diff options
Diffstat (limited to 'kernel/time/timekeeping.c')
| -rw-r--r-- | kernel/time/timekeeping.c | 748 |
1 files changed, 440 insertions, 308 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 6f46a00a1e8a..e16af197a2bc 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -24,32 +24,32 @@ /* Structure holding internal timekeeping values. */ struct timekeeper { /* Current clocksource used for timekeeping. */ - struct clocksource *clock; + struct clocksource *clock; /* NTP adjusted clock multiplier */ - u32 mult; + u32 mult; /* The shift value of the current clocksource. */ - int shift; - + u32 shift; /* Number of clock cycles in one NTP interval. */ - cycle_t cycle_interval; + cycle_t cycle_interval; /* Number of clock shifted nano seconds in one NTP interval. */ - u64 xtime_interval; + u64 xtime_interval; /* shifted nano seconds left over when rounding cycle_interval */ - s64 xtime_remainder; + s64 xtime_remainder; /* Raw nano seconds accumulated per NTP interval. */ - u32 raw_interval; + u32 raw_interval; + + /* Current CLOCK_REALTIME time in seconds */ + u64 xtime_sec; + /* Clock shifted nano seconds */ + u64 xtime_nsec; - /* 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; + s64 ntp_error; /* Shift conversion between clock shifted nano seconds and * ntp shifted nano seconds. */ - int ntp_error_shift; + u32 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 @@ -64,14 +64,17 @@ struct timekeeper { * - wall_to_monotonic is no longer the boot time, getboottime must be * used instead. */ - struct timespec wall_to_monotonic; + struct timespec wall_to_monotonic; + /* Offset clock monotonic -> clock realtime */ + ktime_t offs_real; /* time spent in suspend */ - struct timespec total_sleep_time; + struct timespec total_sleep_time; + /* Offset clock monotonic -> clock boottime */ + ktime_t offs_boot; /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */ - struct timespec raw_time; - + struct timespec raw_time; /* Seqlock for all timekeeper values */ - seqlock_t lock; + seqlock_t lock; }; static struct timekeeper timekeeper; @@ -82,11 +85,62 @@ static struct timekeeper timekeeper; */ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); - /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; +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 struct timespec tk_xtime(struct timekeeper *tk) +{ + struct timespec ts; + + ts.tv_sec = tk->xtime_sec; + ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift); + return ts; +} +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; +} + +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); +} + +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. @@ -98,12 +152,14 @@ int __read_mostly timekeeping_suspended; * * 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, ntpinterval; + struct clocksource *old_clock; - timekeeper.clock = clock; + old_clock = tk->clock; + tk->clock = clock; clock->cycle_last = clock->read(clock); /* Do the ns -> cycle conversion first, using original mult */ @@ -116,74 +172,89 @@ static void timekeeper_setup_internals(struct clocksource *clock) 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.xtime_remainder = ntpinterval - timekeeper.xtime_interval; - 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) +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 gettimeoffset() */ + return nsec + arch_gettimeoffset(); } -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. */ - 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 gettimeoffset() */ + return nsec + arch_gettimeoffset(); } /* must hold write on timekeeper.lock */ -static void timekeeping_update(bool clearntp) +static void timekeeping_update(struct timekeeper *tk, bool clearntp) { + struct timespec xt; + if (clearntp) { - timekeeper.ntp_error = 0; + tk->ntp_error = 0; ntp_clear(); } - update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic, - timekeeper.clock, timekeeper.mult); + xt = tk_xtime(tk); + update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult); } - /** * timekeeping_forward_now - update clock to the current time * @@ -191,27 +262,26 @@ static void timekeeping_update(bool clearntp) * 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; - 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(); + tk->xtime_nsec += arch_gettimeoffset() << tk->shift; - timespec_add_ns(&timekeeper.xtime, nsec); + tk_normalize_xtime(tk); nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); - timespec_add_ns(&timekeeper.raw_time, nsec); + timespec_add_ns(&tk->raw_time, nsec); } /** @@ -222,21 +292,19 @@ static