[PATCH net V4 0/2] igb: ptp hardware clock

[PATCH net V4 0/2] igb: ptp hardware clock

[Richard Cochran]

* ChangeLog
** V4
   - Use standard kernel cyclecounter/timecounter infrastructure
     instead of a home grown counter overflow implementation.
** V3
   - Driver compiles even without CONFIG_PTP_1588_CLOCK.
   - Timestamping always works, even when PTP code missing or fails.
** V2
   - Fixed wrong bit shifting in the 82576 code.
   - Explained the timestamp locking with a comment in the code.
   - Preserved the comments from the original timecompare implementation.
   - Added an additional test within the overflow counter code to fix
     a race condition. Details of the problem are given in the commit
     message.

This patch series implements a PHC driver for the Intel 82576 and
82580 devices, as part of the igb driver.  Only the base clock
operations are implemented. The hardware does have some ancillary
features, but these can be easily added later.

The first patch adds the PHC driver code as a new source module but
does not link it into the main igb driver. Because the system time
counter is not so very wide, the code uses the overflow counter from
the cyclecounter/timecounter code. Every read operation maintains the
overflow counter, as does a "delayed work" watchdog. 

The second patch removes the timecompare code and links in the new
functions.

I have tested the 82580 with good results. However, I don't have the
82576 and so would appreciate testing and feedback.

Thanks,
Richard


Richard Cochran (2):
  igb: add PTP Hardware Clock code
  igb: offer a PTP Hardware Clock instead of the timecompare method

 drivers/net/ethernet/intel/igb/Makefile   |    2 +-
 drivers/net/ethernet/intel/igb/igb.h      |   20 ++-
 drivers/net/ethernet/intel/igb/igb_main.c |  167 +------------
 drivers/net/ethernet/intel/igb/igb_ptp.c  |  388 +++++++++++++++++++++++++++++
 4 files changed, 407 insertions(+), 170 deletions(-)
 create mode 100644 drivers/net/ethernet/intel/igb/igb_ptp.c

-- 
1.7.2.5

[PATCH net V4 1/2] igb: add PTP Hardware Clock code

[Richard Cochran]

This patch adds a source file implementing a PHC. Only the basic
clock operations have been implemented, although the hardware
would offer some ancillary functions. The code is fairly self
contained and is not yet used in the main igb driver.

Every timestamp and clock read operation must consult the overflow
counter to form a correct time value. Access to the counter is
protected by a spin lock, and the counter is implemented using the
standard cyclecounter/timecounter code.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
---
 drivers/net/ethernet/intel/igb/igb.h     |    8 +
 drivers/net/ethernet/intel/igb/igb_ptp.c |  329 ++++++++++++++++++++++++++++++
 2 files changed, 337 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/ethernet/intel/igb/igb_ptp.c

diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index 3d12e67..79f354b 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -37,6 +37,7 @@
 #include <linux/clocksource.h>
 #include <linux/timecompare.h>
 #include <linux/net_tstamp.h>
+#include <linux/ptp_clock_kernel.h>
 #include <linux/bitops.h>
 #include <linux/if_vlan.h>
 
@@ -364,6 +365,13 @@ struct igb_adapter {
 	u32 wvbr;
 	int node;
 	u32 *shadow_vfta;
+
+	struct ptp_clock *ptp_clock;
+	struct ptp_clock_info caps;
+	struct delayed_work overflow_work;
+	spinlock_t tmreg_lock;
+	struct cyclecounter cc;
+	struct timecounter tc;
 };
 
 #define IGB_FLAG_HAS_MSI           (1 << 0)
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
new file mode 100644
index 0000000..a8dc3e5
--- /dev/null
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -0,0 +1,329 @@
+/*
+ * PTP Hardware Clock (PHC) driver for the Intel 82576 and 82580
+ *
+ * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#include <linux/device.h>
+#include <linux/pci.h>
+
+#include "igb.h"
+
+#define INCVALUE_MASK		0x7fffffff
+#define ISGN			0x80000000
+
+/*
+ * Neither the 82576 nor the 82580 offer registers wide enough to hold
+ * nanoseconds time values for very long. For the 82580, SYSTIM always
+ * counts nanoseconds, but the upper 24 bits are not availible. The
+ * frequency is adjusted by changing the 32 bit fractional nanoseconds
+ * register, TIMINCA.
+ *
+ * For the 82576, the SYSTIM register time unit is affect by the
+ * choice of the 24 bit TININCA:IV (incvalue) field. Five bits of this
+ * field are needed to provide the nominal 16 nanosecond period,
+ * leaving 19 bits for fractional nanoseconds.
+ *
+ *
+ *             SYSTIMH            SYSTIML
+ *        +--------------+   +---+---+------+
+ *  82576 |      32      |   | 8 | 5 |  19  |
+ *        +--------------+   +---+---+------+
+ *         \________ 45 bits _______/  fract
+ *
+ *        +----------+---+   +--------------+
+ *  82580 |    24    | 8 |   |      32      |
+ *        +----------+---+   +--------------+
+ *          reserved  \______ 40 bits _____/
+ *
+ *
+ * The 45 bit 82576 SYSTIM overflows every
+ *   2^45 * 10^-9 / 3600 = 9.77 hours.
+ *
+ * The 40 bit 82580 SYSTIM overflows every
+ *   2^40 * 10^-9 /  60  = 18.3 minutes.
+ */
+
+#define IGB_OVERFLOW_PERIOD	(HZ * 60 * 9)
+#define INCPERIOD_82576		(1 << E1000_TIMINCA_16NS_SHIFT)
+#define INCVALUE_82576_MASK	((1 << E1000_TIMINCA_16NS_SHIFT) - 1)
+#define INCVALUE_82576		(16 << IGB_82576_TSYNC_SHIFT)
+#define IGB_NBITS_82580		40
+
+/*
+ * SYSTIM read access for the 82576
+ */
+
+static cycle_t igb_82576_systim_read(const struct cyclecounter *cc)
+{
+	u64 val;
+	u32 lo, hi;
+	struct igb_adapter *igb = container_of(cc, struct igb_adapter, cc);
+	struct e1000_hw *hw = &igb->hw;
+
+	lo = rd32(E1000_SYSTIML);
+	hi = rd32(E1000_SYSTIMH);
+
+	val = ((u64) hi) << 32;
+	val |= lo;
+
+	return val;
+}
+
+/*
+ * SYSTIM read access for the 82580
+ */
+
+static cycle_t igb_82580_systim_read(const struct cyclecounter *cc)
+{
+	u64 val;
+	u32 lo, hi, jk;
+	struct igb_adapter *igb = container_of(cc, struct igb_adapter, cc);
+	struct e1000_hw *hw = &igb->hw;
+
+	jk = rd32(E1000_SYSTIMR);
+	lo = rd32(E1000_SYSTIML);
+	hi = rd32(E1000_SYSTIMH);
+
+	val = ((u64) hi) << 32;
+	val |= lo;
+
+	return val;
+}
+
+/*
+ * PTP clock operations
+ */
+
+static int ptp_82576_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+{
+	u64 rate;
+	u32 incvalue;
+	int neg_adj = 0;
+	struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
+	struct e1000_hw *hw = &igb->hw;
+
+	if (ppb < 0) {
+		neg_adj = 1;
+		ppb = -ppb;
+	}
+	rate = ppb;
+	rate <<= 14;
+	rate = div_u64(rate, 1953125);
+
+	incvalue = 16 << IGB_82576_TSYNC_SHIFT;
+
+	if (neg_adj)
+		incvalue -= rate;
+	else
+		incvalue += rate;
+
+	wr32(E1000_TIMINCA, INCPERIOD_82576 | (incvalue & INCVALUE_82576_MASK));
+
+	return 0;
+}
+
+static int ptp_82580_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+{
+	u64 rate;
+	u32 inca;
+	int neg_adj = 0;
+	struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
+	struct e1000_hw *hw = &igb->hw;
+
+	if (ppb < 0) {
+		neg_adj = 1;
+		ppb = -ppb;
+	}
+	rate = ppb;
+	rate <<= 26;
+	rate = div_u64(rate, 1953125);
+
+	inca = rate & INCVALUE_MASK;
+	if (neg_adj)
+		inca |= ISGN;
+
+	wr32(E1000_TIMINCA, inca);
+
+	return 0;
+}
+
+static int igb_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+	s64 now;
+	unsigned long flags;
+	struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
+
+	spin_lock_irqsave(&igb->tmreg_lock, flags);
+
+	now = timecounter_read(&igb->tc);
+	now += delta;
+	timecounter_init(&igb->tc, &igb->cc, now);
+
+	spin_unlock_irqrestore(&igb->tmreg_lock, flags);
+
+	return 0;
+}
+
+static int igb_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
+{
+	u64 ns;
+	u32 remainder;
+	unsigned long flags;
+	struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
+
+	spin_lock_irqsave(&igb->tmreg_lock, flags);
+
+	ns = timecounter_read(&igb->tc);
+
+	spin_unlock_irqrestore(&igb->tmreg_lock, flags);
+
+	ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
+	ts->tv_nsec = remainder;
+
+	return 0;
+}
+
+static int igb_settime(struct ptp_clock_info *ptp, const struct timespec *ts)
+{
+	u64 ns;
+	unsigned long flags;
+	struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
+
+	ns = ts->tv_sec * 1000000000ULL;
+	ns += ts->tv_nsec;
+
+	spin_lock_irqsave(&igb->tmreg_lock, flags);
+
+	timecounter_init(&igb->tc, &igb->cc, ns);
+
+	spin_unlock_irqrestore(&igb->tmreg_lock, flags);
+
+	return 0;
+}
+
+static int ptp_82576_enable(struct ptp_clock_info *ptp,
+			    struct ptp_clock_request *rq, int on)
+{
+	return -EOPNOTSUPP;
+}
+
+static int ptp_82580_enable(struct ptp_clock_info *ptp,
+			    struct ptp_clock_request *rq, int on)
+{
+	return -EOPNOTSUPP;
+}
+
+static void igb_overflow_check(struct work_struct *work)
+{
+	struct timespec ts;
+	struct igb_adapter *igb =
+		container_of(work, struct igb_adapter, overflow_work.work);
+
+	igb_gettime(&igb->caps, &ts);
+
+	pr_debug("igb overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec);
+
+	schedule_delayed_work(&igb->overflow_work, IGB_OVERFLOW_PERIOD);
+}
+
+void igb_ptp_init(struct igb_adapter *adapter)
+{
+	struct e1000_hw *hw = &adapter->hw;
+
+	switch (hw->mac.type) {
+	case e1000_i350:
+	case e1000_82580:
+		adapter->caps.owner	= THIS_MODULE;
+		strcpy(adapter->caps.name, "igb-82580");
+		adapter->caps.max_adj	= 62499999;
+		adapter->caps.n_ext_ts	= 0;
+		adapter->caps.pps	= 0;
+		adapter->caps.adjfreq	= ptp_82580_adjfreq;
+		adapter->caps.adjtime	= igb_adjtime;
+		adapter->caps.gettime	= igb_gettime;
+		adapter->caps.settime	= igb_settime;
+		adapter->caps.enable	= ptp_82580_enable;
+		adapter->cc.read	= igb_82580_systim_read;
+		adapter->cc.mask	= CLOCKSOURCE_MASK(IGB_NBITS_82580);
+		adapter->cc.mult	= 1;
+		adapter->cc.shift	= 0;
+		/* Enable the timer functions by clearing bit 31. */
+		wr32(E1000_TSAUXC, 0x0);
+		break;
+
+	case e1000_82576:
+		adapter->caps.owner	= THIS_MODULE;
+		strcpy(adapter->caps.name, "igb-82576");
+		adapter->caps.max_adj	= 1000000000;
+		adapter->caps.n_ext_ts	= 0;
+		adapter->caps.pps	= 0;
+		adapter->caps.adjfreq	= ptp_82576_adjfreq;
+		adapter->caps.adjtime	= igb_adjtime;
+		adapter->caps.gettime	= igb_gettime;
+		adapter->caps.settime	= igb_settime;
+		adapter->caps.enable	= ptp_82576_enable;
+		adapter->cc.read	= igb_82576_systim_read;
+		adapter->cc.mask	= CLOCKSOURCE_MASK(64);
+		adapter->cc.mult	= 1;
+		adapter->cc.shift	= IGB_82576_TSYNC_SHIFT;
+		/* Dial the nominal frequency. */
+		wr32(E1000_TIMINCA, INCPERIOD_82576 | INCVALUE_82576);
+		break;
+
+	default:
+		adapter->ptp_clock = NULL;
+		return;
+	}
+
+	wrfl();
+
+	timecounter_init(&adapter->tc, &adapter->cc,
+			 ktime_to_ns(ktime_get_real()));
+
+	INIT_DELAYED_WORK(&adapter->overflow_work, igb_overflow_check);
+
+	spin_lock_init(&adapter->tmreg_lock);
+
+	schedule_delayed_work(&adapter->overflow_work, IGB_OVERFLOW_PERIOD);
+
+#ifdef CONFIG_PTP_1588_CLOCK
+
+	adapter->ptp_clock = ptp_clock_register(&adapter->caps);
+	if (IS_ERR(adapter->ptp_clock)) {
+		adapter->ptp_clock = NULL;
+		dev_err(&adapter->pdev->dev, "ptp_clock_register failed\n");
+	} else
+		dev_info(&adapter->pdev->dev, "added PHC on %s\n",
+			 adapter->netdev->name);
+
+#endif /*CONFIG_PTP_1588_CLOCK*/
+}
+
+void igb_ptp_remove(struct igb_adapter *adapter)
+{
+	cancel_delayed_work_sync(&adapter->overflow_work);
+
+#ifdef CONFIG_PTP_1588_CLOCK
+
+	if (adapter->ptp_clock) {
+		ptp_clock_unregister(adapter->ptp_clock);
+		dev_info(&adapter->pdev->dev, "removed PHC on %s\n",
+			 adapter->netdev->name);
+	}
+
+#endif /*CONFIG_PTP_1588_CLOCK*/
+}
-- 
1.7.2.5


