net: mscc: ocelot: support PTP Sync one-step timestamping

Although HWTSTAMP_TX_ONESTEP_SYNC existed in ioctl for hardware timestamp
configuration, the PTP Sync one-step timestamping had never been supported.

This patch is to truely support it.

- ocelot_port_txtstamp_request()
  This function handles tx timestamp request by storing
  ptp_cmd(tx timestamp type) in OCELOT_SKB_CB(skb)->ptp_cmd,
  and additionally for two-step timestamp storing ts_id in
  OCELOT_SKB_CB(clone)->ptp_cmd.

- ocelot_ptp_rew_op()
  During xmit, this function is called to get rew_op (rewriter option) by
  checking skb->cb for tx timestamp request, and configure to transmitting.

Non-onestep-Sync packet with one-step timestamp request falls back to use
two-step timestamp.

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

2 files changed, 57 insertions, 4 deletions

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 3ff4cce1ce7d..0c4283319d7f 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -6,6 +6,7 @@
  */
 #include <linux/dsa/ocelot.h>
 #include <linux/if_bridge.h>
+#include <linux/ptp_classify.h>
 #include <soc/mscc/ocelot_vcap.h>
 #include "ocelot.h"
 #include "ocelot_vcap.h"
@@ -546,6 +547,46 @@ static void ocelot_port_add_txtstamp_skb(struct ocelot *ocelot, int port,
 	spin_unlock(&ocelot_port->ts_id_lock);
 }
 
+u32 ocelot_ptp_rew_op(struct sk_buff *skb)
+{
+	struct sk_buff *clone = OCELOT_SKB_CB(skb)->clone;
+	u8 ptp_cmd = OCELOT_SKB_CB(skb)->ptp_cmd;
+	u32 rew_op = 0;
+
+	if (ptp_cmd == IFH_REW_OP_TWO_STEP_PTP && clone) {
+		rew_op = ptp_cmd;
+		rew_op |= OCELOT_SKB_CB(clone)->ts_id << 3;
+	} else if (ptp_cmd == IFH_REW_OP_ORIGIN_PTP) {
+		rew_op = ptp_cmd;
+	}
+
+	return rew_op;
+}
+EXPORT_SYMBOL(ocelot_ptp_rew_op);
+
+static bool ocelot_ptp_is_onestep_sync(struct sk_buff *skb)
+{
+	struct ptp_header *hdr;
+	unsigned int ptp_class;
+	u8 msgtype, twostep;
+
+	ptp_class = ptp_classify_raw(skb);
+	if (ptp_class == PTP_CLASS_NONE)
+		return false;
+
+	hdr = ptp_parse_header(skb, ptp_class);
+	if (!hdr)
+		return false;
+
+	msgtype = ptp_get_msgtype(hdr, ptp_class);
+	twostep = hdr->flag_field[0] & 0x2;
+
+	if (msgtype == PTP_MSGTYPE_SYNC && twostep == 0)
+		return true;
+
+	return false;
+}
+
 int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
 				 struct sk_buff *skb,
 				 struct sk_buff **clone)
@@ -553,12 +594,24 @@ int ocelot_port_txtstamp_request(struct ocelot *ocelot, int port,
 	struct ocelot_port *ocelot_port = ocelot->ports[port];
 	u8 ptp_cmd = ocelot_port->ptp_cmd;
 
+	/* Store ptp_cmd in OCELOT_SKB_CB(skb)->ptp_cmd */
+	if (ptp_cmd == IFH_REW_OP_ORIGIN_PTP) {
+		if (ocelot_ptp_is_onestep_sync(skb)) {
+			OCELOT_SKB_CB(skb)->ptp_cmd = ptp_cmd;
+			return 0;
+		}
+
+		/* Fall back to two-step timestamping */
+		ptp_cmd = IFH_REW_OP_TWO_STEP_PTP;
+	}
+
 	if (ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) {
 		*clone = skb_clone_sk(skb);
 		if (!(*clone))
 			return -ENOMEM;
 
 		ocelot_port_add_txtstamp_skb(ocelot, port, *clone);
+		OCELOT_SKB_CB(skb)->ptp_cmd = ptp_cmd;
 	}
 
 	return 0;
diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index e99c8fb3cb15..aad33d22c33f 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -514,10 +514,10 @@ static netdev_tx_t ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev)
 			return NETDEV_TX_OK;
 		}
 
-		if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP) {
-			rew_op = ocelot_port->ptp_cmd;
-			rew_op |= OCELOT_SKB_CB(clone)->ts_id << 3;
-		}
+		if (clone)
+			OCELOT_SKB_CB(skb)->clone = clone;
+
+		rew_op = ocelot_ptp_rew_op(skb);
 	}
 
 	ocelot_port_inject_frame(ocelot, port, 0, rew_op, skb);