void timekeeping_forward_now(void) */ void getnstimeofday(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; unsigned long seq; - s64 nsecs; + s64 nsecs = 0; WARN_ON(timekeeping_suspended); do { - seq = read_seqbegin(&timekeeper.lock); - - *ts = timekeeper.xtime; - nsecs = timekeeping_get_ns(); + seq = read_seqbegin(&tk->lock); - /* If arch requires, add in gettimeoffset() */ - nsecs += arch_gettimeoffset(); + ts->tv_sec = tk->xtime_sec; + ts->tv_nsec = timekeeping_get_ns(tk); - } while (read_seqretry(&timekeeper.lock, seq)); + } while (read_seqretry(&tk->lock, seq)); timespec_add_ns(ts, nsecs); } @@ -244,22 +312,18 @@ 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(&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)); + seq = read_seqbegin(&tk->lock); + secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; + nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec; + + } while (read_seqretry(&tk->lock, seq)); /* * Use ktime_set/ktime_add_ns to create a proper ktime on * 32-bit architectures without CONFIG_KTIME_SCALAR. @@ -278,24 +342,22 @@ EXPORT_SYMBOL_GPL(ktime_get); */ void ktime_get_ts(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; 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(); + seq = read_seqbegin(&tk->lock); + ts->tv_sec = tk->xtime_sec; + ts->tv_nsec = timekeeping_get_ns(tk); + tomono = tk->wall_to_monotonic; - } while (read_seqretry(&timekeeper.lock, seq)); + } while (read_seqretry(&tk->lock, seq)); set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, - ts->tv_nsec + tomono.tv_nsec + nsecs); + ts->tv_nsec + tomono.tv_nsec); } EXPORT_SYMBOL_GPL(ktime_get_ts); @@ -312,28 +374,23 @@ EXPORT_SYMBOL_GPL(ktime_get_ts); */ 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 { - u32 arch_offset; + seq = read_seqbegin(&tk->lock); - seq = read_seqbegin(&timekeeper.lock); + *ts_raw = tk->raw_time; + ts_real->tv_sec = tk->xtime_sec; + ts_real->tv_nsec = 0; - *ts_raw = timekeeper.raw_time; - *ts_real = timekeeper.xtime; + nsecs_raw = timekeeping_get_ns_raw(tk); + nsecs_real = timekeeping_get_ns(tk); - 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)); + } while (read_seqretry(&tk->lock, seq)); timespec_add_ns(ts_raw, nsecs_raw); timespec_add_ns(ts_real, nsecs_real); @@ -366,25 +423,28 @@ EXPORT_SYMBOL(do_gettimeofday); */ 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) return -EINVAL; - write_seqlock_irqsave(&timekeeper.lock, flags); + write_seqlock_irqsave(&tk->lock, flags); + + timekeeping_forward_now(tk); - timekeeping_forward_now(); + xt = tk_xtime(tk); + ts_delta.tv_sec = tv->tv_sec - xt.tv_sec; + ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec; - 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); + tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta)); - timekeeper.xtime = *tv; - timekeeping_update(true); + tk_set_xtime(tk, tv); - write_sequnlock_irqrestore(&timekeeper.lock, flags); + timekeeping_update(tk, true); + + write_sequnlock_irqrestore(&tk->lock, flags); /* signal hrtimers about time change */ clock_was_set(); @@ -393,7 +453,6 @@ int do_settimeofday(const 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 @@ -402,22 +461,23 @@ EXPORT_SYMBOL(do_settimeofday); */ int timekeeping_inject_offset(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; unsigned long flags; if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) return -EINVAL; - write_seqlock_irqsave(&timekeeper.lock, flags); + write_seqlock_irqsave(&tk->lock, flags); - timekeeping_forward_now(); + timekeeping_forward_now(tk); - timekeeper.xtime = timespec_add(timekeeper.xtime, *ts); - timekeeper.wall_to_monotonic = - timespec_sub(timekeeper.wall_to_monotonic, *ts); - timekeeping_update(true); + tk_xtime_add(tk, ts); + tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts)); - write_sequnlock_irqrestore(&timekeeper.lock, flags); + timekeeping_update(tk, true); + + write_sequnlock_irqrestore(&tk->lock, flags); /* signal hrtimers about time change */ clock_was_set(); @@ -433,23 +493,24 @@ EXPORT_SYMBOL(timekeeping_inject_offset); */ static int change_clocksource(void *data) { + struct timekeeper *tk = &timekeeper; struct clocksource *new, *old; unsigned long flags; new = (struct clocksource *) data; - write_seqlock_irqsave(&timekeeper.lock, flags); + write_seqlock_irqsave(&tk->lock, flags); - timekeeping_forward_now(); + timekeeping_forward_now(tk); if (!new->enable || new->enable(new) == 0) { - old = timekeeper.clock; - timekeeper_setup_internals(new); + old = tk->clock; + tk_setup_internals(tk, new); if (old->disable) old->disable(old); } - timekeeping_update(true); + timekeeping_update(tk, true); - write_sequnlock_irqrestore(&timekeeper.lock, flags); + write_sequnlock_irqrestore(&tk->lock, flags); return 0; } @@ -463,7 +524,9 @@ static int change_clocksource(void *data) */ void timekeeping_notify(struct clocksource *clock) { - if (timekeeper.clock == clock) + struct timekeeper *tk = &timekeeper; + + if (tk->clock == clock) return; stop_machine(change_clocksource, clock, NULL); tick_clock_notify(); @@ -492,35 +555,36 @@ EXPORT_SYMBOL_GPL(ktime_get_real); */ void getrawmonotonic(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; unsigned long seq; s64 nsecs; do { - seq = read_seqbegin(&timekeeper.lock); - nsecs = timekeeping_get_ns_raw(); - *ts = timekeeper.raw_time; + seq = read_seqbegin(&tk->lock); + nsecs = timekeeping_get_ns_raw(tk); + *ts = tk->raw_time; - } while (read_seqretry(&timekeeper.lock, seq)); + } while (read_seqretry(&tk->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) { + struct timekeeper *tk = &timekeeper; unsigned long seq; int ret; do { - seq = read_seqbegin(&timekeeper.lock); + seq = read_seqbegin(&tk->lock); - ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; + ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; - } while (read_seqretry(&timekeeper.lock, seq)); + } while (read_seqretry(&tk->lock, seq)); return ret; } @@ -530,14 +594,16 @@ int timekeeping_valid_for_hres(void) */ u64 timekeeping_max_deferment(void) { + struct timekeeper *tk = &timekeeper; unsigned long seq; u64 ret; + do { - seq = read_seqbegin(&timekeeper.lock); + seq = read_seqbegin(&tk->lock); - ret = timekeeper.clock->max_idle_ns; + ret = tk->clock->max_idle_ns; - } while (read_seqretry(&timekeeper.lock, seq)); + } while (read_seqretry(&tk->lock, seq)); return ret; } @@ -577,36 +643,38 @@ 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); - seqlock_init(&timekeeper.lock); + seqlock_init(&tk->lock); ntp_init(); - write_seqlock_irqsave(&timekeeper.lock, flags); + write_seqlock_irqsave(&tk->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); + 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); + + write_sequnlock_irqrestore(&tk->lock, flags); } /* time in seconds when suspend began */ @@ -619,22 +687,19 @@ static struct timespec timekeeping_suspend_time; * 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) +static void __timekeeping_inject_sleeptime(struct timekeeper *tk, + 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); + 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)); } - /** * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values * @delta: pointer to a timespec delta value @@ -647,6 +712,7 @@ static void __timekeeping_inject_sleeptime(struct timespec *delta) */ void timekeeping_inject_sleeptime(struct timespec *delta) { + struct timekeeper *tk = &timekeeper; unsigned long flags; struct timespec ts; @@ -655,21 +721,20 @@ void timekeeping_inject_sleeptime(struct timespec *delta) if (!(ts.tv_sec == 0 && ts.tv_nsec == 0)) return; - write_seqlock_irqsave(&timekeeper.lock, flags); + write_seqlock_irqsave(&tk->lock, flags); - timekeeping_forward_now(); + timekeeping_forward_now(tk); - __timekeeping_inject_sleeptime(delta); + __timekeeping_inject_sleeptime(tk, delta); - timekeeping_update(true); + timekeeping_update(tk, true); - write_sequnlock_irqrestore(&timekeeper.lock, flags); + write_sequnlock_irqrestore(&tk->lock, flags); /* signal hrtimers about time change */ clock_was_set(); } - /** * timekeeping_resume - Resumes the generic timekeeping subsystem. * @@ -679,6 +744,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta) */ static void timekeeping_resume(void) { + struct timekeeper *tk = &timekeeper; unsigned long flags; struct timespec ts; @@ -686,17 +752,18 @@ static void timekeeping_resume(void) clocksource_resume(); - write_seqlock_irqsave(&timekeeper.lock, flags); + write_seqlock_irqsave(&tk->lock, flags); if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { ts = timespec_sub(ts, timekeeping_suspend_time); - __timekeeping_inject_sleeptime(&ts); + __timekeeping_inject_sleeptime(tk, &ts); } /* re-base the last cycle value */ - timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); - timekeeper.ntp_error = 0; + tk->clock->cycle_last = tk->clock->read(tk->clock); + tk->ntp_error = 0; timekeeping_suspended = 0; - write_sequnlock_irqrestore(&timekeeper.lock, flags); + timekeeping_update(tk, false); + write_sequnlock_irqrestore(&tk->lock, flags); touch_softlockup_watchdog(); @@ -708,14 +775,15 @@ static void timekeeping_resume(void) 