Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 1280 insertions, 0 deletions

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
new file mode 100644
index 00000000..2f7b1b42
--- /dev/null
+++ b/kernel/time/timekeeping.c
@@ -0,0 +1,1280 @@
+/*
+ *  linux/kernel/time/timekeeping.c
+ *
+ *  Kernel timekeeping code and accessor functions
+ *
+ *  This code was moved from linux/kernel/timer.c.
+ *  Please see that file for copyright and history logs.
+ *
+ */
+
+#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/syscore_ops.h>
+#include <linux/clocksource.h>
+#include <linux/jiffies.h>
+#include <linux/time.h>
+#include <linux/tick.h>
+#include <linux/stop_machine.h>
+
+/* Structure holding internal timekeeping values. */
+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;
+
+	/* 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;
+	/* shifted nano seconds left over when rounding cycle_interval */
+	s64	xtime_remainder;
+	/* 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;
+
+	/* 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.
+ *
+ * @clock:		Pointer to clocksource.
+ *
+ * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
+ * pair and interval request.
+ *
+ * Unless you're the timekeeping code, you should not be using this!
+ */
+static void timekeeper_setup_internals(struct clocksource *clock)
+{
+	cycle_t interval;
+	u64 tmp, ntpinterval;
+
+	timekeeper.clock = clock;
+	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;
+
+	/* Go back from cycles -> shifted ns */
+	timekeeper.xtime_interval = (u64) interval * clock->mult;
+	timekeeper.xtime_remainder = ntpinterval - timekeeper.xtime_interval;
+	timekeeper.raw_interval =
+		((u64) interval * clock->mult) >> clock->shift;
+
+	timekeeper.xtime_nsec = 0;
+	timekeeper.shift = clock->shift;
+
+	timekeeper.ntp_error = 0;
+	timekeeper.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;
+}
+
+/* Timekeeper helper functions. */
+static inline s64 timekeeping_get_ns(void)
+{
+	cycle_t cycle_now, cycle_delta;
+	struct clocksource *clock;
+
+	/* read clocksource: */
+	clock = timekeeper.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);
+}
+
+static inline s64 timekeeping_get_ns_raw(void)
+{
+	cycle_t cycle_now, cycle_delta;
+	struct clocksource *clock;
+
+	/* read clocksource: */
+	clock = timekeeper.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. */
+	return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
+}
+
+/* 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);
+}
+
+
+/**
+ * timekeeping_forward_now - update clock to the current time
+ *
+ * Forward the current clock to update its state since the last call to
+ * 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)
+{
+	cycle_t cycle_now, cycle_delta;
+	struct clocksource *clock;
+	s64 nsec;
+
+	clock = timekeeper.clock;
+	cycle_now = clock->read(clock);
+	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
+	clock->cycle_last = cycle_now;
+
+	nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult,
+				  timekeeper.shift);
+
+	/* If arch requires, add in gettimeoffset() */
+	nsec += arch_gettimeoffset();
+
+	timespec_add_ns(&timekeeper.xtime, nsec);
+
+	nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
+	timespec_add_ns(&timekeeper.raw_time, nsec);
+}
+
+/**
+ * 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.
+ */
+void getnstimeofday(struct timespec *ts)
+{
+	unsigned long seq;
+	s64 nsecs;
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		seq = read_seqbegin(&timekeeper.lock);
+
+		*ts = timekeeper.xtime;
+		nsecs = timekeeping_get_ns();
+
+		/* If arch requires, add in gettimeoffset() */
+		nsecs += arch_gettimeoffset();
+
+	} while (read_seqretry(&timekeeper.lock, seq));
+
+	timespec_add_ns(ts, nsecs);
+}
+
+EXPORT_SYMBOL(getnstimeofday);
+
+ktime_t ktime_get(void)
+{
+	unsigned int seq;
+	s64 secs, nsecs;
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		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(&timekeeper.lock, seq));
+	/*
+	 * Use ktime_set/ktime_add_ns to create a proper ktime on
+	 * 32-bit architectures without CONFIG_KTIME_SCALAR.
+	 */
+	return ktime_add_ns(ktime_set(secs, 0), nsecs);
+}
+EXPORT_SYMBOL_GPL(ktime_get);
+
+/**
+ * ktime_get_ts - get the monotonic clock in timespec format
+ * @ts:		pointer to timespec variable
+ *
+ * The function calculates the monotonic clock from the realtime
+ * clock and the wall_to_monotonic offset and stores the result
+ * in normalized timespec format in the variable pointed to by @ts.
