Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer changes for v3.4 from Ingo Molnar

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  ntp: Fix integer overflow when setting time
  math: Introduce div64_long
  cs5535-clockevt: Allow the MFGPT IRQ to be shared
  cs5535-clockevt: Don't ignore MFGPT on SMP-capable kernels
  x86/time: Eliminate unused irq0_irqs counter
  clocksource: scx200_hrt: Fix the build
  x86/tsc: Reduce the TSC sync check time for core-siblings
  timer: Fix bad idle check on irq entry
  nohz: Remove ts->Einidle checks before restarting the tick
  nohz: Remove update_ts_time_stat from tick_nohz_start_idle
  clockevents: Leave the broadcast device in shutdown mode when not needed
  clocksource: Load the ACPI PM clocksource asynchronously
  clocksource: scx200_hrt: Convert scx200 to use clocksource_register_hz
  clocksource: Get rid of clocksource_calc_mult_shift()
  clocksource: dbx500: convert to clocksource_register_hz()
  clocksource: scx200_hrt:  use pr_<level> instead of printk
  time: Move common updates to a function
  time: Reorder so the hot data is together
  time: Remove most of xtime_lock usage in timekeeping.c
  ntp: Add ntp_lock to replace xtime_locking
  ...

kernel/softirq.c

@@ -297,7 +297,7 @@ void irq_enter(void)
 	int cpu = smp_processor_id();
 
 	rcu_irq_enter();
-	if (idle_cpu(cpu) && !in_interrupt()) {
+	if (is_idle_task(current) && !in_interrupt()) {
 		/*
 		 * Prevent raise_softirq from needlessly waking up ksoftirqd
 		 * here, as softirq will be serviced on return from interrupt.

kernel/time/ntp.c

@@ -22,13 +22,16 @@
  * NTP timekeeping variables:
  */
 
+DEFINE_SPINLOCK(ntp_lock);
+
+
 /* USER_HZ period (usecs): */
 unsigned long			tick_usec = TICK_USEC;
 
 /* ACTHZ period (nsecs): */
 unsigned long			tick_nsec;
 
-u64				tick_length;
+static u64			tick_length;
 static u64			tick_length_base;
 
 static struct hrtimer		leap_timer;
@@ -49,7 +52,7 @@ static struct hrtimer		leap_timer;
 static int			time_state = TIME_OK;
 
 /* clock status bits:							*/
-int				time_status = STA_UNSYNC;
+static int			time_status = STA_UNSYNC;
 
 /* TAI offset (secs):							*/
 static long			time_tai;
@@ -133,7 +136,7 @@ static inline void pps_reset_freq_interval(void)
 /**
  * pps_clear - Clears the PPS state variables
  *
- * Must be called while holding a write on the xtime_lock
+ * Must be called while holding a write on the ntp_lock
  */
 static inline void pps_clear(void)
 {
@@ -149,7 +152,7 @@ static inline void pps_clear(void)
  * the last PPS signal. When it reaches 0, indicate that PPS signal is
  * missing.
  *
- * Must be called while holding a write on the xtime_lock
+ * Must be called while holding a write on the ntp_lock
  */
 static inline void pps_dec_valid(void)
 {
@@ -233,6 +236,17 @@ static inline void pps_fill_timex(struct timex *txc)
 
 #endif /* CONFIG_NTP_PPS */
 
+
+/**
+ * ntp_synced - Returns 1 if the NTP status is not UNSYNC
+ *
+ */
+static inline int ntp_synced(void)
+{
+	return !(time_status & STA_UNSYNC);
+}
+
+
 /*
  * NTP methods:
  */
@@ -275,7 +289,7 @@ static inline s64 ntp_update_offset_fll(s64 offset64, long secs)
 
 	time_status |= STA_MODE;
 
-	return div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
+	return div64_long(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
 }
 
 static void ntp_update_offset(long offset)
@@ -330,11 +344,13 @@ static void ntp_update_offset(long offset)
 
 /**
  * ntp_clear - Clears the NTP state variables
- *
- * Must be called while holding a write on the xtime_lock
  */
 void ntp_clear(void)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(&ntp_lock, flags);
+
 	time_adjust	= 0;		/* stop active adjtime() */
 	time_status	|= STA_UNSYNC;
 	time_maxerror	= NTP_PHASE_LIMIT;
@@ -347,8 +363,23 @@ void ntp_clear(void)
 