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[PATCH net V4 2/2] igb: offer a PTP Hardware Clock instead of the timecompare method

[Richard Cochran]

This commit removes the legacy timecompare code from the igb driver and
offers a tunable PHC instead.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
---
 drivers/net/ethernet/intel/igb/Makefile   |    2 +-
 drivers/net/ethernet/intel/igb/igb.h      |   12 ++-
 drivers/net/ethernet/intel/igb/igb_main.c |  167 +----------------------------
 drivers/net/ethernet/intel/igb/igb_ptp.c  |   59 ++++++++++
 4 files changed, 70 insertions(+), 170 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/Makefile b/drivers/net/ethernet/intel/igb/Makefile
index c6e4621..42f0868 100644
--- a/drivers/net/ethernet/intel/igb/Makefile
+++ b/drivers/net/ethernet/intel/igb/Makefile
@@ -32,6 +32,6 @@
 
 obj-$(CONFIG_IGB) += igb.o
 
-igb-objs := igb_main.o igb_ethtool.o e1000_82575.o \
+igb-objs := igb_main.o igb_ethtool.o igb_ptp.o e1000_82575.o \
 	    e1000_mac.o e1000_nvm.o e1000_phy.o e1000_mbx.o
 
diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index 79f354b..cd08f73 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -35,7 +35,6 @@
 #include "e1000_82575.h"
 
 #include <linux/clocksource.h>
-#include <linux/timecompare.h>
 #include <linux/net_tstamp.h>
 #include <linux/ptp_clock_kernel.h>
 #include <linux/bitops.h>
@@ -329,9 +328,6 @@ struct igb_adapter {
 
 	/* OS defined structs */
 	struct pci_dev *pdev;
-	struct cyclecounter cycles;
-	struct timecounter clock;
-	struct timecompare compare;
 	struct hwtstamp_config hwtstamp_config;
 
 	spinlock_t stats64_lock;
@@ -386,7 +382,6 @@ struct igb_adapter {
 #define IGB_DMCTLX_DCFLUSH_DIS     0x80000000  /* Disable DMA Coal Flush */
 
 #define IGB_82576_TSYNC_SHIFT 19
-#define IGB_82580_TSYNC_SHIFT 24
 #define IGB_TS_HDR_LEN        16
 enum e1000_state_t {
 	__IGB_TESTING,
@@ -423,6 +418,13 @@ extern bool igb_has_link(struct igb_adapter *adapter);
 extern void igb_set_ethtool_ops(struct net_device *);
 extern void igb_power_up_link(struct igb_adapter *);
 
+extern void igb_ptp_init(struct igb_adapter *adapter);
+extern void igb_ptp_remove(struct igb_adapter *adapter);
+
+extern void igb_systim_to_hwtstamp(struct igb_adapter *adapter,
+				   struct skb_shared_hwtstamps *hwtstamps,
+				   u64 systim);
+
 static inline s32 igb_reset_phy(struct e1000_hw *hw)
 {
 	if (hw->phy.ops.reset)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 01e5e89..4cae135 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -114,7 +114,6 @@ static void igb_free_all_rx_resources(struct igb_adapter *);
 static void igb_setup_mrqc(struct igb_adapter *);
 static int igb_probe(struct pci_dev *, const struct pci_device_id *);
 static void __devexit igb_remove(struct pci_dev *pdev);
-static void igb_init_hw_timer(struct igb_adapter *adapter);
 static int igb_sw_init(struct igb_adapter *);
 static int igb_open(struct net_device *);
 static int igb_close(struct net_device *);
@@ -558,33 +557,6 @@ exit:
 	return;
 }
 
-
-/**
- * igb_read_clock - read raw cycle counter (to be used by time counter)
- */
-static cycle_t igb_read_clock(const struct cyclecounter *tc)
-{
-	struct igb_adapter *adapter =
-		container_of(tc, struct igb_adapter, cycles);
-	struct e1000_hw *hw = &adapter->hw;
-	u64 stamp = 0;
-	int shift = 0;
-
-	/*
-	 * The timestamp latches on lowest register read. For the 82580
-	 * the lowest register is SYSTIMR instead of SYSTIML.  However we never
-	 * adjusted TIMINCA so SYSTIMR will just read as all 0s so ignore it.
-	 */
-	if (hw->mac.type >= e1000_82580) {
-		stamp = rd32(E1000_SYSTIMR) >> 8;
-		shift = IGB_82580_TSYNC_SHIFT;
-	}
-
-	stamp |= (u64)rd32(E1000_SYSTIML) << shift;
-	stamp |= (u64)rd32(E1000_SYSTIMH) << (shift + 32);
-	return stamp;
-}
-
 /**
  * igb_get_hw_dev - return device
  * used by hardware layer to print debugging information
@@ -2090,7 +2062,7 @@ static int __devinit igb_probe(struct pci_dev *pdev,
 
