sfc: Add support for IEEE-1588 PTP

Add PTP IEEE-1588 support and make accesible via the PHC subsystem.

This work is based on prior code by Andrew Jackson

Signed-off-by: Stuart Hodgson <smhodgson@solarflare.com>
[bwh:
 - Add byte order conversion in efx_ptp_send_times()
 - Simplify conversion of PPS event times
 - Add the built-in vs module check to CONFIG_SFC_PTP dependencies]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

11 files changed, 1562 insertions, 1 deletions

diff --git a/drivers/net/ethernet/sfc/Kconfig b/drivers/net/ethernet/sfc/Kconfig
index fb3cbc27063c..25906c1d1b15 100644
--- a/drivers/net/ethernet/sfc/Kconfig
+++ b/drivers/net/ethernet/sfc/Kconfig
@@ -34,3 +34,10 @@ config SFC_SRIOV
 	  This enables support for the SFC9000 I/O Virtualization
 	  features, allowing accelerated network performance in
 	  virtualized environments.
+config SFC_PTP
+	bool "Solarflare SFC9000-family PTP support"
+	depends on SFC && PTP_1588_CLOCK && !(SFC=y && PTP_1588_CLOCK=m)
+	default y
+	---help---
+	  This enables support for the Precision Time Protocol (PTP)
+	  on SFC9000-family NICs
diff --git a/drivers/net/ethernet/sfc/Makefile b/drivers/net/ethernet/sfc/Makefile
index ea1f8db57318..e11f2ecf69d9 100644
--- a/drivers/net/ethernet/sfc/Makefile
+++ b/drivers/net/ethernet/sfc/Makefile
@@ -5,5 +5,6 @@ sfc-y			+= efx.o nic.o falcon.o siena.o tx.o rx.o filter.o \
 			   mcdi.o mcdi_phy.o mcdi_mon.o
 sfc-$(CONFIG_SFC_MTD)	+= mtd.o
 sfc-$(CONFIG_SFC_SRIOV)	+= siena_sriov.o
+sfc-$(CONFIG_SFC_PTP)	+= ptp.o
 
 obj-$(CONFIG_SFC)	+= sfc.o
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 8b79a6413fe4..96bd980e828d 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -1779,6 +1779,9 @@ static int efx_ioctl(struct net_device *net_dev, struct ifreq *ifr, int cmd)
 	struct efx_nic *efx = netdev_priv(net_dev);
 	struct mii_ioctl_data *data = if_mii(ifr);
 
+	if (cmd == SIOCSHWTSTAMP)
+		return efx_ptp_ioctl(efx, ifr, cmd);
+
 	/* Convert phy_id from older PRTAD/DEVAD format */
 	if ((cmd == SIOCGMIIREG || cmd == SIOCSMIIREG) &&
 	    (data->phy_id & 0xfc00) == 0x0400)
diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index f8e7e204981f..9df556c01b8e 100644
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -1174,6 +1174,7 @@ const struct ethtool_ops efx_ethtool_ops = {
 	.get_rxfh_indir_size	= efx_ethtool_get_rxfh_indir_size,
 	.get_rxfh_indir		= efx_ethtool_get_rxfh_indir,
 	.set_rxfh_indir		= efx_ethtool_set_rxfh_indir,
+	.get_ts_info		= efx_ptp_get_ts_info,
 	.get_module_info	= efx_ethtool_get_module_info,
 	.get_module_eeprom	= efx_ethtool_get_module_eeprom,
 };
diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index 2707e86def9e..294df4bca4a6 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -578,6 +578,11 @@ void efx_mcdi_process_event(struct efx_channel *channel,
 	case MCDI_EVENT_CODE_FLR:
 		efx_sriov_flr(efx, MCDI_EVENT_FIELD(*event, FLR_VF));
 		break;
+	case MCDI_EVENT_CODE_PTP_RX:
+	case MCDI_EVENT_CODE_PTP_FAULT:
+	case MCDI_EVENT_CODE_PTP_PPS:
+		efx_ptp_event(efx, event);
+		break;
 
 	default:
 		netif_err(efx, hw, efx->net_dev, "Unknown MCDI event 0x%x\n",
diff --git a/drivers/net/ethernet/sfc/mcdi_pcol.h b/drivers/net/ethernet/sfc/mcdi_pcol.h
index 50389326bec8..9d426d0457bd 100644
--- a/drivers/net/ethernet/sfc/mcdi_pcol.h
+++ b/drivers/net/ethernet/sfc/mcdi_pcol.h
@@ -289,6 +289,7 @@
 #define          MCDI_EVENT_CODE_TX_FLUSH  0xc /* enum */
 #define          MCDI_EVENT_CODE_PTP_RX  0xd /* enum */
 #define          MCDI_EVENT_CODE_PTP_FAULT  0xe /* enum */
+#define          MCDI_EVENT_CODE_PTP_PPS  0xf /* enum */
 #define       MCDI_EVENT_CMDDONE_DATA_OFST 0
 #define       MCDI_EVENT_CMDDONE_DATA_LBN 0
 #define       MCDI_EVENT_CMDDONE_DATA_WIDTH 32
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 0f0926e68963..797dbed25d94 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -56,7 +56,8 @@
 #define EFX_MAX_CHANNELS 32U
 #define EFX_MAX_RX_QUEUES EFX_MAX_CHANNELS
 #define EFX_EXTRA_CHANNEL_IOV	0
-#define EFX_MAX_EXTRA_CHANNELS	1U
+#define EFX_EXTRA_CHANNEL_PTP	1
+#define EFX_MAX_EXTRA_CHANNELS	2U
 
 /* Checksum generation is a per-queue option in hardware, so each
  * queue visible to the networking core is backed by two hardware TX
@@ -68,6 +69,9 @@
 #define EFX_TXQ_TYPES		4
 #define EFX_MAX_TX_QUEUES	(EFX_TXQ_TYPES * EFX_MAX_CHANNELS)
 
+/* Forward declare Precision Time Protocol (PTP) support structure. */
+struct efx_ptp_data;
+
 struct efx_self_tests;
 
 /**
@@ -736,6 +740,7 @@ struct vfdi_status;
  *	%local_addr_list. Protected by %local_lock.
  * @local_lock: Mutex protecting %local_addr_list and %local_page_list.
  * @peer_work: Work item to broadcast peer addresses to VMs.
+ * @ptp_data: PTP state data
  * @monitor_work: Hardware monitor workitem
  * @biu_lock: BIU (bus interface unit) lock
  * @last_irq_cpu: Last CPU to handle a possible test interrupt.  This
@@ -863,6 +868,10 @@ struct efx_nic {
 	struct work_struct peer_work;
 #endif
 
+#ifdef CONFIG_SFC_PTP
+	struct efx_ptp_data *ptp_data;
+#endif
+
 	/* The following fields may be written more often */
 
 	struct delayed_work monitor_work ____cacheline_aligned_in_smp;
@@ -1125,5 +1134,13 @@ static inline void clear_bit_le(unsigned nr, unsigned char *addr)
 #define EFX_MAX_FRAME_LEN(mtu) \
 	((((mtu) + ETH_HLEN + VLAN_HLEN + 4/* FCS */ + 7) & ~7) + 16)
 
+static inline bool efx_xmit_with_hwtstamp(struct sk_buff *skb)
+{
+	return skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP;
+}
+static inline void efx_xmit_hwtstamp_pending(struct sk_buff *skb)
+{
+	skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+}
 
 #endif /* EFX_NET_DRIVER_H */
diff --git a/drivers/net/ethernet/sfc/nic.h b/drivers/net/ethernet/sfc/nic.h
index bab5cd9f5740..438cef11f727 100644
--- a/drivers/net/ethernet/sfc/nic.h
+++ b/drivers/net/ethernet/sfc/nic.h
@@ -11,6 +11,7 @@
 #ifndef EFX_NIC_H
 #define EFX_NIC_H
 
+#include <linux/net_tstamp.h>
 #include <linux/i2c-algo-bit.h>
 #include "net_driver.h"
 #include "efx.h"
@@ -250,6 +251,41 @@ extern int efx_sriov_get_vf_config(struct net_device *dev, int vf,
 extern int efx_sriov_set_vf_spoofchk(struct net_device *net_dev, int vf,
 				     bool spoofchk);
 