+ */
+void ktime_get_ts(struct timespec *ts)
+{
+	struct timespec tomono;
+	unsigned int seq;
+	s64 nsecs;
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		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(&timekeeper.lock, seq));
+
+	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
+				ts->tv_nsec + tomono.tv_nsec + nsecs);
+}
+EXPORT_SYMBOL_GPL(ktime_get_ts);
+
+#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)
+{
+	unsigned long seq;
+	s64 nsecs_raw, nsecs_real;
+
+	WARN_ON_ONCE(timekeeping_suspended);
+
+	do {
+		u32 arch_offset;
+
+		seq = read_seqbegin(&timekeeper.lock);
+
+		*ts_raw = timekeeper.raw_time;
+		*ts_real = timekeeper.xtime;
+
+		nsecs_raw = timekeeping_get_ns_raw();
+		nsecs_real = timekeeping_get_ns();
+
+		/* If arch requires, add in gettimeoffset() */
+		arch_offset = arch_gettimeoffset();
+		nsecs_raw += arch_offset;
+		nsecs_real += arch_offset;
+
+	} while (read_seqretry(&timekeeper.lock, 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
+ *
+ * NOTE: Users should be converted to using getnstimeofday()
+ */
+void do_gettimeofday(struct timeval *tv)
+{
+	struct timespec now;
+
+	getnstimeofday(&now);
+	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(const struct timespec *tv)
+{
+	struct timespec ts_delta;
+	unsigned long flags;
+
+	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+		return -EINVAL;
+
+	write_seqlock_irqsave(&timekeeper.lock, flags);
+
+	timekeeping_forward_now();
+
+	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);
+
+	timekeeper.xtime = *tv;
+	timekeeping_update(true);
+
+	write_sequnlock_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)
+{
+	unsigned long flags;
+
+	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
+		return -EINVAL;
+
+	write_seqlock_irqsave(&timekeeper.lock, flags);
+
+	timekeeping_forward_now();
+
+	timekeeper.xtime = timespec_add(timekeeper.xtime, *ts);
+	timekeeper.wall_to_monotonic =
+				timespec_sub(timekeeper.wall_to_monotonic, *ts);
+
+	timekeeping_update(true);
+
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+
+	/* signal hrtimers about time change */
+	clock_was_set();
+
+	return 0;
+}
+EXPORT_SYMBOL(timekeeping_inject_offset);
+
+/**
+ * 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 clocksource *new, *old;
+	unsigned long flags;
+
+	new = (struct clocksource *) data;
+
+	write_seqlock_irqsave(&timekeeper.lock, flags);
+
+	timekeeping_forward_now();
+	if (!new->enable || new->enable(new) == 0) {
+		old = timekeeper.clock;
+		timekeeper_setup_internals(new);
+		if (old->disable)
+			old->disable(old);
+	}
+	timekeeping_update(true);
+
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+
+	return 0;
+}
+
+/**
+ * timekeeping_notify - Install a new clock source
+ * @clock:		pointer to the clock source
+ *
+ * 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)
+{
+	if (timekeeper.clock == clock)
+		return;
+	stop_machine(change_clocksource, clock, NULL);
+	tick_clock_notify();
+}
+
+/**
+ * ktime_get_real - get the real (wall-) time in ktime_t format
+ *
+ * returns the time in ktime_t format
+ */
+ktime_t ktime_get_real(void)
+{
+	struct timespec now;
+
+	getnstimeofday(&now);
+
+	return timespec_to_ktime(now);
+}
+EXPORT_SYMBOL_GPL(ktime_get_real);
+
+/**
+ * getrawmonotonic - Returns the raw monotonic time in a timespec
+ * @ts:		pointer to the timespec to be set
+ *
+ * Returns the raw monotonic time (completely un-modified by ntp)
+ */
+void getrawmonotonic(struct timespec *ts)
+{
+	unsigned long seq;
+	s64 nsecs;
+
+	do {
+		seq = read_seqbegin(&timekeeper.lock);
+		nsecs = timekeeping_get_ns_raw();
+		*ts = timekeeper.raw_time;
+
+	} while (read_seqretry(&timekeeper.lock, 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)
+{
+	unsigned long seq;
+	int ret;
+
+	do {
+		seq = read_seqbegin(&timekeeper.lock);
+
+		ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
+
+	} while (read_seqretry(&timekeeper.lock, seq));
+
+	return ret;
+}
+
+/**
+ * timekeeping_max_deferment - Returns max time the clocksource can be deferred
+ */
+u64 timekeeping_max_deferment(void)
+{
+	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;
+}
+
+/**
+ * read_persistent_clock -  Return time from the persistent clock.