 #endif
 	/* do hw tstamp init after resetting */
-	igb_init_hw_timer(adapter);
+	igb_ptp_init(adapter);
 
 	dev_info(&pdev->dev, "Intel(R) Gigabit Ethernet Network Connection\n");
 	/* print bus type/speed/width info */
@@ -2164,6 +2136,8 @@ static void __devexit igb_remove(struct pci_dev *pdev)
 
 	pm_runtime_get_noresume(&pdev->dev);
 
+	igb_ptp_remove(adapter);
+
 	/*
 	 * The watchdog timer may be rescheduled, so explicitly
 	 * disable watchdog from being rescheduled.
@@ -2283,112 +2257,6 @@ out:
 }
 
 /**
- * igb_init_hw_timer - Initialize hardware timer used with IEEE 1588 timestamp
- * @adapter: board private structure to initialize
- *
- * igb_init_hw_timer initializes the function pointer and values for the hw
- * timer found in hardware.
- **/
-static void igb_init_hw_timer(struct igb_adapter *adapter)
-{
-	struct e1000_hw *hw = &adapter->hw;
-
-	switch (hw->mac.type) {
-	case e1000_i350:
-	case e1000_82580:
-		memset(&adapter->cycles, 0, sizeof(adapter->cycles));
-		adapter->cycles.read = igb_read_clock;
-		adapter->cycles.mask = CLOCKSOURCE_MASK(64);
-		adapter->cycles.mult = 1;
-		/*
-		 * The 82580 timesync updates the system timer every 8ns by 8ns
-		 * and the value cannot be shifted.  Instead we need to shift
-		 * the registers to generate a 64bit timer value.  As a result
-		 * SYSTIMR/L/H, TXSTMPL/H, RXSTMPL/H all have to be shifted by
-		 * 24 in order to generate a larger value for synchronization.
-		 */
-		adapter->cycles.shift = IGB_82580_TSYNC_SHIFT;
-		/* disable system timer temporarily by setting bit 31 */
-		wr32(E1000_TSAUXC, 0x80000000);
-		wrfl();
-
-		/* Set registers so that rollover occurs soon to test this. */
-		wr32(E1000_SYSTIMR, 0x00000000);
-		wr32(E1000_SYSTIML, 0x80000000);
-		wr32(E1000_SYSTIMH, 0x000000FF);
-		wrfl();
-
-		/* enable system timer by clearing bit 31 */
-		wr32(E1000_TSAUXC, 0x0);
-		wrfl();
-
-		timecounter_init(&adapter->clock,
-				 &adapter->cycles,
-				 ktime_to_ns(ktime_get_real()));
-		/*
-		 * Synchronize our NIC clock against system wall clock. NIC
-		 * time stamp reading requires ~3us per sample, each sample
-		 * was pretty stable even under load => only require 10
-		 * samples for each offset comparison.
-		 */
-		memset(&adapter->compare, 0, sizeof(adapter->compare));
-		adapter->compare.source = &adapter->clock;
-		adapter->compare.target = ktime_get_real;
-		adapter->compare.num_samples = 10;
-		timecompare_update(&adapter->compare, 0);
-		break;
-	case e1000_82576:
-		/*
-		 * Initialize hardware timer: we keep it running just in case
-		 * that some program needs it later on.
-		 */
-		memset(&adapter->cycles, 0, sizeof(adapter->cycles));
-		adapter->cycles.read = igb_read_clock;
-		adapter->cycles.mask = CLOCKSOURCE_MASK(64);
-		adapter->cycles.mult = 1;
-		/**
-		 * Scale the NIC clock cycle by a large factor so that
-		 * relatively small clock corrections can be added or
-		 * subtracted at each clock tick. The drawbacks of a large
-		 * factor are a) that the clock register overflows more quickly
-		 * (not such a big deal) and b) that the increment per tick has
-		 * to fit into 24 bits.  As a result we need to use a shift of
-		 * 19 so we can fit a value of 16 into the TIMINCA register.
-		 */
-		adapter->cycles.shift = IGB_82576_TSYNC_SHIFT;
-		wr32(E1000_TIMINCA,
-		                (1 << E1000_TIMINCA_16NS_SHIFT) |
-		                (16 << IGB_82576_TSYNC_SHIFT));
-
-		/* Set registers so that rollover occurs soon to test this. */
-		wr32(E1000_SYSTIML, 0x00000000);
-		wr32(E1000_SYSTIMH, 0xFF800000);
-		wrfl();
-
-		timecounter_init(&adapter->clock,
-				 &adapter->cycles,
-				 ktime_to_ns(ktime_get_real()));
-		/*
-		 * Synchronize our NIC clock against system wall clock. NIC
-		 * time stamp reading requires ~3us per sample, each sample
-		 * was pretty stable even under load => only require 10
-		 * samples for each offset comparison.
-		 */
-		memset(&adapter->compare, 0, sizeof(adapter->compare));
-		adapter->compare.source = &adapter->clock;
-		adapter->compare.target = ktime_get_real;
-		adapter->compare.num_samples = 10;
-		timecompare_update(&adapter->compare, 0);
-		break;
-	case e1000_82575:
-		/* 82575 does not support timesync */
-	default:
-		break;
-	}
-
-}
-
-/**
  * igb_sw_init - Initialize general software structures (struct igb_adapter)
  * @adapter: board private structure to initialize
  *
@@ -5678,35 +5546,6 @@ static int igb_poll(struct napi_struct *napi, int budget)
 }
 
 /**
- * igb_systim_to_hwtstamp - convert system time value to hw timestamp
- * @adapter: board private structure
- * @shhwtstamps: timestamp structure to update
- * @regval: unsigned 64bit system time value.
- *
- * We need to convert the system time value stored in the RX/TXSTMP registers
- * into a hwtstamp which can be used by the upper level timestamping functions
- */
-static void igb_systim_to_hwtstamp(struct igb_adapter *adapter,
-                                   struct skb_shared_hwtstamps *shhwtstamps,
-                                   u64 regval)
-{
-	u64 ns;
-
-	/*
-	 * The 82580 starts with 1ns at bit 0 in RX/TXSTMPL, shift this up to
-	 * 24 to match clock shift we setup earlier.
-	 */
-	if (adapter->hw.mac.type >= e1000_82580)
-		regval <<= IGB_82580_TSYNC_SHIFT;
-
-	ns = timecounter_cyc2time(&adapter->clock, regval);
-	timecompare_update(&adapter->compare, ns);
-	memset(shhwtstamps, 0, sizeof(struct skb_shared_hwtstamps));
-	shhwtstamps->hwtstamp = ns_to_ktime(ns);
-	shhwtstamps->syststamp = timecompare_transform(&adapter->compare, ns);
-}
-
-/**
  * igb_tx_hwtstamp - utility function which checks for TX time stamp
  * @q_vector: pointer to q_vector containing needed info
  * @buffer: pointer to igb_tx_buffer structure
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index a8dc3e5..061a897 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -26,6 +26,9 @@
 #define ISGN			0x80000000
 
 /*
+ * The 82580 timesync updates the system timer every 8ns by 8ns,
+ * and this update value cannot be reprogrammed.
+ *
  * Neither the 82576 nor the 82580 offer registers wide enough to hold
  * nanoseconds time values for very long. For the 82580, SYSTIM always
  * counts nanoseconds, but the upper 24 bits are not availible. The
@@ -37,6 +40,14 @@
  * field are needed to provide the nominal 16 nanosecond period,
  * leaving 19 bits for fractional nanoseconds.
  *
+ * We scale the NIC clock cycle by a large factor so that relatively
+ * small clock corrections can be added or subtracted at each clock
+ * tick. The drawbacks of a large factor are a) that the clock
+ * register overflows more quickly (not such a big deal) and b) that
+ * the increment per tick has to fit into 24 bits.  As a result we
+ * need to use a shift of 19 so we can fit a value of 16 into the
+ * TIMINCA register.
+ *
  *
  *             SYSTIMH            SYSTIML
  *        +--------------+   +---+---+------+
@@ -94,6 +105,11 @@ static cycle_t igb_82580_systim_read(const struct cyclecounter *cc)
 	struct igb_adapter *igb = container_of(cc, struct igb_adapter, cc);
 	struct e1000_hw *hw = &igb->hw;
 
+	/*
+	 * The timestamp latches on lowest register read. For the 82580
+	 * the lowest register is SYSTIMR instead of SYSTIML.  However we only
+	 * need to provide nanosecond resolution, so we just ignore it.
+	 */
 	jk = rd32(E1000_SYSTIMR);
 	lo = rd32(E1000_SYSTIML);
 	hi = rd32(E1000_SYSTIMH);
@@ -327,3 +343,46 @@ void igb_ptp_remove(struct igb_adapter *adapter)
 
