e1000e: add support for hardware timestamping on some devices

On 82574, 82583, 82579, I217 and I218 add support for hardware time
stamping of all or no Rx packets and Tx packets which have the
SKBTX_HW_TSTAMP flag set.  Update the .get_ts_info ethtool operation to
report the supported time stamping modes, and enable and disable hardware
time stamping with the SIOCSHWTSTAMP ioctl.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

7 files changed, 462 insertions, 8 deletions

diff --git a/drivers/net/ethernet/intel/e1000e/82571.c b/drivers/net/ethernet/intel/e1000e/82571.c
index c77d010d5c59..587890d2d55e 100644
--- a/drivers/net/ethernet/intel/e1000e/82571.c
+++ b/drivers/net/ethernet/intel/e1000e/82571.c
@@ -2044,6 +2044,7 @@ const struct e1000_info e1000_82574_info = {
 				  | FLAG_HAS_MSIX
 				  | FLAG_HAS_JUMBO_FRAMES
 				  | FLAG_HAS_WOL
+				  | FLAG_HAS_HW_TIMESTAMP
 				  | FLAG_APME_IN_CTRL3
 				  | FLAG_HAS_SMART_POWER_DOWN
 				  | FLAG_HAS_AMT
@@ -2065,6 +2066,7 @@ const struct e1000_info e1000_82583_info = {
 	.mac			= e1000_82583,
 	.flags			= FLAG_HAS_HW_VLAN_FILTER
 				  | FLAG_HAS_WOL
+				  | FLAG_HAS_HW_TIMESTAMP
 				  | FLAG_APME_IN_CTRL3
 				  | FLAG_HAS_SMART_POWER_DOWN
 				  | FLAG_HAS_AMT
diff --git a/drivers/net/ethernet/intel/e1000e/defines.h b/drivers/net/ethernet/intel/e1000e/defines.h
index 3041a54e3a61..36f9fad19a76 100644
--- a/drivers/net/ethernet/intel/e1000e/defines.h
+++ b/drivers/net/ethernet/intel/e1000e/defines.h
@@ -107,6 +107,7 @@
 #define E1000_RXD_ERR_RXE       0x80    /* Rx Data Error */
 #define E1000_RXD_SPC_VLAN_MASK 0x0FFF  /* VLAN ID is in lower 12 bits */
 
+#define E1000_RXDEXT_STATERR_TST   0x00000100	/* Time Stamp taken */
 #define E1000_RXDEXT_STATERR_CE    0x01000000
 #define E1000_RXDEXT_STATERR_SE    0x02000000
 #define E1000_RXDEXT_STATERR_SEQ   0x04000000
@@ -318,6 +319,7 @@
 #define E1000_TXD_CMD_IP     0x02000000 /* IP packet */
 #define E1000_TXD_CMD_TSE    0x04000000 /* TCP Seg enable */
 #define E1000_TXD_STAT_TC    0x00000004 /* Tx Underrun */
+#define E1000_TXD_EXTCMD_TSTAMP	0x00000010 /* IEEE1588 Timestamp packet */
 
 /* Transmit Control */
 #define E1000_TCTL_EN     0x00000002    /* enable Tx */
@@ -536,6 +538,18 @@
 #define E1000_RXCW_C          0x20000000        /* Receive config */
 #define E1000_RXCW_SYNCH      0x40000000        /* Receive config synch */
 
+#define E1000_TSYNCTXCTL_VALID		0x00000001 /* Tx timestamp valid */
+#define E1000_TSYNCRXCTL_TYPE_ALL	0x08
+#define E1000_TSYNCTXCTL_ENABLED	0x00000010 /* enable Tx timestamping */
+
+#define E1000_TSYNCRXCTL_VALID		0x00000001 /* Rx timestamp valid */
+#define E1000_TSYNCRXCTL_TYPE_MASK	0x0000000E /* Rx type mask */
+#define E1000_TSYNCRXCTL_ENABLED	0x00000010 /* enable Rx timestamping */
+#define E1000_TSYNCRXCTL_SYSCFI		0x00000020 /* Sys clock frequency */
+
+#define E1000_TIMINCA_INCPERIOD_SHIFT	24
+#define E1000_TIMINCA_INCVALUE_MASK	0x00FFFFFF
+
 /* PCI Express Control */
 #define E1000_GCR_RXD_NO_SNOOP          0x00000001
 #define E1000_GCR_RXDSCW_NO_SNOOP       0x00000002
diff --git a/drivers/net/ethernet/intel/e1000e/e1000.h b/drivers/net/ethernet/intel/e1000e/e1000.h
index b89b181da7b1..dea9e5552966 100644
--- a/drivers/net/ethernet/intel/e1000e/e1000.h
+++ b/drivers/net/ethernet/intel/e1000e/e1000.h
@@ -41,6 +41,8 @@
 #include <linux/pci-aspm.h>
 #include <linux/crc32.h>
 #include <linux/if_vlan.h>
+#include <linux/clocksource.h>
+#include <linux/net_tstamp.h>
 
