1 files changed, 1161 insertions, 317 deletions

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 49010d822f7..32d8d6aaedb 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -8,50 +8,92 @@
  *
  */
 
+#include <linux/timekeeper_internal.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/percpu.h>
 #include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/sched.h>
-#include <linux/sysdev.h>
+#include <linux/syscore_ops.h>
 #include <linux/clocksource.h>
 #include <linux/jiffies.h>
 #include <linux/time.h>
 #include <linux/tick.h>
 #include <linux/stop_machine.h>
+#include <linux/pvclock_gtod.h>
+#include <linux/compiler.h>
 
-/* Structure holding internal timekeeping values. */
-struct timekeeper {
-	/* Current clocksource used for timekeeping. */
-	struct clocksource *clock;
-	/* The shift value of the current clocksource. */
-	int	shift;
-
-	/* Number of clock cycles in one NTP interval. */
-	cycle_t cycle_interval;
-	/* Number of clock shifted nano seconds in one NTP interval. */
-	u64	xtime_interval;
-	/* Raw nano seconds accumulated per NTP interval. */
-	u32	raw_interval;
-
-	/* Clock shifted nano seconds remainder not stored in xtime.tv_nsec. */
-	u64	xtime_nsec;
-	/* Difference between accumulated time and NTP time in ntp
-	 * shifted nano seconds. */
-	s64	ntp_error;
-	/* Shift conversion between clock shifted nano seconds and
-	 * ntp shifted nano seconds. */
-	int	ntp_error_shift;
-	/* NTP adjusted clock multiplier */
-	u32	mult;
-};
+#include "tick-internal.h"
+#include "ntp_internal.h"
+#include "timekeeping_internal.h"
+
+#define TK_CLEAR_NTP		(1 << 0)
+#define TK_MIRROR		(1 << 1)
+#define TK_CLOCK_WAS_SET	(1 << 2)
+
+static struct timekeeper timekeeper;
+static DEFINE_RAW_SPINLOCK(timekeeper_lock);
+static seqcount_t timekeeper_seq;
+static struct timekeeper shadow_timekeeper;
+
+/* flag for if timekeeping is suspended */
+int __read_mostly timekeeping_suspended;
 
-struct timekeeper timekeeper;
+/* Flag for if there is a persistent clock on this platform */
+bool __read_mostly persistent_clock_exist = false;
+
+static inline void tk_normalize_xtime(struct timekeeper *tk)
+{
+	while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) {
+		tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift;
+		tk->xtime_sec++;
+	}
+}
+
+static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts)
+{
+	tk->xtime_sec = ts->tv_sec;
+	tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift;
+}
+
+static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts)
+{
+	tk->xtime_sec += ts->tv_sec;
+	tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift;
+	tk_normalize_xtime(tk);
+}
+
+static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm)
+{
+	struct timespec tmp;
+
+	/*
+	 * Verify consistency of: offset_real = -wall_to_monotonic
+	 * before modifying anything
+	 */
+	set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec,
+					-tk->wall_to_monotonic.tv_nsec);
+	WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64);
+	tk->wall_to_monotonic = wtm;
+	set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
+	tk->offs_real = timespec_to_ktime(tmp);
+	tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0));
+}
+
+static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
+{
+	/* Verify consistency before modifying */
+	WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64);
+
+	tk->total_sleep_time	= t;
+	tk->offs_boot		= timespec_to_ktime(t);
+}
 
 /**
- * timekeeper_setup_internals - Set up internals to use clocksource clock.
+ * tk_setup_internals - Set up internals to use clocksource clock.
  *
+ * @tk:		The target timekeeper to setup.
  * @clock:		Pointer to clocksource.
  *
  * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
@@ -59,119 +101,164 @@ struct timekeeper timekeeper;
  *
  * Unless you're the timekeeping code, you should not be using this!
  */
-static void timekeeper_setup_internals(struct clocksource *clock)
+static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
 {
 	cycle_t interval;
-	u64 tmp;
+	u64 tmp, ntpinterval;
+	struct clocksource *old_clock;
 
-	timekeeper.clock = clock;
-	clock->cycle_last = clock->read(clock);
+	old_clock = tk->clock;
+	tk->clock = clock;
+	tk->cycle_last = clock->cycle_last = clock->read(clock);
 
 	/* Do the ns -> cycle conversion first, using original mult */
 	tmp = NTP_INTERVAL_LENGTH;
 	tmp <<= clock->shift;
+	ntpinterval = tmp;
 	tmp += clock->mult/2;
 	do_div(tmp, clock->mult);
 	if (tmp == 0)
 		tmp = 1;
 
 	interval = (cycle_t) tmp;
-	timekeeper.cycle_interval = interval;
+	tk->cycle_interval = interval;
 
 	/* Go back from cycles -> shifted ns */
-	timekeeper.xtime_interval = (u64) interval * clock->mult;
-	timekeeper.raw_interval =
+	tk->xtime_interval = (u64) interval * clock->mult;
+	tk->xtime_remainder = ntpinterval - tk->xtime_interval;
+	tk->raw_interval =
 		((u64) interval * clock->mult) >> clock->shift;
 
-	timekeeper.xtime_nsec = 0;
-	timekeeper.shift = clock->shift;
+	 /* if changing clocks, convert xtime_nsec shift units */
+	if (old_clock) {
+		int shift_change = clock->shift - old_clock->shift;
+		if (shift_change < 0)
+			tk->xtime_nsec >>= -shift_change;
+		else
+			tk->xtime_nsec <<= shift_change;
+	}
+	tk->shift = clock->shift;
 
-	timekeeper.ntp_error = 0;
-	timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
+	tk->ntp_error = 0;
+	tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
 
 	/*
 	 * The timekeeper keeps its own mult values for the currently
 	 * active clocksource. These value will be adjusted via NTP
 	 * to counteract clock drifting.
 	 */
-	timekeeper.mult = clock->mult;
+	tk->mult = clock->mult;
 }
 
 /* Timekeeper helper functions. */
-static inline s64 timekeeping_get_ns(void)
+
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
+u32 (*arch_gettimeoffset)(void);
+
+u32 get_arch_timeoffset(void)
+{
+	if (likely(arch_gettimeoffset))
+		return arch_gettimeoffset();
+	return 0;
+}
+#else
+static inline u32 get_arch_timeoffset(void) { return 0; }
+#endif
+
+static inline s64 timekeeping_get_ns(struct timekeeper *tk)
 {
 	cycle_t cycle_now, cycle_delta;
 	struct clocksource *clock;
+	s64 nsec;
 
 	/* read clocksource: */
-	clock = timekeeper.clock;
+	clock = tk->clock;
 	cycle_now = clock->read(clock);
 
 	/* calculate the delta since the last update_wall_time: */
 	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
 
-	/* return delta convert to nanoseconds using ntp adjusted mult. */
-	return clocksource_cyc2ns(cycle_delta, timekeeper.mult,
-				  timekeeper.shift);
+	nsec = cycle_delta * tk->mult + tk->xtime_nsec;
+	nsec >>= tk->shift;
+
+	/* If arch requires, add in get_arch_timeoffset() */
+	return nsec + get_arch_timeoffset();
 }
 
-static inline s64 timekeeping_get_ns_raw(void)
+static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
 {
 	cycle_t cycle_now, cycle_delta;
 	struct clocksource *clock;
+	s64 nsec;
 