 	/* Clear PPS state variables */
 	pps_clear();
+	spin_unlock_irqrestore(&ntp_lock, flags);
+
 }
 
+
+u64 ntp_tick_length(void)
+{
+	unsigned long flags;
+	s64 ret;
+
+	spin_lock_irqsave(&ntp_lock, flags);
+	ret = tick_length;
+	spin_unlock_irqrestore(&ntp_lock, flags);
+	return ret;
+}
+
+
 /*
  * Leap second processing. If in leap-insert state at the end of the
  * day, the system clock is set back one second; if in leap-delete
@@ -357,14 +388,15 @@ void ntp_clear(void)
 static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
 {
 	enum hrtimer_restart res = HRTIMER_NORESTART;
+	unsigned long flags;
+	int leap = 0;
 
-	write_seqlock(&xtime_lock);
-
+	spin_lock_irqsave(&ntp_lock, flags);
 	switch (time_state) {
 	case TIME_OK:
 		break;
 	case TIME_INS:
-		timekeeping_leap_insert(-1);
+		leap = -1;
 		time_state = TIME_OOP;
 		printk(KERN_NOTICE
 			"Clock: inserting leap second 23:59:60 UTC\n");
@@ -372,7 +404,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
 		res = HRTIMER_RESTART;
 		break;
 	case TIME_DEL:
-		timekeeping_leap_insert(1);
+		leap = 1;
 		time_tai--;
 		time_state = TIME_WAIT;
 		printk(KERN_NOTICE
@@ -387,8 +419,14 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
 			time_state = TIME_OK;
 		break;
 	}
+	spin_unlock_irqrestore(&ntp_lock, flags);
 
-	write_sequnlock(&xtime_lock);
+	/*
+	 * We have to call this outside of the ntp_lock to keep
+	 * the proper locking hierarchy
+	 */
+	if (leap)
+		timekeeping_leap_insert(leap);
 
 	return res;
 }
@@ -404,6 +442,9 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
 void second_overflow(void)
 {
 	s64 delta;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ntp_lock, flags);
 
 	/* Bump the maxerror field */
 	time_maxerror += MAXFREQ / NSEC_PER_USEC;
@@ -423,23 +464,25 @@ void second_overflow(void)
 	pps_dec_valid();
 
 	if (!time_adjust)
-		return;
+		goto out;
 
 	if (time_adjust > MAX_TICKADJ) {
 		time_adjust -= MAX_TICKADJ;
 		tick_length += MAX_TICKADJ_SCALED;
-		return;
+		goto out;
 	}
 
 	if (time_adjust < -MAX_TICKADJ) {
 		time_adjust += MAX_TICKADJ;
 		tick_length -= MAX_TICKADJ_SCALED;
-		return;
+		goto out;
 	}
 
 	tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
 							 << NTP_SCALE_SHIFT;
 	time_adjust = 0;
+out:
+	spin_unlock_irqrestore(&ntp_lock, flags);
 }
 
 #ifdef CONFIG_GENERIC_CMOS_UPDATE
@@ -663,7 +706,7 @@ int do_adjtimex(struct timex *txc)
 
 	getnstimeofday(&ts);
 
-	write_seqlock_irq(&xtime_lock);
+	spin_lock_irq(&ntp_lock);
 
 	if (txc->modes & ADJ_ADJTIME) {
 		long save_adjust = time_adjust;
@@ -705,7 +748,7 @@ int do_adjtimex(struct timex *txc)
 	/* fill PPS status fields */
 	pps_fill_timex(txc);
 
-	write_sequnlock_irq(&xtime_lock);
+	spin_unlock_irq(&ntp_lock);
 
 	txc->time.tv_sec = ts.tv_sec;
 	txc->time.tv_usec = ts.tv_nsec;
@@ -903,7 +946,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
 
 	pts_norm = pps_normalize_ts(*phase_ts);
 
-	write_seqlock_irqsave(&xtime_lock, flags);
+	spin_lock_irqsave(&ntp_lock, flags);
 
 	/* clear the error bits, they will be set again if needed */
 	time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
@@ -916,7 +959,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
 	 * just start the frequency interval */
 	if (unlikely(pps_fbase.tv_sec == 0)) {
 		pps_fbase = *raw_ts;
-		write_sequnlock_irqrestore(&xtime_lock, flags);
+		spin_unlock_irqrestore(&ntp_lock, flags);
 		return;
 	}
 