 #include "hw.h"
 
@@ -353,6 +355,7 @@ struct e1000_adapter {
 	u64 gorc_old;
 	u32 alloc_rx_buff_failed;
 	u32 rx_dma_failed;
+	u32 rx_hwtstamp_cleared;
 
 	unsigned int rx_ps_pages;
 	u16 rx_ps_bsize0;
@@ -402,6 +405,14 @@ struct e1000_adapter {
 
 	u16 tx_ring_count;
 	u16 rx_ring_count;
+
+	struct hwtstamp_config hwtstamp_config;
+	struct delayed_work systim_overflow_work;
+	struct sk_buff *tx_hwtstamp_skb;
+	struct work_struct tx_hwtstamp_work;
+	spinlock_t systim_lock;	/* protects SYSTIML/H regsters */
+	struct cyclecounter cc;
+	struct timecounter tc;
 };
 
 struct e1000_info {
@@ -416,6 +427,38 @@ struct e1000_info {
 	const struct e1000_nvm_operations *nvm_ops;
 };
 
+/* The system time is maintained by a 64-bit counter comprised of the 32-bit
+ * SYSTIMH and SYSTIML registers.  How the counter increments (and therefore
+ * its resolution) is based on the contents of the TIMINCA register - it
+ * increments every incperiod (bits 31:24) clock ticks by incvalue (bits 23:0).
+ * For the best accuracy, the incperiod should be as small as possible.  The
+ * incvalue is scaled by a factor as large as possible (while still fitting
+ * in bits 23:0) so that relatively small clock corrections can be made.
+ *
+ * As a result, a shift of INCVALUE_SHIFT_n is used to fit a value of
+ * INCVALUE_n into the TIMINCA register allowing 32+8+(24-INCVALUE_SHIFT_n)
+ * bits to count nanoseconds leaving the rest for fractional nonseconds.
+ */
+#define INCVALUE_96MHz		125
+#define INCVALUE_SHIFT_96MHz	17
+#define INCPERIOD_SHIFT_96MHz	2
+#define INCPERIOD_96MHz		(12 >> INCPERIOD_SHIFT_96MHz)
+
+#define INCVALUE_25MHz		40
+#define INCVALUE_SHIFT_25MHz	18
+#define INCPERIOD_25MHz		1
+
+/* Another drawback of scaling the incvalue by a large factor is the
+ * 64-bit SYSTIM register overflows more quickly.  This is dealt with
+ * by simply reading the clock before it overflows.
+ *
+ * Clock	ns bits	Overflows after
+ * ~~~~~~	~~~~~~~	~~~~~~~~~~~~~~~
+ * 96MHz	47-bit	2^(47-INCPERIOD_SHIFT_96MHz) / 10^9 / 3600 = 9.77 hrs
+ * 25MHz	46-bit	2^46 / 10^9 / 3600 = 19.55 hours
+ */
+#define E1000_SYSTIM_OVERFLOW_PERIOD	(HZ * 60 * 60 * 4)
+
 /* hardware capability, feature, and workaround flags */
 #define FLAG_HAS_AMT                      (1 << 0)
 #define FLAG_HAS_FLASH                    (1 << 1)
@@ -431,7 +474,7 @@ struct e1000_info {
 #define FLAG_HAS_SMART_POWER_DOWN         (1 << 11)
 #define FLAG_IS_QUAD_PORT_A               (1 << 12)
 #define FLAG_IS_QUAD_PORT                 (1 << 13)
-/* reserved bit14 */
+#define FLAG_HAS_HW_TIMESTAMP             (1 << 14)
 #define FLAG_APME_IN_WUC                  (1 << 15)
 #define FLAG_APME_IN_CTRL3                (1 << 16)
 #define FLAG_APME_CHECK_PORT_B            (1 << 17)
@@ -463,6 +506,7 @@ struct e1000_info {
 #define FLAG2_NO_DISABLE_RX               (1 << 10)
 #define FLAG2_PCIM2PCI_ARBITER_WA         (1 << 11)
 #define FLAG2_DFLT_CRC_STRIPPING          (1 << 12)
+#define FLAG2_CHECK_RX_HWTSTAMP           (1 << 13)
 