+struct ethtool_ts_info;
+#ifdef CONFIG_SFC_PTP
+extern void efx_ptp_probe(struct efx_nic *efx);
+extern int efx_ptp_ioctl(struct efx_nic *efx, struct ifreq *ifr, int cmd);
+extern int efx_ptp_get_ts_info(struct net_device *net_dev,
+			       struct ethtool_ts_info *ts_info);
+extern bool efx_ptp_is_ptp_tx(struct efx_nic *efx, struct sk_buff *skb);
+extern int efx_ptp_tx(struct efx_nic *efx, struct sk_buff *skb);
+extern void efx_ptp_event(struct efx_nic *efx, efx_qword_t *ev);
+#else
+static inline void efx_ptp_probe(struct efx_nic *efx) {}
+static inline int efx_ptp_ioctl(struct efx_nic *efx, struct ifreq *ifr, int cmd)
+{
+	return -EOPNOTSUPP;
+}
+static inline int efx_ptp_get_ts_info(struct net_device *net_dev,
+				      struct ethtool_ts_info *ts_info)
+{
+	ts_info->so_timestamping = (SOF_TIMESTAMPING_SOFTWARE |
+				    SOF_TIMESTAMPING_RX_SOFTWARE);
+	ts_info->phc_index = -1;
+
+	return 0;
+}
+static inline bool efx_ptp_is_ptp_tx(struct efx_nic *efx, struct sk_buff *skb)
+{
+	return false;
+}
+static inline int efx_ptp_tx(struct efx_nic *efx, struct sk_buff *skb)
+{
+	return NETDEV_TX_OK;
+}
+static inline void efx_ptp_event(struct efx_nic *efx, efx_qword_t *ev) {}
+#endif
+
 extern const struct efx_nic_type falcon_a1_nic_type;
 extern const struct efx_nic_type falcon_b0_nic_type;
 extern const struct efx_nic_type siena_a0_nic_type;
diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
new file mode 100644
index 000000000000..2b07a4eae07e
--- /dev/null
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -0,0 +1,1483 @@
+/****************************************************************************
+ * Driver for Solarflare Solarstorm network controllers and boards
+ * Copyright 2011 Solarflare Communications Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, incorporated herein by reference.
+ */
+
+/* Theory of operation:
+ *
+ * PTP support is assisted by firmware running on the MC, which provides
+ * the hardware timestamping capabilities.  Both transmitted and received
+ * PTP event packets are queued onto internal queues for subsequent processing;
+ * this is because the MC operations are relatively long and would block
+ * block NAPI/interrupt operation.
+ *
+ * Receive event processing:
+ *	The event contains the packet's UUID and sequence number, together
+ *	with the hardware timestamp.  The PTP receive packet queue is searched
+ *	for this UUID/sequence number and, if found, put on a pending queue.
+ *	Packets not matching are delivered without timestamps (MCDI events will
+ *	always arrive after the actual packet).
+ *	It is important for the operation of the PTP protocol that the ordering
+ *	of packets between the event and general port is maintained.
+ *
+ * Work queue processing:
+ *	If work waiting, synchronise host/hardware time
+ *
+ *	Transmit: send packet through MC, which returns the transmission time
+ *	that is converted to an appropriate timestamp.
+ *
+ *	Receive: the packet's reception time is converted to an appropriate
+ *	timestamp.
+ */
+#include <linux/ip.h>
+#include <linux/udp.h>
+#include <linux/time.h>
+#include <linux/ktime.h>
+#include <linux/module.h>
+#include <linux/net_tstamp.h>
+#include <linux/pps_kernel.h>
+#include <linux/ptp_clock_kernel.h>
+#include "net_driver.h"
+#include "efx.h"
+#include "mcdi.h"
+#include "mcdi_pcol.h"
+#include "io.h"
+#include "regs.h"
+#include "nic.h"
+
+/* Maximum number of events expected to make up a PTP event */
+#define	MAX_EVENT_FRAGS			3
+
+/* Maximum delay, ms, to begin synchronisation */
+#define	MAX_SYNCHRONISE_WAIT_MS		2
+
+/* How long, at most, to spend synchronising */
+#define	SYNCHRONISE_PERIOD_NS		250000
+
+/* How often to update the shared memory time */
+#define	SYNCHRONISATION_GRANULARITY_NS	200
+
+/* Minimum permitted length of a (corrected) synchronisation time */
+#define	MIN_SYNCHRONISATION_NS		120
+
+/* Maximum permitted length of a (corrected) synchronisation time */
+#define	MAX_SYNCHRONISATION_NS		1000
+
+/* How many (MC) receive events that can be queued */
+#define	MAX_RECEIVE_EVENTS		8
+
+/* Length of (modified) moving average. */
+#define	AVERAGE_LENGTH			16
+
+/* How long an unmatched event or packet can be held */
+#define PKT_EVENT_LIFETIME_MS		10
+
+/* Offsets into PTP packet for identification.  These offsets are from the
+ * start of the IP header, not the MAC header.  Note that neither PTP V1 nor
+ * PTP V2 permit the use of IPV4 options.
+ */
+#define PTP_DPORT_OFFSET	22
+
+#define PTP_V1_VERSION_LENGTH	2
+#define PTP_V1_VERSION_OFFSET	28
+
+#define PTP_V1_UUID_LENGTH	6
+#define PTP_V1_UUID_OFFSET	50
+
+#define PTP_V1_SEQUENCE_LENGTH	2
+#define PTP_V1_SEQUENCE_OFFSET	58
+
+/* The minimum length of a PTP V1 packet for offsets, etc. to be valid:
+ * includes IP header.
+ */
+#define	PTP_V1_MIN_LENGTH	64
+
+#define PTP_V2_VERSION_LENGTH	1
+#define PTP_V2_VERSION_OFFSET	29
+
+/* Although PTP V2 UUIDs are comprised a ClockIdentity (8) and PortNumber (2),
+ * the MC only captures the last six bytes of the clock identity. These values
+ * reflect those, not the ones used in the standard.  The standard permits
+ * mapping of V1 UUIDs to V2 UUIDs with these same values.
+ */
+#define PTP_V2_MC_UUID_LENGTH	6
+#define PTP_V2_MC_UUID_OFFSET	50
+
+#define PTP_V2_SEQUENCE_LENGTH	2
+#define PTP_V2_SEQUENCE_OFFSET	58
+
+/* The minimum length of a PTP V2 packet for offsets, etc. to be valid:
+ * includes IP header.
+ */
+#define	PTP_V2_MIN_LENGTH	63
+
+#define	PTP_MIN_LENGTH		63
+
+#define PTP_ADDRESS		0xe0000181	/* 224.0.1.129 */
+#define PTP_EVENT_PORT		319
+#define PTP_GENERAL_PORT	320
+
+/* Annoyingly the format of the version numbers are different between
+ * versions 1 and 2 so it isn't possible to simply look for 1 or 2.
+ */
+#define	PTP_VERSION_V1		1
+
+#define	PTP_VERSION_V2		2
+#define	PTP_VERSION_V2_MASK	0x0f
+
+enum ptp_packet_state {
+	PTP_PACKET_STATE_UNMATCHED = 0,
+	PTP_PACKET_STATE_MATCHED,
+	PTP_PACKET_STATE_TIMED_OUT,
+	PTP_PACKET_STATE_MATCH_UNWANTED
+};
+
+/* NIC synchronised with single word of time only comprising
+ * partial seconds and full nanoseconds: 10^9 ~ 2^30 so 2 bits for seconds.
+ */
+#define	MC_NANOSECOND_BITS	30
+#define	MC_NANOSECOND_MASK	((1 << MC_NANOSECOND_BITS) - 1)
+#define	MC_SECOND_MASK		((1 << (32 - MC_NANOSECOND_BITS)) - 1)
+
+/* Maximum parts-per-billion adjustment that is acceptable */
+#define MAX_PPB			1000000
+
+/* Number of bits required to hold the above */
+#define	MAX_PPB_BITS		20
+
+/* Number of extra bits allowed when calculating fractional ns.
+ * EXTRA_BITS + MC_CMD_PTP_IN_ADJUST_BITS + MAX_PPB_BITS should
+ * be less than 63.
+ */
+#define	PPB_EXTRA_BITS		2
+
+/* Precalculate scale word to avoid long long division at runtime */
+#define	PPB_SCALE_WORD	((1LL << (PPB_EXTRA_BITS + MC_CMD_PTP_IN_ADJUST_BITS +\
