net: dsa: no longer clone skb in core driver

It was a waste to clone skb directly in dsa_skb_tx_timestamp().
For one-step timestamping, a clone was not needed. For any failure of
port_txtstamp (this may usually happen), the skb clone had to be freed.

So this patch moves skb cloning for tx timestamp out of dsa core, and
let drivers clone skb in port_txtstamp if they really need.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Tested-by: Kurt Kanzenbach <kurt@linutronix.de>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 10 deletions

diff --git a/drivers/net/dsa/hirschmann/hellcreek_hwtstamp.c b/drivers/net/dsa/hirschmann/hellcreek_hwtstamp.c
index 5b2e023468fe..40b41c794dfa 100644
--- a/drivers/net/dsa/hirschmann/hellcreek_hwtstamp.c
+++ b/drivers/net/dsa/hirschmann/hellcreek_hwtstamp.c
@@ -373,31 +373,38 @@ long hellcreek_hwtstamp_work(struct ptp_clock_info *ptp)
 	return restart ? 1 : -1;
 }
 
-bool hellcreek_port_txtstamp(struct dsa_switch *ds, int port,
-			     struct sk_buff *clone)
+void hellcreek_port_txtstamp(struct dsa_switch *ds, int port,
+			     struct sk_buff *skb)
 {
 	struct hellcreek *hellcreek = ds->priv;
 	struct hellcreek_port_hwtstamp *ps;
 	struct ptp_header *hdr;
+	struct sk_buff *clone;
 	unsigned int type;
 
 	ps = &hellcreek->ports[port].port_hwtstamp;
 
-	type = ptp_classify_raw(clone);
+	type = ptp_classify_raw(skb);
 	if (type == PTP_CLASS_NONE)
-		return false;
+		return;
 
 	/* Make sure the message is a PTP message that needs to be timestamped
 	 * and the interaction with the HW timestamping is enabled. If not, stop
 	 * here
 	 */
-	hdr = hellcreek_should_tstamp(hellcreek, port, clone, type);
+	hdr = hellcreek_should_tstamp(hellcreek, port, skb, type);
 	if (!hdr)
-		return false;
+		return;
+
+	clone = skb_clone_sk(skb);
+	if (!clone)
+		return;
 
 	if (test_and_set_bit_lock(HELLCREEK_HWTSTAMP_TX_IN_PROGRESS,
-				  &ps->state))
-		return false;
+				  &ps->state)) {
+		kfree_skb(clone);
+		return;
+	}
 
 	ps->tx_skb = clone;
 
@@ -407,8 +414,6 @@ bool hellcreek_port_txtstamp(struct dsa_switch *ds, int port,
 	ps->tx_tstamp_start = jiffies;
 
 	ptp_schedule_worker(hellcreek->ptp_clock, 0);
-
-	return true;
 }
 
 bool hellcreek_port_rxtstamp(struct dsa_switch *ds, int port,