@@ -931,7 +974,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
 		time_status |= STA_PPSJITTER;
 		/* restart the frequency calibration interval */
 		pps_fbase = *raw_ts;
-		write_sequnlock_irqrestore(&xtime_lock, flags);
+		spin_unlock_irqrestore(&ntp_lock, flags);
 		pr_err("hardpps: PPSJITTER: bad pulse\n");
 		return;
 	}
@@ -948,7 +991,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
 
 	hardpps_update_phase(pts_norm.nsec);
 
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+	spin_unlock_irqrestore(&ntp_lock, flags);
 }
 EXPORT_SYMBOL(hardpps);
 

kernel/time/tick-broadcast.c

@@ -575,11 +575,15 @@ void tick_broadcast_switch_to_oneshot(void)
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
+	if (cpumask_empty(tick_get_broadcast_mask()))
+		goto end;
 
 	tick_broadcast_device.mode = TICKDEV_MODE_ONESHOT;
 	bc = tick_broadcast_device.evtdev;
 	if (bc)
 		tick_broadcast_setup_oneshot(bc);
+
+end:
 	raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
 }
 

kernel/time/tick-sched.c

@@ -182,11 +182,7 @@ static void tick_nohz_stop_idle(int cpu, ktime_t now)
 
 static ktime_t tick_nohz_start_idle(int cpu, struct tick_sched *ts)
 {
-	ktime_t now;
-
-	now = ktime_get();
-
-	update_ts_time_stats(cpu, ts, now, NULL);
+	ktime_t now = ktime_get();
 
 	ts->idle_entrytime = now;
 	ts->idle_active = 1;
@@ -562,20 +558,21 @@ void tick_nohz_idle_exit(void)
 
 	local_irq_disable();
 
-	if (ts->idle_active || (ts->inidle && ts->tick_stopped))
+	WARN_ON_ONCE(!ts->inidle);
+
+	ts->inidle = 0;
+
+	if (ts->idle_active || ts->tick_stopped)
 		now = ktime_get();
 
 	if (ts->idle_active)
 		tick_nohz_stop_idle(cpu, now);
 
-	if (!ts->inidle || !ts->tick_stopped) {
-		ts->inidle = 0;
+	if (!ts->tick_stopped) {
 		local_irq_enable();
 		return;
 	}
 
-	ts->inidle = 0;
-
 	/* Update jiffies first */
 	select_nohz_load_balancer(0);
 	tick_do_update_jiffies64(now);

kernel/time/timekeeping.c

@@ -25,6 +25,8 @@
 struct timekeeper {
 	/* Current clocksource used for timekeeping. */
 	struct clocksource *clock;
+	/* NTP adjusted clock multiplier */
+	u32	mult;
 	/* The shift value of the current clocksource. */
 	int	shift;
 
@@ -45,12 +47,47 @@ struct timekeeper {
 	/* Shift conversion between clock shifted nano seconds and
 	 * ntp shifted nano seconds. */
 	int	ntp_error_shift;
-	/* NTP adjusted clock multiplier */
-	u32	mult;
+
+	/* The current time */
+	struct timespec xtime;
+	/*
+	 * wall_to_monotonic is what we need to add to xtime (or xtime corrected
+	 * for sub jiffie times) to get to monotonic time.  Monotonic is pegged
+	 * at zero at system boot time, so wall_to_monotonic will be negative,
+	 * however, we will ALWAYS keep the tv_nsec part positive so we can use
+	 * the usual normalization.
+	 *
+	 * wall_to_monotonic is moved after resume from suspend for the
+	 * monotonic time not to jump. We need to add total_sleep_time to
+	 * wall_to_monotonic to get the real boot based time offset.
+	 *
+	 * - wall_to_monotonic is no longer the boot time, getboottime must be
+	 * used instead.
+	 */
+	struct timespec wall_to_monotonic;
+	/* time spent in suspend */
+	struct timespec total_sleep_time;
+	/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
+	struct timespec raw_time;
+
+	/* Seqlock for all timekeeper values */
+	seqlock_t lock;
 };
 
 static struct timekeeper timekeeper;
 
+/*
+ * This read-write spinlock protects us from races in SMP while
+ * playing with xtime.
+ */
+__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
+
+
+/* flag for if timekeeping is suspended */
+int __read_mostly timekeeping_suspended;
+
+
+
 /**
  * timekeeper_setup_internals - Set up internals to use clocksource clock.
  *
@@ -135,47 +172,28 @@ static inline s64 timekeeping_get_ns_raw(void)
 	return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
 }
 
