i40e: enable PTP

New feature: Enable PTP support in the i40e driver.

Change-ID: I6a8e799f582705191f9583afb1b9231a8db96cc8
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Matthew Vick <matthew.vick@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/Kconfig

@@ -243,6 +243,7 @@ config IXGBEVF
 
 config I40E
 	tristate "Intel(R) Ethernet Controller XL710 Family support"
+	select PTP_1588_CLOCK
 	depends on PCI
 	---help---
 	  This driver supports Intel(R) Ethernet Controller XL710 Family of

drivers/net/ethernet/intel/i40e/Makefile

@@ -40,4 +40,5 @@ i40e-objs := i40e_main.o \
 	i40e_debugfs.o	\
 	i40e_diag.o	\
 	i40e_txrx.o	\
+	i40e_ptp.o	\
 	i40e_virtchnl_pf.o

drivers/net/ethernet/intel/i40e/i40e.h

@@ -50,6 +50,9 @@
 #include <net/ip6_checksum.h>
 #include <linux/ethtool.h>
 #include <linux/if_vlan.h>
+#include <linux/clocksource.h>
+#include <linux/net_tstamp.h>
+#include <linux/ptp_clock_kernel.h>
 #include "i40e_type.h"
 #include "i40e_prototype.h"
 #include "i40e_virtchnl.h"
@@ -242,6 +245,7 @@ struct i40e_pf {
 #define I40E_FLAG_DCB_ENABLED                  (u64)(1 << 20)
 #define I40E_FLAG_FDIR_ENABLED                 (u64)(1 << 21)
 #define I40E_FLAG_FDIR_ATR_ENABLED             (u64)(1 << 22)
+#define I40E_FLAG_PTP                          (u64)(1 << 25)
 #define I40E_FLAG_MFP_ENABLED                  (u64)(1 << 26)
 #ifdef CONFIG_I40E_VXLAN
 #define I40E_FLAG_VXLAN_FILTER_SYNC            (u64)(1 << 27)
@@ -302,6 +306,20 @@ struct i40e_pf {
 	u32	fcoe_hmc_filt_num;
 	u32	fcoe_hmc_cntx_num;
 	struct i40e_filter_control_settings filter_settings;
+
+	struct ptp_clock *ptp_clock;
+	struct ptp_clock_info ptp_caps;
+	struct sk_buff *ptp_tx_skb;
+	struct work_struct ptp_tx_work;
+	struct hwtstamp_config tstamp_config;
+	unsigned long ptp_tx_start;
+	unsigned long last_rx_ptp_check;
+	spinlock_t tmreg_lock; /* Used to protect the device time registers. */
+	u64 ptp_base_adj;
+	u32 tx_hwtstamp_timeouts;
+	u32 rx_hwtstamp_cleared;
+	bool ptp_tx;
+	bool ptp_rx;
 };
 
 struct i40e_mac_filter {
@@ -566,4 +584,12 @@ struct i40e_mac_filter *i40e_find_mac(struct i40e_vsi *vsi, u8 *macaddr,
 				      bool is_vf, bool is_netdev);
 void i40e_vlan_stripping_enable(struct i40e_vsi *vsi);
 
+void i40e_ptp_rx_hang(struct i40e_vsi *vsi);
+void i40e_ptp_tx_hwtstamp(struct i40e_pf *pf);
+void i40e_ptp_rx_hwtstamp(struct i40e_pf *pf, struct sk_buff *skb, u8 index);
+void i40e_ptp_set_increment(struct i40e_pf *pf);
+int i40e_ptp_set_ts_config(struct i40e_pf *pf, struct ifreq *ifr);
+int i40e_ptp_get_ts_config(struct i40e_pf *pf, struct ifreq *ifr);
+void i40e_ptp_init(struct i40e_pf *pf);
+void i40e_ptp_stop(struct i40e_pf *pf);
 #endif /* _I40E_H_ */

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

@@ -108,6 +108,8 @@ static struct i40e_stats i40e_gstrings_stats[] = {
 	I40E_PF_STAT("rx_oversize", stats.rx_oversize),
 	I40E_PF_STAT("rx_jabber", stats.rx_jabber),
 	I40E_PF_STAT("VF_admin_queue_requests", vf_aq_requests),
+	I40E_PF_STAT("tx_hwtstamp_timeouts", tx_hwtstamp_timeouts),
+	I40E_PF_STAT("rx_hwtstamp_cleared", rx_hwtstamp_cleared),
 };
 