 	/* read clocksource: */
-	clock = timekeeper.clock;
+	clock = tk->clock;
 	cycle_now = clock->read(clock);
 
 	/* calculate the delta since the last update_wall_time: */
 	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
 
-	/* return delta convert to nanoseconds using ntp adjusted mult. */
-	return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
+	/* convert delta to nanoseconds. */
+	nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
+
+	/* If arch requires, add in get_arch_timeoffset() */
+	return nsec + get_arch_timeoffset();
 }
 
-/*
- * This read-write spinlock protects us from races in SMP while
- * playing with xtime.
- */
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
+static RAW_NOTIFIER_HEAD(pvclock_gtod_chain);
 
+static void update_pvclock_gtod(struct timekeeper *tk, bool was_set)
+{
+	raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk);
+}
 
-/*
- * 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.
+/**
+ * pvclock_gtod_register_notifier - register a pvclock timedata update listener
  */
-static struct timespec xtime __attribute__ ((aligned (16)));
-static struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
-static struct timespec total_sleep_time;
+int pvclock_gtod_register_notifier(struct notifier_block *nb)
+{
+	struct timekeeper *tk = &timekeeper;
+	unsigned long flags;
+	int ret;
 
-/*
- * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock.
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb);
+	update_pvclock_gtod(tk, true);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier);
+
+/**
+ * pvclock_gtod_unregister_notifier - unregister a pvclock
+ * timedata update listener
  */
-struct timespec raw_time;
+int pvclock_gtod_unregister_notifier(struct notifier_block *nb)
+{
+	unsigned long flags;
+	int ret;
 
-/* flag for if timekeeping is suspended */
-int __read_mostly timekeeping_suspended;
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier);
 
-/* must hold xtime_lock */
-void timekeeping_leap_insert(int leapsecond)
+/* must hold timekeeper_lock */
+static void timekeeping_update(struct timekeeper *tk, unsigned int action)
 {
-	xtime.tv_sec += leapsecond;
-	wall_to_monotonic.tv_sec -= leapsecond;
-	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-			timekeeper.mult);
+	if (action & TK_CLEAR_NTP) {
+		tk->ntp_error = 0;
+		ntp_clear();
+	}
+	update_vsyscall(tk);
+	update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET);
+
+	if (action & TK_MIRROR)
+		memcpy(&shadow_timekeeper, &timekeeper, sizeof(timekeeper));
 }
 
 /**
@@ -181,72 +268,88 @@ void timekeeping_leap_insert(int leapsecond)
  * update_wall_time(). This is useful before significant clock changes,
  * as it avoids having to deal with this time offset explicitly.
  */
-static void timekeeping_forward_now(void)
+static void timekeeping_forward_now(struct timekeeper *tk)
 {
 	cycle_t cycle_now, cycle_delta;
 	struct clocksource *clock;
 	s64 nsec;
 
-	clock = timekeeper.clock;
+	clock = tk->clock;
 	cycle_now = clock->read(clock);
 	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
-	clock->cycle_last = cycle_now;
+	tk->cycle_last = clock->cycle_last = cycle_now;
 
-	nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult,
-				  timekeeper.shift);
+	tk->xtime_nsec += cycle_delta * tk->mult;
 
-	/* If arch requires, add in gettimeoffset() */
-	nsec += arch_gettimeoffset();
+	/* If arch requires, add in get_arch_timeoffset() */
+	tk->xtime_nsec += (u64)get_arch_timeoffset() << tk->shift;
 
-	timespec_add_ns(&xtime, nsec);
+	tk_normalize_xtime(tk);
 
 	nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
-	timespec_add_ns(&raw_time, nsec);
+	timespec_add_ns(&tk->raw_time, nsec);
 }
 
 /**
- * getnstimeofday - Returns the time of day in a timespec
+ * __getnstimeofday - Returns the time of day in a timespec.
  * @ts:		pointer to the timespec to be set
  *
- * Returns the time of day in a timespec.
+ * Updates the time of day in the timespec.
+ * Returns 0 on success, or -ve when suspended (timespec will be undefined).
  */
-void getnstimeofday(struct timespec *ts)
+int __getnstimeofday(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
-	s64 nsecs;
-
-	WARN_ON(timekeeping_suspended);
+	s64 nsecs = 0;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
+		seq = read_seqcount_begin(&timekeeper_seq);
 
-		*ts = xtime;
-		nsecs = timekeeping_get_ns();
+		ts->tv_sec = tk->xtime_sec;
+		nsecs = timekeeping_get_ns(tk);
 
-		/* If arch requires, add in gettimeoffset() */
-		nsecs += arch_gettimeoffset();
-
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
 
+	ts->tv_nsec = 0;
 	timespec_add_ns(ts, nsecs);
+
+	/*
+	 * Do not bail out early, in case there were callers still using
+	 * the value, even in the face of the WARN_ON.
+	 */
+	if (unlikely(timekeeping_suspended))
+		return -EAGAIN;
+	return 0;
 }
+EXPORT_SYMBOL(__getnstimeofday);
 
+/**
+ * getnstimeofday - Returns the time of day in a timespec.
+ * @ts:		pointer to the timespec to be set
+ *
+ * Returns the time of day in a timespec (WARN if suspended).
+ */
+void getnstimeofday(struct timespec *ts)
+{
+	WARN_ON(__getnstimeofday(ts));
+}
 EXPORT_SYMBOL(getnstimeofday);
 
 ktime_t ktime_get(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned int seq;
 	s64 secs, nsecs;
 
 	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;
-		nsecs += timekeeping_get_ns();
+		seq = read_seqcount_begin(&timekeeper_seq);
+		secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
+		nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec;
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
 	/*
 	 * Use ktime_set/ktime_add_ns to create a proper ktime on
 	 * 32-bit architectures without CONFIG_KTIME_SCALAR.
@@ -265,25 +368,109 @@ EXPORT_SYMBOL_GPL(ktime_get);
  */
 void ktime_get_ts(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec tomono;
+	s64 nsec;
 	unsigned int seq;
-	s64 nsecs;
 
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
-		*ts = xtime;
-		tomono = wall_to_monotonic;
-		nsecs = timekeeping_get_ns();
+		seq = read_seqcount_begin(&timekeeper_seq);
+		ts->tv_sec = tk->xtime_sec;
+		nsec = timekeeping_get_ns(tk);
+		tomono = tk->wall_to_monotonic;
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
 
-	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
-				ts->tv_nsec + tomono.tv_nsec + nsecs);
+	ts->tv_sec += tomono.tv_sec;
+	ts->tv_nsec = 0;
+	timespec_add_ns(ts, nsec + tomono.tv_nsec);
 }
 EXPORT_SYMBOL_GPL(ktime_get_ts);
 