-/*
- * This read-write spinlock protects us from races in SMP while
- * playing with xtime.
- */
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
+/* must hold write on timekeeper.lock */
+static void timekeeping_update(bool clearntp)
+{
+	if (clearntp) {
+		timekeeper.ntp_error = 0;
+		ntp_clear();
+	}
+	update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic,
+			 timekeeper.clock, timekeeper.mult);
+}
 
 
-/*
- * The current time
- * wall_to_monotonic is what we need to add to xtime (or xtime corrected
- * for sub jiffie times) to get to monotonic time.  Monotonic is pegged
- * at zero at system boot time, so wall_to_monotonic will be negative,
- * however, we will ALWAYS keep the tv_nsec part positive so we can use
- * the usual normalization.
- *
- * wall_to_monotonic is moved after resume from suspend for the monotonic
- * time not to jump. We need to add total_sleep_time to wall_to_monotonic
- * to get the real boot based time offset.
- *
- * - wall_to_monotonic is no longer the boot time, getboottime must be
- * used instead.
- */
-static struct timespec xtime __attribute__ ((aligned (16)));
-static struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
-static struct timespec total_sleep_time;
-
-/*
- * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock.
- */
-static struct timespec raw_time;
-
-/* flag for if timekeeping is suspended */
-int __read_mostly timekeeping_suspended;
-
-/* must hold xtime_lock */
 void timekeeping_leap_insert(int leapsecond)
 {
-	xtime.tv_sec += leapsecond;
-	wall_to_monotonic.tv_sec -= leapsecond;
-	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-			timekeeper.mult);
+	unsigned long flags;
+
+	write_seqlock_irqsave(&timekeeper.lock, flags);
+	timekeeper.xtime.tv_sec += leapsecond;
+	timekeeper.wall_to_monotonic.tv_sec -= leapsecond;
+	timekeeping_update(false);
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+
 }
 
 /**
@@ -202,10 +220,10 @@ static void timekeeping_forward_now(void)
 	/* If arch requires, add in gettimeoffset() */
 	nsec += arch_gettimeoffset();
 
-	timespec_add_ns(&xtime, nsec);
+	timespec_add_ns(&timekeeper.xtime, nsec);
 
 	nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
-	timespec_add_ns(&raw_time, nsec);
+	timespec_add_ns(&timekeeper.raw_time, nsec);
 }
 
 /**
@@ -222,15 +240,15 @@ void getnstimeofday(struct timespec *ts)
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
+		seq = read_seqbegin(&timekeeper.lock);
 
-		*ts = xtime;
+		*ts = timekeeper.xtime;
 		nsecs = timekeeping_get_ns();
 
 		/* If arch requires, add in gettimeoffset() */
 		nsecs += arch_gettimeoffset();
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqretry(&timekeeper.lock, seq));
 
 	timespec_add_ns(ts, nsecs);
 }
@@ -245,14 +263,16 @@ ktime_t ktime_get(void)
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
-		secs = xtime.tv_sec + wall_to_monotonic.tv_sec;
-		nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec;
+		seq = read_seqbegin(&timekeeper.lock);
+		secs = timekeeper.xtime.tv_sec +
+				timekeeper.wall_to_monotonic.tv_sec;
+		nsecs = timekeeper.xtime.tv_nsec +
+				timekeeper.wall_to_monotonic.tv_nsec;
 		nsecs += timekeeping_get_ns();
 		/* If arch requires, add in gettimeoffset() */
 		nsecs += arch_gettimeoffset();
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqretry(&timekeeper.lock, seq));
 	/*
 	 * Use ktime_set/ktime_add_ns to create a proper ktime on
 	 * 32-bit architectures without CONFIG_KTIME_SCALAR.
@@ -278,14 +298,14 @@ void ktime_get_ts(struct timespec *ts)
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
-		*ts = xtime;
-		tomono = wall_to_monotonic;
+		seq = read_seqbegin(&timekeeper.lock);
+		*ts = timekeeper.xtime;
+		tomono = timekeeper.wall_to_monotonic;
 		nsecs = timekeeping_get_ns();
 		/* If arch requires, add in gettimeoffset() */
 		nsecs += arch_gettimeoffset();
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqretry(&timekeeper.lock, seq));
 