 #define I40E_QUEUE_STATS_LEN(n) \
@@ -748,7 +750,36 @@ static void i40e_get_strings(struct net_device *netdev, u32 stringset,
 static int i40e_get_ts_info(struct net_device *dev,
 			    struct ethtool_ts_info *info)
 {
-	return ethtool_op_get_ts_info(dev, info);
+	struct i40e_pf *pf = i40e_netdev_to_pf(dev);
+
+	info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE |
+				SOF_TIMESTAMPING_RX_SOFTWARE |
+				SOF_TIMESTAMPING_SOFTWARE |
+				SOF_TIMESTAMPING_TX_HARDWARE |
+				SOF_TIMESTAMPING_RX_HARDWARE |
+				SOF_TIMESTAMPING_RAW_HARDWARE;
+
+	if (pf->ptp_clock)
+		info->phc_index = ptp_clock_index(pf->ptp_clock);
+	else
+		info->phc_index = -1;
+
+	info->tx_types = (1 << HWTSTAMP_TX_OFF) | (1 << HWTSTAMP_TX_ON);
+
+	info->rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
+			   (1 << HWTSTAMP_FILTER_PTP_V1_L4_SYNC) |
+			   (1 << HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ) |
+			   (1 << HWTSTAMP_FILTER_PTP_V2_EVENT) |
+			   (1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
+			   (1 << HWTSTAMP_FILTER_PTP_V2_L4_EVENT) |
+			   (1 << HWTSTAMP_FILTER_PTP_V2_SYNC) |
+			   (1 << HWTSTAMP_FILTER_PTP_V2_L2_SYNC) |
+			   (1 << HWTSTAMP_FILTER_PTP_V2_L4_SYNC) |
+			   (1 << HWTSTAMP_FILTER_PTP_V2_DELAY_REQ) |
+			   (1 << HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ) |
+			   (1 << HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ);
+
+	return 0;
 }
 
 static int i40e_link_test(struct net_device *netdev, u64 *data)

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -1697,6 +1697,27 @@ static int i40e_change_mtu(struct net_device *netdev, int new_mtu)
 	return 0;
 }
 
+/**
+ * i40e_ioctl - Access the hwtstamp interface
+ * @netdev: network interface device structure
+ * @ifr: interface request data
+ * @cmd: ioctl command
+ **/
+int i40e_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
+{
+	struct i40e_netdev_priv *np = netdev_priv(netdev);
+	struct i40e_pf *pf = np->vsi->back;
+
+	switch (cmd) {
+	case SIOCGHWTSTAMP:
+		return i40e_ptp_get_ts_config(pf, ifr);
+	case SIOCSHWTSTAMP:
+		return i40e_ptp_set_ts_config(pf, ifr);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 /**
  * i40e_vlan_stripping_enable - Turn on vlan stripping for the VSI
  * @vsi: the vsi being adjusted
@@ -2151,6 +2172,7 @@ static int i40e_configure_tx_ring(struct i40e_ring *ring)
 	tx_ctx.qlen = ring->count;
 	tx_ctx.fd_ena = !!(vsi->back->flags & (I40E_FLAG_FDIR_ENABLED |
 					       I40E_FLAG_FDIR_ATR_ENABLED));
+	tx_ctx.timesync_ena = !!(vsi->back->flags & I40E_FLAG_PTP);
 
 	/* As part of VSI creation/update, FW allocates certain
 	 * Tx arbitration queue sets for each TC enabled for
@@ -2488,6 +2510,7 @@ static void i40e_enable_misc_int_causes(struct i40e_hw *hw)
 	      I40E_PFINT_ICR0_ENA_GRST_MASK          |
 	      I40E_PFINT_ICR0_ENA_PCI_EXCEPTION_MASK |
 	      I40E_PFINT_ICR0_ENA_GPIO_MASK          |
+	      I40E_PFINT_ICR0_ENA_TIMESYNC_MASK      |
 	      I40E_PFINT_ICR0_ENA_STORM_DETECT_MASK  |
 	      I40E_PFINT_ICR0_ENA_HMC_ERR_MASK       |
 	      I40E_PFINT_ICR0_ENA_VFLR_MASK          |
@@ -2831,6 +2854,18 @@ static irqreturn_t i40e_intr(int irq, void *data)
 		dev_info(&pf->pdev->dev, "HMC error interrupt\n");
 	}
 
+	if (icr0 & I40E_PFINT_ICR0_TIMESYNC_MASK) {
+		u32 prttsyn_stat = rd32(hw, I40E_PRTTSYN_STAT_0);
+
+		if (prttsyn_stat & I40E_PRTTSYN_STAT_0_TXTIME_MASK) {
+			ena_mask &= ~I40E_PFINT_ICR0_ENA_TIMESYNC_MASK;
+			i40e_ptp_tx_hwtstamp(pf);
+			prttsyn_stat &= ~I40E_PRTTSYN_STAT_0_TXTIME_MASK;
+		}
+
+		wr32(hw, I40E_PRTTSYN_STAT_0, prttsyn_stat);
+	}
+
 	/* If a critical error is pending we have no choice but to reset the
 	 * device.
 	 * Report and mask out any remaining unexpected interrupts.
@@ -4304,6 +4339,9 @@ static void i40e_link_event(struct i40e_pf *pf)
 
 	if (pf->vf)
 		i40e_vc_notify_link_state(pf);
+
+	if (pf->flags & I40E_FLAG_PTP)
+		i40e_ptp_set_increment(pf);
 }
 
 /**
@@ -4385,6 +4423,8 @@ static void i40e_watchdog_subtask(struct i40e_pf *pf)
 	for (i = 0; i < I40E_MAX_VEB; i++)
 		if (pf->veb[i])
 			i40e_update_veb_stats(pf->veb[i]);
+
+	i40e_ptp_rx_hang(pf->vsi[pf->lan_vsi]);
 }
 
