diff options
Diffstat (limited to 'kernel/time/timekeeping.c')
| -rw-r--r-- | kernel/time/timekeeping.c | 280 |
1 files changed, 246 insertions, 34 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 49010d822f7..8e6a05a5915 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -14,7 +14,7 @@ #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> @@ -32,6 +32,8 @@ struct timekeeper { 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; @@ -47,7 +49,7 @@ struct timekeeper { u32 mult; }; -struct timekeeper timekeeper; +static struct timekeeper timekeeper; /** * timekeeper_setup_internals - Set up internals to use clocksource clock. @@ -62,7 +64,7 @@ struct timekeeper timekeeper; static void timekeeper_setup_internals(struct clocksource *clock) { cycle_t interval; - u64 tmp; + u64 tmp, ntpinterval; timekeeper.clock = clock; clock->cycle_last = clock->read(clock); @@ -70,6 +72,7 @@ static void timekeeper_setup_internals(struct clocksource *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) @@ -80,6 +83,7 @@ static void timekeeper_setup_internals(struct clocksource *clock) /* 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; @@ -160,7 +164,7 @@ static struct timespec total_sleep_time; /* * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */ -struct timespec raw_time; +static struct timespec raw_time; /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; @@ -284,6 +288,49 @@ void ktime_get_ts(struct timespec *ts) } 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 @@ -306,7 +353,7 @@ EXPORT_SYMBOL(do_gettimeofday); * * 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; unsigned long flags; @@ -340,6 +387,42 @@ int do_settimeofday(struct timespec *tv) 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 * @@ -513,14 +596,65 @@ void __init timekeeping_init(void) 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) +{ + xtime = timespec_add(xtime, *delta); + wall_to_monotonic = timespec_sub(wall_to_monotonic, *delta); + total_sleep_time = timespec_add(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(&xtime_lock, flags); + timekeeping_forward_now(); + + __timekeeping_inject_sleeptime(delta); + + timekeeper.ntp_error = 0; + ntp_clear(); + update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, + timekeeper.mult); + + write_sequnlock_irqrestore(&xtime_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) { unsigned long flags; struct timespec ts; @@ -533,9 +667,7 @@ static int timekeeping_resume(struct sys_device *dev) 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); + __timekeeping_inject_sleeptime(&ts); } /* re-base the last cycle value */ timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); @@ -549,11 +681,9 @@ static int timekeeping_resume(struct sys_device *dev) /* Resume hrtimers */ hres_timers_resume(); - - return 0; } -static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) +static int timekeeping_suspend(void) { unsigned long flags; @@ -571,26 +701,18 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) } /* 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 @@ -719,7 +841,8 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) /* Accumulate error between NTP and clock interval */ timekeeper.ntp_error += tick_length << shift; - timekeeper.ntp_error -= timekeeper.xtime_interval << + timekeeper.ntp_error -= + (timekeeper.xtime_interval + timekeeper.xtime_remainder) << (timekeeper.ntp_error_shift + shift); return offset; @@ -731,7 +854,7 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) * * Called from the timer interrupt, must hold a write on xtime_lock. */ -void update_wall_time(void) +static void update_wall_time(void) { struct clocksource *clock; cycle_t offset; @@ -823,7 +946,7 @@ void update_wall_time(void) * 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 @@ -841,6 +964,55 @@ 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 timespec tomono, sleep; + unsigned int seq; + s64 nsecs; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqbegin(&xtime_lock); + *ts = xtime; + tomono = wall_to_monotonic; + sleep = total_sleep_time; + nsecs = timekeeping_get_ns(); + + } while (read_seqretry(&xtime_lock, seq)); + + set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec, + ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec + nsecs); +} +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 @@ -862,11 +1034,6 @@ struct timespec __current_kernel_time(void) return xtime; } -struct timespec __get_wall_to_monotonic(void) -{ - return wall_to_monotonic; -} - struct timespec current_kernel_time(void) { struct timespec now; @@ -898,3 +1065,48 @@ struct timespec get_monotonic_coarse(void) 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(&xtime_lock); + *xtim = xtime; + *wtom = wall_to_monotonic; + *sleep = total_sleep_time; + } while (read_seqretry(&xtime_lock, seq)); +} + +/** + * 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); +} |