+
+/**
+ * timekeeping_clocktai - Returns the TAI time of day in a timespec
+ * @ts:		pointer to the timespec to be set
+ *
+ * Returns the time of day in a timespec.
+ */
+void timekeeping_clocktai(struct timespec *ts)
+{
+	struct timekeeper *tk = &timekeeper;
+	unsigned long seq;
+	u64 nsecs;
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		seq = read_seqcount_begin(&timekeeper_seq);
+
+		ts->tv_sec = tk->xtime_sec + tk->tai_offset;
+		nsecs = timekeeping_get_ns(tk);
+
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
+
+	ts->tv_nsec = 0;
+	timespec_add_ns(ts, nsecs);
+
+}
+EXPORT_SYMBOL(timekeeping_clocktai);
+
+
+/**
+ * ktime_get_clocktai - Returns the TAI time of day in a ktime
+ *
+ * Returns the time of day in a ktime.
+ */
+ktime_t ktime_get_clocktai(void)
+{
+	struct timespec ts;
+
+	timekeeping_clocktai(&ts);
+	return timespec_to_ktime(ts);
+}
+EXPORT_SYMBOL(ktime_get_clocktai);
+
+#ifdef CONFIG_NTP_PPS
+
+/**
+ * getnstime_raw_and_real - get day and raw monotonic time in timespec format
+ * @ts_raw:	pointer to the timespec to be set to raw monotonic time
+ * @ts_real:	pointer to the timespec to be set to the time of day
+ *
+ * This function reads both the time of day and raw monotonic time at the
+ * same time atomically and stores the resulting timestamps in timespec
+ * format.
+ */
+void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
+{
+	struct timekeeper *tk = &timekeeper;
+	unsigned long seq;
+	s64 nsecs_raw, nsecs_real;
+
+	WARN_ON_ONCE(timekeeping_suspended);
+
+	do {
+		seq = read_seqcount_begin(&timekeeper_seq);
+
+		*ts_raw = tk->raw_time;
+		ts_real->tv_sec = tk->xtime_sec;
+		ts_real->tv_nsec = 0;
+
+		nsecs_raw = timekeeping_get_ns_raw(tk);
+		nsecs_real = timekeeping_get_ns(tk);
+
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
+
+	timespec_add_ns(ts_raw, nsecs_raw);
+	timespec_add_ns(ts_real, nsecs_real);
+}
+EXPORT_SYMBOL(getnstime_raw_and_real);
+
+#endif /* CONFIG_NTP_PPS */
+
 /**
  * do_gettimeofday - Returns the time of day in a timeval
  * @tv:		pointer to the timeval to be set
@@ -298,66 +485,176 @@ void do_gettimeofday(struct timeval *tv)
 	tv->tv_sec = now.tv_sec;
 	tv->tv_usec = now.tv_nsec/1000;
 }
-
 EXPORT_SYMBOL(do_gettimeofday);
+
 /**
  * do_settimeofday - Sets the time of day
  * @tv:		pointer to the timespec variable containing the new time
  *
  * Sets the time of day to the new time and update NTP and notify hrtimers
  */
-int do_settimeofday(struct timespec *tv)
+int do_settimeofday(const struct timespec *tv)
 {
-	struct timespec ts_delta;
+	struct timekeeper *tk = &timekeeper;
+	struct timespec ts_delta, xt;
 	unsigned long flags;
 
-	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+	if (!timespec_valid_strict(tv))
 		return -EINVAL;
 
-	write_seqlock_irqsave(&xtime_lock, flags);
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	write_seqcount_begin(&timekeeper_seq);
 
-	timekeeping_forward_now();
+	timekeeping_forward_now(tk);
 
-	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);
+	xt = tk_xtime(tk);
+	ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
+	ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
 
-	xtime = *tv;
+	tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta));
 
-	timekeeper.ntp_error = 0;
-	ntp_clear();
+	tk_set_xtime(tk, tv);
 
-	update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
-				timekeeper.mult);
+	timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
 
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+	write_seqcount_end(&timekeeper_seq);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
 	/* signal hrtimers about time change */
 	clock_was_set();
 
 	return 0;
 }
-
 EXPORT_SYMBOL(do_settimeofday);
 
 /**
+ * timekeeping_inject_offset - Adds or subtracts from the current time.
+ * @tv:		pointer to the timespec variable containing the offset
+ *
+ * Adds or subtracts an offset value from the current time.
+ */
+int timekeeping_inject_offset(struct timespec *ts)
+{
+	struct timekeeper *tk = &timekeeper;
+	unsigned long flags;
+	struct timespec tmp;
+	int ret = 0;
+
+	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
+		return -EINVAL;
+
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	write_seqcount_begin(&timekeeper_seq);
+
+	timekeeping_forward_now(tk);
+
+	/* Make sure the proposed value is valid */
+	tmp = timespec_add(tk_xtime(tk),  *ts);
+	if (!timespec_valid_strict(&tmp)) {
+		ret = -EINVAL;
+		goto error;
+	}
+
+	tk_xtime_add(tk, ts);
+	tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts));
+
+error: /* even if we error out, we forwarded the time, so call update */
+	timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
+
+	write_seqcount_end(&timekeeper_seq);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+
+	/* signal hrtimers about time change */
+	clock_was_set();
+
+	return ret;
+}
+EXPORT_SYMBOL(timekeeping_inject_offset);
+
+
+/**
+ * timekeeping_get_tai_offset - Returns current TAI offset from UTC
+ *
+ */
+s32 timekeeping_get_tai_offset(void)
+{
+	struct timekeeper *tk = &timekeeper;
+	unsigned int seq;
+	s32 ret;
+
+	do {
+		seq = read_seqcount_begin(&timekeeper_seq);
+		ret = tk->tai_offset;
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
+
+	return ret;
+}
+
+/**
+ * __timekeeping_set_tai_offset - Lock free worker function
+ *
+ */
+static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
+{
+	tk->tai_offset = tai_offset;
+	tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0));
+}
+
+/**
+ * timekeeping_set_tai_offset - Sets the current TAI offset from UTC
+ *
+ */
+void timekeeping_set_tai_offset(s32 tai_offset)
+{
+	struct timekeeper *tk = &timekeeper;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	write_seqcount_begin(&timekeeper_seq);
+	__timekeeping_set_tai_offset(tk, tai_offset);
+	timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
+	write_seqcount_end(&timekeeper_seq);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+	clock_was_set();
+}
+
+/**
  * change_clocksource - Swaps clocksources if a new one is available
  *
  * Accumulates current time interval and initializes new clocksource
  */
 static int change_clocksource(void *data)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct clocksource *new, *old;
+	unsigned long flags;
 
 	new = (struct clocksource *) data;
 
-	timekeeping_forward_now();
-	if (!new->enable || new->enable(new) == 0) {
-		old = timekeeper.clock;
-		timekeeper_setup_internals(new);
-		if (old->disable)
-			old->disable(old);
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	write_seqcount_begin(&timekeeper_seq);
+
+	timekeeping_forward_now(tk);
+	/*
+	 * If the cs is in module, get a module reference. Succeeds
+	 * for built-in code (owner == NULL) as well.
+	 */
+	if (try_module_get(new->owner)) {
+		if (!new->enable || new->enable(new) == 0) {
+			old = tk->clock;
+			tk_setup_internals(tk, new);
+			if (old->disable)
+				old->disable(old);
+			module_put(old->owner);
+		} else {
+			module_put(new->owner);
+		}
 	}
+	timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
+
+	write_seqcount_end(&timekeeper_seq);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+
 	return 0;
 }
 
@@ -368,12 +665,15 @@ static int change_clocksource(void *data)
  * This function is called from clocksource.c after a new, better clock
  * source has been registered. The caller holds the clocksource_mutex.
  */
-void timekeeping_notify(struct clocksource *clock)
+int timekeeping_notify(struct clocksource *clock)
 {
-	if (timekeeper.clock == clock)
-		return;
+	struct timekeeper *tk = &timekeeper;
+
+	if (tk->clock == clock)
+		return 0;
 	stop_machine(change_clocksource, clock, NULL);
 	tick_clock_notify();
+	return tk->clock == clock ? 0 : -1;
 }
 