 /**
@@ -6033,6 +6073,7 @@ static const struct net_device_ops i40e_netdev_ops = {
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_set_mac_address	= i40e_set_mac,
 	.ndo_change_mtu		= i40e_change_mtu,
+	.ndo_do_ioctl		= i40e_ioctl,
 	.ndo_tx_timeout		= i40e_tx_timeout,
 	.ndo_vlan_rx_add_vid	= i40e_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid	= i40e_vlan_rx_kill_vid,
@@ -7299,6 +7340,8 @@ static int i40e_setup_pf_switch(struct i40e_pf *pf, bool reinit)
 					 ~I40E_PRTDCB_MFLCN_RFCE_MASK);
 
 fc_complete:
+	i40e_ptp_init(pf);
+
 	return ret;
 }
 
@@ -7803,6 +7846,8 @@ static void i40e_remove(struct pci_dev *pdev)
 
 	i40e_dbg_pf_exit(pf);
 
+	i40e_ptp_stop(pf);
+
 	if (pf->flags & I40E_FLAG_SRIOV_ENABLED) {
 		i40e_free_vfs(pf);
 		pf->flags &= ~I40E_FLAG_SRIOV_ENABLED;

drivers/net/ethernet/intel/i40e/i40e_ptp.c

+/*******************************************************************************
+ *
+ * Intel Ethernet Controller XL710 Family Linux Driver
+ * Copyright(c) 2013 - 2014 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Contact Information:
+ * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *
+ ******************************************************************************/
+
+#include "i40e.h"
+#include <linux/export.h>
+#include <linux/ptp_classify.h>
+
+/* The XL710 timesync is very much like Intel's 82599 design when it comes to
+ * the fundamental clock design. However, the clock operations are much simpler
+ * in the XL710 because the device supports a full 64 bits of nanoseconds.
+ * Because the field is so wide, we can forgo the cycle counter and just
+ * operate with the nanosecond field directly without fear of overflow.
+ *
+ * Much like the 82599, the update period is dependent upon the link speed:
+ * At 40Gb link or no link, the period is 1.6ns.
+ * At 10Gb link, the period is multiplied by 2. (3.2ns)
+ * At 1Gb link, the period is multiplied by 20. (32ns)
+ * 1588 functionality is not supported at 100Mbps.
+ */
+#define I40E_PTP_40GB_INCVAL 0x0199999999ULL
+#define I40E_PTP_10GB_INCVAL 0x0333333333ULL
+#define I40E_PTP_1GB_INCVAL  0x2000000000ULL
+
+#define I40E_PRTTSYN_CTL1_TSYNTYPE_V1  (0x1 << \
+					I40E_PRTTSYN_CTL1_TSYNTYPE_SHIFT)
+#define I40E_PRTTSYN_CTL1_TSYNTYPE_V2  (0x2 << \
+					I40E_PRTTSYN_CTL1_TSYNTYPE_SHIFT)
+#define I40E_PTP_TX_TIMEOUT  (HZ * 15)
+
+/**
+ * i40e_ptp_read - Read the PHC time from the device
+ * @pf: Board private structure
+ * @ts: timespec structure to hold the current time value
+ *
+ * This function reads the PRTTSYN_TIME registers and stores them in a
+ * timespec. However, since the registers are 64 bits of nanoseconds, we must
+ * convert the result to a timespec before we can return.
+ **/
+static void i40e_ptp_read(struct i40e_pf *pf, struct timespec *ts)
+{
+	struct i40e_hw *hw = &pf->hw;
+	u32 hi, lo;
+	u64 ns;
+
+	/* The timer latches on the lowest register read. */
+	lo = rd32(hw, I40E_PRTTSYN_TIME_L);
+	hi = rd32(hw, I40E_PRTTSYN_TIME_H);
+
+	ns = (((u64)hi) << 32) | lo;
+
+	*ts = ns_to_timespec(ns);
+}
+
+/**
+ * i40e_ptp_write - Write the PHC time to the device
+ * @pf: Board private structure
+ * @ts: timespec structure that holds the new time value
+ *
+ * This function writes the PRTTSYN_TIME registers with the user value. Since
+ * we receive a timespec from the stack, we must convert that timespec into
+ * nanoseconds before programming the registers.
+ **/
+static void i40e_ptp_write(struct i40e_pf *pf, const struct timespec *ts)
+{
+	struct i40e_hw *hw = &pf->hw;
+	u64 ns = timespec_to_ns(ts);
+
+	/* The timer will not update until the high register is written, so
+	 * write the low register first.
+	 */
+	wr32(hw, I40E_PRTTSYN_TIME_L, ns & 0xFFFFFFFF);
+	wr32(hw, I40E_PRTTSYN_TIME_H, ns >> 32);
+}
+
+/**
+ * i40e_ptp_convert_to_hwtstamp - Convert device clock to system time
+ * @hwtstamps: Timestamp structure to update
+ * @timestamp: Timestamp from the hardware
+ *
+ * We need to convert the NIC clock value into a hwtstamp which can be used by
+ * the upper level timestamping functions. Since the timestamp is simply a 64-
