/* * 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; /* 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; /* NTP adjusted clock multiplier */ u32 mult;}; static struct timekeeper timekeeper; /** * 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 using ntp adjusted mult. */ return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);} /* * This read-write spinlock protects us from races in SMP while * playing with xtime. */__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); /* * The current time * wall_to_monotonic is what we need to add to xtime (or xtime corrected * for sub jiffie times) to get to monotonic time. Monotonic is pegged * at zero at system boot time, so wall_to_monotonic will be negative, * however, we will ALWAYS keep the tv_nsec part positive so we can use * the usual normalization. * * wall_to_monotonic is moved after resume from suspend for the monotonic * time not to jump. We need to add total_sleep_time to wall_to_monotonic * to get the real boot based time offset. * * - wall_to_monotonic is no longer the boot time, getboottime must be * used instead. */static struct timespec xtime __attribute__ ((aligned (16)));static struct timespec wall_to_monotonic __attribute__ ((aligned (16)));static struct timespec total_sleep_time; /* * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */static struct timespec raw_time; /* flag for if timekeeping is suspended */int __read_mostly timekeeping_suspended; /* must hold xtime_lock */void timekeeping_leap_insert(int leapsecond){ xtime.tv_sec += leapsecond; wall_to_monotonic.tv_sec -= leapsecond; update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, timekeeper.mult);} /** * 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(&xtime, nsec); nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); timespec_add_ns(&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(&xtime_lock); *ts = xtime; nsecs = timekeeping_get_ns(); /* If arch requires, add in gettimeoffset() */ nsecs += arch_gettimeoffset(); } while (read_seqretry(&xtime_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(&xtime_lock); secs = xtime.tv_sec + wall_to_monotonic.tv_sec; nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; nsecs += timekeeping_get_ns(); } while (read_seqretry(&xtime_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(&xtime_lock); *ts = xtime; tomono = wall_to_monotonic; nsecs = timekeeping_get_ns(); } while (read_seqretry(&xtime_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(&xtime_lock); *ts_raw = raw_time; *ts_real = 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(&xtime_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(&xtime_lock, flags); timekeeping_forward_now(); ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec; ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec; wall_to_monotonic = timespec_sub(wall_to_monotonic, ts_delta); xtime = *tv; timekeeper.ntp_error = 0; ntp_clear(); update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, timekeeper.mult); write_sequnlock_irqrestore(&xtime_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(&xtime_lock, flags); timekeeping_forward_now(); xtime = timespec_add(xtime, *ts); wall_to_monotonic = timespec_sub(wall_to_monotonic, *ts); timekeeper.ntp_error = 0; ntp_clear(); update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, timekeeper.mult); write_sequnlock_irqrestore(&xtime_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; 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); } 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(&xtime_lock); nsecs = timekeeping_get_ns_raw(); *ts = raw_time; } while (read_seqretry(&xtime_lock, seq)); timespec_add_ns(ts, nsecs);}EXPORT_SYMBOL(getrawmonotonic); /**Lines 1–500 of 1062. Load more
/* * 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; /* 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; /* NTP adjusted clock multiplier */ u32 mult; }; static struct timekeeper timekeeper; /** * 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 using ntp adjusted mult. */ return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); } /* * This read-write spinlock protects us from races in SMP while * playing with xtime. */ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); /* * The current time * wall_to_monotonic is what we need to add to xtime (or xtime corrected * for sub jiffie times) to get to monotonic time. Monotonic is pegged * at zero at system boot time, so wall_to_monotonic will be negative, * however, we will ALWAYS keep the tv_nsec part positive so we can use * the usual normalization. * * wall_to_monotonic is moved after resume from suspend for the monotonic * time not to jump. We need to add total_sleep_time to wall_to_monotonic * to get the real boot based time offset. * * - wall_to_monotonic is no longer the boot time, getboottime must be * used instead. */ static struct timespec xtime __attribute__ ((aligned (16))); static struct timespec wall_to_monotonic __attribute__ ((aligned (16))); static struct timespec total_sleep_time; /* * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */ static struct timespec raw_time; /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; /* must hold xtime_lock */ void timekeeping_leap_insert(int leapsecond) { xtime.tv_sec += leapsecond; wall_to_monotonic.tv_sec -= leapsecond; update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, timekeeper.mult); } /** * 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(&xtime, nsec); nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); timespec_add_ns(&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(&xtime_lock); *ts = xtime; nsecs = timekeeping_get_ns(); /* If arch requires, add in gettimeoffset() */ nsecs += arch_gettimeoffset(); } while (read_seqretry(&xtime_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(&xtime_lock); secs = xtime.tv_sec + wall_to_monotonic.tv_sec; nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; nsecs += timekeeping_get_ns(); } while (read_seqretry(&xtime_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(&xtime_lock); *ts = xtime; tomono = wall_to_monotonic; nsecs = timekeeping_get_ns(); } while (read_seqretry(&xtime_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(&xtime_lock); *ts_raw = raw_time; *ts_real = 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(&xtime_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(&xtime_lock, flags); timekeeping_forward_now(); ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec; ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec; wall_to_monotonic = timespec_sub(wall_to_monotonic, ts_delta); xtime = *tv; timekeeper.ntp_error = 0; ntp_clear(); update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, timekeeper.mult); write_sequnlock_irqrestore(&xtime_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(&xtime_lock, flags); timekeeping_forward_now(); xtime = timespec_add(xtime, *ts); wall_to_monotonic = timespec_sub(wall_to_monotonic, *ts); timekeeper.ntp_error = 0; ntp_clear(); update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, timekeeper.mult); write_sequnlock_irqrestore(&xtime_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; 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); } 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(&xtime_lock); nsecs = timekeeping_get_ns_raw(); *ts = raw_time; } while (read_seqretry(&xtime_lock, seq)); timespec_add_ns(ts, nsecs); } EXPORT_SYMBOL(getrawmonotonic); /**