Merge branch 'net-dsa-mv88e6xxx-lag-fixes'

Tobias Waldekranz says:

====================
net: dsa: mv88e6xxx: LAG fixes

The kernel test robot kindly pointed out that Global 2 support in
mv88e6xxx is optional.

This also made me realize that we should verify that the hardware
actually supports LAG offloading before trying to configure it.
====================

Link: https://lore.kernel.org/r/20210115125259.22542-1-tobias@waldekranz.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -5385,9 +5385,13 @@ static bool mv88e6xxx_lag_can_offload(struct dsa_switch *ds,
 				      struct net_device *lag,
 				      struct netdev_lag_upper_info *info)
 {
+	struct mv88e6xxx_chip *chip = ds->priv;
 	struct dsa_port *dp;
 	int id, members = 0;
 
+	if (!mv88e6xxx_has_lag(chip))
+		return false;
+
 	id = dsa_lag_id(ds->dst, lag);
 	if (id < 0 || id >= ds->num_lag_ids)
 		return false;
@@ -5727,7 +5731,7 @@ static int mv88e6xxx_register_switch(struct mv88e6xxx_chip *chip)
 	 * 5-bit port mode, which we do not support. 640k^W16 ought to
 	 * be enough for anyone.
 	 */
-	ds->num_lag_ids = 16;
+	ds->num_lag_ids = mv88e6xxx_has_lag(chip) ? 16 : 0;
 
 	dev_set_drvdata(dev, ds);
 

drivers/net/dsa/mv88e6xxx/chip.h

@@ -662,6 +662,11 @@ static inline bool mv88e6xxx_has_pvt(struct mv88e6xxx_chip *chip)
 	return chip->info->pvt;
 }
 
+static inline bool mv88e6xxx_has_lag(struct mv88e6xxx_chip *chip)
+{
+	return !!chip->info->global2_addr;
+}
+
 static inline unsigned int mv88e6xxx_num_databases(struct mv88e6xxx_chip *chip)
 {
 	return chip->info->num_databases;

drivers/net/dsa/mv88e6xxx/global2.h

@@ -525,6 +525,18 @@ static inline int mv88e6xxx_g2_trunk_clear(struct mv88e6xxx_chip *chip)
 	return -EOPNOTSUPP;
 }
 
+static inline int mv88e6xxx_g2_trunk_mask_write(struct mv88e6xxx_chip *chip,
+						int num, bool hash, u16 mask)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int mv88e6xxx_g2_trunk_mapping_write(struct mv88e6xxx_chip *chip,
+						   int id, u16 map)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline int mv88e6xxx_g2_device_mapping_write(struct mv88e6xxx_chip *chip,
 						    int target, int port)
 {