+			MAX_PPB_BITS)) / 1000000000LL)
+
+#define PTP_SYNC_ATTEMPTS	4
+
+/**
+ * struct efx_ptp_match - Matching structure, stored in sk_buff's cb area.
+ * @words: UUID and (partial) sequence number
+ * @expiry: Time after which the packet should be delivered irrespective of
+ *            event arrival.
+ * @state: The state of the packet - whether it is ready for processing or
+ *         whether that is of no interest.
+ */
+struct efx_ptp_match {
+	u32 words[DIV_ROUND_UP(PTP_V1_UUID_LENGTH, 4)];
+	unsigned long expiry;
+	enum ptp_packet_state state;
+};
+
+/**
+ * struct efx_ptp_event_rx - A PTP receive event (from MC)
+ * @seq0: First part of (PTP) UUID
+ * @seq1: Second part of (PTP) UUID and sequence number
+ * @hwtimestamp: Event timestamp
+ */
+struct efx_ptp_event_rx {
+	struct list_head link;
+	u32 seq0;
+	u32 seq1;
+	ktime_t hwtimestamp;
+	unsigned long expiry;
+};
+
+/**
+ * struct efx_ptp_timeset - Synchronisation between host and MC
+ * @host_start: Host time immediately before hardware timestamp taken
+ * @seconds: Hardware timestamp, seconds
+ * @nanoseconds: Hardware timestamp, nanoseconds
+ * @host_end: Host time immediately after hardware timestamp taken
+ * @waitns: Number of nanoseconds between hardware timestamp being read and
+ *          host end time being seen
+ * @window: Difference of host_end and host_start
+ * @valid: Whether this timeset is valid
+ */
+struct efx_ptp_timeset {
+	u32 host_start;
+	u32 seconds;
+	u32 nanoseconds;
+	u32 host_end;
+	u32 waitns;
+	u32 window;	/* Derived: end - start, allowing for wrap */
+};
+
+/**
+ * struct efx_ptp_data - Precision Time Protocol (PTP) state
+ * @channel: The PTP channel
+ * @rxq: Receive queue (awaiting timestamps)
+ * @txq: Transmit queue
+ * @evt_list: List of MC receive events awaiting packets
+ * @evt_free_list: List of free events
+ * @evt_lock: Lock for manipulating evt_list and evt_free_list
+ * @rx_evts: Instantiated events (on evt_list and evt_free_list)
+ * @workwq: Work queue for processing pending PTP operations
+ * @work: Work task
+ * @reset_required: A serious error has occurred and the PTP task needs to be
+ *                  reset (disable, enable).
+ * @rxfilter_event: Receive filter when operating
+ * @rxfilter_general: Receive filter when operating
+ * @config: Current timestamp configuration
+ * @enabled: PTP operation enabled
+ * @mode: Mode in which PTP operating (PTP version)
+ * @evt_frags: Partly assembled PTP events
+ * @evt_frag_idx: Current fragment number
+ * @evt_code: Last event code
+ * @start: Address at which MC indicates ready for synchronisation
+ * @host_time_pps: Host time at last PPS
+ * @last_sync_ns: Last number of nanoseconds between readings when synchronising
+ * @base_sync_ns: Number of nanoseconds for last synchronisation.
+ * @base_sync_valid: Whether base_sync_time is valid.
+ * @current_adjfreq: Current ppb adjustment.
+ * @phc_clock: Pointer to registered phc device
+ * @phc_clock_info: Registration structure for phc device
+ * @pps_work: pps work task for handling pps events
+ * @pps_workwq: pps work queue
+ * @nic_ts_enabled: Flag indicating if NIC generated TS events are handled
+ * @txbuf: Buffer for use when transmitting (PTP) packets to MC (avoids
+ *         allocations in main data path).
+ * @debug_ptp_dir: PTP debugfs directory
+ * @missed_rx_sync: Number of packets received without syncrhonisation.
+ * @good_syncs: Number of successful synchronisations.
+ * @no_time_syncs: Number of synchronisations with no good times.
+ * @bad_sync_durations: Number of synchronisations with bad durations.
+ * @bad_syncs: Number of failed synchronisations.
+ * @last_sync_time: Number of nanoseconds for last synchronisation.
+ * @sync_timeouts: Number of synchronisation timeouts
+ * @fast_syncs: Number of synchronisations requiring short delay
+ * @min_sync_delta: Minimum time between event and synchronisation
+ * @max_sync_delta: Maximum time between event and synchronisation
+ * @average_sync_delta: Average time between event and synchronisation.
+ *                      Modified moving average.
+ * @last_sync_delta: Last time between event and synchronisation
+ * @mc_stats: Context value for MC statistics
+ * @timeset: Last set of synchronisation statistics.
+ */
+struct efx_ptp_data {
+	struct efx_channel *channel;
+	struct sk_buff_head rxq;
+	struct sk_buff_head txq;
+	struct list_head evt_list;
+	struct list_head evt_free_list;
+	spinlock_t evt_lock;
+	struct efx_ptp_event_rx rx_evts[MAX_RECEIVE_EVENTS];
+	struct workqueue_struct *workwq;
+	struct work_struct work;
+	bool reset_required;
+	u32 rxfilter_event;
+	u32 rxfilter_general;
+	bool rxfilter_installed;
+	struct hwtstamp_config config;
+	bool enabled;
+	unsigned int mode;
+	efx_qword_t evt_frags[MAX_EVENT_FRAGS];
+	int evt_frag_idx;
+	int evt_code;
+	struct efx_buffer start;
+	struct pps_event_time host_time_pps;
+	unsigned last_sync_ns;
+	unsigned base_sync_ns;
+	bool base_sync_valid;
+	s64 current_adjfreq;
+	struct ptp_clock *phc_clock;
+	struct ptp_clock_info phc_clock_info;
+	struct work_struct pps_work;
+	struct workqueue_struct *pps_workwq;
+	bool nic_ts_enabled;
+	u8 txbuf[ALIGN(MC_CMD_PTP_IN_TRANSMIT_LEN(
+			       MC_CMD_PTP_IN_TRANSMIT_PACKET_MAXNUM), 4)];
+	struct efx_ptp_timeset
+	timeset[MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_MAXNUM];
+};
+
+static int efx_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta);
+static int efx_phc_adjtime(struct ptp_clock_info *ptp, s64 delta);
+static int efx_phc_gettime(struct ptp_clock_info *ptp, struct timespec *ts);
+static int efx_phc_settime(struct ptp_clock_info *ptp,
+			   const struct timespec *e_ts);
+static int efx_phc_enable(struct ptp_clock_info *ptp,
+			  struct ptp_clock_request *request, int on);
+
+/* Enable MCDI PTP support. */
+static int efx_ptp_enable(struct efx_nic *efx)
+{
+	u8 inbuf[MC_CMD_PTP_IN_ENABLE_LEN];
+
+	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_ENABLE);
+	MCDI_SET_DWORD(inbuf, PTP_IN_ENABLE_QUEUE,
+		       efx->ptp_data->channel->channel);
+	MCDI_SET_DWORD(inbuf, PTP_IN_ENABLE_MODE, efx->ptp_data->mode);
+
+	return efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
+			    NULL, 0, NULL);
+}
+
+/* Disable MCDI PTP support.
+ *
+ * Note that this function should never rely on the presence of ptp_data -
+ * may be called before that exists.
+ */
+static int efx_ptp_disable(struct efx_nic *efx)
+{
+	u8 inbuf[MC_CMD_PTP_IN_DISABLE_LEN];
+
+	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_DISABLE);
+	return efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
+			    NULL, 0, NULL);
+}
+
+static void efx_ptp_deliver_rx_queue(struct sk_buff_head *q)
+{
+	struct sk_buff *skb;
+
+	while ((skb = skb_dequeue(q))) {
