From 90af1059c52c0031f3bfd8279c9ede153ca83275 Mon Sep 17 00:00:00 2001 From: Brandon Streiff Date: Wed, 14 Feb 2018 01:07:49 +0100 Subject: [PATCH] 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: Brandon Streiff Signed-off-by: Richard Cochran Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller --- include/net/dsa.h | 5 +++++ net/dsa/dsa.c | 36 ++++++++++++++++++++++++++++++++++++ net/dsa/slave.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 71 insertions(+) diff --git a/include/net/dsa.h b/include/net/dsa.h index 4c0df83dddaf..0ad17b63684d 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -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 { diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c index 6a9d0f50fbee..e63c554e0623 100644 --- a/net/dsa/dsa.c +++ b/net/dsa/dsa.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include @@ -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; diff --git a/net/dsa/slave.c b/net/dsa/slave.c index 935d93f0d36c..3376dad6dcfd 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -21,6 +21,7 @@ #include #include #include +#include #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. */