 	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
 				ts->tv_nsec + tomono.tv_nsec + nsecs);
@@ -313,10 +333,10 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
 	do {
 		u32 arch_offset;
 
-		seq = read_seqbegin(&xtime_lock);
+		seq = read_seqbegin(&timekeeper.lock);
 
-		*ts_raw = raw_time;
-		*ts_real = xtime;
+		*ts_raw = timekeeper.raw_time;
+		*ts_real = timekeeper.xtime;
 
 		nsecs_raw = timekeeping_get_ns_raw();
 		nsecs_real = timekeeping_get_ns();
@@ -326,7 +346,7 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
 		nsecs_raw += arch_offset;
 		nsecs_real += arch_offset;
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqretry(&timekeeper.lock, seq));
 
 	timespec_add_ns(ts_raw, nsecs_raw);
 	timespec_add_ns(ts_real, nsecs_real);
@@ -365,23 +385,19 @@ int do_settimeofday(const struct timespec *tv)
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
-	write_seqlock_irqsave(&xtime_lock, flags);
+	write_seqlock_irqsave(&timekeeper.lock, flags);
 
 	timekeeping_forward_now();
 
-	ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec;
-	ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec;
-	wall_to_monotonic = timespec_sub(wall_to_monotonic, ts_delta);
+	ts_delta.tv_sec = tv->tv_sec - timekeeper.xtime.tv_sec;
+	ts_delta.tv_nsec = tv->tv_nsec - timekeeper.xtime.tv_nsec;
+	timekeeper.wall_to_monotonic =
+			timespec_sub(timekeeper.wall_to_monotonic, ts_delta);
 
-	xtime = *tv;
+	timekeeper.xtime = *tv;
+	timekeeping_update(true);
 
-	timekeeper.ntp_error = 0;
-	ntp_clear();
-
-	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-				timekeeper.mult);
-
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
 
 	/* signal hrtimers about time change */
 	clock_was_set();
@@ -405,20 +421,17 @@ int timekeeping_inject_offset(struct timespec *ts)
 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
-	write_seqlock_irqsave(&xtime_lock, flags);
+	write_seqlock_irqsave(&timekeeper.lock, flags);
 
 	timekeeping_forward_now();
 
-	xtime = timespec_add(xtime, *ts);
-	wall_to_monotonic = timespec_sub(wall_to_monotonic, *ts);
+	timekeeper.xtime = timespec_add(timekeeper.xtime, *ts);
+	timekeeper.wall_to_monotonic =
+				timespec_sub(timekeeper.wall_to_monotonic, *ts);
 
-	timekeeper.ntp_error = 0;
-	ntp_clear();
+	timekeeping_update(true);
 
-	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-				timekeeper.mult);
-
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
 
 	/* signal hrtimers about time change */
 	clock_was_set();
@@ -490,11 +503,11 @@ void getrawmonotonic(struct timespec *ts)
 	s64 nsecs;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
+		seq = read_seqbegin(&timekeeper.lock);
 		nsecs = timekeeping_get_ns_raw();
-		*ts = raw_time;
+		*ts = timekeeper.raw_time;
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqretry(&timekeeper.lock, seq));
 
 	timespec_add_ns(ts, nsecs);
 }
@@ -510,24 +523,30 @@ int timekeeping_valid_for_hres(void)
 	int ret;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
+		seq = read_seqbegin(&timekeeper.lock);
 
 		ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqretry(&timekeeper.lock, seq));
 
 	return ret;
 }
 
 /**
  * timekeeping_max_deferment - Returns max time the clocksource can be deferred
- *
- * Caller must observe xtime_lock via read_seqbegin/read_seqretry to
- * ensure that the clocksource does not change!
  */
 u64 timekeeping_max_deferment(void)
 {
-	return timekeeper.clock->max_idle_ns;
+	unsigned long seq;
+	u64 ret;
+	do {
+		seq = read_seqbegin(&timekeeper.lock);
+
+		ret = timekeeper.clock->max_idle_ns;
+
+	} while (read_seqretry(&timekeeper.lock, seq));
+
+	return ret;
 }
 
 /**
@@ -572,28 +591,29 @@ void __init timekeeping_init(void)
 	read_persistent_clock(&now);
 	read_boot_clock(&boot);
 
-	write_seqlock_irqsave(&xtime_lock, flags);
+	seqlock_init(&timekeeper.lock);
 
 	ntp_init();
 