+		local_bh_disable();
+		netif_receive_skb(skb);
+		local_bh_enable();
+	}
+}
+
+static void efx_ptp_handle_no_channel(struct efx_nic *efx)
+{
+	netif_err(efx, drv, efx->net_dev,
+		  "ERROR: PTP requires MSI-X and 1 additional interrupt"
+		  "vector. PTP disabled\n");
+}
+
+/* Repeatedly send the host time to the MC which will capture the hardware
+ * time.
+ */
+static void efx_ptp_send_times(struct efx_nic *efx,
+			       struct pps_event_time *last_time)
+{
+	struct pps_event_time now;
+	struct timespec limit;
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	struct timespec start;
+	int *mc_running = ptp->start.addr;
+
+	pps_get_ts(&now);
+	start = now.ts_real;
+	limit = now.ts_real;
+	timespec_add_ns(&limit, SYNCHRONISE_PERIOD_NS);
+
+	/* Write host time for specified period or until MC is done */
+	while ((timespec_compare(&now.ts_real, &limit) < 0) &&
+	       ACCESS_ONCE(*mc_running)) {
+		struct timespec update_time;
+		unsigned int host_time;
+
+		/* Don't update continuously to avoid saturating the PCIe bus */
+		update_time = now.ts_real;
+		timespec_add_ns(&update_time, SYNCHRONISATION_GRANULARITY_NS);
+		do {
+			pps_get_ts(&now);
+		} while ((timespec_compare(&now.ts_real, &update_time) < 0) &&
+			 ACCESS_ONCE(*mc_running));
+
+		/* Synchronise NIC with single word of time only */
+		host_time = (now.ts_real.tv_sec << MC_NANOSECOND_BITS |
+			     now.ts_real.tv_nsec);
+		/* Update host time in NIC memory */
+		_efx_writed(efx, cpu_to_le32(host_time),
+			    FR_CZ_MC_TREG_SMEM + MC_SMEM_P0_PTP_TIME_OFST);
+	}
+	*last_time = now;
+}
+
+/* Read a timeset from the MC's results and partial process. */
+static void efx_ptp_read_timeset(u8 *data, struct efx_ptp_timeset *timeset)
+{
+	unsigned start_ns, end_ns;
+
+	timeset->host_start = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_HOSTSTART);
+	timeset->seconds = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_SECONDS);
+	timeset->nanoseconds = MCDI_DWORD(data,
+					 PTP_OUT_SYNCHRONIZE_NANOSECONDS);
+	timeset->host_end = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_HOSTEND),
+	timeset->waitns = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_WAITNS);
+
+	/* Ignore seconds */
+	start_ns = timeset->host_start & MC_NANOSECOND_MASK;
+	end_ns = timeset->host_end & MC_NANOSECOND_MASK;
+	/* Allow for rollover */
+	if (end_ns < start_ns)
+		end_ns += NSEC_PER_SEC;
+	/* Determine duration of operation */
+	timeset->window = end_ns - start_ns;
+}
+
+/* Process times received from MC.
+ *
+ * Extract times from returned results, and establish the minimum value
+ * seen.  The minimum value represents the "best" possible time and events
+ * too much greater than this are rejected - the machine is, perhaps, too
+ * busy. A number of readings are taken so that, hopefully, at least one good
+ * synchronisation will be seen in the results.
+ */
+static int efx_ptp_process_times(struct efx_nic *efx, u8 *synch_buf,
+				 size_t response_length,
+				 const struct pps_event_time *last_time)
+{
+	unsigned number_readings = (response_length /
+			       MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_LEN);
+	unsigned i;
+	unsigned min;
+	unsigned min_set = 0;
+	unsigned total;
+	unsigned ngood = 0;
+	unsigned last_good = 0;
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	bool min_valid = false;
+	u32 last_sec;
+	u32 start_sec;
+	struct timespec delta;
+
+	if (number_readings == 0)
+		return -EAGAIN;
+
+	/* Find minimum value in this set of results, discarding clearly
+	 * erroneous results.
+	 */
+	for (i = 0; i < number_readings; i++) {
+		efx_ptp_read_timeset(synch_buf, &ptp->timeset[i]);
+		synch_buf += MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_LEN;
+		if (ptp->timeset[i].window > SYNCHRONISATION_GRANULARITY_NS) {
+			if (min_valid) {
+				if (ptp->timeset[i].window < min_set)
+					min_set = ptp->timeset[i].window;
+			} else {
+				min_valid = true;
+				min_set = ptp->timeset[i].window;
+			}
+		}
+	}
+
+	if (min_valid) {
+		if (ptp->base_sync_valid && (min_set > ptp->base_sync_ns))
+			min = ptp->base_sync_ns;
+		else
+			min = min_set;
+	} else {
+		min = SYNCHRONISATION_GRANULARITY_NS;
+	}
+
+	/* Discard excessively long synchronise durations.  The MC times
+	 * when it finishes reading the host time so the corrected window
+	 * time should be fairly constant for a given platform.
+	 */
+	total = 0;
+	for (i = 0; i < number_readings; i++)
+		if (ptp->timeset[i].window > ptp->timeset[i].waitns) {
+			unsigned win;
+
+			win = ptp->timeset[i].window - ptp->timeset[i].waitns;
+			if (win >= MIN_SYNCHRONISATION_NS &&
+			    win < MAX_SYNCHRONISATION_NS) {
+				total += ptp->timeset[i].window;
+				ngood++;
+				last_good = i;
+			}
+		}
+
+	if (ngood == 0) {
+		netif_warn(efx, drv, efx->net_dev,
+			   "PTP no suitable synchronisations %dns %dns\n",
+			   ptp->base_sync_ns, min_set);
+		return -EAGAIN;
+	}
+
+	/* Average minimum this synchronisation */
+	ptp->last_sync_ns = DIV_ROUND_UP(total, ngood);
+	if (!ptp->base_sync_valid || (ptp->last_sync_ns < ptp->base_sync_ns)) {
+		ptp->base_sync_valid = true;
+		ptp->base_sync_ns = ptp->last_sync_ns;
+	}
+
+	/* Calculate delay from actual PPS to last_time */
+	delta.tv_nsec =
+		ptp->timeset[last_good].nanoseconds +
+		last_time->ts_real.tv_nsec -
+		(ptp->timeset[last_good].host_start & MC_NANOSECOND_MASK);
+
+	/* It is possible that the seconds rolled over between taking
+	 * the start reading and the last value written by the host.  The
+	 * timescales are such that a gap of more than one second is never
+	 * expected.
+	 */
+	start_sec = ptp->timeset[last_good].host_start >> MC_NANOSECOND_BITS;
+	last_sec = last_time->ts_real.tv_sec & MC_SECOND_MASK;
+	if (start_sec != last_sec) {
+		if (((start_sec + 1) & MC_SECOND_MASK) != last_sec) {
+			netif_warn(efx, hw, efx->net_dev,
+				   "PTP bad synchronisation seconds\n");
+			return -EAGAIN;
+		} else {
+			delta.tv_sec = 1;
+		}
+	} else {
+		delta.tv_sec = 0;
+	}
+
+	ptp->host_time_pps = *last_time;
+	pps_sub_ts(&ptp->host_time_pps, delta);
+
+	return 0;
+}
+
+/* Synchronize times between the host and the MC */
+static int efx_ptp_synchronize(struct efx_nic *efx, unsigned int num_readings)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	u8 synch_buf[MC_CMD_PTP_OUT_SYNCHRONIZE_LENMAX];
+	size_t response_length;
+	int rc;
+	unsigned long timeout;
+	struct pps_event_time last_time = {};
+	unsigned int loops = 0;
+	int *start = ptp->start.addr;
+
+	MCDI_SET_DWORD(synch_buf, PTP_IN_OP, MC_CMD_PTP_OP_SYNCHRONIZE);
+	MCDI_SET_DWORD(synch_buf, PTP_IN_SYNCHRONIZE_NUMTIMESETS,
+		       num_readings);
+	MCDI_SET_DWORD(synch_buf, PTP_IN_SYNCHRONIZE_START_ADDR_LO,
+		       (u32)ptp->start.dma_addr);
+	MCDI_SET_DWORD(synch_buf, PTP_IN_SYNCHRONIZE_START_ADDR_HI,
