Time Counter fixes and improvements

index f9ec762..2af6aff 100644
@@ -124,7 +124,7 @@
 #include <linux/if_vlan.h>
 #include <linux/bitops.h>
 #include <linux/ptp_clock_kernel.h>
-#include <linux/clocksource.h>
+#include <linux/timecounter.h>
 #include <linux/net_tstamp.h>
 #include <net/dcbnl.h>
 

index c3a6072..792ba72 100644
@@ -22,7 +22,7 @@
 
 #include <linux/ptp_clock_kernel.h>
 #include <linux/net_tstamp.h>
-#include <linux/clocksource.h>
+#include <linux/timecounter.h>
 
 /* compilation time flags */
 

index 469691a..df8bbdd 100644
@@ -16,6 +16,7 @@
 #include <linux/clocksource.h>
 #include <linux/net_tstamp.h>
 #include <linux/ptp_clock_kernel.h>
+#include <linux/timecounter.h>
 
 #if defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x) || \
     defined(CONFIG_M520x) || defined(CONFIG_M532x) || \

index 7785240..9416e5a 100644
@@ -34,7 +34,7 @@
 #include <linux/pci-aspm.h>
 #include <linux/crc32.h>
 #include <linux/if_vlan.h>
-#include <linux/clocksource.h>
+#include <linux/timecounter.h>
 #include <linux/net_tstamp.h>
 #include <linux/ptp_clock_kernel.h>
 #include <linux/ptp_classify.h>

index 82d891e..ee22da3 100644
@@ -29,7 +29,7 @@
 #include "e1000_mac.h"
 #include "e1000_82575.h"
 
-#include <linux/clocksource.h>
+#include <linux/timecounter.h>
 #include <linux/net_tstamp.h>
 #include <linux/ptp_clock_kernel.h>
 #include <linux/bitops.h>

index b6137be..38fc64c 100644
@@ -38,7 +38,7 @@
 #include <linux/if_vlan.h>
 #include <linux/jiffies.h>
 
-#include <linux/clocksource.h>
+#include <linux/timecounter.h>
 #include <linux/net_tstamp.h>
 #include <linux/ptp_clock_kernel.h>
 

index 1a581ef..69a46b9 100644
@@ -27,6 +27,7 @@
 #include <linux/list.h>
 #include <linux/ptp_clock_kernel.h>
 #include <linux/skbuff.h>
+#include <linux/timecounter.h>
 
 struct cpsw_cpts {
 	u32 idver;                /* Identification and version */

index 6d26b40..9916d0e 100644
@@ -16,7 +16,7 @@
 #ifndef __CLKSOURCE_ARM_ARCH_TIMER_H
 #define __CLKSOURCE_ARM_ARCH_TIMER_H
 
-#include <linux/clocksource.h>
+#include <linux/timecounter.h>
 #include <linux/types.h>
 
 #define ARCH_TIMER_CTRL_ENABLE		(1 << 0)

114 lines not on this page · raw message

index 25c791e..f1e41b3 100644
@@ -42,7 +42,7 @@
 
 #include <linux/atomic.h>
 
-#include <linux/clocksource.h>
+#include <linux/timecounter.h>
 
 #define MAX_MSIX_P_PORT		17
 #define MAX_MSIX		64

122 lines not on this page · raw message

index a0bb704..6232382 100644
@@ -213,5 +213,8 @@ struct callback_head {
 };
 #define rcu_head callback_head
 
+/* clocksource cycle base type */
+typedef u64 cycle_t;
+
 #endif /*  __ASSEMBLY__ */
 #endif /* _LINUX_TYPES_H */

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95 lines not on this page · raw message

index aa484fd..3fc7cfe 100644
@@ -15,7 +15,7 @@
 #ifndef __SOUND_HDA_PRIV_H
 #define __SOUND_HDA_PRIV_H
 
-#include <linux/clocksource.h>
+#include <linux/timecounter.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 

index 146f07a..af3dfa4 100644
@@ -79,6 +79,15 @@ static inline u64 cyclecounter_cyc2ns(const struct cyclecounter *cc,
 }
 
 /**
+ * timecounter_adjtime - Shifts the time of the clock.
+ * @delta:	Desired change in nanoseconds.
+ */
+static inline void timecounter_adjtime(struct timecounter *tc, s64 delta)
+{
+	tc->nsec += delta;
+}
+
+/**
  * timecounter_init - initialize a time counter
  * @tc:			Pointer to time counter which is to be initialized/reset
  * @cc:			A cycle counter, ready to be used.

index a1bf9d1c..f5acf4c 100644
@@ -171,15 +171,9 @@ static int xgbe_adjtime(struct ptp_clock_info *info, s64 delta)
 						   struct xgbe_prv_data,
 						   ptp_clock_info);
 	unsigned long flags;
-	u64 nsec;
 
 	spin_lock_irqsave(&pdata->tstamp_lock, flags);
-
-	nsec = timecounter_read(&pdata->tstamp_tc);
-
-	nsec += delta;
-	timecounter_init(&pdata->tstamp_tc, &pdata->tstamp_cc, nsec);
-
+	timecounter_adjtime(&pdata->tstamp_tc, delta);
 	spin_unlock_irqrestore(&pdata->tstamp_lock, flags);
 
 	return 0;

index 691f0bf..7b2cc40 100644
@@ -13265,14 +13265,10 @@ static int bnx2x_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
 static int bnx2x_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 {
 	struct bnx2x *bp = container_of(ptp, struct bnx2x, ptp_clock_info);
-	u64 now;
 