+ * bit nanosecond value, we can call ns_to_ktime directly to handle this.
+ **/
+static void i40e_ptp_convert_to_hwtstamp(struct skb_shared_hwtstamps *hwtstamps,
+					 u64 timestamp)
+{
+	memset(hwtstamps, 0, sizeof(*hwtstamps));
+
+	hwtstamps->hwtstamp = ns_to_ktime(timestamp);
+}
+
+/**
+ * i40e_ptp_adjfreq - Adjust the PHC frequency
+ * @ptp: The PTP clock structure
+ * @ppb: Parts per billion adjustment from the base
+ *
+ * Adjust the frequency of the PHC by the indicated parts per billion from the
+ * base frequency.
+ **/
+static int i40e_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+{
+	struct i40e_pf *pf = container_of(ptp, struct i40e_pf, ptp_caps);
+	struct i40e_hw *hw = &pf->hw;
+	u64 adj, freq, diff;
+	int neg_adj = 0;
+
+	if (ppb < 0) {
+		neg_adj = 1;
+		ppb = -ppb;
+	}
+
+	smp_mb(); /* Force any pending update before accessing. */
+	adj = ACCESS_ONCE(pf->ptp_base_adj);
+
+	freq = adj;
+	freq *= ppb;
+	diff = div_u64(freq, 1000000000ULL);
+
+	if (neg_adj)
+		adj -= diff;
+	else
+		adj += diff;
+
+	wr32(hw, I40E_PRTTSYN_INC_L, adj & 0xFFFFFFFF);
+	wr32(hw, I40E_PRTTSYN_INC_H, adj >> 32);
+
+	return 0;
+}
+
+/**
+ * i40e_ptp_adjtime - Adjust the PHC time
+ * @ptp: The PTP clock structure
+ * @delta: Offset in nanoseconds to adjust the PHC time by
+ *
+ * Adjust the frequency of the PHC by the indicated parts per billion from the
+ * base frequency.
+ **/
+static int i40e_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+	struct i40e_pf *pf = container_of(ptp, struct i40e_pf, ptp_caps);
+	struct timespec now, then = ns_to_timespec(delta);
+	unsigned long flags;
+
+	spin_lock_irqsave(&pf->tmreg_lock, flags);
+
+	i40e_ptp_read(pf, &now);
+	now = timespec_add(now, then);
+	i40e_ptp_write(pf, (const struct timespec *)&now);
+
+	spin_unlock_irqrestore(&pf->tmreg_lock, flags);
+
+	return 0;
+}
+
+/**
+ * i40e_ptp_gettime - Get the time of the PHC
+ * @ptp: The PTP clock structure
+ * @ts: timespec structure to hold the current time value
+ *
+ * Read the device clock and return the correct value on ns, after converting it
+ * into a timespec struct.
+ **/
+static int i40e_ptp_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
+{
+	struct i40e_pf *pf = container_of(ptp, struct i40e_pf, ptp_caps);
+	unsigned long flags;
+
+	spin_lock_irqsave(&pf->tmreg_lock, flags);
+	i40e_ptp_read(pf, ts);
+	spin_unlock_irqrestore(&pf->tmreg_lock, flags);
+
+	return 0;
+}
+
+/**
+ * i40e_ptp_settime - Set the time of the PHC
+ * @ptp: The PTP clock structure
+ * @ts: timespec structure that holds the new time value
+ *
+ * Set the device clock to the user input value. The conversion from timespec
+ * to ns happens in the write function.
+ **/
+static int i40e_ptp_settime(struct ptp_clock_info *ptp,
+			    const struct timespec *ts)
+{
+	struct i40e_pf *pf = container_of(ptp, struct i40e_pf, ptp_caps);
+	unsigned long flags;
+
+	spin_lock_irqsave(&pf->tmreg_lock, flags);
+	i40e_ptp_write(pf, ts);
+	spin_unlock_irqrestore(&pf->tmreg_lock, flags);
+
+	return 0;
+}
+
+/**
+ * i40e_ptp_tx_work
+ * @work: pointer to work struct
+ *
+ * This work function polls the PRTTSYN_STAT_0.TXTIME bit to determine when a
+ * Tx timestamp event has occurred, in order to pass the Tx timestamp value up
+ * the stack in the skb.
+ */
+static void i40e_ptp_tx_work(struct work_struct *work)
+{
+	struct i40e_pf *pf = container_of(work, struct i40e_pf,
+					  ptp_tx_work);
+	struct i40e_hw *hw = &pf->hw;
+	u32 prttsyn_stat_0;
+
+	if (!pf->ptp_tx_skb)
+		return;
+
+	if (time_is_before_jiffies(pf->ptp_tx_start +
+				   I40E_PTP_TX_TIMEOUT)) {
+		dev_kfree_skb_any(pf->ptp_tx_skb);
+		pf->ptp_tx_skb = NULL;
+		pf->tx_hwtstamp_timeouts++;
+		dev_warn(&pf->pdev->dev, "clearing Tx timestamp hang");
+		return;
+	}
+
+	prttsyn_stat_0 = rd32(hw, I40E_PRTTSYN_STAT_0);
+	if (prttsyn_stat_0 & I40E_PRTTSYN_STAT_0_TXTIME_MASK)
+		i40e_ptp_tx_hwtstamp(pf);
+	else
+		schedule_work(&pf->ptp_tx_work);
+}
+
+/**
+ * i40e_ptp_enable - Enable/disable ancillary features of the PHC subsystem
+ * @ptp: The PTP clock structure
+ * @rq: The requested feature to change
+ * @on: Enable/disable flag
+ *
+ * The XL710 does not support any of the ancillary features of the PHC
