net: thunderx: add timestamping support

This adds timestamping support for both receive and transmit
paths. On the receive side no filters are supported i.e either
all pkts will get a timestamp appended infront of the packet or none.
On the transmit side HW doesn't support timestamp insertion but
only generates a separate CQE with transmitted packet's timestamp.
Also HW supports only one packet at a time for timestamping on the
transmit side.

Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@cavium.com>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 36 insertions, 0 deletions

diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
index 4a02e618e318..4cacce5d2b16 100644
--- a/drivers/net/ethernet/cavium/thunder/nic.h
+++ b/drivers/net/ethernet/cavium/thunder/nic.h
@@ -263,6 +263,8 @@ struct nicvf_drv_stats {
 	struct u64_stats_sync   syncp;
 };
 
+struct cavium_ptp;
+
 struct nicvf {
 	struct nicvf		*pnicvf;
 	struct net_device	*netdev;
@@ -312,6 +314,33 @@ struct nicvf {
 	struct tasklet_struct	qs_err_task;
 	struct work_struct	reset_task;
 
+	/* PTP timestamp */
+	struct cavium_ptp	*ptp_clock;
+	/* Inbound timestamping is on */
+	bool			hw_rx_tstamp;
+	/* When the packet that requires timestamping is sent, hardware inserts
+	 * two entries to the completion queue.  First is the regular
+	 * CQE_TYPE_SEND entry that signals that the packet was sent.
+	 * The second is CQE_TYPE_SEND_PTP that contains the actual timestamp
+	 * for that packet.
+	 * `ptp_skb` is initialized in the handler for the CQE_TYPE_SEND
+	 * entry and is used and zeroed in the handler for the CQE_TYPE_SEND_PTP
+	 * entry.
+	 * So `ptp_skb` is used to hold the pointer to the packet between
+	 * the calls to CQE_TYPE_SEND and CQE_TYPE_SEND_PTP handlers.
+	 */
+	struct sk_buff		*ptp_skb;
+	/* `tx_ptp_skbs` is set when the hardware is sending a packet that
+	 * requires timestamping.  Cavium hardware can not process more than one
+	 * such packet at once so this is set each time the driver submits
+	 * a packet that requires timestamping to the send queue and clears
+	 * each time it receives the entry on the completion queue saying
+	 * that such packet was sent.
+	 * So `tx_ptp_skbs` prevents driver from submitting more than one
+	 * packet that requires timestamping to the hardware for transmitting.
+	 */
+	atomic_t		tx_ptp_skbs;
+
 	/* Interrupt coalescing settings */
 	u32			cq_coalesce_usecs;
 	u32			msg_enable;
@@ -371,6 +400,7 @@ struct nicvf {
 #define	NIC_MBOX_MSG_LOOPBACK		0x16	/* Set interface in loopback */
 #define	NIC_MBOX_MSG_RESET_STAT_COUNTER 0x17	/* Reset statistics counters */
 #define	NIC_MBOX_MSG_PFC		0x18	/* Pause frame control */
+#define	NIC_MBOX_MSG_PTP_CFG		0x19	/* HW packet timestamp */
 #define	NIC_MBOX_MSG_CFG_DONE		0xF0	/* VF configuration done */
 #define	NIC_MBOX_MSG_SHUTDOWN		0xF1	/* VF is being shutdown */
 
@@ -521,6 +551,11 @@ struct pfc {
 	u8    fc_tx;
 };
 
+struct set_ptp {
+	u8    msg;
+	bool  enable;
+};
+
 /* 128 bit shared memory between PF and each VF */
 union nic_mbx {
 	struct { u8 msg; }	msg;
@@ -540,6 +575,7 @@ union nic_mbx {
 	struct set_loopback	lbk;
 	struct reset_stat_cfg	reset_stat;
 	struct pfc		pfc;
+	struct set_ptp		ptp;
 };
 
 #define NIC_NODE_ID_MASK	0x03