+	write_seqlock_irqsave(&timekeeper.lock, flags);
 	clock = clocksource_default_clock();
 	if (clock->enable)
 		clock->enable(clock);
 	timekeeper_setup_internals(clock);
 
-	xtime.tv_sec = now.tv_sec;
-	xtime.tv_nsec = now.tv_nsec;
-	raw_time.tv_sec = 0;
-	raw_time.tv_nsec = 0;
+	timekeeper.xtime.tv_sec = now.tv_sec;
+	timekeeper.xtime.tv_nsec = now.tv_nsec;
+	timekeeper.raw_time.tv_sec = 0;
+	timekeeper.raw_time.tv_nsec = 0;
 	if (boot.tv_sec == 0 && boot.tv_nsec == 0) {
-		boot.tv_sec = xtime.tv_sec;
-		boot.tv_nsec = xtime.tv_nsec;
+		boot.tv_sec = timekeeper.xtime.tv_sec;
+		boot.tv_nsec = timekeeper.xtime.tv_nsec;
 	}
-	set_normalized_timespec(&wall_to_monotonic,
+	set_normalized_timespec(&timekeeper.wall_to_monotonic,
 				-boot.tv_sec, -boot.tv_nsec);
-	total_sleep_time.tv_sec = 0;
-	total_sleep_time.tv_nsec = 0;
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+	timekeeper.total_sleep_time.tv_sec = 0;
+	timekeeper.total_sleep_time.tv_nsec = 0;
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
 }
 
 /* time in seconds when suspend began */
@@ -614,9 +634,11 @@ static void __timekeeping_inject_sleeptime(struct timespec *delta)
 		return;
 	}
 
-	xtime = timespec_add(xtime, *delta);
-	wall_to_monotonic = timespec_sub(wall_to_monotonic, *delta);
-	total_sleep_time = timespec_add(total_sleep_time, *delta);
+	timekeeper.xtime = timespec_add(timekeeper.xtime, *delta);
+	timekeeper.wall_to_monotonic =
+			timespec_sub(timekeeper.wall_to_monotonic, *delta);
+	timekeeper.total_sleep_time = timespec_add(
+					timekeeper.total_sleep_time, *delta);
 }
 
 
@@ -640,17 +662,15 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
 	if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
 		return;
 
-	write_seqlock_irqsave(&xtime_lock, flags);
+	write_seqlock_irqsave(&timekeeper.lock, flags);
+
 	timekeeping_forward_now();
 
 	__timekeeping_inject_sleeptime(delta);
 
-	timekeeper.ntp_error = 0;
-	ntp_clear();
-	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-				timekeeper.mult);
+	timekeeping_update(true);
 
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
 
 	/* signal hrtimers about time change */
 	clock_was_set();
@@ -673,7 +693,7 @@ static void timekeeping_resume(void)
 
 	clocksource_resume();
 
-	write_seqlock_irqsave(&xtime_lock, flags);
+	write_seqlock_irqsave(&timekeeper.lock, flags);
 
 	if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
 		ts = timespec_sub(ts, timekeeping_suspend_time);
@@ -683,7 +703,7 @@ static void timekeeping_resume(void)
 	timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
 	timekeeper.ntp_error = 0;
 	timekeeping_suspended = 0;
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
 
 	touch_softlockup_watchdog();
 
@@ -701,7 +721,7 @@ static int timekeeping_suspend(void)
 
 	read_persistent_clock(&timekeeping_suspend_time);
 
-	write_seqlock_irqsave(&xtime_lock, flags);
+	write_seqlock_irqsave(&timekeeper.lock, flags);
 	timekeeping_forward_now();
 	timekeeping_suspended = 1;
 
@@ -711,7 +731,7 @@ static int timekeeping_suspend(void)
 	 * try to compensate so the difference in system time
 	 * and persistent_clock time stays close to constant.
 	 */
-	delta = timespec_sub(xtime, timekeeping_suspend_time);
+	delta = timespec_sub(timekeeper.xtime, timekeeping_suspend_time);
 	delta_delta = timespec_sub(delta, old_delta);
 	if (abs(delta_delta.tv_sec)  >= 2) {
 		/*
@@ -724,7 +744,7 @@ static int timekeeping_suspend(void)
 		timekeeping_suspend_time =
 			timespec_add(timekeeping_suspend_time, delta_delta);
 	}
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
 
 	clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
 	clocksource_suspend();
@@ -775,7 +795,7 @@ static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
 	 * Now calculate the error in (1 << look_ahead) ticks, but first
 	 * remove the single look ahead already included in the error.
 	 */
-	tick_error = tick_length >> (timekeeper.ntp_error_shift + 1);
+	tick_error = ntp_tick_length() >> (timekeeper.ntp_error_shift + 1);
 	tick_error -= timekeeper.xtime_interval >> 1;
 	error = ((error - tick_error) >> look_ahead) + tick_error;
 