+ * subsystem, so this function may just return.
+ **/
+static int i40e_ptp_enable(struct ptp_clock_info *ptp,
+			   struct ptp_clock_request *rq, int on)
+{
+	return -EOPNOTSUPP;
+}
+
+/**
+ * i40e_ptp_rx_hang - Detect error case when Rx timestamp registers are hung
+ * @vsi: The VSI with the rings relevant to 1588
+ *
+ * This watchdog task is scheduled to detect error case where hardware has
+ * dropped an Rx packet that was timestamped when the ring is full. The
+ * particular error is rare but leaves the device in a state unable to timestamp
+ * any future packets.
+ **/
+void i40e_ptp_rx_hang(struct i40e_vsi *vsi)
+{
+	struct i40e_pf *pf = vsi->back;
+	struct i40e_hw *hw = &pf->hw;
+	struct i40e_ring *rx_ring;
+	unsigned long rx_event;
+	u32 prttsyn_stat;
+	int n;
+
+	if (pf->flags & I40E_FLAG_PTP)
+		return;
+
+	prttsyn_stat = rd32(hw, I40E_PRTTSYN_STAT_1);
+
+	/* Unless all four receive timestamp registers are latched, we are not
+	 * concerned about a possible PTP Rx hang, so just update the timeout
+	 * counter and exit.
+	 */
+	if (!(prttsyn_stat & ((I40E_PRTTSYN_STAT_1_RXT0_MASK <<
+			       I40E_PRTTSYN_STAT_1_RXT0_SHIFT) |
+			      (I40E_PRTTSYN_STAT_1_RXT1_MASK <<
+			       I40E_PRTTSYN_STAT_1_RXT1_SHIFT) |
+			      (I40E_PRTTSYN_STAT_1_RXT2_MASK <<
+			       I40E_PRTTSYN_STAT_1_RXT2_SHIFT) |
+			      (I40E_PRTTSYN_STAT_1_RXT3_MASK <<
+			       I40E_PRTTSYN_STAT_1_RXT3_SHIFT)))) {
+		pf->last_rx_ptp_check = jiffies;
+		return;
+	}
+
+	/* Determine the most recent watchdog or rx_timestamp event. */
+	rx_event = pf->last_rx_ptp_check;
+	for (n = 0; n < vsi->num_queue_pairs; n++) {
+		rx_ring = vsi->rx_rings[n];
+		if (time_after(rx_ring->last_rx_timestamp, rx_event))
+			rx_event = rx_ring->last_rx_timestamp;
+	}
+
+	/* Only need to read the high RXSTMP register to clear the lock */
+	if (time_is_before_jiffies(rx_event + 5 * HZ)) {
+		rd32(hw, I40E_PRTTSYN_RXTIME_H(0));
+		rd32(hw, I40E_PRTTSYN_RXTIME_H(1));
+		rd32(hw, I40E_PRTTSYN_RXTIME_H(2));
+		rd32(hw, I40E_PRTTSYN_RXTIME_H(3));
+		pf->last_rx_ptp_check = jiffies;
+		pf->rx_hwtstamp_cleared++;
+		dev_warn(&vsi->back->pdev->dev,
+			 "%s: clearing Rx timestamp hang",
+			 __func__);
+	}
+}
+
+/**
+ * i40e_ptp_tx_hwtstamp - Utility function which returns the Tx timestamp
+ * @pf: Board private structure
+ *
+ * Read the value of the Tx timestamp from the registers, convert it into a
+ * value consumable by the stack, and store that result into the shhwtstamps
+ * struct before returning it up the stack.
+ **/
+void i40e_ptp_tx_hwtstamp(struct i40e_pf *pf)
+{
+	struct skb_shared_hwtstamps shhwtstamps;
+	struct i40e_hw *hw = &pf->hw;
+	u32 hi, lo;
+	u64 ns;
+
+	lo = rd32(hw, I40E_PRTTSYN_TXTIME_L);
+	hi = rd32(hw, I40E_PRTTSYN_TXTIME_H);
+
+	ns = (((u64)hi) << 32) | lo;
+
+	i40e_ptp_convert_to_hwtstamp(&shhwtstamps, ns);
+	skb_tstamp_tx(pf->ptp_tx_skb, &shhwtstamps);
+	dev_kfree_skb_any(pf->ptp_tx_skb);
+	pf->ptp_tx_skb = NULL;
+}
+
+/**
+ * i40e_ptp_rx_hwtstamp - Utility function which checks for an Rx timestamp
+ * @pf: Board private structure
+ * @skb: Particular skb to send timestamp with
+ * @index: Index into the receive timestamp registers for the timestamp
+ *
+ * The XL710 receives a notification in the receive descriptor with an offset
+ * into the set of RXTIME registers where the timestamp is for that skb. This
+ * function goes and fetches the receive timestamp from that offset, if a valid
+ * one exists. The RXTIME registers are in ns, so we must convert the result
+ * first.
+ **/
+void i40e_ptp_rx_hwtstamp(struct i40e_pf *pf, struct sk_buff *skb, u8 index)
+{
+	u32 prttsyn_stat, hi, lo;
+	struct i40e_hw *hw;
+	u64 ns;
+
+	/* Since we cannot turn off the Rx timestamp logic if the device is
+	 * doing Tx timestamping, check if Rx timestamping is configured.
+	 */
+	if (!pf->ptp_rx)
+		return;
+
+	hw = &pf->hw;
+
+	prttsyn_stat = rd32(hw, I40E_PRTTSYN_STAT_1);
+
+	if (!(prttsyn_stat & (1 << index)))
+		return;
+
+	lo = rd32(hw, I40E_PRTTSYN_RXTIME_L(index));
+	hi = rd32(hw, I40E_PRTTSYN_RXTIME_H(index));
+
+	ns = (((u64)hi) << 32) | lo;
+