 /**
@@ -399,48 +699,57 @@ EXPORT_SYMBOL_GPL(ktime_get_real);
  */
 void getrawmonotonic(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	s64 nsecs;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
-		nsecs = timekeeping_get_ns_raw();
-		*ts = raw_time;
+		seq = read_seqcount_begin(&timekeeper_seq);
+		nsecs = timekeeping_get_ns_raw(tk);
+		*ts = tk->raw_time;
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
 
 	timespec_add_ns(ts, nsecs);
 }
 EXPORT_SYMBOL(getrawmonotonic);
 
-
 /**
  * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
  */
 int timekeeping_valid_for_hres(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	int ret;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
+		seq = read_seqcount_begin(&timekeeper_seq);
 
-		ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
+		ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
 
-	} while (read_seqretry(&xtime_lock, seq));
+	} while (read_seqcount_retry(&timekeeper_seq, 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;
+	struct timekeeper *tk = &timekeeper;
+	unsigned long seq;
+	u64 ret;
+
+	do {
+		seq = read_seqcount_begin(&timekeeper_seq);
+
+		ret = tk->clock->max_idle_ns;
+
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
+
+	return ret;
 }
 
 /**
@@ -452,7 +761,7 @@ u64 timekeeping_max_deferment(void)
  *
  *  XXX - Do be sure to remove it once all arches implement it.
  */
-void __attribute__((weak)) read_persistent_clock(struct timespec *ts)
+void __weak read_persistent_clock(struct timespec *ts)
 {
 	ts->tv_sec = 0;
 	ts->tv_nsec = 0;
@@ -467,7 +776,7 @@ void __attribute__((weak)) read_persistent_clock(struct timespec *ts)
  *
  *  XXX - Do be sure to remove it once all arches implement it.
  */
-void __attribute__((weak)) read_boot_clock(struct timespec *ts)
+void __weak read_boot_clock(struct timespec *ts)
 {
 	ts->tv_sec = 0;
 	ts->tv_nsec = 0;
@@ -478,125 +787,278 @@ void __attribute__((weak)) read_boot_clock(struct timespec *ts)
  */
 void __init timekeeping_init(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct clocksource *clock;
 	unsigned long flags;
-	struct timespec now, boot;
+	struct timespec now, boot, tmp;
 
 	read_persistent_clock(&now);
-	read_boot_clock(&boot);
 
-	write_seqlock_irqsave(&xtime_lock, flags);
+	if (!timespec_valid_strict(&now)) {
+		pr_warn("WARNING: Persistent clock returned invalid value!\n"
+			"         Check your CMOS/BIOS settings.\n");
+		now.tv_sec = 0;
+		now.tv_nsec = 0;
+	} else if (now.tv_sec || now.tv_nsec)
+		persistent_clock_exist = true;
 
+	read_boot_clock(&boot);
+	if (!timespec_valid_strict(&boot)) {
+		pr_warn("WARNING: Boot clock returned invalid value!\n"
+			"         Check your CMOS/BIOS settings.\n");
+		boot.tv_sec = 0;
+		boot.tv_nsec = 0;
+	}
+
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	write_seqcount_begin(&timekeeper_seq);
 	ntp_init();
 
 	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;
-	if (boot.tv_sec == 0 && boot.tv_nsec == 0) {
-		boot.tv_sec = xtime.tv_sec;
-		boot.tv_nsec = xtime.tv_nsec;
-	}
-	set_normalized_timespec(&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);
+	tk_setup_internals(tk, clock);
+
+	tk_set_xtime(tk, &now);
+	tk->raw_time.tv_sec = 0;
+	tk->raw_time.tv_nsec = 0;
+	if (boot.tv_sec == 0 && boot.tv_nsec == 0)
+		boot = tk_xtime(tk);
+
+	set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec);
+	tk_set_wall_to_mono(tk, tmp);
+
+	tmp.tv_sec = 0;
+	tmp.tv_nsec = 0;
+	tk_set_sleep_time(tk, tmp);
+
+	memcpy(&shadow_timekeeper, &timekeeper, sizeof(timekeeper));
+
+	write_seqcount_end(&timekeeper_seq);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 }
 
 /* time in seconds when suspend began */
 static struct timespec timekeeping_suspend_time;
 
 /**
+ * __timekeeping_inject_sleeptime - Internal function to add sleep interval
+ * @delta: pointer to a timespec delta value
+ *
+ * Takes a timespec offset measuring a suspend interval and properly
+ * adds the sleep offset to the timekeeping variables.
+ */
+static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
+							struct timespec *delta)
+{
+	if (!timespec_valid_strict(delta)) {
+		printk_deferred(KERN_WARNING
+				"__timekeeping_inject_sleeptime: Invalid "
+				"sleep delta value!\n");
+		return;
+	}
+	tk_xtime_add(tk, delta);
+	tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta));
+	tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta));
+	tk_debug_account_sleep_time(delta);
+}
+
+/**
+ * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
+ * @delta: pointer to a timespec delta value
+ *
+ * This hook is for architectures that cannot support read_persistent_clock
+ * because their RTC/persistent clock is only accessible when irqs are enabled.
+ *
+ * This function should only be called by rtc_resume(), and allows
+ * a suspend offset to be injected into the timekeeping values.
+ */
+void timekeeping_inject_sleeptime(struct timespec *delta)
+{
+	struct timekeeper *tk = &timekeeper;
+	unsigned long flags;
+
+	/*
+	 * Make sure we don't set the clock twice, as timekeeping_resume()
+	 * already did it
+	 */
+	if (has_persistent_clock())
+		return;
+
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	write_seqcount_begin(&timekeeper_seq);
+
+	timekeeping_forward_now(tk);
+
+	__timekeeping_inject_sleeptime(tk, delta);
+
+	timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
+
+	write_seqcount_end(&timekeeper_seq);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+
+	/* signal hrtimers about time change */
+	clock_was_set();
+}
+
+/**
  * timekeeping_resume - Resumes the generic timekeeping subsystem.
- * @dev:	unused
  *
  * This is for the generic clocksource timekeeping.
  * xtime/wall_to_monotonic/jiffies/etc are
  * still managed by arch specific suspend/resume code.
  */
-static int timekeeping_resume(struct sys_device *dev)
+static void timekeeping_resume(void)
 {
+	struct timekeeper *tk = &timekeeper;
+	struct clocksource *clock = tk->clock;
 	unsigned long flags;
-	struct timespec ts;
+	struct timespec ts_new, ts_delta;
+	cycle_t cycle_now, cycle_delta;
+	bool suspendtime_found = false;
 
-	read_persistent_clock(&ts);
+	read_persistent_clock(&ts_new);
 
+	clockevents_resume();
 	clocksource_resume();
 
-	write_seqlock_irqsave(&xtime_lock, flags);
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	write_seqcount_begin(&timekeeper_seq);
 