 	DP(BNX2X_MSG_PTP, "PTP adjtime called, delta = %llx\n", delta);
 
-	now = timecounter_read(&bp->timecounter);
-	now += delta;
-	/* Re-init the timecounter */
-	timecounter_init(&bp->timecounter, &bp->cyclecounter, now);
+	timecounter_adjtime(&bp->timecounter, delta);
 
 	return 0;
 }

index 992c8c3..1f9cf23 100644
@@ -374,23 +374,9 @@ static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 	struct fec_enet_private *fep =
 	    container_of(ptp, struct fec_enet_private, ptp_caps);
 	unsigned long flags;
-	u64 now;
-	u32 counter;
 
 	spin_lock_irqsave(&fep->tmreg_lock, flags);
-
-	now = timecounter_read(&fep->tc);
-	now += delta;
-
-	/* Get the timer value based on adjusted timestamp.
-	 * Update the counter with the masked value.
-	 */
-	counter = now & fep->cc.mask;
-	writel(counter, fep->hwp + FEC_ATIME);
-
-	/* reset the timecounter */
-	timecounter_init(&fep->tc, &fep->cc, now);
-
+	timecounter_adjtime(&fep->tc, delta);
 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
 
 	return 0;

index fb1a914..978ef9c 100644
@@ -90,12 +90,9 @@ static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
 						     ptp_clock_info);
 	unsigned long flags;
-	s64 now;
 
 	spin_lock_irqsave(&adapter->systim_lock, flags);
-	now = timecounter_read(&adapter->tc);
-	now += delta;
-	timecounter_init(&adapter->tc, &adapter->cc, now);
+	timecounter_adjtime(&adapter->tc, delta);
 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
 
 	return 0;

index 794c139..1d27f2d 100644
@@ -256,14 +256,9 @@ static int igb_ptp_adjtime_82576(struct ptp_clock_info *ptp, s64 delta)
 	struct igb_adapter *igb = container_of(ptp, struct igb_adapter,
 					       ptp_caps);
 	unsigned long flags;
-	s64 now;
 
 	spin_lock_irqsave(&igb->tmreg_lock, flags);
-
-	now = timecounter_read(&igb->tc);
-	now += delta;
-	timecounter_init(&igb->tc, &igb->cc, now);
-
+	timecounter_adjtime(&igb->tc, delta);
 	spin_unlock_irqrestore(&igb->tmreg_lock, flags);
 
 	return 0;

index 5fd4b52..47c29ea 100644
@@ -261,18 +261,9 @@ static int ixgbe_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 	struct ixgbe_adapter *adapter =
 		container_of(ptp, struct ixgbe_adapter, ptp_caps);
 	unsigned long flags;
-	u64 now;
 
 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
-
-	now = timecounter_read(&adapter->tc);
-	now += delta;
-
-	/* reset the timecounter */
-	timecounter_init(&adapter->tc,
-			 &adapter->cc,
-			 now);
-
+	timecounter_adjtime(&adapter->tc, delta);
 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
 
 	ixgbe_ptp_setup_sdp(adapter);

index 9990144..df35d0e 100644
@@ -147,12 +147,9 @@ static int mlx4_en_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
 	struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
 						ptp_clock_info);
 	unsigned long flags;
-	s64 now;
 
 	write_lock_irqsave(&mdev->clock_lock, flags);
-	now = timecounter_read(&mdev->clock);
-	now += delta;
-	timecounter_init(&mdev->clock, &mdev->cycles, now);
+	timecounter_adjtime(&mdev->clock, delta);
 	write_unlock_irqrestore(&mdev->clock_lock, flags);
 
 	return 0;

index 4a4388b..fbe42cb 100644
@@ -157,14 +157,11 @@ static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
 
 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 {
-	s64 now;
 	unsigned long flags;
 	struct cpts *cpts = container_of(ptp, struct cpts, info);
 
 	spin_lock_irqsave(&cpts->lock, flags);
-	now = timecounter_read(&cpts->tc);
-	now += delta;
-	timecounter_init(&cpts->tc, &cpts->cc, now);
+	timecounter_adjtime(&cpts->tc, delta);
 	spin_unlock_irqrestore(&cpts->lock, flags);
 
 	return 0;

index df35d0e..e9cce4f 100644
@@ -240,7 +240,7 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev)
 {
 	struct mlx4_dev *dev = mdev->dev;
 	unsigned long flags;
-	u64 ns;
+	u64 ns, zero = 0;
 
 	rwlock_init(&mdev->clock_lock);
 

