net: airoha: Introduce airoha_dev_change_mtu callback

Add airoha_dev_change_mtu callback to update the MTU of a running
device.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250304-airoha-eth-rx-sg-v1-3-283ebc61120e@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index 54a239ab10aaac4a7bfc52977589415936207962..f3a61879e284a7ea12d0ebde2b993f2247cd35d9 100644 (file)
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -1705,6 +1705,20 @@ static void airoha_dev_get_stats64(struct net_device *dev,
        } while (u64_stats_fetch_retry(&port->stats.syncp, start));
 }
 
+static int airoha_dev_change_mtu(struct net_device *dev, int mtu)
+{
+       struct airoha_gdm_port *port = netdev_priv(dev);
+       struct airoha_eth *eth = port->qdma->eth;
+       u32 len = ETH_HLEN + mtu + ETH_FCS_LEN;
+
+       airoha_fe_rmw(eth, REG_GDM_LEN_CFG(port->id),
+                     GDM_LONG_LEN_MASK,
+                     FIELD_PREP(GDM_LONG_LEN_MASK, len));
+       WRITE_ONCE(dev->mtu, mtu);
+
+       return 0;
+}
+
 static u16 airoha_dev_select_queue(struct net_device *dev, struct sk_buff *skb,
                                   struct net_device *sb_dev)
 {
@@ -2400,6 +2414,7 @@ static const struct net_device_ops airoha_netdev_ops = {
        .ndo_init               = airoha_dev_init,
        .ndo_open               = airoha_dev_open,
        .ndo_stop               = airoha_dev_stop,
+       .ndo_change_mtu         = airoha_dev_change_mtu,
        .ndo_select_queue       = airoha_dev_select_queue,
        .ndo_start_xmit         = airoha_dev_xmit,
        .ndo_get_stats64        = airoha_dev_get_stats64,