-	if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
-		ts = timespec_sub(ts, timekeeping_suspend_time);
-		xtime = timespec_add(xtime, ts);
-		wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
-		total_sleep_time = timespec_add(total_sleep_time, ts);
+	/*
+	 * After system resumes, we need to calculate the suspended time and
+	 * compensate it for the OS time. There are 3 sources that could be
+	 * used: Nonstop clocksource during suspend, persistent clock and rtc
+	 * device.
+	 *
+	 * One specific platform may have 1 or 2 or all of them, and the
+	 * preference will be:
+	 *	suspend-nonstop clocksource -> persistent clock -> rtc
+	 * The less preferred source will only be tried if there is no better
+	 * usable source. The rtc part is handled separately in rtc core code.
+	 */
+	cycle_now = clock->read(clock);
+	if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) &&
+		cycle_now > clock->cycle_last) {
+		u64 num, max = ULLONG_MAX;
+		u32 mult = clock->mult;
+		u32 shift = clock->shift;
+		s64 nsec = 0;
+
+		cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
+
+		/*
+		 * "cycle_delta * mutl" may cause 64 bits overflow, if the
+		 * suspended time is too long. In that case we need do the
+		 * 64 bits math carefully
+		 */
+		do_div(max, mult);
+		if (cycle_delta > max) {
+			num = div64_u64(cycle_delta, max);
+			nsec = (((u64) max * mult) >> shift) * num;
+			cycle_delta -= num * max;
+		}
+		nsec += ((u64) cycle_delta * mult) >> shift;
+
+		ts_delta = ns_to_timespec(nsec);
+		suspendtime_found = true;
+	} else if (timespec_compare(&ts_new, &timekeeping_suspend_time) > 0) {
+		ts_delta = timespec_sub(ts_new, timekeeping_suspend_time);
+		suspendtime_found = true;
 	}
-	/* re-base the last cycle value */
-	timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
-	timekeeper.ntp_error = 0;
+
+	if (suspendtime_found)
+		__timekeeping_inject_sleeptime(tk, &ts_delta);
+
+	/* Re-base the last cycle value */
+	tk->cycle_last = clock->cycle_last = cycle_now;
+	tk->ntp_error = 0;
 	timekeeping_suspended = 0;
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+	timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
+	write_seqcount_end(&timekeeper_seq);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
 	touch_softlockup_watchdog();
 
 	clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
 
 	/* Resume hrtimers */
-	hres_timers_resume();
-
-	return 0;
+	hrtimers_resume();
 }
 
-static int timekeeping_suspend(struct sys_device *dev, pm_message_t state)
+static int timekeeping_suspend(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
+	struct timespec		delta, delta_delta;
+	static struct timespec	old_delta;
 
 	read_persistent_clock(&timekeeping_suspend_time);
 
-	write_seqlock_irqsave(&xtime_lock, flags);
-	timekeeping_forward_now();
+	/*
+	 * On some systems the persistent_clock can not be detected at
+	 * timekeeping_init by its return value, so if we see a valid
+	 * value returned, update the persistent_clock_exists flag.
+	 */
+	if (timekeeping_suspend_time.tv_sec || timekeeping_suspend_time.tv_nsec)
+		persistent_clock_exist = true;
+
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	write_seqcount_begin(&timekeeper_seq);
+	timekeeping_forward_now(tk);
 	timekeeping_suspended = 1;
-	write_sequnlock_irqrestore(&xtime_lock, flags);
+
+	/*
+	 * To avoid drift caused by repeated suspend/resumes,
+	 * which each can add ~1 second drift error,
+	 * try to compensate so the difference in system time
+	 * and persistent_clock time stays close to constant.
+	 */
+	delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time);
+	delta_delta = timespec_sub(delta, old_delta);
+	if (abs(delta_delta.tv_sec)  >= 2) {
+		/*
+		 * if delta_delta is too large, assume time correction
+		 * has occured and set old_delta to the current delta.
+		 */
+		old_delta = delta;
+	} else {
+		/* Otherwise try to adjust old_system to compensate */
+		timekeeping_suspend_time =
+			timespec_add(timekeeping_suspend_time, delta_delta);
+	}
+
+	timekeeping_update(tk, TK_MIRROR);
+	write_seqcount_end(&timekeeper_seq);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
 	clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
 	clocksource_suspend();
+	clockevents_suspend();
 
 	return 0;
 }
 
 /* sysfs resume/suspend bits for timekeeping */
-static struct sysdev_class timekeeping_sysclass = {
-	.name		= "timekeeping",
+static struct syscore_ops timekeeping_syscore_ops = {
 	.resume		= timekeeping_resume,
 	.suspend	= timekeeping_suspend,
 };
 
-static struct sys_device device_timer = {
-	.id		= 0,
-	.cls		= &timekeeping_sysclass,
-};
-
-static int __init timekeeping_init_device(void)
+static int __init timekeeping_init_ops(void)
 {
-	int error = sysdev_class_register(&timekeeping_sysclass);
-	if (!error)
-		error = sysdev_register(&device_timer);
-	return error;
+	register_syscore_ops(&timekeeping_syscore_ops);
+	return 0;
 }
 
-device_initcall(timekeeping_init_device);
+device_initcall(timekeeping_init_ops);
 
 /*
  * If the error is already larger, we look ahead even further
  * to compensate for late or lost adjustments.
  */
-static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
+static __always_inline int timekeeping_bigadjust(struct timekeeper *tk,
+						 s64 error, s64 *interval,
 						 s64 *offset)
 {
 	s64 tick_error, i;
@@ -612,7 +1074,7 @@ static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
 	 * here.  This is tuned so that an error of about 1 msec is adjusted
 	 * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
 	 */
-	error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
+	error2 = tk->ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
 	error2 = abs(error2);
 	for (look_ahead = 0; error2 > 0; look_ahead++)
 		error2 >>= 2;
@@ -621,8 +1083,8 @@ 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 -= timekeeper.xtime_interval >> 1;
+	tick_error = ntp_tick_length() >> (tk->ntp_error_shift + 1);
+	tick_error -= tk->xtime_interval >> 1;
 	error = ((error - tick_error) >> look_ahead) + tick_error;
 
 	/* Finally calculate the adjustment shift value.  */
@@ -647,36 +1109,175 @@ static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
  * this is optimized for the most common adjustments of -1,0,1,
  * for other values we can do a bit more work.
  */
-static void timekeeping_adjust(s64 offset)
+static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
 {
-	s64 error, interval = timekeeper.cycle_interval;
+	s64 error, interval = tk->cycle_interval;
 	int adj;
 