+		       (u32)((u64)ptp->start.dma_addr >> 32));
+
+	/* Clear flag that signals MC ready */
+	ACCESS_ONCE(*start) = 0;
+	efx_mcdi_rpc_start(efx, MC_CMD_PTP, synch_buf,
+			   MC_CMD_PTP_IN_SYNCHRONIZE_LEN);
+
+	/* Wait for start from MCDI (or timeout) */
+	timeout = jiffies + msecs_to_jiffies(MAX_SYNCHRONISE_WAIT_MS);
+	while (!ACCESS_ONCE(*start) && (time_before(jiffies, timeout))) {
+		udelay(20);	/* Usually start MCDI execution quickly */
+		loops++;
+	}
+
+	if (ACCESS_ONCE(*start))
+		efx_ptp_send_times(efx, &last_time);
+
+	/* Collect results */
+	rc = efx_mcdi_rpc_finish(efx, MC_CMD_PTP,
+				 MC_CMD_PTP_IN_SYNCHRONIZE_LEN,
+				 synch_buf, sizeof(synch_buf),
+				 &response_length);
+	if (rc == 0)
+		rc = efx_ptp_process_times(efx, synch_buf, response_length,
+					   &last_time);
+
+	return rc;
+}
+
+/* Transmit a PTP packet, via the MCDI interface, to the wire. */
+static int efx_ptp_xmit_skb(struct efx_nic *efx, struct sk_buff *skb)
+{
+	u8 *txbuf = efx->ptp_data->txbuf;
+	struct skb_shared_hwtstamps timestamps;
+	int rc = -EIO;
+	/* MCDI driver requires word aligned lengths */
+	size_t len = ALIGN(MC_CMD_PTP_IN_TRANSMIT_LEN(skb->len), 4);
+	u8 txtime[MC_CMD_PTP_OUT_TRANSMIT_LEN];
+
+	MCDI_SET_DWORD(txbuf, PTP_IN_OP, MC_CMD_PTP_OP_TRANSMIT);
+	MCDI_SET_DWORD(txbuf, PTP_IN_TRANSMIT_LENGTH, skb->len);
+	if (skb_shinfo(skb)->nr_frags != 0) {
+		rc = skb_linearize(skb);
+		if (rc != 0)
+			goto fail;
+	}
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		rc = skb_checksum_help(skb);
+		if (rc != 0)
+			goto fail;
+	}
+	skb_copy_from_linear_data(skb,
+				  &txbuf[MC_CMD_PTP_IN_TRANSMIT_PACKET_OFST],
+				  len);
+	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, txbuf, len, txtime,
+			  sizeof(txtime), &len);
+	if (rc != 0)
+		goto fail;
+
+	memset(&timestamps, 0, sizeof(timestamps));
+	timestamps.hwtstamp = ktime_set(
+		MCDI_DWORD(txtime, PTP_OUT_TRANSMIT_SECONDS),
+		MCDI_DWORD(txtime, PTP_OUT_TRANSMIT_NANOSECONDS));
+
+	skb_tstamp_tx(skb, &timestamps);
+
+	rc = 0;
+
+fail:
+	dev_kfree_skb(skb);
+
+	return rc;
+}
+
+static void efx_ptp_drop_time_expired_events(struct efx_nic *efx)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	struct list_head *cursor;
+	struct list_head *next;
+
+	/* Drop time-expired events */
+	spin_lock_bh(&ptp->evt_lock);
+	if (!list_empty(&ptp->evt_list)) {
+		list_for_each_safe(cursor, next, &ptp->evt_list) {
+			struct efx_ptp_event_rx *evt;
+
+			evt = list_entry(cursor, struct efx_ptp_event_rx,
+					 link);
+			if (time_after(jiffies, evt->expiry)) {
+				list_del(&evt->link);
+				list_add(&evt->link, &ptp->evt_free_list);
+				netif_warn(efx, hw, efx->net_dev,
+					   "PTP rx event dropped\n");
+			}
+		}
+	}
+	spin_unlock_bh(&ptp->evt_lock);
+}
+
+static enum ptp_packet_state efx_ptp_match_rx(struct efx_nic *efx,
+					      struct sk_buff *skb)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	bool evts_waiting;
+	struct list_head *cursor;
+	struct list_head *next;
+	struct efx_ptp_match *match;
+	enum ptp_packet_state rc = PTP_PACKET_STATE_UNMATCHED;
+
+	spin_lock_bh(&ptp->evt_lock);
+	evts_waiting = !list_empty(&ptp->evt_list);
+	spin_unlock_bh(&ptp->evt_lock);
+
+	if (!evts_waiting)
+		return PTP_PACKET_STATE_UNMATCHED;
+
+	match = (struct efx_ptp_match *)skb->cb;
+	/* Look for a matching timestamp in the event queue */
+	spin_lock_bh(&ptp->evt_lock);
+	list_for_each_safe(cursor, next, &ptp->evt_list) {
+		struct efx_ptp_event_rx *evt;
+
+		evt = list_entry(cursor, struct efx_ptp_event_rx, link);
+		if ((evt->seq0 == match->words[0]) &&
+		    (evt->seq1 == match->words[1])) {
+			struct skb_shared_hwtstamps *timestamps;
+
+			/* Match - add in hardware timestamp */
+			timestamps = skb_hwtstamps(skb);
+			timestamps->hwtstamp = evt->hwtimestamp;
+
+			match->state = PTP_PACKET_STATE_MATCHED;
+			rc = PTP_PACKET_STATE_MATCHED;
+			list_del(&evt->link);
+			list_add(&evt->link, &ptp->evt_free_list);
+			break;
+		}
+	}
+	spin_unlock_bh(&ptp->evt_lock);
+
+	return rc;
+}
+
+/* Process any queued receive events and corresponding packets
+ *
+ * q is returned with all the packets that are ready for delivery.
+ * true is returned if at least one of those packets requires
+ * synchronisation.
+ */
+static bool efx_ptp_process_events(struct efx_nic *efx, struct sk_buff_head *q)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	bool rc = false;
+	struct sk_buff *skb;
+
+	while ((skb = skb_dequeue(&ptp->rxq))) {
+		struct efx_ptp_match *match;
+
+		match = (struct efx_ptp_match *)skb->cb;
+		if (match->state == PTP_PACKET_STATE_MATCH_UNWANTED) {
+			__skb_queue_tail(q, skb);
+		} else if (efx_ptp_match_rx(efx, skb) ==
+			   PTP_PACKET_STATE_MATCHED) {
+			rc = true;
+			__skb_queue_tail(q, skb);
+		} else if (time_after(jiffies, match->expiry)) {
+			match->state = PTP_PACKET_STATE_TIMED_OUT;
+			netif_warn(efx, rx_err, efx->net_dev,
+				   "PTP packet - no timestamp seen\n");
+			__skb_queue_tail(q, skb);
+		} else {
+			/* Replace unprocessed entry and stop */
+			skb_queue_head(&ptp->rxq, skb);
+			break;
+		}
+	}
+
+	return rc;
+}
+
+/* Complete processing of a received packet */
+static inline void efx_ptp_process_rx(struct efx_nic *efx, struct sk_buff *skb)
+{
+	local_bh_disable();
+	netif_receive_skb(skb);
+	local_bh_enable();
+}
+
+static int efx_ptp_start(struct efx_nic *efx)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	struct efx_filter_spec rxfilter;
+	int rc;
+
+	ptp->reset_required = false;
+
+	/* Must filter on both event and general ports to ensure
+	 * that there is no packet re-ordering.
+	 */
+	efx_filter_init_rx(&rxfilter, EFX_FILTER_PRI_REQUIRED, 0,
+			   efx_rx_queue_index(
+				   efx_channel_get_rx_queue(ptp->channel)));
+	rc = efx_filter_set_ipv4_local(&rxfilter, IPPROTO_UDP,
+				       htonl(PTP_ADDRESS),
+				       htons(PTP_EVENT_PORT));
+	if (rc != 0)
+		return rc;
+
+	rc = efx_filter_insert_filter(efx, &rxfilter, true);
+	if (rc < 0)
+		return rc;
+	ptp->rxfilter_event = rc;
+
+	efx_filter_init_rx(&rxfilter, EFX_FILTER_PRI_REQUIRED, 0,
+			   efx_rx_queue_index(
+				   efx_channel_get_rx_queue(ptp->channel)));
+	rc = efx_filter_set_ipv4_local(&rxfilter, IPPROTO_UDP,
+				       htonl(PTP_ADDRESS),
+				       htons(PTP_GENERAL_PORT));
+	if (rc != 0)
+		goto fail;
+
+	rc = efx_filter_insert_filter(efx, &rxfilter, true);
+	if (rc < 0)
+		goto fail;
+	ptp->rxfilter_general = rc;
+
+	rc = efx_ptp_enable(efx);
+	if (rc != 0)
+		goto fail2;
+
+	ptp->evt_frag_idx = 0;
+	ptp->current_adjfreq = 0;
+	ptp->rxfilter_installed = true;
+
+	return 0;
+
+fail2:
+	efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
+				  ptp->rxfilter_general);
+fail:
+	efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
+				  ptp->rxfilter_event);
+
+	return rc;
+}