 #endif /*CONFIG_PTP_1588_CLOCK*/
 }
+
+/**
+ * igb_systim_to_hwtstamp - convert system time value to hw timestamp
+ * @adapter: board private structure
+ * @hwtstamps: timestamp structure to update
+ * @systim: unsigned 64bit system time value.
+ *
+ * We need to convert the system time value stored in the RX/TXSTMP registers
+ * into a hwtstamp which can be used by the upper level timestamping functions.
+ *
+ * The 'tmreg_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 (or three) 32 bit registers. The first
+ * read latches the value. Ditto for writing.
+ *
+ * In addition, here have extended the system time with an overflow
+ * counter in software.
+ */
+void igb_systim_to_hwtstamp(struct igb_adapter *adapter,
+			    struct skb_shared_hwtstamps *hwtstamps,
+			    u64 systim)
+{
+	u64 ns;
+	unsigned long flags;
+
+	switch (adapter->hw.mac.type) {
+	case e1000_i350:
+	case e1000_82580:
+	case e1000_82576:
+		break;
+	default:
+		return;
+	}
+
+	spin_lock_irqsave(&adapter->tmreg_lock, flags);
+
+	ns = timecounter_cyc2time(&adapter->tc, systim);
+
+	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
+
+	memset(hwtstamps, 0, sizeof(*hwtstamps));
+	hwtstamps->hwtstamp = ns_to_ktime(ns);
+}
-- 
1.7.2.5


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Re: [PATCH net V4 0/2] igb: ptp hardware clock

[Jeff Kirsher]

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On Sat, 2012-01-21 at 17:03 +0100, Richard Cochran wrote:
> * ChangeLog
> ** V4
>    - Use standard kernel cyclecounter/timecounter infrastructure
>      instead of a home grown counter overflow implementation.
> ** V3
>    - Driver compiles even without CONFIG_PTP_1588_CLOCK.
>    - Timestamping always works, even when PTP code missing or fails.
> ** V2
>    - Fixed wrong bit shifting in the 82576 code.
>    - Explained the timestamp locking with a comment in the code.
>    - Preserved the comments from the original timecompare implementation.
>    - Added an additional test within the overflow counter code to fix
>      a race condition. Details of the problem are given in the commit
>      message.
> 
> This patch series implements a PHC driver for the Intel 82576 and
> 82580 devices, as part of the igb driver.  Only the base clock
> operations are implemented. The hardware does have some ancillary
> features, but these can be easily added later.
> 
> The first patch adds the PHC driver code as a new source module but
> does not link it into the main igb driver. Because the system time
> counter is not so very wide, the code uses the overflow counter from
> the cyclecounter/timecounter code. Every read operation maintains the
> overflow counter, as does a "delayed work" watchdog. 
> 
> The second patch removes the timecompare code and links in the new
> functions.
> 
> I have tested the 82580 with good results. However, I don't have the
> 82576 and so would appreciate testing and feedback.
> 
> Thanks,
> Richard
> 
> 
> Richard Cochran (2):
>   igb: add PTP Hardware Clock code
>   igb: offer a PTP Hardware Clock instead of the timecompare method
> 
>  drivers/net/ethernet/intel/igb/Makefile   |    2 +-
>  drivers/net/ethernet/intel/igb/igb.h      |   20 ++-
>  drivers/net/ethernet/intel/igb/igb_main.c |  167 +------------
>  drivers/net/ethernet/intel/igb/igb_ptp.c  |  388 +++++++++++++++++++++++++++++
>  4 files changed, 407 insertions(+), 170 deletions(-)
>  create mode 100644 drivers/net/ethernet/intel/igb/igb_ptp.c
> 

Thanks Richard, I have added the patches to my queue.

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RE: [PATCH net V4 1/2] igb: add PTP Hardware Clock code

[Keller, Jacob E]

> -----Original Message-----
> From: Richard Cochran [mailto:richardcochran@gmail.com]
> Sent: Saturday, January 21, 2012 8:04 AM
> To: netdev@vger.kernel.org
> Cc: e1000-devel@lists.sourceforge.net; Keller, Jacob E; Kirsher,
> Jeffrey T; Ronciak, John; John Stultz; Thomas Gleixner
> Subject: [PATCH net V4 1/2] igb: add PTP Hardware Clock code
> 
> This patch adds a source file implementing a PHC. Only the basic
> clock operations have been implemented, although the hardware
> would offer some ancillary functions. The code is fairly self
> contained and is not yet used in the main igb driver.
> 
> Every timestamp and clock read operation must consult the overflow
> counter to form a correct time value. Access to the counter is
> protected by a spin lock, and the counter is implemented using the
> standard cyclecounter/timecounter code.
> 

Looks good overall other than the comments/questions inlined below.


> Signed-off-by: Richard Cochran <richardcochran@gmail.com>
> ---
>  drivers/net/ethernet/intel/igb/igb.h     |    8 +
>  drivers/net/ethernet/intel/igb/igb_ptp.c |  329
> ++++++++++++++++++++++++++++++
>  2 files changed, 337 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/net/ethernet/intel/igb/igb_ptp.c
> 
> diff --git a/drivers/net/ethernet/intel/igb/igb.h
> b/drivers/net/ethernet/intel/igb/igb.h
> index 3d12e67..79f354b 100644
> --- a/drivers/net/ethernet/intel/igb/igb.h
> +++ b/drivers/net/ethernet/intel/igb/igb.h
> @@ -37,6 +37,7 @@
>  #include <linux/clocksource.h>
>  #include <linux/timecompare.h>
>  #include <linux/net_tstamp.h>
> +#include <linux/ptp_clock_kernel.h>
>  #include <linux/bitops.h>
>  #include <linux/if_vlan.h>
> 
> @@ -364,6 +365,13 @@ struct igb_adapter {
>  	u32 wvbr;
>  	int node;
>  	u32 *shadow_vfta;
> +
> +	struct ptp_clock *ptp_clock;
> +	struct ptp_clock_info caps;
> +	struct delayed_work overflow_work;
> +	spinlock_t tmreg_lock;
> +	struct cyclecounter cc;
> +	struct timecounter tc;
>  };
> 
>  #define IGB_FLAG_HAS_MSI           (1 << 0)
> diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c
> b/drivers/net/ethernet/intel/igb/igb_ptp.c
> new file mode 100644
> index 0000000..a8dc3e5
> --- /dev/null
> +++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
> @@ -0,0 +1,329 @@
> +/*
> + * PTP Hardware Clock (PHC) driver for the Intel 82576 and 82580
> + *
> + * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or
> modify
> + * it under the terms of the GNU General Public License as published
> by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that 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, write to the Free Software Foundation,
> Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> + */
> +#include <linux/device.h>
> +#include <linux/pci.h>
> +
> +#include "igb.h"
> +
> +#define INCVALUE_MASK		0x7fffffff
> +#define ISGN			0x80000000
> +
> +/*
> + * Neither the 82576 nor the 82580 offer registers wide enough to hold
> + * nanoseconds time values for very long. For the 82580, SYSTIM always
> + * counts nanoseconds, but the upper 24 bits are not availible. The
> + * frequency is adjusted by changing the 32 bit fractional nanoseconds
> + * register, TIMINCA.
> + *
> + * For the 82576, the SYSTIM register time unit is affect by the
> + * choice of the 24 bit TININCA:IV (incvalue) field. Five bits of this
> + * field are needed to provide the nominal 16 nanosecond period,
> + * leaving 19 bits for fractional nanoseconds.
> + *
> + *
> + *             SYSTIMH            SYSTIML
> + *        +--------------+   +---+---+------+
> + *  82576 |      32      |   | 8 | 5 |  19  |
> + *        +--------------+   +---+---+------+
> + *         \________ 45 bits _______/  fract
> + *
> + *        +----------+---+   +--------------+
> + *  82580 |    24    | 8 |   |      32      |
> + *        +----------+---+   +--------------+
> + *          reserved  \______ 40 bits _____/
> + *
> + *
> + * The 45 bit 82576 SYSTIM overflows every
> + *   2^45 * 10^-9 / 3600 = 9.77 hours.
> + *
> + * The 40 bit 82580 SYSTIM overflows every
> + *   2^40 * 10^-9 /  60  = 18.3 minutes.
> + */
> +
> +#define IGB_OVERFLOW_PERIOD	(HZ * 60 * 9)
> +#define INCPERIOD_82576		(1 << E1000_TIMINCA_16NS_SHIFT)
> +#define INCVALUE_82576_MASK	((1 << E1000_TIMINCA_16NS_SHIFT) - 1)
> +#define INCVALUE_82576		(16 << IGB_82576_TSYNC_SHIFT)
> +#define IGB_NBITS_82580		40
> +
> +/*
> + * SYSTIM read access for the 82576
> + */
> +
> +static cycle_t igb_82576_systim_read(const struct cyclecounter *cc)
> +{
> +	u64 val;
> +	u32 lo, hi;
> +	struct igb_adapter *igb = container_of(cc, struct igb_adapter,
> cc);
> +	struct e1000_hw *hw = &igb->hw;
> +
> +	lo = rd32(E1000_SYSTIML);
> +	hi = rd32(E1000_SYSTIMH);
> +
> +	val = ((u64) hi) << 32;
> +	val |= lo;
> +
> +	return val;
> +}
> +
> +/*
> + * SYSTIM read access for the 82580
> + */
> +
> +static cycle_t igb_82580_systim_read(const struct cyclecounter *cc)
> +{
> +	u64 val;
> +	u32 lo, hi, jk;
> +	struct igb_adapter *igb = container_of(cc, struct igb_adapter,
> cc);
> +	struct e1000_hw *hw = &igb->hw;
> +
> +	jk = rd32(E1000_SYSTIMR);
> +	lo = rd32(E1000_SYSTIML);
> +	hi = rd32(E1000_SYSTIMH);
> +
> +	val = ((u64) hi) << 32;
> +	val |= lo;
> +
> +	return val;
> +}
> +
> +/*
> + * PTP clock operations
> + */
> +
> +static int ptp_82576_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
> +{
> +	u64 rate;
> +	u32 incvalue;
> +	int neg_adj = 0;
> +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> +	struct e1000_hw *hw = &igb->hw;
> +
> +	if (ppb < 0) {
> +		neg_adj = 1;
> +		ppb = -ppb;
> +	}
> +	rate = ppb;
> +	rate <<= 14;
> +	rate = div_u64(rate, 1953125);
> +

So is the rate ppb accumulating? I was under the impression that it calculated from the current clock frequency so it would need to be applied to the current incvalue, not the base... Is this not the case? What was the intention of the ppb?