-	error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1);
+	/*
+	 * The point of this is to check if the error is greater than half
+	 * an interval.
+	 *
+	 * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs.
+	 *
+	 * Note we subtract one in the shift, so that error is really error*2.
+	 * This "saves" dividing(shifting) interval twice, but keeps the
+	 * (error > interval) comparison as still measuring if error is
+	 * larger than half an interval.
+	 *
+	 * Note: It does not "save" on aggravation when reading the code.
+	 */
+	error = tk->ntp_error >> (tk->ntp_error_shift - 1);
 	if (error > interval) {
+		/*
+		 * We now divide error by 4(via shift), which checks if
+		 * the error is greater than twice the interval.
+		 * If it is greater, we need a bigadjust, if its smaller,
+		 * we can adjust by 1.
+		 */
 		error >>= 2;
 		if (likely(error <= interval))
 			adj = 1;
 		else
-			adj = timekeeping_bigadjust(error, &interval, &offset);
-	} else if (error < -interval) {
-		error >>= 2;
-		if (likely(error >= -interval)) {
-			adj = -1;
-			interval = -interval;
-			offset = -offset;
-		} else
-			adj = timekeeping_bigadjust(error, &interval, &offset);
-	} else
-		return;
+			adj = timekeeping_bigadjust(tk, error, &interval, &offset);
+	} else {
+		if (error < -interval) {
+			/* See comment above, this is just switched for the negative */
+			error >>= 2;
+			if (likely(error >= -interval)) {
+				adj = -1;
+				interval = -interval;
+				offset = -offset;
+			} else {
+				adj = timekeeping_bigadjust(tk, error, &interval, &offset);
+			}
+		} else {
+			goto out_adjust;
+		}
+	}
+
+	if (unlikely(tk->clock->maxadj &&
+		(tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) {
+		printk_deferred_once(KERN_WARNING
+			"Adjusting %s more than 11%% (%ld vs %ld)\n",
+			tk->clock->name, (long)tk->mult + adj,
+			(long)tk->clock->mult + tk->clock->maxadj);
+	}
+	/*
+	 * So the following can be confusing.
+	 *
+	 * To keep things simple, lets assume adj == 1 for now.
+	 *
+	 * When adj != 1, remember that the interval and offset values
+	 * have been appropriately scaled so the math is the same.
+	 *
+	 * The basic idea here is that we're increasing the multiplier
+	 * by one, this causes the xtime_interval to be incremented by
+	 * one cycle_interval. This is because:
+	 *	xtime_interval = cycle_interval * mult
+	 * So if mult is being incremented by one:
+	 *	xtime_interval = cycle_interval * (mult + 1)
+	 * Its the same as:
+	 *	xtime_interval = (cycle_interval * mult) + cycle_interval
+	 * Which can be shortened to:
+	 *	xtime_interval += cycle_interval
+	 *
+	 * So offset stores the non-accumulated cycles. Thus the current
+	 * time (in shifted nanoseconds) is:
+	 *	now = (offset * adj) + xtime_nsec
+	 * Now, even though we're adjusting the clock frequency, we have
+	 * to keep time consistent. In other words, we can't jump back
+	 * in time, and we also want to avoid jumping forward in time.
+	 *
+	 * So given the same offset value, we need the time to be the same
+	 * both before and after the freq adjustment.
+	 *	now = (offset * adj_1) + xtime_nsec_1
+	 *	now = (offset * adj_2) + xtime_nsec_2
+	 * So:
+	 *	(offset * adj_1) + xtime_nsec_1 =
+	 *		(offset * adj_2) + xtime_nsec_2
+	 * And we know:
+	 *	adj_2 = adj_1 + 1
+	 * So:
+	 *	(offset * adj_1) + xtime_nsec_1 =
+	 *		(offset * (adj_1+1)) + xtime_nsec_2
+	 *	(offset * adj_1) + xtime_nsec_1 =
+	 *		(offset * adj_1) + offset + xtime_nsec_2
+	 * Canceling the sides:
+	 *	xtime_nsec_1 = offset + xtime_nsec_2
+	 * Which gives us:
+	 *	xtime_nsec_2 = xtime_nsec_1 - offset
+	 * Which simplfies to:
+	 *	xtime_nsec -= offset
+	 *
+	 * XXX - TODO: Doc ntp_error calculation.
+	 */
+	tk->mult += adj;
+	tk->xtime_interval += interval;
+	tk->xtime_nsec -= offset;
+	tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
+
+out_adjust:
+	/*
+	 * It may be possible that when we entered this function, xtime_nsec
+	 * was very small.  Further, if we're slightly speeding the clocksource
+	 * in the code above, its possible the required corrective factor to
+	 * xtime_nsec could cause it to underflow.
+	 *
+	 * Now, since we already accumulated the second, cannot simply roll
+	 * the accumulated second back, since the NTP subsystem has been
+	 * notified via second_overflow. So instead we push xtime_nsec forward
+	 * by the amount we underflowed, and add that amount into the error.
+	 *
+	 * We'll correct this error next time through this function, when
+	 * xtime_nsec is not as small.
+	 */
+	if (unlikely((s64)tk->xtime_nsec < 0)) {
+		s64 neg = -(s64)tk->xtime_nsec;
+		tk->xtime_nsec = 0;
+		tk->ntp_error += neg << tk->ntp_error_shift;
+	}
 
-	timekeeper.mult += adj;
-	timekeeper.xtime_interval += interval;
-	timekeeper.xtime_nsec -= offset;
-	timekeeper.ntp_error -= (interval - offset) <<
-				timekeeper.ntp_error_shift;
 }
 
+/**
+ * accumulate_nsecs_to_secs - Accumulates nsecs into secs
+ *
+ * Helper function that accumulates a the nsecs greater then a second
+ * from the xtime_nsec field to the xtime_secs field.
+ * It also calls into the NTP code to handle leapsecond processing.
+ *
+ */
+static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk)
+{
+	u64 nsecps = (u64)NSEC_PER_SEC << tk->shift;
+	unsigned int clock_set = 0;
+
+	while (tk->xtime_nsec >= nsecps) {
+		int leap;
+
+		tk->xtime_nsec -= nsecps;
+		tk->xtime_sec++;
+
+		/* Figure out if its a leap sec and apply if needed */
+		leap = second_overflow(tk->xtime_sec);
+		if (unlikely(leap)) {
+			struct timespec ts;
+
+			tk->xtime_sec += leap;
+
+			ts.tv_sec = leap;
+			ts.tv_nsec = 0;
+			tk_set_wall_to_mono(tk,
+				timespec_sub(tk->wall_to_monotonic, ts));
+
+			__timekeeping_set_tai_offset(tk, tk->tai_offset - leap);
+
+			clock_set = TK_CLOCK_WAS_SET;
+		}
+	}
+	return clock_set;
+}
 
 /**
  * logarithmic_accumulation - shifted accumulation of cycles
@@ -687,143 +1288,164 @@ static void timekeeping_adjust(s64 offset)
  *
  * Returns the unconsumed cycles.
  */
-static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
+static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
+						u32 shift,
+						unsigned int *clock_set)
 {
-	u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift;
+	cycle_t interval = tk->cycle_interval << shift;
 	u64 raw_nsecs;
 
 	/* If the offset is smaller then a shifted interval, do nothing */
-	if (offset < timekeeper.cycle_interval<<shift)
+	if (offset < interval)
 		return offset;
 
 	/* Accumulate one shifted interval */
-	offset -= timekeeper.cycle_interval << shift;
-	timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift;
-
-	timekeeper.xtime_nsec += timekeeper.xtime_interval << shift;
-	while (timekeeper.xtime_nsec >= nsecps) {
-		timekeeper.xtime_nsec -= nsecps;
-		xtime.tv_sec++;
-		second_overflow();
-	}
+	offset -= interval;
+	tk->cycle_last += interval;
+
+	tk->xtime_nsec += tk->xtime_interval << shift;
+	*clock_set |= accumulate_nsecs_to_secs(tk);
 
 	/* Accumulate raw time */
-	raw_nsecs = timekeeper.raw_interval << shift;
-	raw_nsecs += raw_time.tv_nsec;
+	raw_nsecs = (u64)tk->raw_interval << shift;
+	raw_nsecs += tk->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;
+		tk->raw_time.tv_sec += raw_secs;
 	}
-	raw_time.tv_nsec = raw_nsecs;
+	tk->raw_time.tv_nsec = raw_nsecs;
 