@@ -265,7 +265,7 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev)
 	/* Calculate period in seconds to call the overflow watchdog - to make
 	 * sure counter is checked at least once every wrap around.
 	 */
-	ns = cyclecounter_cyc2ns(&mdev->cycles, mdev->cycles.mask);
+	ns = cyclecounter_cyc2ns(&mdev->cycles, mdev->cycles.mask, zero, &zero);
 	do_div(ns, NSEC_PER_SEC / 2 / HZ);
 	mdev->overflow_period = ns;
 

index af3dfa4..74f4549 100644
@@ -55,27 +55,32 @@ struct cyclecounter {
  * @cycle_last:		most recent cycle counter value seen by
  *			timecounter_read()
  * @nsec:		continuously increasing count
+ * @mask:		bit mask for maintaining the 'frac' field
+ * @frac:		accumulated fractional nanoseconds
  */
 struct timecounter {
 	const struct cyclecounter *cc;
 	cycle_t cycle_last;
 	u64 nsec;
+	u64 mask;
+	u64 frac;
 };
 
 /**
  * cyclecounter_cyc2ns - converts cycle counter cycles to nanoseconds
  * @cc:		Pointer to cycle counter.
  * @cycles:	Cycles
- *
- * XXX - This could use some mult_lxl_ll() asm optimization. Same code
- * as in cyc2ns, but with unsigned result.
+ * @mask:	bit mask for maintaining the 'frac' field
+ * @frac:	pointer to storage for the fractional nanoseconds.
  */
 static inline u64 cyclecounter_cyc2ns(const struct cyclecounter *cc,
-				      cycle_t cycles)
+				      cycle_t cycles, u64 mask, u64 *frac)
 {
-	u64 ret = (u64)cycles;
-	ret = (ret * cc->mult) >> cc->shift;
-	return ret;
+	u64 ns = (u64) cycles;
+
+	ns = (ns * cc->mult) + *frac;
+	*frac = ns & mask;
+	return ns >> cc->shift;
 }
 
 /**

index 59a1ec3..4687b31 100644
@@ -25,6 +25,8 @@ void timecounter_init(struct timecounter *tc,
 	tc->cc = cc;
 	tc->cycle_last = cc->read(cc);
 	tc->nsec = start_tstamp;
+	tc->mask = (1ULL << cc->shift) - 1;
+	tc->frac = 0;
 }
 EXPORT_SYMBOL_GPL(timecounter_init);
 

@@ -51,7 +53,8 @@ static u64 timecounter_read_delta(struct timecounter *tc)
 	cycle_delta = (cycle_now - tc->cycle_last) & tc->cc->mask;
 
 	/* convert to nanoseconds: */
-	ns_offset = cyclecounter_cyc2ns(tc->cc, cycle_delta);
+	ns_offset = cyclecounter_cyc2ns(tc->cc, cycle_delta,
+					tc->mask, &tc->frac);
 
 	/* update time stamp of timecounter_read_delta() call: */
 	tc->cycle_last = cycle_now;

@@ -72,22 +75,36 @@ u64 timecounter_read(struct timecounter *tc)
 }
 EXPORT_SYMBOL_GPL(timecounter_read);
 
+/*
+ * This is like cyclecounter_cyc2ns(), but it is used for computing a
+ * time previous to the time stored in the cycle counter.
+ */
+static u64 cc_cyc2ns_backwards(const struct cyclecounter *cc,
+			       cycle_t cycles, u64 mask, u64 frac)
+{
+	u64 ns = (u64) cycles;
+
+	ns = ((ns * cc->mult) - frac) >> cc->shift;
+
+	return ns;
+}
+
 u64 timecounter_cyc2time(struct timecounter *tc,
 			 cycle_t cycle_tstamp)
 {
-	u64 cycle_delta = (cycle_tstamp - tc->cycle_last) & tc->cc->mask;
-	u64 nsec;
+	u64 delta = (cycle_tstamp - tc->cycle_last) & tc->cc->mask;
+	u64 nsec = tc->nsec, frac = tc->frac;
 
 	/*
 	 * Instead of always treating cycle_tstamp as more recent
 	 * than tc->cycle_last, detect when it is too far in the
 	 * future and treat it as old time stamp instead.
 	 */
-	if (cycle_delta > tc->cc->mask / 2) {
-		cycle_delta = (tc->cycle_last - cycle_tstamp) & tc->cc->mask;
-		nsec = tc->nsec - cyclecounter_cyc2ns(tc->cc, cycle_delta);
+	if (delta > tc->cc->mask / 2) {
+		delta = (tc->cycle_last - cycle_tstamp) & tc->cc->mask;
+		nsec -= cc_cyc2ns_backwards(tc->cc, delta, tc->mask, frac);
 	} else {
-		nsec = cyclecounter_cyc2ns(tc->cc, cycle_delta) + tc->nsec;
+		nsec += cyclecounter_cyc2ns(tc->cc, delta, tc->mask, &frac);
 	}
 
 	return nsec;

index 22fa819..75d9564 100644
@@ -150,7 +150,8 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
 		return;
 	}
 
-	ns = cyclecounter_cyc2ns(timecounter->cc, cval - now);
+	ns = cyclecounter_cyc2ns(timecounter->cc, cval - now, timecounter->mask,
+				 &timecounter->frac);
 	timer_arm(timer, ns);
 }