diff options
Diffstat (limited to 'kernel/time/timekeeping.c')
| -rw-r--r-- | kernel/time/timekeeping.c | 1277 |
1 files changed, 888 insertions, 389 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 0c635818640..32d8d6aaedb 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -8,6 +8,7 @@ * */ +#include <linux/timekeeper_internal.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/percpu.h> @@ -20,40 +21,79 @@ #include <linux/time.h> #include <linux/tick.h> #include <linux/stop_machine.h> +#include <linux/pvclock_gtod.h> +#include <linux/compiler.h> -/* Structure holding internal timekeeping values. */ -struct timekeeper { - /* Current clocksource used for timekeeping. */ - struct clocksource *clock; - /* The shift value of the current clocksource. */ - int shift; - - /* Number of clock cycles in one NTP interval. */ - cycle_t cycle_interval; - /* Number of clock shifted nano seconds in one NTP interval. */ - u64 xtime_interval; - /* 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; -}; +#include "tick-internal.h" +#include "ntp_internal.h" +#include "timekeeping_internal.h" + +#define TK_CLEAR_NTP (1 << 0) +#define TK_MIRROR (1 << 1) +#define TK_CLOCK_WAS_SET (1 << 2) static struct timekeeper timekeeper; +static DEFINE_RAW_SPINLOCK(timekeeper_lock); +static seqcount_t timekeeper_seq; +static struct timekeeper shadow_timekeeper; + +/* flag for if timekeeping is suspended */ +int __read_mostly timekeeping_suspended; + +/* Flag for if there is a persistent clock on this platform */ +bool __read_mostly persistent_clock_exist = false; + +static inline void tk_normalize_xtime(struct timekeeper *tk) +{ + while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) { + tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift; + tk->xtime_sec++; + } +} + +static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts) +{ + tk->xtime_sec = ts->tv_sec; + tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift; +} + +static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts) +{ + tk->xtime_sec += ts->tv_sec; + tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift; + tk_normalize_xtime(tk); +} + +static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm) +{ + struct timespec tmp; + + /* + * Verify consistency of: offset_real = -wall_to_monotonic + * before modifying anything + */ + set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec, + -tk->wall_to_monotonic.tv_nsec); + WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64); + tk->wall_to_monotonic = wtm; + set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec); + tk->offs_real = timespec_to_ktime(tmp); + tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0)); +} + +static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t) +{ + /* Verify consistency before modifying */ + WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64); + + tk->total_sleep_time = t; + tk->offs_boot = timespec_to_ktime(t); +} /** - * timekeeper_setup_internals - Set up internals to use clocksource clock. + * tk_setup_internals - Set up internals to use clocksource clock. * + * @tk: The target timekeeper to setup. * @clock: Pointer to clocksource. * * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment @@ -61,13 +101,15 @@ static struct timekeeper timekeeper; * * Unless you're the timekeeping code, you should not be using this! */ -static void timekeeper_setup_internals(struct clocksource *clock) +static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) { cycle_t interval; u64 tmp, ntpinterval; + struct clocksource *old_clock; - timekeeper.clock = clock; - clock->cycle_last = clock->read(clock); + old_clock = tk->clock; + tk->clock = clock; + tk->cycle_last = clock->cycle_last = clock->read(clock); /* Do the ns -> cycle conversion first, using original mult */ tmp = NTP_INTERVAL_LENGTH; @@ -79,103 +121,144 @@ 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) + +#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET +u32 (*arch_gettimeoffset)(void); + +u32 get_arch_timeoffset(void) +{ + if (likely(arch_gettimeoffset)) + return arch_gettimeoffset(); + return 0; +} +#else +static inline u32 get_arch_timeoffset(void) { return 0; } +#endif + +static inline s64 timekeeping_get_ns(struct timekeeper *tk) { cycle_t cycle_now, cycle_delta; struct clocksource *clock; + s64 nsec; /* read clocksource: */ - clock = timekeeper.clock; + clock = tk->clock; cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - /* return delta convert to nanoseconds using ntp adjusted mult. */ - return clocksource_cyc2ns(cycle_delta, timekeeper.mult, - timekeeper.shift); + nsec = cycle_delta * tk->mult + tk->xtime_nsec; + nsec >>= tk->shift; + + /* If arch requires, add in get_arch_timeoffset() */ + return nsec + get_arch_timeoffset(); } -static inline s64 timekeeping_get_ns_raw(void) +static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) { cycle_t cycle_now, cycle_delta; struct clocksource *clock; + s64 nsec; /* read clocksource: */ - clock = timekeeper.clock; + clock = tk->clock; cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - /* return delta convert to nanoseconds. */ - return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); + /* convert delta to nanoseconds. */ + nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); + + /* If arch requires, add in get_arch_timeoffset() */ + return nsec + get_arch_timeoffset(); } -/* - * This read-write spinlock protects us from races in SMP while - * playing with xtime. - */ -__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); +static RAW_NOTIFIER_HEAD(pvclock_gtod_chain); +static void update_pvclock_gtod(struct timekeeper *tk, bool was_set) +{ + raw_notifier_call_chain(&pvclock_gtod_chain, was_set, tk); +} -/* - * The current time - * wall_to_monotonic is what we need to add to xtime (or xtime corrected - * for sub jiffie times) to get to monotonic time. Monotonic is pegged - * at zero at system boot time, so wall_to_monotonic will be negative, - * however, we will ALWAYS keep the tv_nsec part positive so we can use - * the usual normalization. - * - * wall_to_monotonic is moved after resume from suspend for the monotonic - * time not to jump. We need to add total_sleep_time to wall_to_monotonic - * to get the real boot based time offset. - * - * - wall_to_monotonic is no longer the boot time, getboottime must be - * used instead. +/** + * pvclock_gtod_register_notifier - register a pvclock timedata update listener */ -static struct timespec xtime __attribute__ ((aligned (16))); -static struct timespec wall_to_monotonic __attribute__ ((aligned (16))); -static struct timespec total_sleep_time; +int pvclock_gtod_register_notifier(struct notifier_block *nb) +{ + struct timekeeper *tk = &timekeeper; + unsigned long flags; + int ret; -/* - * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. + raw_spin_lock_irqsave(&timekeeper_lock, flags); + ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); + update_pvclock_gtod(tk, true); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + + return ret; +} +EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier); + +/** + * pvclock_gtod_unregister_notifier - unregister a pvclock + * timedata update listener */ -static struct timespec raw_time; +int pvclock_gtod_unregister_notifier(struct notifier_block *nb) +{ + unsigned long flags; + int ret; -/* flag for if timekeeping is suspended */ -int __read_mostly timekeeping_suspended; + raw_spin_lock_irqsave(&timekeeper_lock, flags); + ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); -/* must hold xtime_lock */ -void timekeeping_leap_insert(int leapsecond) + return ret; +} +EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); + +/* must hold timekeeper_lock */ +static void timekeeping_update(struct timekeeper *tk, unsigned int action) { - xtime.tv_sec += leapsecond; - wall_to_monotonic.tv_sec -= leapsecond; - update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, - timekeeper.mult); + if (action & TK_CLEAR_NTP) { + tk->ntp_error = 0; + ntp_clear(); + } + update_vsyscall(tk); + update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); + + if (action & TK_MIRROR) + memcpy(&shadow_timekeeper, &timekeeper, sizeof(timekeeper)); } /** @@ -185,74 +268,88 @@ void timekeeping_leap_insert(int leapsecond) * update_wall_time(). This is useful before significant clock changes, * as it avoids having to deal with this time offset explicitly. */ -static void timekeeping_forward_now(void) +static void timekeeping_forward_now(struct timekeeper *tk) { cycle_t cycle_now, cycle_delta; struct clocksource *clock; s64 nsec; - clock = timekeeper.clock; + clock = tk->clock; cycle_now = clock->read(clock); cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - clock->cycle_last = cycle_now; + tk->cycle_last = clock->cycle_last = cycle_now; - nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult, - timekeeper.shift); + tk->xtime_nsec += cycle_delta * tk->mult; - /* If arch requires, add in gettimeoffset() */ - nsec += arch_gettimeoffset(); + /* If arch requires, add in