 	/* Accumulate error between NTP and clock interval */
-	timekeeper.ntp_error += tick_length << shift;
-	timekeeper.ntp_error -= timekeeper.xtime_interval <<
-				(timekeeper.ntp_error_shift + shift);
+	tk->ntp_error += ntp_tick_length() << shift;
+	tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) <<
+						(tk->ntp_error_shift + shift);
 
 	return offset;
 }
 
+#ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
+static inline void old_vsyscall_fixup(struct timekeeper *tk)
+{
+	s64 remainder;
+
+	/*
+	* Store only full nanoseconds into xtime_nsec after rounding
+	* it up and add the remainder to the error difference.
+	* XXX - This is necessary to avoid small 1ns inconsistnecies caused
+	* by truncating the remainder in vsyscalls. However, it causes
+	* additional work to be done in timekeeping_adjust(). Once
+	* the vsyscall implementations are converted to use xtime_nsec
+	* (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
+	* users are removed, this can be killed.
+	*/
+	remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
+	tk->xtime_nsec -= remainder;
+	tk->xtime_nsec += 1ULL << tk->shift;
+	tk->ntp_error += remainder << tk->ntp_error_shift;
+	tk->ntp_error -= (1ULL << tk->shift) << tk->ntp_error_shift;
+}
+#else
+#define old_vsyscall_fixup(tk)
+#endif
+
+
 
 /**
  * update_wall_time - Uses the current clocksource to increment the wall time
  *
- * Called from the timer interrupt, must hold a write on xtime_lock.
  */
 void update_wall_time(void)
 {
 	struct clocksource *clock;
+	struct timekeeper *real_tk = &timekeeper;
+	struct timekeeper *tk = &shadow_timekeeper;
 	cycle_t offset;
 	int shift = 0, maxshift;
+	unsigned int clock_set = 0;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
 
 	/* Make sure we're fully resumed: */
 	if (unlikely(timekeeping_suspended))
-		return;
+		goto out;
 
-	clock = timekeeper.clock;
+	clock = real_tk->clock;
 
 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
-	offset = timekeeper.cycle_interval;
+	offset = real_tk->cycle_interval;
 #else
 	offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
 #endif
-	timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift;
+
+	/* Check if there's really nothing to do */
+	if (offset < real_tk->cycle_interval)
+		goto out;
 
 	/*
 	 * With NO_HZ we may have to accumulate many cycle_intervals
 	 * (think "ticks") worth of time at once. To do this efficiently,
 	 * we calculate the largest doubling multiple of cycle_intervals
-	 * that is smaller then the offset. We then accumulate that
+	 * that is smaller than the offset.  We then accumulate that
 	 * chunk in one go, and then try to consume the next smaller
 	 * doubled multiple.
 	 */
-	shift = ilog2(offset) - ilog2(timekeeper.cycle_interval);
+	shift = ilog2(offset) - ilog2(tk->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;
+	/* Bound shift to one less than what overflows tick_length */
+	maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
 	shift = min(shift, maxshift);
-	while (offset >= timekeeper.cycle_interval) {
-		offset = logarithmic_accumulation(offset, shift);
-		if(offset < timekeeper.cycle_interval<<shift)
+	while (offset >= tk->cycle_interval) {
+		offset = logarithmic_accumulation(tk, offset, shift,
+							&clock_set);
+		if (offset < tk->cycle_interval<<shift)
 			shift--;
 	}
 
 	/* correct the clock when NTP error is too big */
-	timekeeping_adjust(offset);
+	timekeeping_adjust(tk, offset);
 
 	/*
-	 * Since in the loop above, we accumulate any amount of time
-	 * in xtime_nsec over a second into xtime.tv_sec, its possible for
-	 * xtime_nsec to be fairly small after the loop. Further, if we're
-	 * slightly speeding the clocksource up in timekeeping_adjust(),
-	 * its possible the required corrective factor to xtime_nsec could
-	 * cause it to underflow.
-	 *
-	 * Now, we cannot simply roll the accumulated second back, since
-	 * the NTP subsystem has been notified via second_overflow. So
-	 * instead we push xtime_nsec forward by the amount we underflowed,
-	 * and add that amount into the error.
-	 *
-	 * We'll correct this error next time through this function, when
-	 * xtime_nsec is not as small.
+	 * XXX This can be killed once everyone converts
+	 * to the new update_vsyscall.
 	 */
-	if (unlikely((s64)timekeeper.xtime_nsec < 0)) {
-		s64 neg = -(s64)timekeeper.xtime_nsec;
-		timekeeper.xtime_nsec = 0;
-		timekeeper.ntp_error += neg << timekeeper.ntp_error_shift;
-	}
-
+	old_vsyscall_fixup(tk);
 
 	/*
-	 * Store full nanoseconds into xtime after rounding it up and
-	 * add the remainder to the error difference.
+	 * Finally, make sure that after the rounding
+	 * xtime_nsec isn't larger than NSEC_PER_SEC
 	 */
-	xtime.tv_nsec =	((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1;
-	timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift;
-	timekeeper.ntp_error +=	timekeeper.xtime_nsec <<
-				timekeeper.ntp_error_shift;
+	clock_set |= accumulate_nsecs_to_secs(tk);
 
+	write_seqcount_begin(&timekeeper_seq);
+	/* Update clock->cycle_last with the new value */
+	clock->cycle_last = tk->cycle_last;
 	/*
-	 * Finally, make sure that after the rounding
-	 * xtime.tv_nsec isn't larger then NSEC_PER_SEC
+	 * Update the real timekeeper.
+	 *
+	 * We could avoid this memcpy by switching pointers, but that
+	 * requires changes to all other timekeeper usage sites as
+	 * well, i.e. move the timekeeper pointer getter into the
+	 * spinlocked/seqcount protected sections. And we trade this
+	 * memcpy under the timekeeper_seq against one before we start
+	 * updating.
 	 */
-	if (unlikely(xtime.tv_nsec >= NSEC_PER_SEC)) {
-		xtime.tv_nsec -= NSEC_PER_SEC;
-		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);
+	memcpy(real_tk, tk, sizeof(*tk));
+	timekeeping_update(real_tk, clock_set);
+	write_seqcount_end(&timekeeper_seq);
+out:
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+	if (clock_set)
+		/* Have to call _delayed version, since in irq context*/
+		clock_was_set_delayed();
 }
 
 /**
  * getboottime - Return the real time of system boot.
  * @ts:		pointer to the timespec to be set
  *
- * Returns the time of day in a timespec.
+ * Returns the wall-time of boot in a timespec.
  *
  * This is based on the wall_to_monotonic offset and the total suspend
  * time. Calls to settimeofday will affect the value returned (which
@@ -832,9 +1454,12 @@ void update_wall_time(void)
  */
 void getboottime(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	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 = tk->wall_to_monotonic.tv_sec +
+				tk->total_sleep_time.tv_sec,
+		.tv_nsec = tk->wall_to_monotonic.tv_nsec +
+				tk->total_sleep_time.tv_nsec
 	};
 
 	set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
@@ -842,41 +1467,93 @@ void getboottime(struct timespec *ts)
 EXPORT_SYMBOL_GPL(getboottime);
 
