[PATCH v2 net-next 11/14] net: mscc: ocelot: drop the use of the "lags" array

[Vladimir Oltean <olteanv@gmail.com>]

From: Vladimir Oltean <vladimir.oltean@nxp.com>

We can now simplify the implementation by always using ocelot_get_bond_mask
to look up the other ports that are offloading the same bonding interface
as us.

In ocelot_set_aggr_pgids, the code had a way to uniquely iterate through
LAGs. We need to achieve the same behavior by marking each LAG as visited,
which we do now by temporarily allocating an array of pointers to bonding
uppers of each port, and marking each bonding upper as NULL once it has
been treated by the first port that is a member. And because we now do
some dynamic allocation, we need to propagate errors from
ocelot_set_aggr_pgid all the way to ocelot_port_lag_leave.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
Changes in v2:
Context looks a bit different.

 drivers/net/ethernet/mscc/ocelot.c     | 104 ++++++++++---------------
 drivers/net/ethernet/mscc/ocelot.h     |   4 +-
 drivers/net/ethernet/mscc/ocelot_net.c |   4 +-
 include/soc/mscc/ocelot.h              |   2 -
 4 files changed, 47 insertions(+), 67 deletions(-)

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 1bcf68bd1bff..fa2ebfbb33eb 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -904,21 +904,17 @@ static void ocelot_apply_bridge_fwd_mask(struct ocelot *ocelot)
 	 * source port's forwarding mask.
 	 */
 	for (port = 0; port < ocelot->num_phys_ports; port++) {
-		if (ocelot->bridge_fwd_mask & BIT(port)) {
-			unsigned long mask = ocelot->bridge_fwd_mask & ~BIT(port);
-			int lag;
+		struct ocelot_port *ocelot_port = ocelot->ports[port];
 
-			for (lag = 0; lag < ocelot->num_phys_ports; lag++) {
-				unsigned long bond_mask = ocelot->lags[lag];
+		if (!ocelot_port)
+			continue;
 
-				if (!bond_mask)
-					continue;
+		if (ocelot->bridge_fwd_mask & BIT(port)) {
+			unsigned long mask = ocelot->bridge_fwd_mask & ~BIT(port);
+			struct net_device *bond = ocelot_port->bond;
 
-				if (bond_mask & BIT(port)) {
-					mask &= ~bond_mask;
-					break;
-				}
-			}
+			if (bond)
+				mask &= ~ocelot_get_bond_mask(ocelot, bond);
 
 			ocelot_write_rix(ocelot, mask,
 					 ANA_PGID_PGID, PGID_SRC + port);
@@ -1219,10 +1215,16 @@ int ocelot_port_bridge_leave(struct ocelot *ocelot, int port,
 }
 EXPORT_SYMBOL(ocelot_port_bridge_leave);
 
-static void ocelot_set_aggr_pgids(struct ocelot *ocelot)
+static int ocelot_set_aggr_pgids(struct ocelot *ocelot)
 {
+	struct net_device **bonds;
 	int i, port, lag;
 
+	bonds = kcalloc(ocelot->num_phys_ports, sizeof(struct net_device *),
+			GFP_KERNEL);
+	if (!bonds)
+		return -ENOMEM;
+
 	/* Reset destination and aggregation PGIDS */
 	for_each_unicast_dest_pgid(ocelot, port)
 		ocelot_write_rix(ocelot, BIT(port), ANA_PGID_PGID, port);
@@ -1231,16 +1233,26 @@ static void ocelot_set_aggr_pgids(struct ocelot *ocelot)
 		ocelot_write_rix(ocelot, GENMASK(ocelot->num_phys_ports - 1, 0),
 				 ANA_PGID_PGID, i);
 
+	for (port = 0; port < ocelot->num_phys_ports; port++) {
+		struct ocelot_port *ocelot_port = ocelot->ports[port];
+
+		if (!ocelot_port)
+			continue;
+
+		bonds[port] = ocelot_port->bond;
+	}
+
 	/* Now, set PGIDs for each LAG */
 	for (lag = 0; lag < ocelot->num_phys_ports; lag++) {
 		unsigned long bond_mask;
 		int aggr_count = 0;
 		u8 aggr_idx[16];
 
-		bond_mask = ocelot->lags[lag];
-		if (!bond_mask)
+		if (!bonds[lag])
 			continue;
 
+		bond_mask = ocelot_get_bond_mask(ocelot, bonds[lag]);
+
 		for_each_set_bit(port, &bond_mask, ocelot->num_phys_ports) {
 			// Destination mask
 			ocelot_write_rix(ocelot, bond_mask,
@@ -1257,7 +1269,19 @@ static void ocelot_set_aggr_pgids(struct ocelot *ocelot)
 			ac |= BIT(aggr_idx[i % aggr_count]);
 			ocelot_write_rix(ocelot, ac, ANA_PGID_PGID, i);
 		}
+
+		/* Mark the bonding interface as visited to avoid applying
+		 * the same config again
+		 */
+		for (i = lag + 1; i < ocelot->num_phys_ports; i++)
+			if (bonds[i] == bonds[lag])
+				bonds[i] = NULL;
+
+		bonds[lag] = NULL;
 	}
+
+	kfree(bonds);
+	return 0;
 }
 
