Commit 62bf5fde authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller
Browse files

net: dsa: tag_ocelot: single out PTP-related transmit tag processing 



There is one place where we cannot avoid accessing driver data, and that
is 2-step PTP TX timestamping, since the switch wants us to provide a
timestamp request ID through the injection header, which naturally must
come from a sequence number kept by the driver (it is generated by the
.port_txtstamp method prior to the tagger's xmit).

However, since other drivers like dsa_loop do not claim PTP support
anyway, the DSA_SKB_CB(skb)->clone will always be NULL anyway, so if we
move all PTP-related dereferences of struct ocelot and struct ocelot_port
into a separate function, we can effectively ensure that this is dead
code when the ocelot tagger is attached to non-ocelot switches, and the
stateful portion of the tagger is more self-contained.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 40d3f295

net/dsa/tag_ocelot.c

+21 −11
Original line number Diff line number Diff line
@@ -5,6 +5,25 @@ 
#include <soc/mscc/ocelot.h>

#include "dsa_priv.h"



static void ocelot_xmit_ptp(struct dsa_port *dp, void *injection,

			    struct sk_buff *clone)

{

	struct ocelot *ocelot = dp->ds->priv;

	struct ocelot_port *ocelot_port;

	u64 rew_op;



	ocelot_port = ocelot->ports[dp->index];

	rew_op = ocelot_port->ptp_cmd;



	/* Retrieve timestamp ID populated inside skb->cb[0] of the

	 * clone by ocelot_port_add_txtstamp_skb

	 */

	if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP)

		rew_op |= clone->cb[0] << 3;



	ocelot_ifh_set_rew_op(injection, rew_op);

}



static struct sk_buff *ocelot_xmit(struct sk_buff *skb,

				   struct net_device *netdev)

{
@@ -29,17 +48,8 @@ static struct sk_buff *ocelot_xmit(struct sk_buff *skb, 
	ocelot_ifh_set_qos_class(injection, skb->priority);



	/* TX timestamping was requested */

	if (clone) {

		u64 rew_op = ocelot_port->ptp_cmd;



		/* Retrieve timestamp ID populated inside skb->cb[0] of the

		 * clone by ocelot_port_add_txtstamp_skb

		 */

		if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP)

			rew_op |= clone->cb[0] << 3;



		ocelot_ifh_set_rew_op(injection, rew_op);

	}

	if (clone)

		ocelot_xmit_ptp(dp, injection, clone);



	return skb;

}