 /**
+ * get_monotonic_boottime - Returns monotonic time since boot
+ * @ts:		pointer to the timespec to be set
+ *
+ * Returns the monotonic time since boot in a timespec.
+ *
+ * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also
+ * includes the time spent in suspend.
+ */
+void get_monotonic_boottime(struct timespec *ts)
+{
+	struct timekeeper *tk = &timekeeper;
+	struct timespec tomono, sleep;
+	s64 nsec;
+	unsigned int seq;
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		seq = read_seqcount_begin(&timekeeper_seq);
+		ts->tv_sec = tk->xtime_sec;
+		nsec = timekeeping_get_ns(tk);
+		tomono = tk->wall_to_monotonic;
+		sleep = tk->total_sleep_time;
+
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
+
+	ts->tv_sec += tomono.tv_sec + sleep.tv_sec;
+	ts->tv_nsec = 0;
+	timespec_add_ns(ts, nsec + tomono.tv_nsec + sleep.tv_nsec);
+}
+EXPORT_SYMBOL_GPL(get_monotonic_boottime);
+
+/**
+ * ktime_get_boottime - Returns monotonic time since boot in a ktime
+ *
+ * Returns the monotonic time since boot in a ktime
+ *
+ * This is similar to CLOCK_MONTONIC/ktime_get, but also
+ * includes the time spent in suspend.
+ */
+ktime_t ktime_get_boottime(void)
+{
+	struct timespec ts;
+
+	get_monotonic_boottime(&ts);
+	return timespec_to_ktime(ts);
+}
+EXPORT_SYMBOL_GPL(ktime_get_boottime);
+
+/**
  * monotonic_to_bootbased - Convert the monotonic time to boot based.
  * @ts:		pointer to the timespec to be converted
  */
 void monotonic_to_bootbased(struct timespec *ts)
 {
-	*ts = timespec_add(*ts, total_sleep_time);
+	struct timekeeper *tk = &timekeeper;
+
+	*ts = timespec_add(*ts, tk->total_sleep_time);
 }
 EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
 
 unsigned long get_seconds(void)
 {
-	return xtime.tv_sec;
+	struct timekeeper *tk = &timekeeper;
+
+	return tk->xtime_sec;
 }
 EXPORT_SYMBOL(get_seconds);
 
 struct timespec __current_kernel_time(void)
 {
-	return xtime;
-}
+	struct timekeeper *tk = &timekeeper;
 
-struct timespec __get_wall_to_monotonic(void)
-{
-	return wall_to_monotonic;
+	return tk_xtime(tk);
 }
 
 struct timespec current_kernel_time(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec now;
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
+		seq = read_seqcount_begin(&timekeeper_seq);
 
-		now = xtime;
-	} while (read_seqretry(&xtime_lock, seq));
+		now = tk_xtime(tk);
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
 
 	return now;
 }
@@ -884,17 +1561,184 @@ EXPORT_SYMBOL(current_kernel_time);
 
 struct timespec get_monotonic_coarse(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec now, mono;
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
+		seq = read_seqcount_begin(&timekeeper_seq);
 
-		now = xtime;
-		mono = wall_to_monotonic;
-	} while (read_seqretry(&xtime_lock, seq));
+		now = tk_xtime(tk);
+		mono = tk->wall_to_monotonic;
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
 
 	set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
 				now.tv_nsec + mono.tv_nsec);
 	return now;
 }
+
+/*
+ * Must hold jiffies_lock
+ */
+void do_timer(unsigned long ticks)
+{
+	jiffies_64 += ticks;
+	calc_global_load(ticks);
+}
+
+/**
+ * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic,
+ *    and sleep offsets.
+ * @xtim:	pointer to timespec to be set with xtime
+ * @wtom:	pointer to timespec to be set with wall_to_monotonic
+ * @sleep:	pointer to timespec to be set with time in suspend
+ */
+void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
+				struct timespec *wtom, struct timespec *sleep)
+{
+	struct timekeeper *tk = &timekeeper;
+	unsigned long seq;
+
+	do {
+		seq = read_seqcount_begin(&timekeeper_seq);
+		*xtim = tk_xtime(tk);
+		*wtom = tk->wall_to_monotonic;
+		*sleep = tk->total_sleep_time;
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
+}
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+/**
+ * ktime_get_update_offsets - hrtimer helper
+ * @offs_real:	pointer to storage for monotonic -> realtime offset
+ * @offs_boot:	pointer to storage for monotonic -> boottime offset
+ * @offs_tai:	pointer to storage for monotonic -> clock tai offset
+ *
+ * Returns current monotonic time and updates the offsets
+ * Called from hrtimer_interrupt() or retrigger_next_event()
+ */
+ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot,
+							ktime_t *offs_tai)
+{
+	struct timekeeper *tk = &timekeeper;
+	ktime_t now;
+	unsigned int seq;
+	u64 secs, nsecs;
+
+	do {
+		seq = read_seqcount_begin(&timekeeper_seq);
+
+		secs = tk->xtime_sec;
+		nsecs = timekeeping_get_ns(tk);
+
+		*offs_real = tk->offs_real;
+		*offs_boot = tk->offs_boot;
+		*offs_tai = tk->offs_tai;
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
+
+	now = ktime_add_ns(ktime_set(secs, 0), nsecs);
+	now = ktime_sub(now, *offs_real);
+	return now;
+}
+#endif
+
+/**
+ * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format
+ */
+ktime_t ktime_get_monotonic_offset(void)
+{
+	struct timekeeper *tk = &timekeeper;
+	unsigned long seq;
+	struct timespec wtom;
+
+	do {
+		seq = read_seqcount_begin(&timekeeper_seq);
+		wtom = tk->wall_to_monotonic;
+	} while (read_seqcount_retry(&timekeeper_seq, seq));
+
+	return timespec_to_ktime(wtom);
+}
+EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
+
+/**
+ * do_adjtimex() - Accessor function to NTP __do_adjtimex function
+ */
+int do_adjtimex(struct timex *txc)
+{
+	struct timekeeper *tk = &timekeeper;
+	unsigned long flags;
+	struct timespec ts;
+	s32 orig_tai, tai;
+	int ret;
+
+	/* Validate the data before disabling interrupts */
+	ret = ntp_validate_timex(txc);
+	if (ret)
+		return ret;
+
+	if (txc->modes & ADJ_SETOFFSET) {
+		struct timespec delta;
+		delta.tv_sec  = txc->time.tv_sec;
+		delta.tv_nsec = txc->time.tv_usec;
+		if (!(txc->modes & ADJ_NANO))
+			delta.tv_nsec *= 1000;
+		ret = timekeeping_inject_offset(&delta);
+		if (ret)
+			return ret;
+	}
+
+	getnstimeofday(&ts);
+
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	write_seqcount_begin(&timekeeper_seq);
+
+	orig_tai = tai = tk->tai_offset;
+	ret = __do_adjtimex(txc, &ts, &tai);
+
+	if (tai != orig_tai) {
+		__timekeeping_set_tai_offset(tk, tai);
+		timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
+	}
+	write_seqcount_end(&timekeeper_seq);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+
+	if (tai != orig_tai)
+		clock_was_set();
+
+	ntp_notify_cmos_timer();
+
+	return ret;
+}
+
+#ifdef CONFIG_NTP_PPS
+/**
+ * hardpps() - Accessor function to NTP __hardpps function
+ */
+void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	write_seqcount_begin(&timekeeper_seq);
+
+	__hardpps(phase_ts, raw_ts);
+
+	write_seqcount_end(&timekeeper_seq);
+	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+}
+EXPORT_SYMBOL(hardpps);
+#endif
+
+/**
+ * xtime_update() - advances the timekeeping infrastructure
+ * @ticks:	number of ticks, that have elapsed since the last call.
+ *
+ * Must be called with interrupts disabled.
+ */
+void xtime_update(unsigned long ticks)
+{
+	write_seqlock(&jiffies_lock);
+	do_timer(ticks);
+	write_sequnlock(&jiffies_lock);
+	update_wall_time();
+}