diff mbox series

[v2,net-next,13/14] net: mscc: ocelot: rebalance LAGs on link up/down events

Message ID 20210116005943.219479-14-olteanv@gmail.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series LAG offload for Ocelot DSA switches | expand

Checks

Context Check Description
netdev/apply fail Patch does not apply to net-next
netdev/tree_selection success Clearly marked for net-next

Commit Message

Vladimir Oltean Jan. 16, 2021, 12:59 a.m. UTC 
From: Vladimir Oltean <vladimir.oltean@nxp.com>

At present there is an issue when ocelot is offloading a bonding
interface, but one of the links of the physical ports goes down. Traffic
keeps being hashed towards that destination, and of course gets dropped
on egress.

Monitor the netdev notifier events emitted by the bonding driver for
changes in the physical state of lower interfaces, to determine which
ports are active and which ones are no longer.

Then extend ocelot_get_bond_mask to return either the configured bonding
interfaces, or the active ones, depending on a boolean argument. The
code that does rebalancing only needs to do so among the active ports,
whereas the bridge forwarding mask and the logical port IDs still need
to look at the permanently bonded ports.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
Changes in v2:
- Adapt to the merged version of the DSA API, which now passes just a
  bool lag_tx_active in .port_lag_change instead of the full struct
  netdev_lag_lower_state_info *info.
- Renamed "just_active_ports" -> "only_active_ports"

 drivers/net/ethernet/mscc/ocelot.c     | 38 ++++++++++++++++++++------
 drivers/net/ethernet/mscc/ocelot.h     |  1 +
 drivers/net/ethernet/mscc/ocelot_net.c | 30 ++++++++++++++++++++
 include/soc/mscc/ocelot.h              |  1 +
 4 files changed, 61 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 78a468d39e9b..c31a63d9fe2a 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -876,7 +876,8 @@  int ocelot_get_ts_info(struct ocelot *ocelot, int port,
 }
 EXPORT_SYMBOL(ocelot_get_ts_info);
 
-static u32 ocelot_get_bond_mask(struct ocelot *ocelot, struct net_device *bond)
+static u32 ocelot_get_bond_mask(struct ocelot *ocelot, struct net_device *bond,
+				bool only_active_ports)
 {
 	u32 bond_mask = 0;
 	int port;
@@ -887,8 +888,12 @@  static u32 ocelot_get_bond_mask(struct ocelot *ocelot, struct net_device *bond)
 		if (!ocelot_port)
 			continue;
 
-		if (ocelot_port->bond == bond)
+		if (ocelot_port->bond == bond) {
+			if (only_active_ports && !ocelot_port->lag_tx_active)
+				continue;
+
 			bond_mask |= BIT(port);
+		}
 	}
 
 	return bond_mask;
@@ -914,7 +919,7 @@  static void ocelot_apply_bridge_fwd_mask(struct ocelot *ocelot)
 			struct net_device *bond = ocelot_port->bond;
 
 			if (bond)
-				mask &= ~ocelot_get_bond_mask(ocelot, bond);
+				mask &= ~ocelot_get_bond_mask(ocelot, bond, false);
 
 			ocelot_write_rix(ocelot, mask,
 					 ANA_PGID_PGID, PGID_SRC + port);
@@ -1242,22 +1247,22 @@  static int ocelot_set_aggr_pgids(struct ocelot *ocelot)
 		bonds[port] = ocelot_port->bond;
 	}
 
-	/* Now, set PGIDs for each LAG */
+	/* Now, set PGIDs for each active LAG */
 	for (lag = 0; lag < ocelot->num_phys_ports; lag++) {
-		int num_ports_in_lag = 0;
+		int num_active_ports = 0;
 		unsigned long bond_mask;
 		u8 aggr_idx[16];
 
 		if (!bonds[lag])
 			continue;
 
-		bond_mask = ocelot_get_bond_mask(ocelot, bonds[lag]);
+		bond_mask = ocelot_get_bond_mask(ocelot, bonds[lag], true);
 
 		for_each_set_bit(port, &bond_mask, ocelot->num_phys_ports) {
 			// Destination mask
 			ocelot_write_rix(ocelot, bond_mask,
 					 ANA_PGID_PGID, port);
-			aggr_idx[num_ports_in_lag++] = port;
+			aggr_idx[num_active_ports++] = port;
 		}
 
 		for_each_aggr_pgid(ocelot, i) {
@@ -1265,7 +1270,11 @@  static int ocelot_set_aggr_pgids(struct ocelot *ocelot)
 
 			ac = ocelot_read_rix(ocelot, ANA_PGID_PGID, i);
 			ac &= ~bond_mask;
-			ac |= BIT(aggr_idx[i % num_ports_in_lag]);
+			/* Don't do division by zero if there was no active
+			 * port. Just make all aggregation codes zero.
+			 */
+			if (num_active_ports)
+				ac |= BIT(aggr_idx[i % num_active_ports]);
 			ocelot_write_rix(ocelot, ac, ANA_PGID_PGID, i);
 		}
 
