net: support time stamping in phy devices.

This patch adds a new networking option to allow hardware time stamps
from PHY devices. When enabled, likely candidates among incoming and
outgoing network packets are offered to the PHY driver for possible
time stamping. When accepted by the PHY driver, incoming packets are
deferred for later delivery by the driver.

The patch also adds phylib driver methods for the SIOCSHWTSTAMP ioctl
and callbacks for transmit and receive time stamping. Drivers may
optionally implement these functions.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 57 insertions, 0 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index c4fedf000541..fdc3f2992230 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -54,6 +54,7 @@
 
 struct vlan_group;
 struct netpoll_info;
+struct phy_device;
 /* 802.11 specific */
 struct wireless_dev;
                                         /* source back-compat hooks */
@@ -1065,6 +1066,9 @@ struct net_device {
 #endif
         /* n-tuple filter list attached to this device */
         struct ethtool_rx_ntuple_list ethtool_ntuple_list;
+
+        /* phy device may attach itself for hardware timestamping */
+        struct phy_device *phydev;
 };
 #define to_net_dev(d) container_of(d, struct net_device, dev)
 
diff --git a/include/linux/phy.h b/include/linux/phy.h
index d63736a84002..6b0a782c6224 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -234,6 +234,8 @@ enum phy_state {
         PHY_RESUMING
 };
 
+struct sk_buff;
+
 /* phy_device: An instance of a PHY
  *
  * drv: Pointer to the driver for this PHY instance
@@ -402,6 +404,26 @@ struct phy_driver {
         /* Clears up any memory if needed */
         void (*remove)(struct phy_device *phydev);
 
+        /* Handles SIOCSHWTSTAMP ioctl for hardware time stamping. */
+        int  (*hwtstamp)(struct phy_device *phydev, struct ifreq *ifr);
+
+        /*
+         * Requests a Rx timestamp for 'skb'. If the skb is accepted,
+         * the phy driver promises to deliver it using netif_rx() as
+         * soon as a timestamp becomes available. One of the
+         * PTP_CLASS_ values is passed in 'type'. The function must
+         * return true if the skb is accepted for delivery.
+         */
+        bool (*rxtstamp)(struct phy_device *dev, struct sk_buff *skb, int type);
+
+        /*
+         * Requests a Tx timestamp for 'skb'. The phy driver promises
+         * to deliver it to the socket's error queue as soon as a
+         * timestamp becomes available. One of the PTP_CLASS_ values
+         * is passed in 'type'.
+         */
+        void (*txtstamp)(struct phy_device *dev, struct sk_buff *skb, int type);
+
         struct device_driver driver;
 };
 #define to_phy_driver(d) container_of(d, struct phy_driver, driver)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a1b0400c8d86..f5aa87e1e0c8 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1933,6 +1933,36 @@ static inline ktime_t net_invalid_timestamp(void)
         return ktime_set(0, 0);
 }
 
+extern void skb_timestamping_init(void);
+
+#ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
+
+extern void skb_clone_tx_timestamp(struct sk_buff *skb);
+extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
+
+#else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
+
+static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
+{
+}
+
+static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
+{
+        return false;
+}
+
+#endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
+
+/**
+ * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
+ *
+ * @skb: clone of the the original outgoing packet
+ * @hwtstamps: hardware time stamps
+ *
+ */
+void skb_complete_tx_timestamp(struct sk_buff *skb,
+                               struct skb_shared_hwtstamps *hwtstamps);
+
 /**
  * skb_tstamp_tx - queue clone of skb with send time stamps
  * @orig_skb:   the original outgoing packet
@@ -1965,6 +1995,7 @@ static inline void sw_tx_timestamp(struct sk_buff *skb)
  */
 static inline void skb_tx_timestamp(struct sk_buff *skb)
 {
+        skb_clone_tx_timestamp(skb);
         sw_tx_timestamp(skb);
 }