+
+static int efx_ptp_stop(struct efx_nic *efx)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	int rc = efx_ptp_disable(efx);
+	struct list_head *cursor;
+	struct list_head *next;
+
+	if (ptp->rxfilter_installed) {
+		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
+					  ptp->rxfilter_general);
+		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
+					  ptp->rxfilter_event);
+		ptp->rxfilter_installed = false;
+	}
+
+	/* Make sure RX packets are really delivered */
+	efx_ptp_deliver_rx_queue(&efx->ptp_data->rxq);
+	skb_queue_purge(&efx->ptp_data->txq);
+
+	/* Drop any pending receive events */
+	spin_lock_bh(&efx->ptp_data->evt_lock);
+	list_for_each_safe(cursor, next, &efx->ptp_data->evt_list) {
+		list_del(cursor);
+		list_add(cursor, &efx->ptp_data->evt_free_list);
+	}
+	spin_unlock_bh(&efx->ptp_data->evt_lock);
+
+	return rc;
+}
+
+static void efx_ptp_pps_worker(struct work_struct *work)
+{
+	struct efx_ptp_data *ptp =
+		container_of(work, struct efx_ptp_data, pps_work);
+	struct efx_nic *efx = ptp->channel->efx;
+	struct ptp_clock_event ptp_evt;
+
+	if (efx_ptp_synchronize(efx, PTP_SYNC_ATTEMPTS))
+		return;
+
+	ptp_evt.type = PTP_CLOCK_PPSUSR;
+	ptp_evt.pps_times = ptp->host_time_pps;
+	ptp_clock_event(ptp->phc_clock, &ptp_evt);
+}
+
+/* Process any pending transmissions and timestamp any received packets.
+ */
+static void efx_ptp_worker(struct work_struct *work)
+{
+	struct efx_ptp_data *ptp_data =
+		container_of(work, struct efx_ptp_data, work);
+	struct efx_nic *efx = ptp_data->channel->efx;
+	struct sk_buff *skb;
+	struct sk_buff_head tempq;
+
+	if (ptp_data->reset_required) {
+		efx_ptp_stop(efx);
+		efx_ptp_start(efx);
+		return;
+	}
+
+	efx_ptp_drop_time_expired_events(efx);
+
+	__skb_queue_head_init(&tempq);
+	if (efx_ptp_process_events(efx, &tempq) ||
+	    !skb_queue_empty(&ptp_data->txq)) {
+
+		while ((skb = skb_dequeue(&ptp_data->txq)))
+			efx_ptp_xmit_skb(efx, skb);
+	}
+
+	while ((skb = __skb_dequeue(&tempq)))
+		efx_ptp_process_rx(efx, skb);
+}
+
+/* Initialise PTP channel and state.
+ *
+ * Setting core_index to zero causes the queue to be initialised and doesn't
+ * overlap with 'rxq0' because ptp.c doesn't use skb_record_rx_queue.
+ */
+static int efx_ptp_probe_channel(struct efx_channel *channel)
+{
+	struct efx_nic *efx = channel->efx;
+	struct efx_ptp_data *ptp;
+	int rc = 0;
+	unsigned int pos;
+
+	channel->irq_moderation = 0;
+	channel->rx_queue.core_index = 0;
+
+	ptp = kzalloc(sizeof(struct efx_ptp_data), GFP_KERNEL);
+	efx->ptp_data = ptp;
+	if (!efx->ptp_data)
+		return -ENOMEM;
+
+	rc = efx_nic_alloc_buffer(efx, &ptp->start, sizeof(int));
+	if (rc != 0)
+		goto fail1;
+
+	ptp->channel = channel;
+	skb_queue_head_init(&ptp->rxq);
+	skb_queue_head_init(&ptp->txq);
+	ptp->workwq = create_singlethread_workqueue("sfc_ptp");
+	if (!ptp->workwq) {
+		rc = -ENOMEM;
+		goto fail2;
+	}
+
+	INIT_WORK(&ptp->work, efx_ptp_worker);
+	ptp->config.flags = 0;
+	ptp->config.tx_type = HWTSTAMP_TX_OFF;
+	ptp->config.rx_filter = HWTSTAMP_FILTER_NONE;
+	INIT_LIST_HEAD(&ptp->evt_list);
+	INIT_LIST_HEAD(&ptp->evt_free_list);
+	spin_lock_init(&ptp->evt_lock);
+	for (pos = 0; pos < MAX_RECEIVE_EVENTS; pos++)
+		list_add(&ptp->rx_evts[pos].link, &ptp->evt_free_list);
+
+	ptp->phc_clock_info.owner = THIS_MODULE;
+	snprintf(ptp->phc_clock_info.name,
+		 sizeof(ptp->phc_clock_info.name),
+		 "%pm", efx->net_dev->perm_addr);
+	ptp->phc_clock_info.max_adj = MAX_PPB;
+	ptp->phc_clock_info.n_alarm = 0;
+	ptp->phc_clock_info.n_ext_ts = 0;
+	ptp->phc_clock_info.n_per_out = 0;
+	ptp->phc_clock_info.pps = 1;
+	ptp->phc_clock_info.adjfreq = efx_phc_adjfreq;
+	ptp->phc_clock_info.adjtime = efx_phc_adjtime;
+	ptp->phc_clock_info.gettime = efx_phc_gettime;
+	ptp->phc_clock_info.settime = efx_phc_settime;
+	ptp->phc_clock_info.enable = efx_phc_enable;
+
+	ptp->phc_clock = ptp_clock_register(&ptp->phc_clock_info);
+	if (!ptp->phc_clock)
+		goto fail3;
+
+	INIT_WORK(&ptp->pps_work, efx_ptp_pps_worker);
+	ptp->pps_workwq = create_singlethread_workqueue("sfc_pps");
+	if (!ptp->pps_workwq) {
+		rc = -ENOMEM;
+		goto fail4;
+	}
+	ptp->nic_ts_enabled = false;
+
+	return 0;
+fail4:
+	ptp_clock_unregister(efx->ptp_data->phc_clock);
+
+fail3:
+	destroy_workqueue(efx->ptp_data->workwq);
+
+fail2:
+	efx_nic_free_buffer(efx, &ptp->start);
+
+fail1:
+	kfree(efx->ptp_data);
+	efx->ptp_data = NULL;
+
+	return rc;
+}
+
+static void efx_ptp_remove_channel(struct efx_channel *channel)
+{
+	struct efx_nic *efx = channel->efx;
+
+	if (!efx->ptp_data)
+		return;
+
+	(void)efx_ptp_disable(channel->efx);
+
+	cancel_work_sync(&efx->ptp_data->work);
+	cancel_work_sync(&efx->ptp_data->pps_work);
+
+	skb_queue_purge(&efx->ptp_data->rxq);
+	skb_queue_purge(&efx->ptp_data->txq);
+
+	ptp_clock_unregister(efx->ptp_data->phc_clock);
+
+	destroy_workqueue(efx->ptp_data->workwq);
+	destroy_workqueue(efx->ptp_data->pps_workwq);
+
+	efx_nic_free_buffer(efx, &efx->ptp_data->start);
+	kfree(efx->ptp_data);
+}
+
+static void efx_ptp_get_channel_name(struct efx_channel *channel,
+				     char *buf, size_t len)
+{
+	snprintf(buf, len, "%s-ptp", channel->efx->name);
+}
+
+/* Determine whether this packet should be processed by the PTP module
+ * or transmitted conventionally.
+ */
+bool efx_ptp_is_ptp_tx(struct efx_nic *efx, struct sk_buff *skb)
+{
+	return efx->ptp_data &&
+		efx->ptp_data->enabled &&
+		skb->len >= PTP_MIN_LENGTH &&
+		skb->len <= MC_CMD_PTP_IN_TRANSMIT_PACKET_MAXNUM &&
+		likely(skb->protocol == htons(ETH_P_IP)) &&
+		ip_hdr(skb)->protocol == IPPROTO_UDP &&
+		udp_hdr(skb)->dest == htons(PTP_EVENT_PORT);
+}
+
+/* Receive a PTP packet.  Packets are queued until the arrival of
+ * the receive timestamp from the MC - this will probably occur after the
+ * packet arrival because of the processing in the MC.
+ */
+static void efx_ptp_rx(struct efx_channel *channel, struct sk_buff *skb)
+{
+	struct efx_nic *efx = channel->efx;
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	struct efx_ptp_match *match = (struct efx_ptp_match *)skb->cb;
+	u8 *data;
+	unsigned int version;
+
+	match->expiry = jiffies + msecs_to_jiffies(PKT_EVENT_LIFETIME_MS);
+
+	/* Correct version? */
+	if (ptp->mode == MC_CMD_PTP_MODE_V1) {
+		if (skb->len < PTP_V1_MIN_LENGTH) {
+			netif_receive_skb(skb);
+			return;
+		}
+		version = ntohs(*(__be16 *)&skb->data[PTP_V1_VERSION_OFFSET]);
+		if (version != PTP_VERSION_V1) {
+			netif_receive_skb(skb);
+			return;
+		}
+	} else {
+		if (skb->len < PTP_V2_MIN_LENGTH) {
+			netif_receive_skb(skb);
+			return;
+		}
+		version = skb->data[PTP_V2_VERSION_OFFSET];
+
+		BUG_ON(ptp->mode != MC_CMD_PTP_MODE_V2);
+		BUILD_BUG_ON(PTP_V1_UUID_OFFSET != PTP_V2_MC_UUID_OFFSET);
+		BUILD_BUG_ON(PTP_V1_UUID_LENGTH != PTP_V2_MC_UUID_LENGTH);