+ *
+ * Weak dummy function for arches that do not yet support it.
+ * Reads the time from the battery backed persistent clock.
+ * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
+ *
+ *  XXX - Do be sure to remove it once all arches implement it.
+ */
+void __attribute__((weak)) read_persistent_clock(struct timespec *ts)
+{
+	ts->tv_sec = 0;
+	ts->tv_nsec = 0;
+}
+
+/**
+ * read_boot_clock -  Return time of the system start.
+ *
+ * Weak dummy function for arches that do not yet support it.
+ * Function to read the exact time the system has been started.
+ * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
+ *
+ *  XXX - Do be sure to remove it once all arches implement it.
+ */
+void __attribute__((weak)) read_boot_clock(struct timespec *ts)
+{
+	ts->tv_sec = 0;
+	ts->tv_nsec = 0;
+}
+
+/*
+ * timekeeping_init - Initializes the clocksource and common timekeeping values
+ */
+void __init timekeeping_init(void)
+{
+	struct clocksource *clock;
+	unsigned long flags;
+	struct timespec now, boot;
+
+	read_persistent_clock(&now);
+	read_boot_clock(&boot);
+
+	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);
+
+	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 = timekeeper.xtime.tv_sec;
+		boot.tv_nsec = timekeeper.xtime.tv_nsec;
+	}
+	set_normalized_timespec(&timekeeper.wall_to_monotonic,
+				-boot.tv_sec, -boot.tv_nsec);
+	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 */
+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 timespec *delta)
+{
+	if (!timespec_valid(delta)) {
+		printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid "
+					"sleep delta value!\n");
+		return;
+	}
+
+	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);
+}
+
+
+/**
+ * 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)
+{
+	unsigned long flags;
+	struct timespec ts;
+
+	/* Make sure we don't set the clock twice */
+	read_persistent_clock(&ts);
+	if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
+		return;
+
+	write_seqlock_irqsave(&timekeeper.lock, flags);
+
+	timekeeping_forward_now();
+
+	__timekeeping_inject_sleeptime(delta);
+
+	timekeeping_update(true);
+
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+
+	/* signal hrtimers about time change */
+	clock_was_set();
+}
+
+
+/**
+ * timekeeping_resume - Resumes the generic timekeeping subsystem.
+ *
+ * This is for the generic clocksource timekeeping.
+ * xtime/wall_to_monotonic/jiffies/etc are
+ * still managed by arch specific suspend/resume code.
+ */
+static void timekeeping_resume(void)
+{
+	unsigned long flags;
+	struct timespec ts;
+
+	read_persistent_clock(&ts);
+
+	clocksource_resume();
+
+	write_seqlock_irqsave(&timekeeper.lock, flags);
+
+	if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
+		ts = timespec_sub(ts, timekeeping_suspend_time);
+		__timekeeping_inject_sleeptime(&ts);
+	}
+	/* re-base the last cycle value */
+	timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
+	timekeeper.ntp_error = 0;
+	timekeeping_suspended = 0;
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+
+	touch_softlockup_watchdog();
+
+	clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
+
+	/* Resume hrtimers */
+	hrtimers_resume();
+}
+
+static int timekeeping_suspend(void)
+{
+	unsigned long flags;
+	struct timespec		delta, delta_delta;
+	static struct timespec	old_delta;
+
+	read_persistent_clock(&timekeeping_suspend_time);
+
+	write_seqlock_irqsave(&timekeeper.lock, flags);
+	timekeeping_forward_now();
+	timekeeping_suspended = 1;
+
+	/*
+	 * 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(timekeeper.xtime, 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);
+	}
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+
+	clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
+	clocksource_suspend();
+
+	return 0;
+}
+
+/* sysfs resume/suspend bits for timekeeping */
+static struct syscore_ops timekeeping_syscore_ops = {
+	.resume		= timekeeping_resume,
+	.suspend	= timekeeping_suspend,
+};
+
+static int __init timekeeping_init_ops(void)
+{
+	register_syscore_ops(&timekeeping_syscore_ops);
+	return 0;
+}
+
+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,
+						 s64 *offset)
+{
+	s64 tick_error, i;
+	u32 look_ahead, adj;
+	s32 error2, mult;
+
+	/*
+	 * Use the current error value to determine how much to look ahead.