@@ -1301,7 +1310,8 @@  static void ocelot_setup_logical_port_ids(struct ocelot *ocelot)
 
 		bond = ocelot_port->bond;
 		if (bond) {
-			int lag = __ffs(ocelot_get_bond_mask(ocelot, bond));
+			int lag = __ffs(ocelot_get_bond_mask(ocelot, bond,
+							     false));
 
 			ocelot_rmw_gix(ocelot,
 				       ANA_PORT_PORT_CFG_PORTID_VAL(lag),
@@ -1342,6 +1352,16 @@  int ocelot_port_lag_leave(struct ocelot *ocelot, int port,
 }
 EXPORT_SYMBOL(ocelot_port_lag_leave);
 
+int ocelot_port_lag_change(struct ocelot *ocelot, int port, bool lag_tx_active)
+{
+	struct ocelot_port *ocelot_port = ocelot->ports[port];
+
+	ocelot_port->lag_tx_active = lag_tx_active;
+
+	/* Rebalance the LAGs */
+	return ocelot_set_aggr_pgids(ocelot);
+}
+
 /* Configure the maximum SDU (L2 payload) on RX to the value specified in @sdu.
  * The length of VLAN tags is accounted for automatically via DEV_MAC_TAGS_CFG.
  * In the special case that it's the NPI port that we're configuring, the
diff --git a/drivers/net/ethernet/mscc/ocelot.h b/drivers/net/ethernet/mscc/ocelot.h
index c018a54f4e49..fc055525fd88 100644
--- a/drivers/net/ethernet/mscc/ocelot.h
+++ b/drivers/net/ethernet/mscc/ocelot.h
@@ -114,6 +114,7 @@  int ocelot_port_lag_join(struct ocelot *ocelot, int port,
 			 struct netdev_lag_upper_info *info);
 int ocelot_port_lag_leave(struct ocelot *ocelot, int port,
 			  struct net_device *bond);
+int ocelot_port_lag_change(struct ocelot *ocelot, int port, bool lag_tx_active);
 struct net_device *ocelot_port_to_netdev(struct ocelot *ocelot, int port);
 int ocelot_netdev_to_port(struct net_device *dev);
 
diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 871bfbaa8ff1..3cba1c2de6fe 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -1163,6 +1163,27 @@  ocelot_netdevice_lag_changeupper(struct net_device *dev,
 	return NOTIFY_DONE;
 }
 
+static int
+ocelot_netdevice_changelowerstate(struct net_device *dev,
+				  struct netdev_lag_lower_state_info *info)
+{
+	struct ocelot_port_private *priv = netdev_priv(dev);
+	bool is_active = info->link_up && info->tx_enabled;
+	struct ocelot_port *ocelot_port = &priv->port;
+	struct ocelot *ocelot = ocelot_port->ocelot;
+	int port = priv->chip_port;
+	int err;
+
+	if (!ocelot_port->bond)
+		return NOTIFY_DONE;
+
+	if (ocelot_port->lag_tx_active == is_active)
+		return 0;
+
+	err = ocelot_port_lag_change(ocelot, port, is_active);
+	return notifier_from_errno(err);
+}
+
 static int ocelot_netdevice_event(struct notifier_block *unused,
 				  unsigned long event, void *ptr)
 {
@@ -1180,6 +1201,15 @@  static int ocelot_netdevice_event(struct notifier_block *unused,
 
 		break;
 	}
+	case NETDEV_CHANGELOWERSTATE: {
+		struct netdev_notifier_changelowerstate_info *info = ptr;
+
+		if (!ocelot_netdevice_dev_check(dev))
+			break;
+
+		return ocelot_netdevice_changelowerstate(dev,
+							 info->lower_state_info);
+	}
 	default:
 		break;
 	}
diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index 1bb16527f490..7bd7c58a7490 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -612,6 +612,7 @@  struct ocelot_port {
 	u8				*xmit_template;
 
 	struct net_device		*bond;
+	bool				lag_tx_active;
 };
 
 struct ocelot {