+		BUILD_BUG_ON(PTP_V1_SEQUENCE_OFFSET != PTP_V2_SEQUENCE_OFFSET);
+		BUILD_BUG_ON(PTP_V1_SEQUENCE_LENGTH != PTP_V2_SEQUENCE_LENGTH);
+
+		if ((version & PTP_VERSION_V2_MASK) != PTP_VERSION_V2) {
+			netif_receive_skb(skb);
+			return;
+		}
+	}
+
+	/* Does this packet require timestamping? */
+	if (ntohs(*(__be16 *)&skb->data[PTP_DPORT_OFFSET]) == PTP_EVENT_PORT) {
+		struct skb_shared_hwtstamps *timestamps;
+
+		match->state = PTP_PACKET_STATE_UNMATCHED;
+
+		/* Clear all timestamps held: filled in later */
+		timestamps = skb_hwtstamps(skb);
+		memset(timestamps, 0, sizeof(*timestamps));
+
+		/* Extract UUID/Sequence information */
+		data = skb->data + PTP_V1_UUID_OFFSET;
+		match->words[0] = (data[0]         |
+				   (data[1] << 8)  |
+				   (data[2] << 16) |
+				   (data[3] << 24));
+		match->words[1] = (data[4]         |
+				   (data[5] << 8)  |
+				   (skb->data[PTP_V1_SEQUENCE_OFFSET +
+					      PTP_V1_SEQUENCE_LENGTH - 1] <<
+				    16));
+	} else {
+		match->state = PTP_PACKET_STATE_MATCH_UNWANTED;
+	}
+
+	skb_queue_tail(&ptp->rxq, skb);
+	queue_work(ptp->workwq, &ptp->work);
+}
+
+/* Transmit a PTP packet.  This has to be transmitted by the MC
+ * itself, through an MCDI call.  MCDI calls aren't permitted
+ * in the transmit path so defer the actual transmission to a suitable worker.
+ */
+int efx_ptp_tx(struct efx_nic *efx, struct sk_buff *skb)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+
+	skb_queue_tail(&ptp->txq, skb);
+
+	if ((udp_hdr(skb)->dest == htons(PTP_EVENT_PORT)) &&
+	    (skb->len <= MC_CMD_PTP_IN_TRANSMIT_PACKET_MAXNUM))
+		efx_xmit_hwtstamp_pending(skb);
+	queue_work(ptp->workwq, &ptp->work);
+
+	return NETDEV_TX_OK;
+}
+
+static int efx_ptp_change_mode(struct efx_nic *efx, bool enable_wanted,
+			       unsigned int new_mode)
+{
+	if ((enable_wanted != efx->ptp_data->enabled) ||
+	    (enable_wanted && (efx->ptp_data->mode != new_mode))) {
+		int rc;
+
+		if (enable_wanted) {
+			/* Change of mode requires disable */
+			if (efx->ptp_data->enabled &&
+			    (efx->ptp_data->mode != new_mode)) {
+				efx->ptp_data->enabled = false;
+				rc = efx_ptp_stop(efx);
+				if (rc != 0)
+					return rc;
+			}
+
+			/* Set new operating mode and establish
+			 * baseline synchronisation, which must
+			 * succeed.
+			 */
+			efx->ptp_data->mode = new_mode;
+			rc = efx_ptp_start(efx);
+			if (rc == 0) {
+				rc = efx_ptp_synchronize(efx,
+							 PTP_SYNC_ATTEMPTS * 2);
+				if (rc != 0)
+					efx_ptp_stop(efx);
+			}
+		} else {
+			rc = efx_ptp_stop(efx);
+		}
+
+		if (rc != 0)
+			return rc;
+
+		efx->ptp_data->enabled = enable_wanted;
+	}
+
+	return 0;
+}
+
+static int efx_ptp_ts_init(struct efx_nic *efx, struct hwtstamp_config *init)
+{
+	bool enable_wanted = false;
+	unsigned int new_mode;
+	int rc;
+
+	if (init->flags)
+		return -EINVAL;
+
+	if ((init->tx_type != HWTSTAMP_TX_OFF) &&
+	    (init->tx_type != HWTSTAMP_TX_ON))
+		return -ERANGE;
+
+	new_mode = efx->ptp_data->mode;
+	/* Determine whether any PTP HW operations are required */
+	switch (init->rx_filter) {
+	case HWTSTAMP_FILTER_NONE:
+		break;
+	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
+	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
+	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
+		init->rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_EVENT;
+		new_mode = MC_CMD_PTP_MODE_V1;
+		enable_wanted = true;
+		break;
+	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
+	/* Although these three are accepted only IPV4 packets will be
+	 * timestamped
+	 */
+		init->rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_EVENT;
+		new_mode = MC_CMD_PTP_MODE_V2;
+		enable_wanted = true;
+		break;
+	case HWTSTAMP_FILTER_PTP_V2_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
+		/* Non-IP + IPv6 timestamping not supported */
+		return -ERANGE;
+		break;
+	default:
+		return -ERANGE;
+	}
+
+	if (init->tx_type != HWTSTAMP_TX_OFF)
+		enable_wanted = true;
+
+	rc = efx_ptp_change_mode(efx, enable_wanted, new_mode);
+	if (rc != 0)
+		return rc;
+
+	efx->ptp_data->config = *init;
+
+	return 0;
+}
+
+int
+efx_ptp_get_ts_info(struct net_device *net_dev, struct ethtool_ts_info *ts_info)
+{
+	struct efx_nic *efx = netdev_priv(net_dev);
+	struct efx_ptp_data *ptp = efx->ptp_data;
+
+	if (!ptp)
+		return -EOPNOTSUPP;
+
+	ts_info->so_timestamping = (SOF_TIMESTAMPING_TX_HARDWARE |
+				    SOF_TIMESTAMPING_RX_HARDWARE |
+				    SOF_TIMESTAMPING_RAW_HARDWARE);
+	ts_info->phc_index = ptp_clock_index(ptp->phc_clock);
+	ts_info->tx_types = 1 << HWTSTAMP_TX_OFF | 1 << HWTSTAMP_TX_ON;
+	ts_info->rx_filters = (1 << HWTSTAMP_FILTER_NONE |
+			       1 << HWTSTAMP_FILTER_PTP_V1_L4_EVENT |
+			       1 << HWTSTAMP_FILTER_PTP_V1_L4_SYNC |
+			       1 << HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ |
+			       1 << HWTSTAMP_FILTER_PTP_V2_L4_EVENT |
+			       1 << HWTSTAMP_FILTER_PTP_V2_L4_SYNC |
+			       1 << HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ);
+	return 0;
+}
+
+int efx_ptp_ioctl(struct efx_nic *efx, struct ifreq *ifr, int cmd)
+{
+	struct hwtstamp_config config;
+	int rc;
+
+	/* Not a PTP enabled port */
+	if (!efx->ptp_data)
+		return -EOPNOTSUPP;
+
+	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
+		return -EFAULT;
+
+	rc = efx_ptp_ts_init(efx, &config);
+	if (rc != 0)
+		return rc;
+
+	return copy_to_user(ifr->ifr_data, &config, sizeof(config))
+		? -EFAULT : 0;
+}
+
+static void ptp_event_failure(struct efx_nic *efx, int expected_frag_len)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+
+	netif_err(efx, hw, efx->net_dev,
+		"PTP unexpected event length: got %d expected %d\n",
+		ptp->evt_frag_idx, expected_frag_len);
+	ptp->reset_required = true;
+	queue_work(ptp->workwq, &ptp->work);
+}
+
+/* Process a completed receive event.  Put it on the event queue and
+ * start worker thread.  This is required because event and their
+ * correspoding packets may come in either order.
+ */
+static void ptp_event_rx(struct efx_nic *efx, struct efx_ptp_data *ptp)
+{
+	struct efx_ptp_event_rx *evt = NULL;
+
+	if (ptp->evt_frag_idx != 3) {
+		ptp_event_failure(efx, 3);
+		return;
+	}
+
+	spin_lock_bh(&ptp->evt_lock);
+	if (!list_empty(&ptp->evt_free_list)) {
+		evt = list_first_entry(&ptp->evt_free_list,
+				       struct efx_ptp_event_rx, link);
+		list_del(&evt->link);
+
+		evt->seq0 = EFX_QWORD_FIELD(ptp->evt_frags[2], MCDI_EVENT_DATA);
+		evt->seq1 = (EFX_QWORD_FIELD(ptp->evt_frags[2],
+					     MCDI_EVENT_SRC)        |
+			     (EFX_QWORD_FIELD(ptp->evt_frags[1],
+					      MCDI_EVENT_SRC) << 8) |
+			     (EFX_QWORD_FIELD(ptp->evt_frags[0],
+					      MCDI_EVENT_SRC) << 16));
+		evt->hwtimestamp = ktime_set(
+			EFX_QWORD_FIELD(ptp->evt_frags[0], MCDI_EVENT_DATA),
+			EFX_QWORD_FIELD(ptp->evt_frags[1], MCDI_EVENT_DATA));
