu_match(struct dsa_switch *ds, int port,
+ struct dsa_notifier_mtu_info *info)
+{
+ if (ds->index == info->sw_index)
+ return (port == info->port) || dsa_is_dsa_port(ds, port);
+
+ if (!info->propagate_upstream)
+ return false;
+
+ if (dsa_is_dsa_port(ds, port) || dsa_is_cpu_port(ds, port))
+ return true;
+
+ return false;
+}
+
+static int dsa_switch_mtu(struct dsa_switch *ds,
+ struct dsa_notifier_mtu_info *info)
+{
+ int port, ret;
+
+ if (!ds->ops->port_change_mtu)
+ return -EOPNOTSUPP;
+
+ for (port = 0; port < ds->num_ports; port++) {
+ if (dsa_switch_mtu_match(ds, port, info)) {
+ ret = ds->ops->port_change_mtu(ds, port, info->mtu);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
static int dsa_switch_bridge_join(struct dsa_switch *ds,
struct dsa_notifier_bridge_info *info)
{
@@ -328,6 +362,9 @@ static int dsa_switch_event(struct notifier_block *nb,
case DSA_NOTIFIER_VLAN_DEL:
err = dsa_switch_vlan_del(ds, info);
break;
+ case DSA_NOTIFIER_MTU:
+ err = dsa_switch_mtu(ds, info);
+ break;
default:
err = -EOPNOTSUPP;
break;