 #define E1000_RX_DESC_PS(R, i)	    \
 	(&(((union e1000_rx_desc_packet_split *)((R).desc))[i]))
diff --git a/drivers/net/ethernet/intel/e1000e/ethtool.c b/drivers/net/ethernet/intel/e1000e/ethtool.c
index 636ba09ca6fb..f268cbcb751d 100644
--- a/drivers/net/ethernet/intel/e1000e/ethtool.c
+++ b/drivers/net/ethernet/intel/e1000e/ethtool.c
@@ -108,6 +108,7 @@ static const struct e1000_stats e1000_gstrings_stats[] = {
 	E1000_STAT("dropped_smbus", stats.mgpdc),
 	E1000_STAT("rx_dma_failed", rx_dma_failed),
 	E1000_STAT("tx_dma_failed", tx_dma_failed),
+	E1000_STAT("rx_hwtstamp_cleared", rx_hwtstamp_cleared),
 };
 
 #define E1000_GLOBAL_STATS_LEN	ARRAY_SIZE(e1000_gstrings_stats)
@@ -2182,6 +2183,28 @@ static int e1000e_set_eee(struct net_device *netdev, struct ethtool_eee *edata)
 	return 0;
 }
 
+static int e1000e_get_ts_info(struct net_device *netdev,
+			      struct ethtool_ts_info *info)
+{
+	struct e1000_adapter *adapter = netdev_priv(netdev);
+
+	ethtool_op_get_ts_info(netdev, info);
+
+	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
+		return 0;
+
+	info->so_timestamping |= (SOF_TIMESTAMPING_TX_HARDWARE |
+				  SOF_TIMESTAMPING_RX_HARDWARE |
+				  SOF_TIMESTAMPING_RAW_HARDWARE);
+
+	info->tx_types = (1 << HWTSTAMP_TX_OFF) | (1 << HWTSTAMP_TX_ON);
+
+	info->rx_filters = ((1 << HWTSTAMP_FILTER_NONE) |
+			    (1 << HWTSTAMP_FILTER_ALL));
+
+	return 0;
+}
+
 static const struct ethtool_ops e1000_ethtool_ops = {
 	.get_settings		= e1000_get_settings,
 	.set_settings		= e1000_set_settings,
@@ -2209,7 +2232,7 @@ static const struct ethtool_ops e1000_ethtool_ops = {
 	.get_coalesce		= e1000_get_coalesce,
 	.set_coalesce		= e1000_set_coalesce,
 	.get_rxnfc		= e1000_get_rxnfc,
-	.get_ts_info		= ethtool_op_get_ts_info,
+	.get_ts_info		= e1000e_get_ts_info,
 	.get_eee		= e1000e_get_eee,
 	.set_eee		= e1000e_set_eee,
 };
diff --git a/drivers/net/ethernet/intel/e1000e/hw.h b/drivers/net/ethernet/intel/e1000e/hw.h
index 81afad5b80f2..8e7e80345a60 100644
--- a/drivers/net/ethernet/intel/e1000e/hw.h
+++ b/drivers/net/ethernet/intel/e1000e/hw.h
@@ -60,6 +60,7 @@ enum e1e_registers {
 	E1000_EIAC_82574 = 0x000DC, /* Ext. Interrupt Auto Clear - RW */
 	E1000_IAM      = 0x000E0, /* Interrupt Acknowledge Auto Mask */
 	E1000_IVAR     = 0x000E4, /* Interrupt Vector Allocation - RW */
+	E1000_FEXTNVM7  = 0x000E4, /* Future Extended NVM 7 - RW */
 	E1000_EITR_82574_BASE = 0x000E8, /* Interrupt Throttling - RW */
 #define E1000_EITR_82574(_n) (E1000_EITR_82574_BASE + (_n << 2))
 	E1000_LPIC     = 0x000FC, /* Low Power Idle Control - RW */
@@ -241,6 +242,15 @@ enum e1e_registers {
 #define E1000_PCH_RAICC(_n)	(E1000_PCH_RAICC_BASE + ((_n) * 4))
 #define E1000_CRC_OFFSET	E1000_PCH_RAICC_BASE
 	E1000_HICR      = 0x08F00, /* Host Interface Control */
+	E1000_SYSTIML   = 0x0B600, /* System time register Low - RO */
+	E1000_SYSTIMH   = 0x0B604, /* System time register High - RO */
+	E1000_TIMINCA   = 0x0B608, /* Increment attributes register - RW */
+	E1000_TSYNCTXCTL = 0x0B614, /* Tx Time Sync Control register - RW */
+	E1000_TXSTMPL   = 0x0B618, /* Tx timestamp value Low - RO */
+	E1000_TXSTMPH   = 0x0B61C, /* Tx timestamp value High - RO */
+	E1000_TSYNCRXCTL = 0x0B620, /* Rx Time Sync Control register - RW */
+	E1000_RXSTMPL   = 0x0B624, /* Rx timestamp Low - RO */
+	E1000_RXSTMPH   = 0x0B628, /* Rx timestamp High - RO */
 };
 