+		evt->expiry = jiffies + msecs_to_jiffies(PKT_EVENT_LIFETIME_MS);
+		list_add_tail(&evt->link, &ptp->evt_list);
+
+		queue_work(ptp->workwq, &ptp->work);
+	} else {
+		netif_err(efx, rx_err, efx->net_dev, "No free PTP event");
+	}
+	spin_unlock_bh(&ptp->evt_lock);
+}
+
+static void ptp_event_fault(struct efx_nic *efx, struct efx_ptp_data *ptp)
+{
+	int code = EFX_QWORD_FIELD(ptp->evt_frags[0], MCDI_EVENT_DATA);
+	if (ptp->evt_frag_idx != 1) {
+		ptp_event_failure(efx, 1);
+		return;
+	}
+
+	netif_err(efx, hw, efx->net_dev, "PTP error %d\n", code);
+}
+
+static void ptp_event_pps(struct efx_nic *efx, struct efx_ptp_data *ptp)
+{
+	if (ptp->nic_ts_enabled)
+		queue_work(ptp->pps_workwq, &ptp->pps_work);
+}
+
+void efx_ptp_event(struct efx_nic *efx, efx_qword_t *ev)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	int code = EFX_QWORD_FIELD(*ev, MCDI_EVENT_CODE);
+
+	if (!ptp->enabled)
+		return;
+
+	if (ptp->evt_frag_idx == 0) {
+		ptp->evt_code = code;
+	} else if (ptp->evt_code != code) {
+		netif_err(efx, hw, efx->net_dev,
+			  "PTP out of sequence event %d\n", code);
+		ptp->evt_frag_idx = 0;
+	}
+
+	ptp->evt_frags[ptp->evt_frag_idx++] = *ev;
+	if (!MCDI_EVENT_FIELD(*ev, CONT)) {
+		/* Process resulting event */
+		switch (code) {
+		case MCDI_EVENT_CODE_PTP_RX:
+			ptp_event_rx(efx, ptp);
+			break;
+		case MCDI_EVENT_CODE_PTP_FAULT:
+			ptp_event_fault(efx, ptp);
+			break;
+		case MCDI_EVENT_CODE_PTP_PPS:
+			ptp_event_pps(efx, ptp);
+			break;
+		default:
+			netif_err(efx, hw, efx->net_dev,
+				  "PTP unknown event %d\n", code);
+			break;
+		}
+		ptp->evt_frag_idx = 0;
+	} else if (MAX_EVENT_FRAGS == ptp->evt_frag_idx) {
+		netif_err(efx, hw, efx->net_dev,
+			  "PTP too many event fragments\n");
+		ptp->evt_frag_idx = 0;
+	}
+}
+
+static int efx_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
+{
+	struct efx_ptp_data *ptp_data = container_of(ptp,
+						     struct efx_ptp_data,
+						     phc_clock_info);
+	struct efx_nic *efx = ptp_data->channel->efx;
+	u8 inadj[MC_CMD_PTP_IN_ADJUST_LEN];
+	s64 adjustment_ns;
+	int rc;
+
+	if (delta > MAX_PPB)
+		delta = MAX_PPB;
+	else if (delta < -MAX_PPB)
+		delta = -MAX_PPB;
+
+	/* Convert ppb to fixed point ns. */
+	adjustment_ns = (((s64)delta * PPB_SCALE_WORD) >>
+			 (PPB_EXTRA_BITS + MAX_PPB_BITS));
+
+	MCDI_SET_DWORD(inadj, PTP_IN_OP, MC_CMD_PTP_OP_ADJUST);
+	MCDI_SET_DWORD(inadj, PTP_IN_ADJUST_FREQ_LO, (u32)adjustment_ns);
+	MCDI_SET_DWORD(inadj, PTP_IN_ADJUST_FREQ_HI,
+		       (u32)(adjustment_ns >> 32));
+	MCDI_SET_DWORD(inadj, PTP_IN_ADJUST_SECONDS, 0);
+	MCDI_SET_DWORD(inadj, PTP_IN_ADJUST_NANOSECONDS, 0);
+	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, inadj, sizeof(inadj),
+			  NULL, 0, NULL);
+	if (rc != 0)
+		return rc;
+
+	ptp_data->current_adjfreq = delta;
+	return 0;
+}
+
+static int efx_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+	struct efx_ptp_data *ptp_data = container_of(ptp,
+						     struct efx_ptp_data,
+						     phc_clock_info);
+	struct efx_nic *efx = ptp_data->channel->efx;
+	struct timespec delta_ts = ns_to_timespec(delta);
+	u8 inbuf[MC_CMD_PTP_IN_ADJUST_LEN];
+
+	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_ADJUST);
+	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_FREQ_LO, 0);
+	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_FREQ_HI, 0);
+	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_SECONDS, (u32)delta_ts.tv_sec);
+	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_NANOSECONDS, (u32)delta_ts.tv_nsec);
+	return efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
+			    NULL, 0, NULL);
+}
+
+static int efx_phc_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
+{
+	struct efx_ptp_data *ptp_data = container_of(ptp,
+						     struct efx_ptp_data,
+						     phc_clock_info);
+	struct efx_nic *efx = ptp_data->channel->efx;
+	u8 inbuf[MC_CMD_PTP_IN_READ_NIC_TIME_LEN];
+	u8 outbuf[MC_CMD_PTP_OUT_READ_NIC_TIME_LEN];
+	int rc;
+
+	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_READ_NIC_TIME);
+
+	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),
+			  outbuf, sizeof(outbuf), NULL);
+	if (rc != 0)
+		return rc;
+
+	ts->tv_sec = MCDI_DWORD(outbuf, PTP_OUT_READ_NIC_TIME_SECONDS);
+	ts->tv_nsec = MCDI_DWORD(outbuf, PTP_OUT_READ_NIC_TIME_NANOSECONDS);
+	return 0;
+}
+
+static int efx_phc_settime(struct ptp_clock_info *ptp,
+			   const struct timespec *e_ts)
+{
+	/* Get the current NIC time, efx_phc_gettime.
+	 * Subtract from the desired time to get the offset
+	 * call efx_phc_adjtime with the offset
+	 */
+	int rc;
+	struct timespec time_now;
+	struct timespec delta;
+
+	rc = efx_phc_gettime(ptp, &time_now);
+	if (rc != 0)
+		return rc;
+
+	delta = timespec_sub(*e_ts, time_now);
+
+	efx_phc_adjtime(ptp, timespec_to_ns(&delta));
+	if (rc != 0)
+		return rc;
+
+	return 0;
+}
+
+static int efx_phc_enable(struct ptp_clock_info *ptp,
+			  struct ptp_clock_request *request,
+			  int enable)
+{
+	struct efx_ptp_data *ptp_data = container_of(ptp,
+						     struct efx_ptp_data,
+						     phc_clock_info);
+	if (request->type != PTP_CLK_REQ_PPS)
+		return -EOPNOTSUPP;
+
+	ptp_data->nic_ts_enabled = !!enable;
+	return 0;
+}
+
+static const struct efx_channel_type efx_ptp_channel_type = {
+	.handle_no_channel	= efx_ptp_handle_no_channel,
+	.pre_probe		= efx_ptp_probe_channel,
+	.post_remove		= efx_ptp_remove_channel,
+	.get_name		= efx_ptp_get_channel_name,
+	/* no copy operation; there is no need to reallocate this channel */
+	.receive_skb		= efx_ptp_rx,
+	.keep_eventq		= false,
+};
+
+void efx_ptp_probe(struct efx_nic *efx)
+{
+	/* Check whether PTP is implemented on this NIC.  The DISABLE
+	 * operation will succeed if and only if it is implemented.
+	 */
+	if (efx_ptp_disable(efx) == 0)
+		efx->extra_channel_type[EFX_EXTRA_CHANNEL_PTP] =
+			&efx_ptp_channel_type;
+}
diff --git a/drivers/net/ethernet/sfc/siena.c b/drivers/net/ethernet/sfc/siena.c
index 6bafd216e55e..84b41bf08a38 100644
--- a/drivers/net/ethernet/sfc/siena.c
+++ b/drivers/net/ethernet/sfc/siena.c
@@ -335,6 +335,7 @@ static int siena_probe_nic(struct efx_nic *efx)
 		goto fail5;
 
 	efx_sriov_probe(efx);
+	efx_ptp_probe(efx);
 
 	return 0;
 
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index ebca75ed78dc..5e090e54298e 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -339,6 +339,12 @@ netdev_tx_t efx_hard_start_xmit(struct sk_buff *skb,
 
 	EFX_WARN_ON_PARANOID(!netif_device_present(net_dev));
 
+	/* PTP "event" packet */
+	if (unlikely(efx_xmit_with_hwtstamp(skb)) &&
+	    unlikely(efx_ptp_is_ptp_tx(efx, skb))) {
+		return efx_ptp_tx(efx, skb);
+	}
+
 	index = skb_get_queue_mapping(skb);
 	type = skb->ip_summed == CHECKSUM_PARTIAL ? EFX_TXQ_TYPE_OFFLOAD : 0;
 	if (index >= efx->n_tx_channels) {