> +	incvalue = 16 << IGB_82576_TSYNC_SHIFT;
> +
> +	if (neg_adj)
> +		incvalue -= rate;
> +	else
> +		incvalue += rate;
> +
> +	wr32(E1000_TIMINCA, INCPERIOD_82576 | (incvalue &
> INCVALUE_82576_MASK));
> +
> +	return 0;
> +}
> +
> +static int ptp_82580_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
> +{
> +	u64 rate;
> +	u32 inca;
> +	int neg_adj = 0;
> +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> +	struct e1000_hw *hw = &igb->hw;
> +
> +	if (ppb < 0) {
> +		neg_adj = 1;
> +		ppb = -ppb;
> +	}
> +	rate = ppb;
> +	rate <<= 26;
> +	rate = div_u64(rate, 1953125);
> +
> +	inca = rate & INCVALUE_MASK;
> +	if (neg_adj)
> +		inca |= ISGN;
> +
> +	wr32(E1000_TIMINCA, inca);
> +
> +	return 0;
> +}
> +
> +static int igb_adjtime(struct ptp_clock_info *ptp, s64 delta)
> +{
> +	s64 now;
> +	unsigned long flags;
> +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> +
> +	spin_lock_irqsave(&igb->tmreg_lock, flags);
> +
> +	now = timecounter_read(&igb->tc);
> +	now += delta;
> +	timecounter_init(&igb->tc, &igb->cc, now);
> +
> +	spin_unlock_irqrestore(&igb->tmreg_lock, flags);
> +
> +	return 0;
> +}
> +
> +static int igb_gettime(struct ptp_clock_info *ptp, struct timespec
> *ts)
> +{
> +	u64 ns;
> +	u32 remainder;
> +	unsigned long flags;
> +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> +
> +	spin_lock_irqsave(&igb->tmreg_lock, flags);
> +
> +	ns = timecounter_read(&igb->tc);
> +
> +	spin_unlock_irqrestore(&igb->tmreg_lock, flags);
> +
> +	ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
> +	ts->tv_nsec = remainder;
> +
> +	return 0;
> +}
> +
> +static int igb_settime(struct ptp_clock_info *ptp, const struct
> timespec *ts)
> +{
> +	u64 ns;
> +	unsigned long flags;
> +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> +
> +	ns = ts->tv_sec * 1000000000ULL;
> +	ns += ts->tv_nsec;
> +
> +	spin_lock_irqsave(&igb->tmreg_lock, flags);
> +
> +	timecounter_init(&igb->tc, &igb->cc, ns);
> +
> +	spin_unlock_irqrestore(&igb->tmreg_lock, flags);
> +
> +	return 0;
> +}
> +
> +static int ptp_82576_enable(struct ptp_clock_info *ptp,
> +			    struct ptp_clock_request *rq, int on)
> +{
> +	return -EOPNOTSUPP;
> +}
> +
> +static int ptp_82580_enable(struct ptp_clock_info *ptp,
> +			    struct ptp_clock_request *rq, int on)
> +{
> +	return -EOPNOTSUPP;
> +}
> +
> +static void igb_overflow_check(struct work_struct *work)
> +{
> +	struct timespec ts;
> +	struct igb_adapter *igb =
> +		container_of(work, struct igb_adapter, overflow_work.work);
> +
> +	igb_gettime(&igb->caps, &ts);
> +
> +	pr_debug("igb overflow check at %ld.%09lu\n", ts.tv_sec,
> ts.tv_nsec);
> +
> +	schedule_delayed_work(&igb->overflow_work, IGB_OVERFLOW_PERIOD);
> +}
> +
> +void igb_ptp_init(struct igb_adapter *adapter)
> +{
> +	struct e1000_hw *hw = &adapter->hw;
> +
> +	switch (hw->mac.type) {
> +	case e1000_i350:
> +	case e1000_82580:
> +		adapter->caps.owner	= THIS_MODULE;
> +		strcpy(adapter->caps.name, "igb-82580");
> +		adapter->caps.max_adj	= 62499999;
> +		adapter->caps.n_ext_ts	= 0;
> +		adapter->caps.pps	= 0;
> +		adapter->caps.adjfreq	= ptp_82580_adjfreq;
> +		adapter->caps.adjtime	= igb_adjtime;
> +		adapter->caps.gettime	= igb_gettime;
> +		adapter->caps.settime	= igb_settime;
> +		adapter->caps.enable	= ptp_82580_enable;
> +		adapter->cc.read	= igb_82580_systim_read;
> +		adapter->cc.mask	= CLOCKSOURCE_MASK(IGB_NBITS_82580);
> +		adapter->cc.mult	= 1;
> +		adapter->cc.shift	= 0;
> +		/* Enable the timer functions by clearing bit 31. */
> +		wr32(E1000_TSAUXC, 0x0);
> +		break;
> +
> +	case e1000_82576:
> +		adapter->caps.owner	= THIS_MODULE;
> +		strcpy(adapter->caps.name, "igb-82576");
> +		adapter->caps.max_adj	= 1000000000;
> +		adapter->caps.n_ext_ts	= 0;
> +		adapter->caps.pps	= 0;
> +		adapter->caps.adjfreq	= ptp_82576_adjfreq;
> +		adapter->caps.adjtime	= igb_adjtime;
> +		adapter->caps.gettime	= igb_gettime;
> +		adapter->caps.settime	= igb_settime;
> +		adapter->caps.enable	= ptp_82576_enable;
> +		adapter->cc.read	= igb_82576_systim_read;
> +		adapter->cc.mask	= CLOCKSOURCE_MASK(64);
> +		adapter->cc.mult	= 1;
> +		adapter->cc.shift	= IGB_82576_TSYNC_SHIFT;
> +		/* Dial the nominal frequency. */
> +		wr32(E1000_TIMINCA, INCPERIOD_82576 | INCVALUE_82576);
> +		break;
> +

It would be good to check whether the link speed has an impact on the SYSTIME register rate. I know on the 10 Gb parts the systime registers are driven by the DMA clock which is partitioned differently at slower speeds so the values have to be updated whenever the link speed changes..


> +	default:
> +		adapter->ptp_clock = NULL;
> +		return;
> +	}
> +
> +	wrfl();
> +
> +	timecounter_init(&adapter->tc, &adapter->cc,
> +			 ktime_to_ns(ktime_get_real()));
> +
> +	INIT_DELAYED_WORK(&adapter->overflow_work, igb_overflow_check);
> +
> +	spin_lock_init(&adapter->tmreg_lock);
> +
> +	schedule_delayed_work(&adapter->overflow_work,
> IGB_OVERFLOW_PERIOD);
> +
> +#ifdef CONFIG_PTP_1588_CLOCK
> +
> +	adapter->ptp_clock = ptp_clock_register(&adapter->caps);
> +	if (IS_ERR(adapter->ptp_clock)) {
> +		adapter->ptp_clock = NULL;
> +		dev_err(&adapter->pdev->dev, "ptp_clock_register
> failed\n");
> +	} else
> +		dev_info(&adapter->pdev->dev, "added PHC on %s\n",
> +			 adapter->netdev->name);
> +
> +#endif /*CONFIG_PTP_1588_CLOCK*/
> +}
> +
> +void igb_ptp_remove(struct igb_adapter *adapter)
> +{
> +	cancel_delayed_work_sync(&adapter->overflow_work);
> +
> +#ifdef CONFIG_PTP_1588_CLOCK
> +
> +	if (adapter->ptp_clock) {
> +		ptp_clock_unregister(adapter->ptp_clock);
> +		dev_info(&adapter->pdev->dev, "removed PHC on %s\n",
> +			 adapter->netdev->name);
> +	}
> +
> +#endif /*CONFIG_PTP_1588_CLOCK*/
> +}
> --
> 1.7.2.5

Re: [PATCH net V4 1/2] igb: add PTP Hardware Clock code

[Richard Cochran]

On Mon, Jan 23, 2012 at 06:39:44PM +0000, Keller, Jacob E wrote:

> > +static int ptp_82576_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
> > +{
> > +	u64 rate;
> > +	u32 incvalue;
> > +	int neg_adj = 0;
> > +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
> > +	struct e1000_hw *hw = &igb->hw;
> > +
> > +	if (ppb < 0) {
> > +		neg_adj = 1;
> > +		ppb = -ppb;
> > +	}
> > +	rate = ppb;
> > +	rate <<= 14;
> > +	rate = div_u64(rate, 1953125);
> > +
> 
> So is the rate ppb accumulating? I was under the impression that it
> calculated from the current clock frequency so it would need to be
> applied to the current incvalue, not the base... Is this not the
> case? What was the intention of the ppb?

The ppb is simply the desired rate offset in parts per billion. It is
not a delta from the current offset, but rather fixed from the clock's
nominal frequency. This comes from the NTP timex.freq field (but the
unit here is ppb, timex.freq is ppm with a 16 bit fraction.)