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(&timekeeper.lock, flags); - timekeeping_forward_now(); + write_seqlock_irqsave(&tk->lock, flags); + timekeeping_forward_now(tk); timekeeping_suspended = 1; /* @@ -724,7 +792,7 @@ static int timekeeping_suspend(void) * try to compensate so the difference in system time * and persistent_clock time stays close to constant. */ - delta = timespec_sub(timekeeper.xtime, timekeeping_suspend_time); + delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time); delta_delta = timespec_sub(delta, old_delta); if (abs(delta_delta.tv_sec) >= 2) { /* @@ -737,7 +805,7 @@ static int timekeeping_suspend(void) timekeeping_suspend_time = timespec_add(timekeeping_suspend_time, delta_delta); } - write_sequnlock_irqrestore(&timekeeper.lock, flags); + write_sequnlock_irqrestore(&tk->lock, flags); clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); clocksource_suspend(); @@ -763,7 +831,8 @@ 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; @@ -779,7 +848,7 @@ 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; @@ -788,8 +857,8 @@ 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 = ntp_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. */ @@ -814,9 +883,9 @@ 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; /* @@ -832,7 +901,7 @@ static void timekeeping_adjust(s64 offset) * * Note: It does not "save" on aggravation when reading the code. */ - error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1); + error = tk->ntp_error >> (tk->ntp_error_shift - 1); if (error > interval) { /* * We now divide error by 4(via shift), which checks if @@ -847,34 +916,36 @@ static void timekeeping_adjust(s64 offset) * 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 + * the high precision tk->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; + 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(timekeeper.clock->maxadj && - (timekeeper.mult + adj > - timekeeper.clock->mult + timekeeper.clock->maxadj))) { + if (unlikely(tk->clock->maxadj && + (tk->mult + adj > tk->clock->mult + tk->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); + tk->clock->name, (long)tk->mult + adj, + (long)tk->clock->mult + tk->clock->maxadj); } /* * So the following can be confusing. @@ -925,13 +996,68 @@ static void timekeeping_adjust(s64 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; + 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; + } + } +/** + * 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 void accumulate_nsecs_to_secs(struct timekeeper *tk) +{ + u64 nsecps = (u64)NSEC_PER_SEC << tk->shift; + + 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)); + + clock_was_set_delayed(); + } + } +} /** * logarithmic_accumulation - shifted accumulation of cycles @@ -942,49 +1068,40 @@ 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) { - 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) + /* If the offset is smaller then a shifted interval, do nothing */ + if (offset < tk->cycle_interval<<shift) return offset; /* Accumulate one shifted interval */ - offset -= timekeeper.cycle_interval << shift; - timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift; + offset -= tk->cycle_interval << shift; + tk->clock->cycle_last += tk->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; - } + tk->xtime_nsec += tk->xtime_interval << shift; + accumulate_nsecs_to_secs(tk); /* Accumulate raw time */ - raw_nsecs = timekeeper.raw_interval << shift; - raw_nsecs += timekeeper.raw_time.tv_nsec; + raw_nsecs = 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); - timekeeper.raw_time.tv_sec += raw_secs; + tk->raw_time.tv_sec += raw_secs; } - timekeeper.raw_time.tv_nsec = raw_nsecs; + tk->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); + tk->ntp_error += ntp_tick_length() << shift; + tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) << + (tk->ntp_error_shift + shift); return offset; } - /** * update_wall_time - Uses the current clocksource to increment the wall time * @@ -992,25 +1109,25 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) static void update_wall_time(void) { struct clocksource *clock; + struct timekeeper *tk = &timekeeper; cycle_t offset; int shift = 0, maxshift; unsigned long flags; + s64 remainder; - write_seqlock_irqsave(&timekeeper.lock, flags); + write_seqlock_irqsave(&tk->lock, flags); /* Make sure we're fully resumed: */ if (unlikely(timekeeping_suspended)) goto out; - clock = timekeeper.clock; + clock = tk->clock; #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET - offset = timekeeper.cycle_interval; + offset = tk->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 @@ -1020,71 +1137,45 @@ static void update_wall_time(void) * 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 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); + if (offset < tk->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; - } + timekeeping_adjust(tk, offset); /* - * 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; + * 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), this can be killed. + */ + remainder = tk->xtime_nsec & ((1 << tk->shift) - 1); + tk->xtime_nsec -= remainder; + tk->xtime_nsec += 1 << tk->shift; + tk->ntp_error += remainder << tk->ntp_error_shift; /* * Finally, make sure that after the rounding - * xtime.tv_nsec isn't larger than NSEC_PER_SEC + * xtime_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; - } + accumulate_nsecs_to_secs(tk); - timekeeping_update(false); + timekeeping_update(tk, false); out: - write_sequnlock_irqrestore(&timekeeper.lock, flags); + write_sequnlock_irqrestore(&tk->lock, flags); } @@ -1101,18 +1192,18 @@ out: */ void getboottime(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; 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 + .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); } EXPORT_SYMBOL_GPL(getboottime); - /** * get_monotonic_boottime - Returns monotonic time since boot * @ts: pointer to the timespec to be set @@ -1124,23 +1215,23 @@ EXPORT_SYMBOL_GPL(getboottime); */ void get_monotonic_boottime(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; 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(); + seq = read_seqbegin(&tk->lock); + ts->tv_sec = tk->xtime_sec; + ts->tv_nsec = timekeeping_get_ns(tk); + tomono = tk->wall_to_monotonic; + sleep = tk->total_sleep_time; - } while (read_seqretry(&timekeeper.lock, seq)); + } while (read_seqretry(&tk->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); + ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec); } EXPORT_SYMBOL_GPL(get_monotonic_boottime); @@ -1167,31 +1258,38 @@ EXPORT_SYMBOL_GPL(ktime_get_boottime); */ void monotonic_to_bootbased(struct timespec *ts) { - *ts = timespec_add(*ts, timekeeper.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 timekeeper.xtime.tv_sec; + struct timekeeper *tk = &timekeeper; + + return tk->xtime_sec; } EXPORT_SYMBOL(get_seconds); struct timespec __current_kernel_time(void) { - return timekeeper.xtime; + struct timekeeper *tk = &timekeeper; + + return tk_xtime(tk); } struct timespec current_kernel_time(void) { + struct timekeeper *tk = &timekeeper; struct timespec now; unsigned long seq; do { - seq = read_seqbegin(&timekeeper.lock); + seq = read_seqbegin(&tk->lock); - now = timekeeper.xtime; - } while (read_seqretry(&timekeeper.lock, seq)); + now = tk_xtime(tk); + } while (read_seqretry(&tk->lock, seq)); return now; } @@ -1199,15 +1297,16 @@ 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(&timekeeper.lock); + seq = read_seqbegin(&tk->lock); - now = timekeeper.xtime; - mono = timekeeper.wall_to_monotonic; - } while (read_seqretry(&timekeeper.lock, seq)); + now = tk_xtime(tk); + mono = tk->wall_to_monotonic; + } while (read_seqretry(&tk->lock, seq)); set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, now.tv_nsec + mono.tv_nsec); @@ -1236,34 +1335,67 @@ void do_timer(unsigned long ticks) 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_seqbegin(&timekeeper.lock); - *xtim = timekeeper.xtime; - *wtom = timekeeper.wall_to_monotonic; - *sleep = timekeeper.total_sleep_time; - } while (read_seqretry(&timekeeper.lock, seq)); + seq = read_seqbegin(&tk->lock); + *xtim = tk_xtime(tk); + *wtom = tk->wall_to_monotonic; + *sleep = tk->total_sleep_time; + } while (read_seqretry(&tk->lock, 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 + * + * Returns current monotonic time and updates the offsets + * Called from hrtimer_interupt() or retrigger_next_event() + */ +ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot) +{ + struct timekeeper *tk = &timekeeper; + ktime_t now; + unsigned int seq; + u64 secs, nsecs; + + do { + seq = read_seqbegin(&tk->lock); + + secs = tk->xtime_sec; + nsecs = timekeeping_get_ns(tk); + + *offs_real = tk->offs_real; + *offs_boot = tk->offs_boot; + } while (read_seqretry(&tk->lock, 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_seqbegin(&timekeeper.lock); - wtom = timekeeper.wall_to_monotonic; - } while (read_seqretry(&timekeeper.lock, seq)); + seq = read_seqbegin(&tk->lock); + wtom = tk->wall_to_monotonic; + } while (read_seqretry(&tk->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. |