 #define E1000_MAX_PHY_ADDR		4
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index 3829f7fd1d97..50935ef48171 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -4601,6 +4601,7 @@ const struct e1000_info e1000_pch2_info = {
 	.mac			= e1000_pch2lan,
 	.flags			= FLAG_IS_ICH
 				  | FLAG_HAS_WOL
+				  | FLAG_HAS_HW_TIMESTAMP
 				  | FLAG_HAS_CTRLEXT_ON_LOAD
 				  | FLAG_HAS_AMT
 				  | FLAG_HAS_FLASH
@@ -4620,6 +4621,7 @@ const struct e1000_info e1000_pch_lpt_info = {
 	.mac			= e1000_pch_lpt,
 	.flags			= FLAG_IS_ICH
 				  | FLAG_HAS_WOL
+				  | FLAG_HAS_HW_TIMESTAMP
 				  | FLAG_HAS_CTRLEXT_ON_LOAD
 				  | FLAG_HAS_AMT
 				  | FLAG_HAS_FLASH
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index bf2c84cf250f..c15b7e438a44 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -488,20 +488,87 @@ static int e1000_desc_unused(struct e1000_ring *ring)
 }
 
 /**
+ * e1000e_systim_to_hwtstamp - convert system time value to hw time stamp
+ * @adapter: board private structure
+ * @hwtstamps: time stamp structure to update
+ * @systim: unsigned 64bit system time value.
+ *
+ * Convert the system time value stored in the RX/TXSTMP registers into a
+ * hwtstamp which can be used by the upper level time stamping functions.
+ *
+ * The 'systim_lock' spinlock is used to protect the consistency of the
+ * system time value. This is needed because reading the 64 bit time
+ * value involves reading two 32 bit registers. The first read latches the
+ * value.
+ **/
+static void e1000e_systim_to_hwtstamp(struct e1000_adapter *adapter,
+				      struct skb_shared_hwtstamps *hwtstamps,
+				      u64 systim)
+{
+	u64 ns;
+	unsigned long flags;
+
+	spin_lock_irqsave(&adapter->systim_lock, flags);
+	ns = timecounter_cyc2time(&adapter->tc, systim);
+	spin_unlock_irqrestore(&adapter->systim_lock, flags);
+
+	memset(hwtstamps, 0, sizeof(*hwtstamps));
+	hwtstamps->hwtstamp = ns_to_ktime(ns);
+}
+
+/**
+ * e1000e_rx_hwtstamp - utility function which checks for Rx time stamp
+ * @adapter: board private structure
+ * @status: descriptor extended error and status field
+ * @skb: particular skb to include time stamp
+ *
+ * If the time stamp is valid, convert it into the timecounter ns value
+ * and store that result into the shhwtstamps structure which is passed
+ * up the network stack.
+ **/
+static void e1000e_rx_hwtstamp(struct e1000_adapter *adapter, u32 status,
+			       struct sk_buff *skb)
+{
+	struct e1000_hw *hw = &adapter->hw;
+	u64 rxstmp;
+
+	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP) ||
+	    !(status & E1000_RXDEXT_STATERR_TST) ||
+	    !(er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_VALID))
+		return;
+
+	/* The Rx time stamp registers contain the time stamp.  No other
+	 * received packet will be time stamped until the Rx time stamp
+	 * registers are read.  Because only one packet can be time stamped
+	 * at a time, the register values must belong to this packet and
+	 * therefore none of the other additional attributes need to be
+	 * compared.
+	 */
+	rxstmp = (u64)er32(RXSTMPL);
+	rxstmp |= (u64)er32(RXSTMPH) << 32;
+	e1000e_systim_to_hwtstamp(adapter, skb_hwtstamps(skb), rxstmp);
+
+	adapter->flags2 &= ~FLAG2_CHECK_RX_HWTSTAMP;
+}
+
+/**
  * e1000_receive_skb - helper function to handle Rx indications
  * @adapter: board private structure
- * @status: descriptor status field as written by hardware
+ * @staterr: descriptor extended error and status field as written by hardware
  * @vlan: descriptor vlan field as written by hardware (no le/be conversion)
  * @skb: pointer to sk_buff to be indicated to stack
  **/
 static void e1000_receive_skb(struct e1000_adapter *adapter,
 			      struct net_device *netdev, struct sk_buff *skb,
-			      u8 status, __le16 vlan)
+			      u32 staterr, __le16 vlan)
 {
 	u16 tag = le16_to_cpu(vlan);
+
+	e1000e_rx_hwtstamp(adapter, staterr, skb);
+
 	skb->protocol = eth_type_trans(skb, netdev);
 