+	i40e_ptp_convert_to_hwtstamp(skb_hwtstamps(skb), ns);
+}
+
+/**
+ * i40e_ptp_set_increment - Utility function to update clock increment rate
+ * @pf: Board private structure
+ *
+ * During a link change, the DMA frequency that drives the 1588 logic will
+ * change. In order to keep the PRTTSYN_TIME registers in units of nanoseconds,
+ * we must update the increment value per clock tick.
+ **/
+void i40e_ptp_set_increment(struct i40e_pf *pf)
+{
+	struct i40e_link_status *hw_link_info;
+	struct i40e_hw *hw = &pf->hw;
+	u64 incval;
+
+	hw_link_info = &hw->phy.link_info;
+
+	i40e_aq_get_link_info(&pf->hw, true, NULL, NULL);
+
+	switch (hw_link_info->link_speed) {
+	case I40E_LINK_SPEED_10GB:
+		incval = I40E_PTP_10GB_INCVAL;
+		break;
+	case I40E_LINK_SPEED_1GB:
+		incval = I40E_PTP_1GB_INCVAL;
+		break;
+	case I40E_LINK_SPEED_100MB:
+		dev_warn(&pf->pdev->dev,
+			 "%s: 1588 functionality is not supported at 100 Mbps. Stopping the PHC.\n",
+			 __func__);
+		incval = 0;
+		break;
+	case I40E_LINK_SPEED_40GB:
+	default:
+		incval = I40E_PTP_40GB_INCVAL;
+		break;
+	}
+
+	/* Write the new increment value into the increment register. The
+	 * hardware will not update the clock until both registers have been
+	 * written.
+	 */
+	wr32(hw, I40E_PRTTSYN_INC_L, incval & 0xFFFFFFFF);
+	wr32(hw, I40E_PRTTSYN_INC_H, incval >> 32);
+
+	/* Update the base adjustement value. */
+	ACCESS_ONCE(pf->ptp_base_adj) = incval;
+	smp_mb(); /* Force the above update. */
+}
+
+/**
+ * i40e_ptp_get_ts_config - ioctl interface to read the HW timestamping
+ * @pf: Board private structure
+ * @ifreq: ioctl data
+ *
+ * Obtain the current hardware timestamping settigs as requested. To do this,
+ * keep a shadow copy of the timestamp settings rather than attempting to
+ * deconstruct it from the registers.
+ **/
+int i40e_ptp_get_ts_config(struct i40e_pf *pf, struct ifreq *ifr)
+{
+	struct hwtstamp_config *config = &pf->tstamp_config;
+
+	return copy_to_user(ifr->ifr_data, config, sizeof(*config)) ?
+		-EFAULT : 0;
+}
+
+/**
+ * i40e_ptp_set_ts_config - ioctl interface to control the HW timestamping
+ * @pf: Board private structure
+ * @ifreq: ioctl data
+ *
+ * Respond to the user filter requests and make the appropriate hardware
+ * changes here. The XL710 cannot support splitting of the Tx/Rx timestamping
+ * logic, so keep track in software of whether to indicate these timestamps
+ * or not.
+ *
+ * It is permissible to "upgrade" the user request to a broader filter, as long
+ * as the user receives the timestamps they care about and the user is notified
+ * the filter has been broadened.
+ **/
+int i40e_ptp_set_ts_config(struct i40e_pf *pf, struct ifreq *ifr)
+{
+	struct i40e_hw *hw = &pf->hw;
+	struct hwtstamp_config *config = &pf->tstamp_config;
+	u32 pf_id, tsyntype, regval;
+
+	if (copy_from_user(config, ifr->ifr_data, sizeof(*config)))
+		return -EFAULT;
+
+	/* Reserved for future extensions. */
+	if (config->flags)
+		return -EINVAL;
+
+	/* Confirm that 1588 is supported on this PF. */
+	pf_id = (rd32(hw, I40E_PRTTSYN_CTL0) & I40E_PRTTSYN_CTL0_PF_ID_MASK) >>
+		I40E_PRTTSYN_CTL0_PF_ID_SHIFT;
+	if (hw->pf_id != pf_id)
+		return -EINVAL;
+
+	switch (config->tx_type) {
+	case HWTSTAMP_TX_OFF:
+		pf->ptp_tx = false;
+		break;
+	case HWTSTAMP_TX_ON:
+		pf->ptp_tx = true;
+		break;
+	default:
+		return -ERANGE;
+	}
+
+	switch (config->rx_filter) {
+	case HWTSTAMP_FILTER_NONE:
+		pf->ptp_rx = false;
+		tsyntype = 0;
+		break;
+	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
+	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
+		pf->ptp_rx = true;
+		tsyntype = I40E_PRTTSYN_CTL1_V1MESSTYPE0_MASK |
+			   I40E_PRTTSYN_CTL1_TSYNTYPE_V1 |
+			   I40E_PRTTSYN_CTL1_UDP_ENA_MASK;
+		config->rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_EVENT;
+		break;
+	case HWTSTAMP_FILTER_PTP_V2_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
+	case HWTSTAMP_FILTER_PTP_V2_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
+	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
+	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
+		pf->ptp_rx = true;
+		tsyntype = I40E_PRTTSYN_CTL1_V2MESSTYPE0_MASK |