If the clock servo is a typical PI controller for example, then the
servo output already represents the accumulated offset.

> > +	incvalue = 16 << IGB_82576_TSYNC_SHIFT;
> > +
> > +	if (neg_adj)
> > +		incvalue -= rate;
> > +	else
> > +		incvalue += rate;
> > +
> > +	wr32(E1000_TIMINCA, INCPERIOD_82576 | (incvalue & INCVALUE_82576_MASK));
> > +
> > +	return 0;
> > +}

> > +		/* Dial the nominal frequency. */
> > +		wr32(E1000_TIMINCA, INCPERIOD_82576 | INCVALUE_82576);
> > +		break;
> > +
> 
> It would be good to check whether the link speed has an impact on
> the SYSTIME register rate. I know on the 10 Gb parts the systime
> registers are driven by the DMA clock which is partitioned
> differently at slower speeds so the values have to be updated
> whenever the link speed changes..

If this is true for 82576, then it certainly is not documented. I
don't have that card, so maybe someone from Intel can answer this?

I think the documentation for the 82580 is clear about the basic rate
always being the same.

Thanks,
Richard

RE: [PATCH net V4 1/2] igb: add PTP Hardware Clock code

[Keller, Jacob E]

> -----Original Message-----
> From: Richard Cochran [mailto:richardcochran@gmail.com]
> Sent: Tuesday, January 24, 2012 9:44 AM
> To: Keller, Jacob E
> Cc: netdev@vger.kernel.org; e1000-devel@lists.sourceforge.net; Kirsher,
> Jeffrey T; Ronciak, John; John Stultz; Thomas Gleixner
> Subject: Re: [PATCH net V4 1/2] igb: add PTP Hardware Clock code
> 
> On Mon, Jan 23, 2012 at 06:39:44PM +0000, Keller, Jacob E wrote:
> 
> > > +static int ptp_82576_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
> > > +{
> > > +	u64 rate;
> > > +	u32 incvalue;
> > > +	int neg_adj = 0;
> > > +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> > > +	struct e1000_hw *hw = &igb->hw;
> > > +
> > > +	if (ppb < 0) {
> > > +		neg_adj = 1;
> > > +		ppb = -ppb;
> > > +	}
> > > +	rate = ppb;
> > > +	rate <<= 14;
> > > +	rate = div_u64(rate, 1953125);
> > > +
> >
> > So is the rate ppb accumulating? I was under the impression that it
> > calculated from the current clock frequency so it would need to be
> > applied to the current incvalue, not the base... Is this not the
> > case? What was the intention of the ppb?
> 
> The ppb is simply the desired rate offset in parts per billion. It is
> not a delta from the current offset, but rather fixed from the clock's
> nominal frequency. This comes from the NTP timex.freq field (but the
> unit here is ppb, timex.freq is ppm with a 16 bit fraction.)
> 
> If the clock servo is a typical PI controller for example, then the
> servo output already represents the accumulated offset.
> 
> > > +	incvalue = 16 << IGB_82576_TSYNC_SHIFT;
> > > +
> > > +	if (neg_adj)
> > > +		incvalue -= rate;
> > > +	else
> > > +		incvalue += rate;
> > > +
> > > +	wr32(E1000_TIMINCA, INCPERIOD_82576 | (incvalue &
> INCVALUE_82576_MASK));
> > > +
> > > +	return 0;
> > > +}
> 
> > > +		/* Dial the nominal frequency. */
> > > +		wr32(E1000_TIMINCA, INCPERIOD_82576 | INCVALUE_82576);
> > > +		break;
> > > +
> >
> > It would be good to check whether the link speed has an impact on
> > the SYSTIME register rate. I know on the 10 Gb parts the systime
> > registers are driven by the DMA clock which is partitioned
> > differently at slower speeds so the values have to be updated
> > whenever the link speed changes..
> 
> If this is true for 82576, then it certainly is not documented. I
> don't have that card, so maybe someone from Intel can answer this?
> 

I'll look into this.

> I think the documentation for the 82580 is clear about the basic rate
> always being the same.

Yeah, I believe the 82580 stays the same regardless of the device link speed.

> 
> Thanks,
> Richard

Re: [PATCH net V4 0/2] igb: ptp hardware clock

[Jeff Kirsher]

[-- Attachment #1: Type: text/plain, Size: 3116 bytes --]

On Sat, 2012-01-21 at 17:03 +0100, Richard Cochran wrote:
> * ChangeLog
> ** V4
>    - Use standard kernel cyclecounter/timecounter infrastructure
>      instead of a home grown counter overflow implementation.
> ** V3
>    - Driver compiles even without CONFIG_PTP_1588_CLOCK.
>    - Timestamping always works, even when PTP code missing or fails.
> ** V2
>    - Fixed wrong bit shifting in the 82576 code.
>    - Explained the timestamp locking with a comment in the code.
>    - Preserved the comments from the original timecompare implementation.
>    - Added an additional test within the overflow counter code to fix
>      a race condition. Details of the problem are given in the commit
>      message.
> 
> This patch series implements a PHC driver for the Intel 82576 and
> 82580 devices, as part of the igb driver.  Only the base clock
> operations are implemented. The hardware does have some ancillary
> features, but these can be easily added later.
> 
> The first patch adds the PHC driver code as a new source module but
> does not link it into the main igb driver. Because the system time
> counter is not so very wide, the code uses the overflow counter from
> the cyclecounter/timecounter code. Every read operation maintains the
> overflow counter, as does a "delayed work" watchdog. 
> 
> The second patch removes the timecompare code and links in the new
> functions.
> 
> I have tested the 82580 with good results. However, I don't have the
> 82576 and so would appreciate testing and feedback.
> 
> Thanks,
> Richard
> 
> 
> Richard Cochran (2):
>   igb: add PTP Hardware Clock code
>   igb: offer a PTP Hardware Clock instead of the timecompare method
> 
>  drivers/net/ethernet/intel/igb/Makefile   |    2 +-
>  drivers/net/ethernet/intel/igb/igb.h      |   20 ++-
>  drivers/net/ethernet/intel/igb/igb_main.c |  167 +------------
>  drivers/net/ethernet/intel/igb/igb_ptp.c  |  388 +++++++++++++++++++++++++++++
>  4 files changed, 407 insertions(+), 170 deletions(-)
>  create mode 100644 drivers/net/ethernet/intel/igb/igb_ptp.c
> 

Added Aaron Brown to the thread

Richard-

Did you compile test?  Why I ask is our validation team is getting the
following errors when trying to compile in PTP support:

---------------------------
drivers/net/ethernet/intel/igb/igb_ptp.c: In function âigb_ptp_initâ:
drivers/net/ethernet/intel/igb/igb_ptp.c:266: error: âTHIS_MODULEâ undeclared (first use in this function)
drivers/net/ethernet/intel/igb/igb_ptp.c:266: error: (Each undeclared identifier is reported only once
drivers/net/ethernet/intel/igb/igb_ptp.c:266: error: for each function it appears in.)
make[5]: *** [drivers/net/ethernet/intel/igb/igb_ptp.o] Error 1
make[4]: *** [drivers/net/ethernet/intel/igb] Error 2
make[4]: *** Waiting for unfinished jobs....
make[3]: *** [drivers/net/ethernet/intel] Error 2
make[2]: *** [drivers/net/ethernet] Error 2
make[1]: *** [drivers/net] Error 2
make[1]: *** Waiting for unfinished jobs....
make: *** [drivers] Error 2
-------------------------------

Cheers,
Jeff

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Re: [PATCH net V4 0/2] igb: ptp hardware clock

[Richard Cochran]

On Thu, Jan 26, 2012 at 08:24:53PM -0800, Jeff Kirsher wrote:
> Richard-
> 
> Did you compile test?  Why I ask is our validation team is getting the
> following errors when trying to compile in PTP support:

I did compile and also tested the driver.

What .config are you using? What kernel version?

Thanks,
Richard

Re: [PATCH net V4 0/2] igb: ptp hardware clock

[Jeff Kirsher]

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On Fri, 2012-01-27 at 11:11 +0100, Richard Cochran wrote:
> On Thu, Jan 26, 2012 at 08:24:53PM -0800, Jeff Kirsher wrote:
> > Richard-
> > 
> > Did you compile test?  Why I ask is our validation team is getting the
> > following errors when trying to compile in PTP support:
> 
> I did compile and also tested the driver.
> 
> What .config are you using? What kernel version?
> 
> Thanks,
> Richard

I will have Aaron post his .config's that he tried.  I know that he
tried multiple configs with no success.  As far as kernel version, he
was using the latest net-next tree from David Miller.

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Re: [PATCH net V4 0/2] igb: ptp hardware clock

[Eric Dumazet]

Le vendredi 27 janvier 2012 à 02:15 -0800, Jeff Kirsher a écrit :
> On Fri, 2012-01-27 at 11:11 +0100, Richard Cochran wrote:
> > On Thu, Jan 26, 2012 at 08:24:53PM -0800, Jeff Kirsher wrote:
> > > Richard-
> > > 
> > > Did you compile test?  Why I ask is our validation team is getting the
> > > following errors when trying to compile in PTP support:
> > 
> > I did compile and also tested the driver.
> > 
> > What .config are you using? What kernel version?
> > 
> > Thanks,
> > Richard
> 
> I will have Aaron post his .config's that he tried.  I know that he
> tried multiple configs with no success.  As far as kernel version, he
> was using the latest net-next tree from David Miller.