-	if (status & E1000_RXD_STAT_VP)
+	if (staterr & E1000_RXD_STAT_VP)
 		__vlan_hwaccel_put_tag(skb, tag);
 
 	napi_gro_receive(&adapter->napi, skb);
@@ -1092,6 +1159,41 @@ static void e1000_print_hw_hang(struct work_struct *work)
 }
 
 /**
+ * e1000e_tx_hwtstamp_work - check for Tx time stamp
+ * @work: pointer to work struct
+ *
+ * This work function polls the TSYNCTXCTL valid bit to determine when a
+ * timestamp has been taken for the current stored skb.  The timestamp must
+ * be for this skb because only one such packet is allowed in the queue.
+ */
+static void e1000e_tx_hwtstamp_work(struct work_struct *work)
+{
+	struct e1000_adapter *adapter = container_of(work, struct e1000_adapter,
+						     tx_hwtstamp_work);
+	struct e1000_hw *hw = &adapter->hw;
+
+	if (!adapter->tx_hwtstamp_skb)
+		return;
+
+	if (er32(TSYNCTXCTL) & E1000_TSYNCTXCTL_VALID) {
+		struct skb_shared_hwtstamps shhwtstamps;
+		u64 txstmp;
+
+		txstmp = er32(TXSTMPL);
+		txstmp |= (u64)er32(TXSTMPH) << 32;
+
+		e1000e_systim_to_hwtstamp(adapter, &shhwtstamps, txstmp);
+
+		skb_tstamp_tx(adapter->tx_hwtstamp_skb, &shhwtstamps);
+		dev_kfree_skb_any(adapter->tx_hwtstamp_skb);
+		adapter->tx_hwtstamp_skb = NULL;
+	} else {
+		/* reschedule to check later */
+		schedule_work(&adapter->tx_hwtstamp_work);
+	}
+}
+
+/**
  * e1000_clean_tx_irq - Reclaim resources after transmit completes
  * @tx_ring: Tx descriptor ring
  *
@@ -1345,8 +1447,8 @@ copydone:
 			   cpu_to_le16(E1000_RXDPS_HDRSTAT_HDRSP))
 			adapter->rx_hdr_split++;
 
-		e1000_receive_skb(adapter, netdev, skb,
-				  staterr, rx_desc->wb.middle.vlan);
+		e1000_receive_skb(adapter, netdev, skb, staterr,
+				  rx_desc->wb.middle.vlan);
 
 next_desc:
 		rx_desc->wb.middle.status_error &= cpu_to_le32(~0xFF);
@@ -3304,6 +3406,159 @@ static void e1000e_setup_rss_hash(struct e1000_adapter *adapter)
 }
 