+	 * The larger the error the slower we adjust for it to avoid problems
+	 * with losing too many ticks, otherwise we would overadjust and
+	 * produce an even larger error.  The smaller the adjustment the
+	 * faster we try to adjust for it, as lost ticks can do less harm
+	 * 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 = abs(error2);
+	for (look_ahead = 0; error2 > 0; look_ahead++)
+		error2 >>= 2;
+
+	/*
+	 * Now calculate the error in (1 << look_ahead) ticks, but first
+	 * remove the single look ahead already included in the error.
+	 */
+	tick_error = ntp_tick_length() >> (timekeeper.ntp_error_shift + 1);
+	tick_error -= timekeeper.xtime_interval >> 1;
+	error = ((error - tick_error) >> look_ahead) + tick_error;
+
+	/* Finally calculate the adjustment shift value.  */
+	i = *interval;
+	mult = 1;
+	if (error < 0) {
+		error = -error;
+		*interval = -*interval;
+		*offset = -*offset;
+		mult = -1;
+	}
+	for (adj = 0; error > i; adj++)
+		error >>= 1;
+
+	*interval <<= adj;
+	*offset <<= adj;
+	return mult << adj;
+}
+
+/*
+ * Adjust the multiplier to reduce the error value,
+ * 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)
+{
+	s64 error, interval = timekeeper.cycle_interval;
+	int adj;
+
+	/*
+	 * 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 = timekeeper.ntp_error >> (timekeeper.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;
+		/*
+		 * XXX - In update_wall_time, we round up to the next
+		 * nanosecond, and store the amount rounded up into
+		 * the error. This causes the likely below to be unlikely.
+		 *
+		 * The proper fix is to avoid rounding up by using
+		 * the high precision timekeeper.xtime_nsec instead of
+		 * xtime.tv_nsec everywhere. Fixing this will take some
+		 * time.
+		 */
+		if (likely(error <= interval))
+			adj = 1;
+		else
+			adj = timekeeping_bigadjust(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(error, &interval, &offset);
+	} else /* No adjustment needed */
+		return;
+
+	if (unlikely(timekeeper.clock->maxadj &&
+			(timekeeper.mult + adj >
+			timekeeper.clock->mult + timekeeper.clock->maxadj))) {
+		printk_once(KERN_WARNING
+			"Adjusting %s more than 11%% (%ld vs %ld)\n",
+			timekeeper.clock->name, (long)timekeeper.mult + adj,
+			(long)timekeeper.clock->mult +
+				timekeeper.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.
+	 */
+	timekeeper.mult += adj;
+	timekeeper.xtime_interval += interval;
+	timekeeper.xtime_nsec -= offset;
+	timekeeper.ntp_error -= (interval - offset) <<
+				timekeeper.ntp_error_shift;
+}
+
+
+/**
+ * logarithmic_accumulation - shifted accumulation of cycles
+ *
+ * This functions accumulates a shifted interval of cycles into
+ * into a shifted interval nanoseconds. Allows for O(log) accumulation
+ * loop.
+ *
+ * Returns the unconsumed cycles.
+ */
+static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
+{
+	u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift;
+	u64 raw_nsecs;
+
+	/* If the offset is smaller than a shifted interval, do nothing */
+	if (offset < timekeeper.cycle_interval<<shift)
+		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) {
+		int leap;
+		timekeeper.xtime_nsec -= nsecps;
+		timekeeper.xtime.tv_sec++;
+		leap = second_overflow(timekeeper.xtime.tv_sec);
+		timekeeper.xtime.tv_sec += leap;
+		timekeeper.wall_to_monotonic.tv_sec -= leap;
+	}
+
+	/* Accumulate raw time */
+	raw_nsecs = timekeeper.raw_interval << shift;
+	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);
+		timekeeper.raw_time.tv_sec += raw_secs;
+	}
+	timekeeper.raw_time.tv_nsec = raw_nsecs;
+
+	/* Accumulate error between NTP and clock interval */
+	timekeeper.ntp_error += ntp_tick_length() << shift;
+	timekeeper.ntp_error -=
+	    (timekeeper.xtime_interval + timekeeper.xtime_remainder) <<
+				(timekeeper.ntp_error_shift + shift);
+
+	return offset;
+}
+
+
+/**
+ * update_wall_time - Uses the current clocksource to increment the wall time
+ *
+ */
+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))
+		goto out;
+
+	clock = timekeeper.clock;
+
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
+	offset = timekeeper.cycle_interval;
+#else
+	offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
+#endif
+	timekeeper.xtime_nsec = (s64)timekeeper.xtime.tv_nsec <<
+						timekeeper.shift;
+
+	/*
+	 * 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 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 = max(0, shift);
+	/* 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)
+			shift--;
+	}
+
+	/* correct the clock when NTP error is too big */
+	timekeeping_adjust(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.