This might coming from

commit 36a1211970193ce215de50ed1e4e1272bc814df1
Author: Paul Gortmaker <paul.gortmaker@windriver.com>
Date:   Tue Jan 24 11:33:19 2012 +0000

    netprio_cgroup.h: dont include module.h from other includes
    
    A considerable effort was invested in wiping out module.h
    from being present in all the other standard includes.  This
    one leaked back in, but once again isn't strictly necessary,
    so remove it.
    

Re: [PATCH net V4 0/2] igb: ptp hardware clock

[Jeff Kirsher]

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On Fri, 2012-01-27 at 11:22 +0100, Eric Dumazet wrote:
> Le vendredi 27 janvier 2012 à 02:15 -0800, Jeff Kirsher a écrit :
> > On Fri, 2012-01-27 at 11:11 +0100, Richard Cochran wrote:
> > > On Thu, Jan 26, 2012 at 08:24:53PM -0800, Jeff Kirsher wrote:
> > > > Richard-
> > > > 
> > > > Did you compile test?  Why I ask is our validation team is getting the
> > > > following errors when trying to compile in PTP support:
> > > 
> > > I did compile and also tested the driver.
> > > 
> > > What .config are you using? What kernel version?
> > > 
> > > Thanks,
> > > Richard
> > 
> > I will have Aaron post his .config's that he tried.  I know that he
> > tried multiple configs with no success.  As far as kernel version, he
> > was using the latest net-next tree from David Miller.
> 
> This might coming from
> 
> commit 36a1211970193ce215de50ed1e4e1272bc814df1
> Author: Paul Gortmaker <paul.gortmaker@windriver.com>
> Date:   Tue Jan 24 11:33:19 2012 +0000
> 
>     netprio_cgroup.h: dont include module.h from other includes
>     
>     A considerable effort was invested in wiping out module.h
>     from being present in all the other standard includes.  This
>     one leaked back in, but once again isn't strictly necessary,
>     so remove it.
>     
> 
> 

Eric was correct.  I added #include <linux/mdoule.h> to the igb_ptp.c
file and the error goes away.

Richard are you fine with me adding that change to your first patch of
the series?  That way I can have the validation team finish up testing
your patches.

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Re: [PATCH net V4 0/2] igb: ptp hardware clock

[Richard Cochran]

On Fri, Jan 27, 2012 at 02:56:29AM -0800, Jeff Kirsher wrote:
> Eric was correct.  I added #include <linux/mdoule.h> to the igb_ptp.c
> file and the error goes away.
> 
> Richard are you fine with me adding that change to your first patch of
> the series?  That way I can have the validation team finish up testing
> your patches.

By all means, please go right ahead.

Thanks,
Richard

RE: [PATCH net V4 1/2] igb: add PTP Hardware Clock code

[Keller, Jacob E]

Have you tested this with ptp support configured as a module instead of directly compiled into the kernel? My experience in the past has been that the CONFIG_PTP_1588_CLOCK flag is not defined when support is not directly compiled into the kernel. (A different flag, which signifies module vs compiled) is defined. I would like to know the results, Thanks.