 /**
+ * e1000e_get_base_timinca - get default SYSTIM time increment attributes
+ * @adapter: board private structure
+ * @timinca: pointer to returned time increment attributes
+ *
+ * Get attributes for incrementing the System Time Register SYSTIML/H at
+ * the default base frequency, and set the cyclecounter shift value.
+ **/
+static s32 e1000e_get_base_timinca(struct e1000_adapter *adapter, u32 *timinca)
+{
+	struct e1000_hw *hw = &adapter->hw;
+	u32 incvalue, incperiod, shift;
+
+	/* Make sure clock is enabled on I217 before checking the frequency */
+	if ((hw->mac.type == e1000_pch_lpt) &&
+	    !(er32(TSYNCTXCTL) & E1000_TSYNCTXCTL_ENABLED) &&
+	    !(er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_ENABLED)) {
+		u32 fextnvm7 = er32(FEXTNVM7);
+
+		if (!(fextnvm7 & (1 << 0))) {
+			ew32(FEXTNVM7, fextnvm7 | (1 << 0));
+			e1e_flush();
+		}
+	}
+
+	switch (hw->mac.type) {
+	case e1000_pch2lan:
+	case e1000_pch_lpt:
+		/* On I217, the clock frequency is 25MHz or 96MHz as
+		 * indicated by the System Clock Frequency Indication
+		 */
+		if ((hw->mac.type != e1000_pch_lpt) ||
+		    (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI)) {
+			/* Stable 96MHz frequency */
+			incperiod = INCPERIOD_96MHz;
+			incvalue = INCVALUE_96MHz;
+			shift = INCVALUE_SHIFT_96MHz;
+			adapter->cc.shift = shift + INCPERIOD_SHIFT_96MHz;
+			break;
+		}
+		/* fall-through */
+	case e1000_82574:
+	case e1000_82583:
+		/* Stable 25MHz frequency */
+		incperiod = INCPERIOD_25MHz;
+		incvalue = INCVALUE_25MHz;
+		shift = INCVALUE_SHIFT_25MHz;
+		adapter->cc.shift = shift;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	*timinca = ((incperiod << E1000_TIMINCA_INCPERIOD_SHIFT) |
+		    ((incvalue << shift) & E1000_TIMINCA_INCVALUE_MASK));
+
+	return 0;
+}
+
+/**
+ * e1000e_config_hwtstamp - configure the hwtstamp registers and enable/disable
+ * @adapter: board private structure
+ *
+ * Outgoing time stamping can be enabled and disabled. Play nice and
+ * disable it when requested, although it shouldn't cause any overhead
+ * when no packet needs it. At most one packet in the queue may be
+ * marked for time stamping, otherwise it would be impossible to tell
+ * for sure to which packet the hardware time stamp belongs.
+ *
+ * Incoming time stamping has to be configured via the hardware filters.
+ * Not all combinations are supported, in particular event type has to be
+ * specified. Matching the kind of event packet is not supported, with the
+ * exception of "all V2 events regardless of level 2 or 4".
+ **/
+static int e1000e_config_hwtstamp(struct e1000_adapter *adapter)
+{
+	struct e1000_hw *hw = &adapter->hw;
+	struct hwtstamp_config *config = &adapter->hwtstamp_config;
+	u32 tsync_tx_ctl = E1000_TSYNCTXCTL_ENABLED;
+	u32 tsync_rx_ctl = E1000_TSYNCRXCTL_ENABLED;
+	u32 regval;
+	s32 ret_val;
+
+	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
+		return -EINVAL;
+
+	/* flags reserved for future extensions - must be zero */
+	if (config->flags)
+		return -EINVAL;
+
+	switch (config->tx_type) {
+	case HWTSTAMP_TX_OFF:
+		tsync_tx_ctl = 0;
+		break;
+	case HWTSTAMP_TX_ON:
+		break;
+	default:
+		return -ERANGE;
+	}
+
+	switch (config->rx_filter) {
+	case HWTSTAMP_FILTER_NONE:
+		tsync_rx_ctl = 0;
+		break;
+	case HWTSTAMP_FILTER_ALL:
+		tsync_rx_ctl |= E1000_TSYNCRXCTL_TYPE_ALL;
+		config->rx_filter = HWTSTAMP_FILTER_ALL;
+		break;
+	default:
+		return -ERANGE;
+	}
+
+	/* enable/disable Tx h/w time stamping */
+	regval = er32(TSYNCTXCTL);
+	regval &= ~E1000_TSYNCTXCTL_ENABLED;
+	regval |= tsync_tx_ctl;
+	ew32(TSYNCTXCTL, regval);
+	if ((er32(TSYNCTXCTL) & E1000_TSYNCTXCTL_ENABLED) !=
+	    (regval & E1000_TSYNCTXCTL_ENABLED)) {
+		e_err("Timesync Tx Control register not set as expected\n");
+		return -EAGAIN;
+	}
+
+	/* enable/disable Rx h/w time stamping */
+	regval = er32(TSYNCRXCTL);
+	regval &= ~(E1000_TSYNCRXCTL_ENABLED | E1000_TSYNCRXCTL_TYPE_MASK);
+	regval |= tsync_rx_ctl;
+	ew32(TSYNCRXCTL, regval);
+	if ((er32(TSYNCRXCTL) & (E1000_TSYNCRXCTL_ENABLED |
+				 E1000_TSYNCRXCTL_TYPE_MASK)) !=
+	    (regval & (E1000_TSYNCRXCTL_ENABLED |
+		       E1000_TSYNCRXCTL_TYPE_MASK))) {
+		e_err("Timesync Rx Control register not set as expected\n");
+		return -EAGAIN;
+	}
+
+	/* Clear TSYNCRXCTL_VALID & TSYNCTXCTL_VALID bit */
+	regval = er32(RXSTMPH);
+	regval = er32(TXSTMPH);
+
+	/* Get and set the System Time Register SYSTIM base frequency */
+	ret_val = e1000e_get_base_timinca(adapter, &regval);
+	if (ret_val)
+		return ret_val;
+	ew32(TIMINCA, regval);
+
+	/* reset the ns time counter */
+	timecounter_init(&adapter->tc, &adapter->cc,
+			 ktime_to_ns(ktime_get_real()));
+
+	return 0;
+}
+
+/**
  * e1000_configure - configure the hardware for Rx and Tx
  * @adapter: private board structure
  **/
@@ -3529,6 +3784,9 @@ void e1000e_reset(struct e1000_adapter *adapter)
 