@@ -943,22 +963,22 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
 	timekeeper.xtime_nsec += timekeeper.xtime_interval << shift;
 	while (timekeeper.xtime_nsec >= nsecps) {
 		timekeeper.xtime_nsec -= nsecps;
-		xtime.tv_sec++;
+		timekeeper.xtime.tv_sec++;
 		second_overflow();
 	}
 
 	/* Accumulate raw time */
 	raw_nsecs = timekeeper.raw_interval << shift;
-	raw_nsecs += raw_time.tv_nsec;
+	raw_nsecs += timekeeper.raw_time.tv_nsec;
 	if (raw_nsecs >= NSEC_PER_SEC) {
 		u64 raw_secs = raw_nsecs;
 		raw_nsecs = do_div(raw_secs, NSEC_PER_SEC);
-		raw_time.tv_sec += raw_secs;
+		timekeeper.raw_time.tv_sec += raw_secs;
 	}
-	raw_time.tv_nsec = raw_nsecs;
+	timekeeper.raw_time.tv_nsec = raw_nsecs;
 
 	/* Accumulate error between NTP and clock interval */
-	timekeeper.ntp_error += tick_length << shift;
+	timekeeper.ntp_error += ntp_tick_length() << shift;
 	timekeeper.ntp_error -=
 	    (timekeeper.xtime_interval + timekeeper.xtime_remainder) <<
 				(timekeeper.ntp_error_shift + shift);
@@ -970,17 +990,19 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
 /**
  * update_wall_time - Uses the current clocksource to increment the wall time
  *
- * Called from the timer interrupt, must hold a write on xtime_lock.
  */
 static void update_wall_time(void)
 {
 	struct clocksource *clock;
 	cycle_t offset;
 	int shift = 0, maxshift;
+	unsigned long flags;
+
+	write_seqlock_irqsave(&timekeeper.lock, flags);
 
 	/* Make sure we're fully resumed: */
 	if (unlikely(timekeeping_suspended))
-		return;
+		goto out;
 
 	clock = timekeeper.clock;
 
@@ -989,7 +1011,8 @@ static void update_wall_time(void)
 #else
 	offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
 #endif
-	timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift;
+	timekeeper.xtime_nsec = (s64)timekeeper.xtime.tv_nsec <<
+						timekeeper.shift;
 
 	/*
 	 * With NO_HZ we may have to accumulate many cycle_intervals
@@ -1002,7 +1025,7 @@ static void update_wall_time(void)
 	shift = ilog2(offset) - ilog2(timekeeper.cycle_interval);
 	shift = max(0, shift);
 	/* Bound shift to one less then what overflows tick_length */
-	maxshift = (8*sizeof(tick_length) - (ilog2(tick_length)+1)) - 1;
+	maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
 	shift = min(shift, maxshift);
 	while (offset >= timekeeper.cycle_interval) {
 		offset = logarithmic_accumulation(offset, shift);
@@ -1040,8 +1063,10 @@ static void update_wall_time(void)
 	 * Store full nanoseconds into xtime after rounding it up and
 	 * add the remainder to the error difference.
 	 */
-	xtime.tv_nsec =	((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1;
-	timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift;
+	timekeeper.xtime.tv_nsec = ((s64)timekeeper.xtime_nsec >>
+						timekeeper.shift) + 1;
+	timekeeper.xtime_nsec -= (s64)timekeeper.xtime.tv_nsec <<
+						timekeeper.shift;
 	timekeeper.ntp_error +=	timekeeper.xtime_nsec <<
 				timekeeper.ntp_error_shift;
 