+			   I40E_PRTTSYN_CTL1_TSYNTYPE_V2 |
+			   I40E_PRTTSYN_CTL1_UDP_ENA_MASK;
+		config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
+		break;
+	case HWTSTAMP_FILTER_ALL:
+	default:
+		return -ERANGE;
+	}
+
+	/* Clear out all 1588-related registers to clear and unlatch them. */
+	rd32(hw, I40E_PRTTSYN_STAT_0);
+	rd32(hw, I40E_PRTTSYN_TXTIME_H);
+	rd32(hw, I40E_PRTTSYN_RXTIME_H(0));
+	rd32(hw, I40E_PRTTSYN_RXTIME_H(1));
+	rd32(hw, I40E_PRTTSYN_RXTIME_H(2));
+	rd32(hw, I40E_PRTTSYN_RXTIME_H(3));
+
+	/* Enable/disable the Tx timestamp interrupt based on user input. */
+	regval = rd32(hw, I40E_PRTTSYN_CTL0);
+	if (pf->ptp_tx)
+		regval |= I40E_PRTTSYN_CTL0_TXTIME_INT_ENA_MASK;
+	else
+		regval &= ~I40E_PRTTSYN_CTL0_TXTIME_INT_ENA_MASK;
+	wr32(hw, I40E_PRTTSYN_CTL0, regval);
+
+	regval = rd32(hw, I40E_PFINT_ICR0_ENA);
+	if (pf->ptp_tx)
+		regval |= I40E_PFINT_ICR0_ENA_TIMESYNC_MASK;
+	else
+		regval &= ~I40E_PFINT_ICR0_ENA_TIMESYNC_MASK;
+	wr32(hw, I40E_PFINT_ICR0_ENA, regval);
+
+	/* There is no simple on/off switch for Rx. To "disable" Rx support,
+	 * ignore any received timestamps, rather than turn off the clock.
+	 */
+	if (pf->ptp_rx) {
+		regval = rd32(hw, I40E_PRTTSYN_CTL1);
+		/* clear everything but the enable bit */
+		regval &= I40E_PRTTSYN_CTL1_TSYNENA_MASK;
+		/* now enable bits for desired Rx timestamps */
+		regval |= tsyntype;
+		wr32(hw, I40E_PRTTSYN_CTL1, regval);
+	}
+
+	return copy_to_user(ifr->ifr_data, config, sizeof(*config)) ?
+		-EFAULT : 0;
+}
+
+/**
+ * i40e_ptp_init - Initialize the 1588 support and register the PHC
+ * @pf: Board private structure
+ *
+ * This function registers the device clock as a PHC. If it is successful, it
+ * starts the clock in the hardware.
+ **/
+void i40e_ptp_init(struct i40e_pf *pf)
+{
+	struct i40e_hw *hw = &pf->hw;
+	struct net_device *netdev = pf->vsi[pf->lan_vsi]->netdev;
+
+	strncpy(pf->ptp_caps.name, "i40e", sizeof(pf->ptp_caps.name));
+	pf->ptp_caps.owner = THIS_MODULE;
+	pf->ptp_caps.max_adj = 999999999;
+	pf->ptp_caps.n_ext_ts = 0;
+	pf->ptp_caps.pps = 0;
+	pf->ptp_caps.adjfreq = i40e_ptp_adjfreq;
+	pf->ptp_caps.adjtime = i40e_ptp_adjtime;
+	pf->ptp_caps.gettime = i40e_ptp_gettime;
+	pf->ptp_caps.settime = i40e_ptp_settime;
+	pf->ptp_caps.enable = i40e_ptp_enable;
+
+	/* Attempt to register the clock before enabling the hardware. */
+	pf->ptp_clock = ptp_clock_register(&pf->ptp_caps, &pf->pdev->dev);
+	if (IS_ERR(pf->ptp_clock)) {
+		pf->ptp_clock = NULL;
+		dev_err(&pf->pdev->dev, "%s: ptp_clock_register failed\n",
+			__func__);
+	} else {
+		struct timespec ts;
+		u32 regval;
+
+		spin_lock_init(&pf->tmreg_lock);
+		INIT_WORK(&pf->ptp_tx_work, i40e_ptp_tx_work);
+
+		dev_info(&pf->pdev->dev, "%s: added PHC on %s\n", __func__,
+			 netdev->name);
+		pf->flags |= I40E_FLAG_PTP;
+
+		/* Ensure the clocks are running. */
+		regval = rd32(hw, I40E_PRTTSYN_CTL0);
+		regval |= I40E_PRTTSYN_CTL0_TSYNENA_MASK;
+		wr32(hw, I40E_PRTTSYN_CTL0, regval);
+		regval = rd32(hw, I40E_PRTTSYN_CTL1);
+		regval |= I40E_PRTTSYN_CTL1_TSYNENA_MASK;
+		wr32(hw, I40E_PRTTSYN_CTL1, regval);
+
+		/* Set the increment value per clock tick. */
+		i40e_ptp_set_increment(pf);
+
+		/* reset the tstamp_config */
+		memset(&pf->tstamp_config, 0, sizeof(pf->tstamp_config));
+
+		/* Set the clock value. */
+		ts = ktime_to_timespec(ktime_get_real());
+		i40e_ptp_settime(&pf->ptp_caps, &ts);
+	}
+}
+
+/**
+ * i40e_ptp_stop - Disable the driver/hardware support and unregister the PHC
+ * @pf: Board private structure
+ *
+ * This function handles the cleanup work required from the initialization by
+ * clearing out the important information and unregistering the PHC.
+ **/
+void i40e_ptp_stop(struct i40e_pf *pf)
+{
+	pf->flags &= ~I40E_FLAG_PTP;
+	pf->ptp_tx = false;
+	pf->ptp_rx = false;
+
+	cancel_work_sync(&pf->ptp_tx_work);
+	if (pf->ptp_tx_skb) {
+		dev_kfree_skb_any(pf->ptp_tx_skb);
+		pf->ptp_tx_skb = NULL;
+	}
+
+	if (pf->ptp_clock) {
+		ptp_clock_unregister(pf->ptp_clock);
+		pf->ptp_clock = NULL;
+		dev_info(&pf->pdev->dev, "%s: removed PHC on %s\n", __func__,
+			 pf->vsi[pf->lan_vsi]->netdev->name);
+	}
+}

