Commit 90af1059 authored by Brandon Streiff's avatar Brandon Streiff Committed by David S. Miller
Browse files

net: dsa: forward timestamping callbacks to switch drivers 



Forward the rx/tx timestamp machinery from the dsa infrastructure to the
switch driver.

On the rx side, defer delivery of skbs until we have an rx timestamp.
This mimicks the behavior of skb_defer_rx_timestamp.

On the tx side, identify PTP packets, clone them, and pass them to the
underlying switch driver before we transmit. This mimicks the behavior
of skb_tx_timestamp.

Adjusted txstamp API to keep the allocation and freeing of the clone
in the same central function by Richard Cochran

Signed-off-by: default avatarBrandon Streiff <brandon.streiff@ni.com>
Signed-off-by: default avatarRichard Cochran <richardcochran@gmail.com>
Signed-off-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0336369d

include/net/dsa.h

+5 −0
Original line number Diff line number Diff line
@@ -102,6 +102,7 @@ struct dsa_platform_data { 
};



struct packet_type;

struct dsa_switch;



struct dsa_device_ops {

	struct sk_buff *(*xmit)(struct sk_buff *skb, struct net_device *dev);
@@ -484,6 +485,10 @@ struct dsa_switch_ops { 
				     struct ifreq *ifr);

	int	(*port_hwtstamp_set)(struct dsa_switch *ds, int port,

				     struct ifreq *ifr);

	bool	(*port_txtstamp)(struct dsa_switch *ds, int port,

				 struct sk_buff *clone, unsigned int type);

	bool	(*port_rxtstamp)(struct dsa_switch *ds, int port,

				 struct sk_buff *skb, unsigned int type);

};



struct dsa_switch_driver {

net/dsa/dsa.c

+36 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/netdevice.h>

#include <linux/sysfs.h>

#include <linux/phy_fixed.h>

#include <linux/ptp_classify.h>

#include <linux/gpio/consumer.h>

#include <linux/etherdevice.h>
@@ -122,6 +123,38 @@ struct net_device *dsa_dev_to_net_device(struct device *dev) 
}

EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);



/* Determine if we should defer delivery of skb until we have a rx timestamp.

 *

 * Called from dsa_switch_rcv. For now, this will only work if tagging is

 * enabled on the switch. Normally the MAC driver would retrieve the hardware

 * timestamp when it reads the packet out of the hardware. However in a DSA

 * switch, the DSA driver owning the interface to which the packet is

 * delivered is never notified unless we do so here.

 */

static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,

				       struct sk_buff *skb)

{

	struct dsa_switch *ds = p->dp->ds;

	unsigned int type;



	if (skb_headroom(skb) < ETH_HLEN)

		return false;



	__skb_push(skb, ETH_HLEN);



	type = ptp_classify_raw(skb);



	__skb_pull(skb, ETH_HLEN);



	if (type == PTP_CLASS_NONE)

		return false;



	if (likely(ds->ops->port_rxtstamp))

		return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);



	return false;

}



static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,

			  struct packet_type *pt, struct net_device *unused)

{
@@ -157,6 +190,9 @@ static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev, 
	s->rx_bytes += skb->len;

	u64_stats_update_end(&s->syncp);



	if (dsa_skb_defer_rx_timestamp(p, skb))

		return 0;



	netif_receive_skb(skb);



	return 0;

net/dsa/slave.c

+30 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <net/tc_act/tc_mirred.h>

#include <linux/if_bridge.h>

#include <linux/netpoll.h>

#include <linux/ptp_classify.h>



#include "dsa_priv.h"
@@ -401,6 +402,30 @@ static inline netdev_tx_t dsa_slave_netpoll_send_skb(struct net_device *dev, 
	return NETDEV_TX_OK;

}



static void dsa_skb_tx_timestamp(struct dsa_slave_priv *p,

				 struct sk_buff *skb)

{

	struct dsa_switch *ds = p->dp->ds;

	struct sk_buff *clone;

	unsigned int type;



	type = ptp_classify_raw(skb);

	if (type == PTP_CLASS_NONE)

		return;



	if (!ds->ops->port_txtstamp)

		return;



	clone = skb_clone_sk(skb);

	if (!clone)

		return;



	if (ds->ops->port_txtstamp(ds, p->dp->index, clone, type))

		return;



	kfree_skb(clone);

}



static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev)

{

	struct dsa_slave_priv *p = netdev_priv(dev);
@@ -413,6 +438,11 @@ static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev) 
	s->tx_bytes += skb->len;

	u64_stats_update_end(&s->syncp);



	/* Identify PTP protocol packets, clone them, and pass them to the

	 * switch driver

	 */

	dsa_skb_tx_timestamp(p, skb);



	/* Transmit function may have to reallocate the original SKB,

	 * in which case it must have freed it. Only free it here on error.

	 */

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