[PATCH net-next 5/8] macsec: inherit lower device's TSO limits when offloading

[Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>]

If macsec is offloaded, we need to follow the lower device's
capabilities, like VLAN devices do.

Leave the limits unchanged when the offload is disabled.

Signed-off-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
---
 drivers/net/macsec.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index e6670e876ff6..24c190d9b959 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -2621,6 +2621,17 @@ static void macsec_set_head_tail_room(struct net_device *dev)
 	dev->needed_tailroom = real_dev->needed_tailroom + needed_tailroom;
 }
 
+static void macsec_inherit_tso_max(struct net_device *dev)
+{
+	struct macsec_dev *macsec = macsec_priv(dev);
+
+	/* if macsec is offloaded, we need to follow the lower
+	 * device's capabilities. otherwise, we can ignore them.
+	 */
+	if (macsec_is_offloaded(macsec))
+		netif_inherit_tso_max(dev, macsec->real_dev);
+}
+
 static int macsec_update_offload(struct net_device *dev, enum macsec_offload offload)
 {
 	enum macsec_offload prev_offload;
@@ -2666,6 +2677,8 @@ static int macsec_update_offload(struct net_device *dev, enum macsec_offload off
 	macsec_set_head_tail_room(dev);
 	macsec->insert_tx_tag = macsec_needs_tx_tag(macsec, ops);
 
+	macsec_inherit_tso_max(dev);
+
 	netdev_update_features(dev);
 
 	return ret;
@@ -3537,6 +3550,8 @@ static int macsec_dev_init(struct net_device *dev)
 	if (err)
 		return err;
 
+	macsec_inherit_tso_max(dev);
+
 	dev->hw_features = real_dev->hw_features & MACSEC_OFFLOAD_FEATURES;
 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
 
@@ -4479,6 +4494,13 @@ static int macsec_notify(struct notifier_block *this, unsigned long event,
 			if (dev->mtu > mtu)
 				dev_set_mtu(dev, mtu);
 		}
+		break;
+	case NETDEV_FEAT_CHANGE:
+		list_for_each_entry(m, &rxd->secys, secys) {
+			macsec_inherit_tso_max(m->secy.netdev);
+			netdev_update_features(m->secy.netdev);
+		}
+		break;
 	}
 
 	return NOTIFY_OK;
-- 
2.47.0