> -----Original Message-----
> From: Richard Cochran [mailto:richardcochran@gmail.com]
> Sent: Saturday, January 21, 2012 8:04 AM
> To: netdev@vger.kernel.org
> Cc: e1000-devel@lists.sourceforge.net; Keller, Jacob E; Kirsher,
> Jeffrey T; Ronciak, John; John Stultz; Thomas Gleixner
> Subject: [PATCH net V4 1/2] igb: add PTP Hardware Clock code
> 
> This patch adds a source file implementing a PHC. Only the basic
> clock operations have been implemented, although the hardware
> would offer some ancillary functions. The code is fairly self
> contained and is not yet used in the main igb driver.
> 
> Every timestamp and clock read operation must consult the overflow
> counter to form a correct time value. Access to the counter is
> protected by a spin lock, and the counter is implemented using the
> standard cyclecounter/timecounter code.
> 
> Signed-off-by: Richard Cochran <richardcochran@gmail.com>
> ---
>  drivers/net/ethernet/intel/igb/igb.h     |    8 +
>  drivers/net/ethernet/intel/igb/igb_ptp.c |  329
> ++++++++++++++++++++++++++++++
>  2 files changed, 337 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/net/ethernet/intel/igb/igb_ptp.c
> 
> diff --git a/drivers/net/ethernet/intel/igb/igb.h
> b/drivers/net/ethernet/intel/igb/igb.h
> index 3d12e67..79f354b 100644
> --- a/drivers/net/ethernet/intel/igb/igb.h
> +++ b/drivers/net/ethernet/intel/igb/igb.h
> @@ -37,6 +37,7 @@
>  #include <linux/clocksource.h>
>  #include <linux/timecompare.h>
>  #include <linux/net_tstamp.h>
> +#include <linux/ptp_clock_kernel.h>
>  #include <linux/bitops.h>
>  #include <linux/if_vlan.h>
> 
> @@ -364,6 +365,13 @@ struct igb_adapter {
>  	u32 wvbr;
>  	int node;
>  	u32 *shadow_vfta;
> +
> +	struct ptp_clock *ptp_clock;
> +	struct ptp_clock_info caps;
> +	struct delayed_work overflow_work;
> +	spinlock_t tmreg_lock;
> +	struct cyclecounter cc;
> +	struct timecounter tc;
>  };
> 
>  #define IGB_FLAG_HAS_MSI           (1 << 0)
> diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c
> b/drivers/net/ethernet/intel/igb/igb_ptp.c
> new file mode 100644
> index 0000000..a8dc3e5
> --- /dev/null
> +++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
> @@ -0,0 +1,329 @@
> +/*
> + * PTP Hardware Clock (PHC) driver for the Intel 82576 and 82580
> + *
> + * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or
> modify
> + * it under the terms of the GNU General Public License as published
> by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that 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, write to the Free Software Foundation,
> Inc.,
> + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> + */
> +#include <linux/device.h>
> +#include <linux/pci.h>
> +
> +#include "igb.h"
> +
> +#define INCVALUE_MASK		0x7fffffff
> +#define ISGN			0x80000000
> +
> +/*
> + * Neither the 82576 nor the 82580 offer registers wide enough to hold
> + * nanoseconds time values for very long. For the 82580, SYSTIM always
> + * counts nanoseconds, but the upper 24 bits are not availible. The
> + * frequency is adjusted by changing the 32 bit fractional nanoseconds
> + * register, TIMINCA.
> + *
> + * For the 82576, the SYSTIM register time unit is affect by the
> + * choice of the 24 bit TININCA:IV (incvalue) field. Five bits of this
> + * field are needed to provide the nominal 16 nanosecond period,
> + * leaving 19 bits for fractional nanoseconds.
> + *
> + *
> + *             SYSTIMH            SYSTIML
> + *        +--------------+   +---+---+------+
> + *  82576 |      32      |   | 8 | 5 |  19  |
> + *        +--------------+   +---+---+------+
> + *         \________ 45 bits _______/  fract
> + *
> + *        +----------+---+   +--------------+
> + *  82580 |    24    | 8 |   |      32      |
> + *        +----------+---+   +--------------+
> + *          reserved  \______ 40 bits _____/
> + *
> + *
> + * The 45 bit 82576 SYSTIM overflows every
> + *   2^45 * 10^-9 / 3600 = 9.77 hours.
> + *
> + * The 40 bit 82580 SYSTIM overflows every
> + *   2^40 * 10^-9 /  60  = 18.3 minutes.
> + */
> +
> +#define IGB_OVERFLOW_PERIOD	(HZ * 60 * 9)
> +#define INCPERIOD_82576		(1 << E1000_TIMINCA_16NS_SHIFT)
> +#define INCVALUE_82576_MASK	((1 << E1000_TIMINCA_16NS_SHIFT) - 1)
> +#define INCVALUE_82576		(16 << IGB_82576_TSYNC_SHIFT)
> +#define IGB_NBITS_82580		40
> +
> +/*
> + * SYSTIM read access for the 82576
> + */
> +
> +static cycle_t igb_82576_systim_read(const struct cyclecounter *cc)
> +{
> +	u64 val;
> +	u32 lo, hi;
> +	struct igb_adapter *igb = container_of(cc, struct igb_adapter,
> cc);
> +	struct e1000_hw *hw = &igb->hw;
> +
> +	lo = rd32(E1000_SYSTIML);
> +	hi = rd32(E1000_SYSTIMH);
> +
> +	val = ((u64) hi) << 32;
> +	val |= lo;
> +
> +	return val;
> +}
> +
> +/*
> + * SYSTIM read access for the 82580
> + */
> +
> +static cycle_t igb_82580_systim_read(const struct cyclecounter *cc)
> +{
> +	u64 val;
> +	u32 lo, hi, jk;
> +	struct igb_adapter *igb = container_of(cc, struct igb_adapter,
> cc);
> +	struct e1000_hw *hw = &igb->hw;
> +
> +	jk = rd32(E1000_SYSTIMR);
> +	lo = rd32(E1000_SYSTIML);
> +	hi = rd32(E1000_SYSTIMH);
> +
> +	val = ((u64) hi) << 32;
> +	val |= lo;
> +
> +	return val;
> +}
> +
> +/*
> + * PTP clock operations
> + */
> +
> +static int ptp_82576_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
> +{
> +	u64 rate;
> +	u32 incvalue;
> +	int neg_adj = 0;
> +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> +	struct e1000_hw *hw = &igb->hw;
> +
> +	if (ppb < 0) {
> +		neg_adj = 1;
> +		ppb = -ppb;
> +	}
> +	rate = ppb;
> +	rate <<= 14;
> +	rate = div_u64(rate, 1953125);
> +
> +	incvalue = 16 << IGB_82576_TSYNC_SHIFT;
> +
> +	if (neg_adj)
> +		incvalue -= rate;
> +	else
> +		incvalue += rate;
> +
> +	wr32(E1000_TIMINCA, INCPERIOD_82576 | (incvalue &
> INCVALUE_82576_MASK));
> +
> +	return 0;
> +}
> +
> +static int ptp_82580_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
> +{
> +	u64 rate;
> +	u32 inca;
> +	int neg_adj = 0;
> +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> +	struct e1000_hw *hw = &igb->hw;
> +
> +	if (ppb < 0) {
> +		neg_adj = 1;
> +		ppb = -ppb;
> +	}
> +	rate = ppb;
> +	rate <<= 26;
> +	rate = div_u64(rate, 1953125);
> +
> +	inca = rate & INCVALUE_MASK;
> +	if (neg_adj)
> +		inca |= ISGN;
> +
> +	wr32(E1000_TIMINCA, inca);
> +
> +	return 0;
> +}
> +
> +static int igb_adjtime(struct ptp_clock_info *ptp, s64 delta)
> +{
> +	s64 now;
> +	unsigned long flags;
> +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> +
> +	spin_lock_irqsave(&igb->tmreg_lock, flags);
> +
> +	now = timecounter_read(&igb->tc);
> +	now += delta;
> +	timecounter_init(&igb->tc, &igb->cc, now);
> +
> +	spin_unlock_irqrestore(&igb->tmreg_lock, flags);
> +
> +	return 0;
> +}
> +
> +static int igb_gettime(struct ptp_clock_info *ptp, struct timespec
> *ts)
> +{
> +	u64 ns;
> +	u32 remainder;
> +	unsigned long flags;
> +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> +
> +	spin_lock_irqsave(&igb->tmreg_lock, flags);
> +
> +	ns = timecounter_read(&igb->tc);
> +
> +	spin_unlock_irqrestore(&igb->tmreg_lock, flags);
> +
> +	ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
> +	ts->tv_nsec = remainder;
> +
> +	return 0;
> +}
> +
> +static int igb_settime(struct ptp_clock_info *ptp, const struct
> timespec *ts)
> +{
> +	u64 ns;
> +	unsigned long flags;
> +	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
> caps);
> +
> +	ns = ts->tv_sec * 1000000000ULL;
> +	ns += ts->tv_nsec;
> +
> +	spin_lock_irqsave(&igb->tmreg_lock, flags);
> +
> +	timecounter_init(&igb->tc, &igb->cc, ns);
> +
> +	spin_unlock_irqrestore(&igb->tmreg_lock, flags);
> +
> +	return 0;
> +}
> +
> +static int ptp_82576_enable(struct ptp_clock_info *ptp,
> +			    struct ptp_clock_request *rq, int on)
> +{
> +	return -EOPNOTSUPP;
> +}
> +
> +static int ptp_82580_enable(struct ptp_clock_info *ptp,
> +			    struct ptp_clock_request *rq, int on)
> +{
> +	return -EOPNOTSUPP;
> +}
> +
> +static void igb_overflow_check(struct work_struct *work)
> +{
> +	struct timespec ts;
> +	struct igb_adapter *igb =
> +		container_of(work, struct igb_adapter, overflow_work.work);
> +
> +	igb_gettime(&igb->caps, &ts);
> +
> +	pr_debug("igb overflow check at %ld.%09lu\n", ts.tv_sec,
> ts.tv_nsec);
> +
> +	schedule_delayed_work(&igb->overflow_work, IGB_OVERFLOW_PERIOD);
> +}
> +
> +void igb_ptp_init(struct igb_adapter *adapter)
> +{
> +	struct e1000_hw *hw = &adapter->hw;
> +
> +	switch (hw->mac.type) {
> +	case e1000_i350:
> +	case e1000_82580:
> +		adapter->caps.owner	= THIS_MODULE;
> +		strcpy(adapter->caps.name, "igb-82580");
> +		adapter->caps.max_adj	= 62499999;
> +		adapter->caps.n_ext_ts	= 0;
> +		adapter->caps.pps	= 0;
> +		adapter->caps.adjfreq	= ptp_82580_adjfreq;
> +		adapter->caps.adjtime	= igb_adjtime;
> +		adapter->caps.gettime	= igb_gettime;
> +		adapter->caps.settime	= igb_settime;
> +		adapter->caps.enable	= ptp_82580_enable;
> +		adapter->cc.read	= igb_82580_systim_read;
> +		adapter->cc.mask	= CLOCKSOURCE_MASK(IGB_NBITS_82580);
> +		adapter->cc.mult	= 1;
> +		adapter->cc.shift	= 0;
> +		/* Enable the timer functions by clearing bit 31. */
> +		wr32(E1000_TSAUXC, 0x0);
> +		break;
> +
> +	case e1000_82576:
> +		adapter->caps.owner	= THIS_MODULE;
> +		strcpy(adapter->caps.name, "igb-82576");
> +		adapter->caps.max_adj	= 1000000000;
> +		adapter->caps.n_ext_ts	= 0;
> +		adapter->caps.pps	= 0;
> +		adapter->caps.adjfreq	= ptp_82576_adjfreq;
> +		adapter->caps.adjtime	= igb_adjtime;
> +		adapter->caps.gettime	= igb_gettime;
> +		adapter->caps.settime	= igb_settime;
> +		adapter->caps.enable	= ptp_82576_enable;
> +		adapter->cc.read	= igb_82576_systim_read;
> +		adapter->cc.mask	= CLOCKSOURCE_MASK(64);
> +		adapter->cc.mult	= 1;
> +		adapter->cc.shift	= IGB_82576_TSYNC_SHIFT;
> +		/* Dial the nominal frequency. */
> +		wr32(E1000_TIMINCA, INCPERIOD_82576 | INCVALUE_82576);
> +		break;
> +
> +	default:
> +		adapter->ptp_clock = NULL;
> +		return;
> +	}
> +
> +	wrfl();
> +
> +	timecounter_init(&adapter->tc, &adapter->cc,
> +			 ktime_to_ns(ktime_get_real()));
> +
> +	INIT_DELAYED_WORK(&adapter->overflow_work, igb_overflow_check);
> +
> +	spin_lock_init(&adapter->tmreg_lock);
> +
> +	schedule_delayed_work(&adapter->overflow_work,
> IGB_OVERFLOW_PERIOD);
> +
> +#ifdef CONFIG_PTP_1588_CLOCK
> +
> +	adapter->ptp_clock = ptp_clock_register(&adapter->caps);
> +	if (IS_ERR(adapter->ptp_clock)) {
> +		adapter->ptp_clock = NULL;
> +		dev_err(&adapter->pdev->dev, "ptp_clock_register
> failed\n");
> +	} else
> +		dev_info(&adapter->pdev->dev, "added PHC on %s\n",
> +			 adapter->netdev->name);
> +
> +#endif /*CONFIG_PTP_1588_CLOCK*/
> +}
> +
> +void igb_ptp_remove(struct igb_adapter *adapter)
> +{
> +	cancel_delayed_work_sync(&adapter->overflow_work);
> +
> +#ifdef CONFIG_PTP_1588_CLOCK
> +
> +	if (adapter->ptp_clock) {
> +		ptp_clock_unregister(adapter->ptp_clock);
> +		dev_info(&adapter->pdev->dev, "removed PHC on %s\n",
> +			 adapter->netdev->name);
> +	}
> +
> +#endif /*CONFIG_PTP_1588_CLOCK*/
> +}
> --
> 1.7.2.5

RE: [PATCH net V4 0/2] igb: ptp hardware clock

[Brown, Aaron F]

> From: Richard Cochran [mailto:richardcochran@gmail.com]
> Sent: Friday, January 27, 2012 4:12 AM
> To: Kirsher, Jeffrey T
> Cc: Eric Dumazet; Brown, Aaron F; netdev@vger.kernel.org; e1000-
> devel@lists.sourceforge.net; Keller, Jacob E; Ronciak, John; John Stultz;
> Thomas Gleixner
> Subject: Re: [PATCH net V4 0/2] igb: ptp hardware clock
> 
> On Fri, Jan 27, 2012 at 02:56:29AM -0800, Jeff Kirsher wrote:
> > Eric was correct.  I added #include <linux/mdoule.h> to the igb_ptp.c
> > file and the error goes away.
> >
> > Richard are you fine with me adding that change to your first patch of
> > the series?  That way I can have the validation team finish up testing
> > your patches.
> 
> By all means, please go right ahead.
> 
> Thanks,
> Richard
> 

Yes, that does indeed resolve the compilation issue I was seeing in the lab, thanks...  I'm assuming a set of .config files that were failing is no longer necessary.

Re: [PATCH net V4 0/2] igb: ptp hardware clock

[Richard Cochran]

On Fri, Jan 27, 2012 at 08:42:20PM +0000, Brown, Aaron F wrote:

> Yes, that does indeed resolve the compilation issue I was seeing in
> the lab, thanks...  I'm assuming a set of .config files that were
> failing is no longer necessary.

Right, don't need them anymore.

Thanks,
Richard