drivers/net/ethernet/intel/i40e/i40e_txrx.c

@@ -1088,6 +1088,13 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 		}
 
 		skb->rxhash = i40e_rx_hash(rx_ring, rx_desc);
+		if (unlikely(rx_status & I40E_RXD_QW1_STATUS_TSYNVALID_MASK)) {
+			i40e_ptp_rx_hwtstamp(vsi->back, skb, (rx_status &
+					   I40E_RXD_QW1_STATUS_TSYNINDX_MASK) >>
+					   I40E_RXD_QW1_STATUS_TSYNINDX_SHIFT);
+			rx_ring->last_rx_timestamp = jiffies;
+		}
+
 		/* probably a little skewed due to removing CRC */
 		total_rx_bytes += skb->len;
 		total_rx_packets++;
@@ -1425,6 +1432,46 @@ static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb,
 	return 1;
 }
 
+/**
+ * i40e_tsyn - set up the tsyn context descriptor
+ * @tx_ring:  ptr to the ring to send
+ * @skb:      ptr to the skb we're sending
+ * @tx_flags: the collected send information
+ *
+ * Returns 0 if no Tx timestamp can happen and 1 if the timestamp will happen
+ **/
+static int i40e_tsyn(struct i40e_ring *tx_ring, struct sk_buff *skb,
+		     u32 tx_flags, u64 *cd_type_cmd_tso_mss)
+{
+	struct i40e_pf *pf;
+
+	if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)))
+		return 0;
+
+	/* Tx timestamps cannot be sampled when doing TSO */
+	if (tx_flags & I40E_TX_FLAGS_TSO)
+		return 0;
+
+	/* only timestamp the outbound packet if the user has requested it and
+	 * we are not already transmitting a packet to be timestamped
+	 */
+	pf = i40e_netdev_to_pf(tx_ring->netdev);
+	if (pf->ptp_tx && !pf->ptp_tx_skb) {
+		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+		pf->ptp_tx_skb = skb_get(skb);
+	} else {
+		return 0;
+	}
+
+	*cd_type_cmd_tso_mss |= (u64)I40E_TX_CTX_DESC_TSYN <<
+				I40E_TXD_CTX_QW1_CMD_SHIFT;
+
+	pf->ptp_tx_start = jiffies;
+	schedule_work(&pf->ptp_tx_work);
+
+	return 1;
+}
+
 /**
  * i40e_tx_enable_csum - Enable Tx checksum offloads
  * @skb: send buffer
@@ -1801,6 +1848,7 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
 	__be16 protocol;
 	u32 td_cmd = 0;
 	u8 hdr_len = 0;
+	int tsyn;
 	int tso;
 	if (0 == i40e_xmit_descriptor_count(skb, tx_ring))
 		return NETDEV_TX_BUSY;
@@ -1831,6 +1879,11 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
 
 	skb_tx_timestamp(skb);
 
+	tsyn = i40e_tsyn(tx_ring, skb, tx_flags, &cd_type_cmd_tso_mss);
+
+	if (tsyn)
+		tx_flags |= I40E_TX_FLAGS_TSYN;
+
 	/* always enable CRC insertion offload */
 	td_cmd |= I40E_TX_DESC_CMD_ICRC;
 

drivers/net/ethernet/intel/i40e/i40e_txrx.h

@@ -136,6 +136,7 @@ enum i40e_dyn_idx_t {
 #define I40E_TX_FLAGS_IPV6		(u32)(1 << 5)
 #define I40E_TX_FLAGS_FCCRC		(u32)(1 << 6)
 #define I40E_TX_FLAGS_FSO		(u32)(1 << 7)
+#define I40E_TX_FLAGS_TSYN		(u32)(1 << 8)
 #define I40E_TX_FLAGS_VLAN_MASK		0xffff0000
 #define I40E_TX_FLAGS_VLAN_PRIO_MASK	0xe0000000
 #define I40E_TX_FLAGS_VLAN_PRIO_SHIFT	29
@@ -248,6 +249,8 @@ struct i40e_ring {
 	u8 atr_sample_rate;
 	u8 atr_count;
 
+	unsigned long last_rx_timestamp;
+
 	bool ring_active;		/* is ring online or not */
 
 	/* stats structs */