 	e1000e_reset_adaptive(hw);
 
+	/* initialize systim and reset the ns time counter */
+	e1000e_config_hwtstamp(adapter);
+
 	if (!netif_running(adapter->netdev) &&
 	    !test_bit(__E1000_TESTING, &adapter->state)) {
 		e1000_power_down_phy(adapter);
@@ -3665,6 +3923,24 @@ void e1000e_reinit_locked(struct e1000_adapter *adapter)
 }
 
 /**
+ * e1000e_cyclecounter_read - read raw cycle counter (used by time counter)
+ * @cc: cyclecounter structure
+ **/
+static cycle_t e1000e_cyclecounter_read(const struct cyclecounter *cc)
+{
+	struct e1000_adapter *adapter = container_of(cc, struct e1000_adapter,
+						     cc);
+	struct e1000_hw *hw = &adapter->hw;
+	cycle_t systim;
+
+	/* latch SYSTIMH on read of SYSTIML */
+	systim = (cycle_t)er32(SYSTIML);
+	systim |= (cycle_t)er32(SYSTIMH) << 32;
+
+	return systim;
+}
+
+/**
  * e1000_sw_init - Initialize general software structures (struct e1000_adapter)
  * @adapter: board private structure to initialize
  *
@@ -3690,6 +3966,17 @@ static int e1000_sw_init(struct e1000_adapter *adapter)
 	if (e1000_alloc_queues(adapter))
 		return -ENOMEM;
 
+	/* Setup hardware time stamping cyclecounter */
+	if (adapter->flags & FLAG_HAS_HW_TIMESTAMP) {
+		adapter->cc.read = e1000e_cyclecounter_read;
+		adapter->cc.mask = CLOCKSOURCE_MASK(64);
+		adapter->cc.mult = 1;
+		/* cc.shift set in e1000e_get_base_tininca() */
+
+		spin_lock_init(&adapter->systim_lock);
+		INIT_WORK(&adapter->tx_hwtstamp_work, e1000e_tx_hwtstamp_work);
+	}
+
 	/* Explicitly disable IRQ since the NIC can be in any state. */
 	e1000_irq_disable(adapter);
 
@@ -4597,6 +4884,17 @@ link_up:
 	if (adapter->flags2 & FLAG2_CHECK_PHY_HANG)
 		e1000e_check_82574_phy_workaround(adapter);
 
+	/* Clear valid timestamp stuck in RXSTMPL/H due to a Rx error */
+	if (adapter->hwtstamp_config.rx_filter != HWTSTAMP_FILTER_NONE) {
+		if ((adapter->flags2 & FLAG2_CHECK_RX_HWTSTAMP) &&
+		    (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_VALID)) {
+			er32(RXSTMPH);
+			adapter->rx_hwtstamp_cleared++;
+		} else {
+			adapter->flags2 |= FLAG2_CHECK_RX_HWTSTAMP;
+		}
+	}
+
 	/* Reset the timer */
 	if (!test_bit(__E1000_DOWN, &adapter->state))
 		mod_timer(&adapter->watchdog_timer,
@@ -4608,6 +4906,7 @@ link_up:
 #define E1000_TX_FLAGS_TSO		0x00000004
 #define E1000_TX_FLAGS_IPV4		0x00000008
 #define E1000_TX_FLAGS_NO_FCS		0x00000010
+#define E1000_TX_FLAGS_HWTSTAMP		0x00000020
 #define E1000_TX_FLAGS_VLAN_MASK	0xffff0000
 #define E1000_TX_FLAGS_VLAN_SHIFT	16
 