 /* When offloading a bonding interface, the switch ports configured under the
@@ -1297,62 +1321,25 @@ int ocelot_port_lag_join(struct ocelot *ocelot, int port,
 			 struct net_device *bond,
 			 struct netdev_lag_upper_info *info)
 {
-	u32 bond_mask = 0;
-	int lag;
-
 	if (info->tx_type != NETDEV_LAG_TX_TYPE_HASH)
 		return -EOPNOTSUPP;
 
 	ocelot->ports[port]->bond = bond;
 
-	bond_mask = ocelot_get_bond_mask(ocelot, bond);
-
-	lag = __ffs(bond_mask);
-
-	/* If the new port is the lowest one, use it as the logical port from
-	 * now on
-	 */
-	if (port == lag) {
-		ocelot->lags[port] = bond_mask;
-		bond_mask &= ~BIT(port);
-		if (bond_mask)
-			ocelot->lags[__ffs(bond_mask)] = 0;
-	} else {
-		ocelot->lags[lag] |= BIT(port);
-	}
-
 	ocelot_setup_logical_port_ids(ocelot);
 	ocelot_apply_bridge_fwd_mask(ocelot);
-	ocelot_set_aggr_pgids(ocelot);
-
-	return 0;
+	return ocelot_set_aggr_pgids(ocelot);
 }
 EXPORT_SYMBOL(ocelot_port_lag_join);
 
-void ocelot_port_lag_leave(struct ocelot *ocelot, int port,
-			   struct net_device *bond)
+int ocelot_port_lag_leave(struct ocelot *ocelot, int port,
+			  struct net_device *bond)
 {
-	int i;
-
 	ocelot->ports[port]->bond = NULL;
 
-	/* Remove port from any lag */
-	for (i = 0; i < ocelot->num_phys_ports; i++)
-		ocelot->lags[i] &= ~BIT(port);
-
-	/* if it was the logical port of the lag, move the lag config to the
-	 * next port
-	 */
-	if (ocelot->lags[port]) {
-		int n = __ffs(ocelot->lags[port]);
-
-		ocelot->lags[n] = ocelot->lags[port];
-		ocelot->lags[port] = 0;
-	}
-
 	ocelot_setup_logical_port_ids(ocelot);
 	ocelot_apply_bridge_fwd_mask(ocelot);
-	ocelot_set_aggr_pgids(ocelot);
+	return ocelot_set_aggr_pgids(ocelot);
 }
 EXPORT_SYMBOL(ocelot_port_lag_leave);
 
@@ -1531,11 +1518,6 @@ int ocelot_init(struct ocelot *ocelot)
 		}
 	}
 
-	ocelot->lags = devm_kcalloc(ocelot->dev, ocelot->num_phys_ports,
-				    sizeof(u32), GFP_KERNEL);
-	if (!ocelot->lags)
-		return -ENOMEM;
-
 	ocelot->stats = devm_kcalloc(ocelot->dev,
 				     ocelot->num_phys_ports * ocelot->num_stats,
 				     sizeof(u64), GFP_KERNEL);
diff --git a/drivers/net/ethernet/mscc/ocelot.h b/drivers/net/ethernet/mscc/ocelot.h
index b6c9ddcee554..c018a54f4e49 100644
--- a/drivers/net/ethernet/mscc/ocelot.h
+++ b/drivers/net/ethernet/mscc/ocelot.h
@@ -112,8 +112,8 @@ int ocelot_mact_forget(struct ocelot *ocelot,
 int ocelot_port_lag_join(struct ocelot *ocelot, int port,
 			 struct net_device *bond,
 			 struct netdev_lag_upper_info *info);
-void ocelot_port_lag_leave(struct ocelot *ocelot, int port,
-			   struct net_device *bond);
+int ocelot_port_lag_leave(struct ocelot *ocelot, int port,
+			  struct net_device *bond);
 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 f246f8fc535d..871bfbaa8ff1 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -1138,8 +1138,8 @@ static int ocelot_netdevice_changeupper(struct net_device *dev,
 				err = 0;
 			}
 		} else {
-			ocelot_port_lag_leave(ocelot, port,
-					      info->upper_dev);
+			err = ocelot_port_lag_leave(ocelot, port,
+						    info->upper_dev);
 		}
 	}
 
diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index d2c587f099c8..1bb16527f490 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -656,8 +656,6 @@ struct ocelot {
 	enum ocelot_tag_prefix		inj_prefix;
 	enum ocelot_tag_prefix		xtr_prefix;
 
-	u32				*lags;
-
 	struct list_head		multicast;
 	struct list_head		pgids;
 
-- 
2.25.1