@@ -1049,15 +1074,17 @@ static void update_wall_time(void)
 	 * Finally, make sure that after the rounding
 	 * xtime.tv_nsec isn't larger then NSEC_PER_SEC
 	 */
-	if (unlikely(xtime.tv_nsec >= NSEC_PER_SEC)) {
-		xtime.tv_nsec -= NSEC_PER_SEC;
-		xtime.tv_sec++;
+	if (unlikely(timekeeper.xtime.tv_nsec >= NSEC_PER_SEC)) {
+		timekeeper.xtime.tv_nsec -= NSEC_PER_SEC;
+		timekeeper.xtime.tv_sec++;
 		second_overflow();
 	}
 
-	/* check to see if there is a new clocksource to use */
-	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-				timekeeper.mult);
+	timekeeping_update(false);
+
+out:
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+
 }
 
 /**
@@ -1074,8 +1101,10 @@ static void update_wall_time(void)
 void getboottime(struct timespec *ts)
 {
 	struct timespec boottime = {
-		.tv_sec = wall_to_monotonic.tv_sec + total_sleep_time.tv_sec,
-		.tv_nsec = wall_to_monotonic.tv_nsec + total_sleep_time.tv_nsec
+		.tv_sec = timekeeper.wall_to_monotonic.tv_sec +
+				timekeeper.total_sleep_time.tv_sec,
+		.tv_nsec = timekeeper.wall_to_monotonic.tv_nsec +
+				timekeeper.total_sleep_time.tv_nsec
 	};
 
 	set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
@@ -1101,13 +1130,13 @@ void get_monotonic_boottime(struct timespec *ts)
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
-		*ts = xtime;
-		tomono = wall_to_monotonic;
-		sleep = total_sleep_time;
+		seq = read_seqbegin(&timekeeper.lock);
+		*ts = timekeeper.xtime;
+		tomono = timekeeper.wall_to_monotonic;
+		sleep = timekeeper.total_sleep_time;
 		nsecs = timekeeping_get_ns();
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqretry(&timekeeper.lock, seq));
 
 	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
 			ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec + nsecs);
@@ -1137,19 +1166,19 @@ EXPORT_SYMBOL_GPL(ktime_get_boottime);
  */
 void monotonic_to_bootbased(struct timespec *ts)
 {
-	*ts = timespec_add(*ts, total_sleep_time);
+	*ts = timespec_add(*ts, timekeeper.total_sleep_time);
 }
 EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
 
 unsigned long get_seconds(void)
 {
-	return xtime.tv_sec;
+	return timekeeper.xtime.tv_sec;
 }
 EXPORT_SYMBOL(get_seconds);
 
 struct timespec __current_kernel_time(void)
 {
-	return xtime;
+	return timekeeper.xtime;
 }
 
 struct timespec current_kernel_time(void)
@@ -1158,10 +1187,10 @@ struct timespec current_kernel_time(void)
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
+		seq = read_seqbegin(&timekeeper.lock);
 
-		now = xtime;
-	} while (read_seqretry(&xtime_lock, seq));
+		now = timekeeper.xtime;
+	} while (read_seqretry(&timekeeper.lock, seq));
 
 	return now;
 }
@@ -1173,11 +1202,11 @@ struct timespec get_monotonic_coarse(void)
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
+		seq = read_seqbegin(&timekeeper.lock);
 
-		now = xtime;
-		mono = wall_to_monotonic;
-	} while (read_seqretry(&xtime_lock, seq));
+		now = timekeeper.xtime;
+		mono = timekeeper.wall_to_monotonic;
+	} while (read_seqretry(&timekeeper.lock, seq));
 
 	set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
 				now.tv_nsec + mono.tv_nsec);
@@ -1209,11 +1238,11 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
-		*xtim = xtime;
-		*wtom = wall_to_monotonic;
-		*sleep = total_sleep_time;
-	} while (read_seqretry(&xtime_lock, seq));
+		seq = read_seqbegin(&timekeeper.lock);
+		*xtim = timekeeper.xtime;
+		*wtom = timekeeper.wall_to_monotonic;
+		*sleep = timekeeper.total_sleep_time;
+	} while (read_seqretry(&timekeeper.lock, seq));
 }
 
 /**
@@ -1225,9 +1254,10 @@ ktime_t ktime_get_monotonic_offset(void)
 	struct timespec wtom;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
-		wtom = wall_to_monotonic;
-	} while (read_seqretry(&xtime_lock, seq));
+		seq = read_seqbegin(&timekeeper.lock);
+		wtom = timekeeper.wall_to_monotonic;
+	} while (read_seqretry(&timekeeper.lock, seq));
+
 	return timespec_to_ktime(wtom);
 }