@@ -4866,6 +5165,11 @@ static void e1000_tx_queue(struct e1000_ring *tx_ring, int tx_flags, int count)
 	if (unlikely(tx_flags & E1000_TX_FLAGS_NO_FCS))
 		txd_lower &= ~(E1000_TXD_CMD_IFCS);
 
+	if (unlikely(tx_flags & E1000_TX_FLAGS_HWTSTAMP)) {
+		txd_lower |= E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D;
+		txd_upper |= E1000_TXD_EXTCMD_TSTAMP;
+	}
+
 	i = tx_ring->next_to_use;
 
 	do {
@@ -5089,7 +5393,15 @@ static netdev_tx_t e1000_xmit_frame(struct sk_buff *skb,
 	count = e1000_tx_map(tx_ring, skb, first, adapter->tx_fifo_limit,
 			     nr_frags);
 	if (count) {
-		skb_tx_timestamp(skb);
+		if (unlikely((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
+			     !adapter->tx_hwtstamp_skb)) {
+			skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+			tx_flags |= E1000_TX_FLAGS_HWTSTAMP;
+			adapter->tx_hwtstamp_skb = skb_get(skb);
+			schedule_work(&adapter->tx_hwtstamp_work);
+		} else {
+			skb_tx_timestamp(skb);
+		}
 
 		netdev_sent_queue(netdev, skb->len);
 		e1000_tx_queue(tx_ring, tx_flags, count);
@@ -5317,6 +5629,43 @@ static int e1000_mii_ioctl(struct net_device *netdev, struct ifreq *ifr,
 	return 0;
 }
 
+/**
+ * e1000e_hwtstamp_ioctl - control hardware time stamping
+ * @netdev: network interface device structure
+ * @ifreq: interface request
+ *
+ * Outgoing time stamping can be enabled and disabled. Play nice and
+ * disable it when requested, although it shouldn't cause any overhead
+ * when no packet needs it. At most one packet in the queue may be
+ * marked for time stamping, otherwise it would be impossible to tell
+ * for sure to which packet the hardware time stamp belongs.
+ *
+ * Incoming time stamping has to be configured via the hardware filters.
+ * Not all combinations are supported, in particular event type has to be
+ * specified. Matching the kind of event packet is not supported, with the
+ * exception of "all V2 events regardless of level 2 or 4".
+ **/
+static int e1000e_hwtstamp_ioctl(struct net_device *netdev, struct ifreq *ifr)
+{
+	struct e1000_adapter *adapter = netdev_priv(netdev);
+	struct hwtstamp_config config;
+	int ret_val;
+
+	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
+		return -EFAULT;
+
+	adapter->hwtstamp_config = config;
+
+	ret_val = e1000e_config_hwtstamp(adapter);
+	if (ret_val)
+		return ret_val;
+
+	config = adapter->hwtstamp_config;
+
+	return copy_to_user(ifr->ifr_data, &config,
+			    sizeof(config)) ? -EFAULT : 0;
+}
+
 static int e1000_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
 {
 	switch (cmd) {
@@ -5324,6 +5673,8 @@ static int e1000_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
 	case SIOCGMIIREG:
 	case SIOCSMIIREG:
 		return e1000_mii_ioctl(netdev, ifr, cmd);
+	case SIOCSHWTSTAMP:
+		return e1000e_hwtstamp_ioctl(netdev, ifr);
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -6380,6 +6731,14 @@ static void e1000_remove(struct pci_dev *pdev)
 	cancel_work_sync(&adapter->update_phy_task);
 	cancel_work_sync(&adapter->print_hang_task);
 
+	if (adapter->flags & FLAG_HAS_HW_TIMESTAMP) {
+		cancel_work_sync(&adapter->tx_hwtstamp_work);
+		if (adapter->tx_hwtstamp_skb) {
+			dev_kfree_skb_any(adapter->tx_hwtstamp_skb);
+			adapter->tx_hwtstamp_skb = NULL;
+		}
+	}
+
 	if (!(netdev->flags & IFF_UP))
 		e1000_power_down_phy(adapter);