net: mscc: ocelot: extract ocelot_xmit_timestamp() helper

Extract the PTP timestamp handling logic from ocelot_port_xmit() into a
separate ocelot_xmit_timestamp() helper function. This is a pure
refactor with no behavioral change.

The helper returns false if the skb was consumed (freed) due to a
timestamp request failure, and true if the caller should continue with
frame injection. The rew_op value is returned via pointer.

This prepares for splitting ocelot_port_xmit() into separate FDMA and
register injection paths in a subsequent patch.

Signed-off-by: Ziyi Guo <n7l8m4@u.northwestern.edu>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20260208225602.1339325-2-n7l8m4@u.northwestern.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 469784d3a1a67b061be22d961b0e953d44dfb39d..ef4a6c768de9bfe85221954fcb8f08d120d03d3c 100644 (file)
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -551,33 +551,41 @@ static int ocelot_port_stop(struct net_device *dev)
        return 0;
 }
 
-static netdev_tx_t ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
+static bool ocelot_xmit_timestamp(struct ocelot *ocelot, int port,
+                                 struct sk_buff *skb, u32 *rew_op)
 {
-       struct ocelot_port_private *priv = netdev_priv(dev);
-       struct ocelot_port *ocelot_port = &priv->port;
-       struct ocelot *ocelot = ocelot_port->ocelot;
-       int port = priv->port.index;
-       u32 rew_op = 0;
-
-       if (!static_branch_unlikely(&ocelot_fdma_enabled) &&
-           !ocelot_can_inject(ocelot, 0))
-               return NETDEV_TX_BUSY;
-
-       /* Check if timestamping is needed */
        if (ocelot->ptp && (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
                struct sk_buff *clone = NULL;
 
                if (ocelot_port_txtstamp_request(ocelot, port, skb, &clone)) {
                        kfree_skb(skb);
-                       return NETDEV_TX_OK;
+                       return false;
                }
 
                if (clone)
                        OCELOT_SKB_CB(skb)->clone = clone;
 
-               rew_op = ocelot_ptp_rew_op(skb);
+               *rew_op = ocelot_ptp_rew_op(skb);
        }
 
+       return true;
+}
+
+static netdev_tx_t ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       struct ocelot_port_private *priv = netdev_priv(dev);
+       struct ocelot_port *ocelot_port = &priv->port;
+       struct ocelot *ocelot = ocelot_port->ocelot;
+       int port = priv->port.index;
+       u32 rew_op = 0;
+
+       if (!static_branch_unlikely(&ocelot_fdma_enabled) &&
+           !ocelot_can_inject(ocelot, 0))
+               return NETDEV_TX_BUSY;
+
+       if (!ocelot_xmit_timestamp(ocelot, port, skb, &rew_op))
+               return NETDEV_TX_OK;
+
        if (static_branch_unlikely(&ocelot_fdma_enabled)) {
                ocelot_fdma_inject_frame(ocelot, port, rew_op, skb, dev);
        } else {