+	 */
+	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;
+	}
+
+
+	/*
+	 * Store full nanoseconds into xtime after rounding it up and
+	 * add the remainder to the error difference.
+	 */
+	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;
+
+	/*
+	 * Finally, make sure that after the rounding
+	 * xtime.tv_nsec isn't larger than NSEC_PER_SEC
+	 */
+	if (unlikely(timekeeper.xtime.tv_nsec >= NSEC_PER_SEC)) {
+		int leap;
+		timekeeper.xtime.tv_nsec -= NSEC_PER_SEC;
+		timekeeper.xtime.tv_sec++;
+		leap = second_overflow(timekeeper.xtime.tv_sec);
+		timekeeper.xtime.tv_sec += leap;
+		timekeeper.wall_to_monotonic.tv_sec -= leap;
+	}
+
+	timekeeping_update(false);
+
+out:
+	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+
+}
+
+/**
+ * getboottime - Return the real time of system boot.
+ * @ts:		pointer to the timespec to be set
+ *
+ * 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
+ * basically means that however wrong your real time clock is at boot time,
+ * you get the right time here).
+ */
+void getboottime(struct timespec *ts)
+{
+	struct timespec boottime = {
+		.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);
+}
+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 timespec tomono, sleep;
+	unsigned int seq;
+	s64 nsecs;
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		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(&timekeeper.lock, seq));
+
+	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
+		(s64)ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec + nsecs);
+}
+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, timekeeper.total_sleep_time);
+}
+EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
+
+unsigned long get_seconds(void)
+{
+	return timekeeper.xtime.tv_sec;
+}
+EXPORT_SYMBOL(get_seconds);
+
+struct timespec __current_kernel_time(void)
+{
+	return timekeeper.xtime;
+}
+
+struct timespec current_kernel_time(void)
+{
+	struct timespec now;
+	unsigned long seq;
+
+	do {
+		seq = read_seqbegin(&timekeeper.lock);
+
+		now = timekeeper.xtime;
+	} while (read_seqretry(&timekeeper.lock, seq));
+
+	return now;
+}
+EXPORT_SYMBOL(current_kernel_time);
+
+struct timespec get_monotonic_coarse(void)
+{
+	struct timespec now, mono;
+	unsigned long seq;
+
+	do {
+		seq = read_seqbegin(&timekeeper.lock);
+
+		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);
+	return now;
+}
+
+/*
+ * The 64-bit jiffies value is not atomic - you MUST NOT read it
+ * without sampling the sequence number in xtime_lock.
+ * jiffies is defined in the linker script...
+ */
+void do_timer(unsigned long ticks)
+{
+	jiffies_64 += ticks;
+	update_wall_time();
+	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)
+{
+	unsigned long seq;
+
+	do {
+		seq = read_seqbegin(&timekeeper.lock);
+		*xtim = timekeeper.xtime;
+		*wtom = timekeeper.wall_to_monotonic;
+		*sleep = timekeeper.total_sleep_time;
+	} while (read_seqretry(&timekeeper.lock, seq));
+}
+
+/**
+ * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format
+ */
+ktime_t ktime_get_monotonic_offset(void)
+{
+	unsigned long seq;
+	struct timespec wtom;
+
+	do {
+		seq = read_seqbegin(&timekeeper.lock);
+		wtom = timekeeper.wall_to_monotonic;
+	} while (read_seqretry(&timekeeper.lock, seq));
+
+	return timespec_to_ktime(wtom);
+}
+EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
+
+
+/**
+ * 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(&xtime_lock);
+	do_timer(ticks);
+	write_sequnlock(&xtime_lock);
+}