get_arch_timeoffset() */ + tk->xtime_nsec += (u64)get_arch_timeoffset() << tk->shift; - timespec_add_ns(&xtime, nsec); + tk_normalize_xtime(tk); nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); - timespec_add_ns(&raw_time, nsec); + timespec_add_ns(&tk->raw_time, nsec); } /** - * getnstimeofday - Returns the time of day in a timespec + * __getnstimeofday - Returns the time of day in a timespec. * @ts: pointer to the timespec to be set * - * Returns the time of day in a timespec. + * Updates the time of day in the timespec. + * Returns 0 on success, or -ve when suspended (timespec will be undefined). */ -void getnstimeofday(struct timespec *ts) +int __getnstimeofday(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; unsigned long seq; - s64 nsecs; - - WARN_ON(timekeeping_suspended); + s64 nsecs = 0; do { - seq = read_seqbegin(&xtime_lock); + seq = read_seqcount_begin(&timekeeper_seq); - *ts = xtime; - nsecs = timekeeping_get_ns(); + ts->tv_sec = tk->xtime_sec; + nsecs = timekeeping_get_ns(tk); - /* If arch requires, add in gettimeoffset() */ - nsecs += arch_gettimeoffset(); - - } while (read_seqretry(&xtime_lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); + ts->tv_nsec = 0; timespec_add_ns(ts, nsecs); + + /* + * Do not bail out early, in case there were callers still using + * the value, even in the face of the WARN_ON. + */ + if (unlikely(timekeeping_suspended)) + return -EAGAIN; + return 0; } +EXPORT_SYMBOL(__getnstimeofday); +/** + * getnstimeofday - Returns the time of day in a timespec. + * @ts: pointer to the timespec to be set + * + * Returns the time of day in a timespec (WARN if suspended). + */ +void getnstimeofday(struct timespec *ts) +{ + WARN_ON(__getnstimeofday(ts)); +} EXPORT_SYMBOL(getnstimeofday); ktime_t ktime_get(void) { + struct timekeeper *tk = &timekeeper; unsigned int seq; s64 secs, nsecs; WARN_ON(timekeeping_suspended); do { - seq = read_seqbegin(&xtime_lock); - secs = xtime.tv_sec + wall_to_monotonic.tv_sec; - nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; - nsecs += timekeeping_get_ns(); - /* If arch requires, add in gettimeoffset() */ - nsecs += arch_gettimeoffset(); - - } while (read_seqretry(&xtime_lock, seq)); + seq = read_seqcount_begin(&timekeeper_seq); + secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; + nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec; + + } while (read_seqcount_retry(&timekeeper_seq, seq)); /* * Use ktime_set/ktime_add_ns to create a proper ktime on * 32-bit architectures without CONFIG_KTIME_SCALAR. @@ -271,27 +368,71 @@ EXPORT_SYMBOL_GPL(ktime_get); */ void ktime_get_ts(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; struct timespec tomono; + s64 nsec; unsigned int seq; - s64 nsecs; WARN_ON(timekeeping_suspended); do { - seq = read_seqbegin(&xtime_lock); - *ts = xtime; - tomono = wall_to_monotonic; - nsecs = timekeeping_get_ns(); - /* If arch requires, add in gettimeoffset() */ - nsecs += arch_gettimeoffset(); + seq = read_seqcount_begin(&timekeeper_seq); + ts->tv_sec = tk->xtime_sec; + nsec = timekeeping_get_ns(tk); + tomono = tk->wall_to_monotonic; - } while (read_seqretry(&xtime_lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); - set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, - ts->tv_nsec + tomono.tv_nsec + nsecs); + ts->tv_sec += tomono.tv_sec; + ts->tv_nsec = 0; + timespec_add_ns(ts, nsec + tomono.tv_nsec); } EXPORT_SYMBOL_GPL(ktime_get_ts); + +/** + * timekeeping_clocktai - Returns the TAI time of day in a timespec + * @ts: pointer to the timespec to be set + * + * Returns the time of day in a timespec. + */ +void timekeeping_clocktai(struct timespec *ts) +{ + struct timekeeper *tk = &timekeeper; + unsigned long seq; + u64 nsecs; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqcount_begin(&timekeeper_seq); + + ts->tv_sec = tk->xtime_sec + tk->tai_offset; + nsecs = timekeeping_get_ns(tk); + + } while (read_seqcount_retry(&timekeeper_seq, seq)); + + ts->tv_nsec = 0; + timespec_add_ns(ts, nsecs); + +} +EXPORT_SYMBOL(timekeeping_clocktai); + + +/** + * ktime_get_clocktai - Returns the TAI time of day in a ktime + * + * Returns the time of day in a ktime. + */ +ktime_t ktime_get_clocktai(void) +{ + struct timespec ts; + + timekeeping_clocktai(&ts); + return timespec_to_ktime(ts); +} +EXPORT_SYMBOL(ktime_get_clocktai); + #ifdef CONFIG_NTP_PPS /** @@ -305,28 +446,23 @@ 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(&xtime_lock); - - *ts_raw = raw_time; - *ts_real = xtime; + seq = read_seqcount_begin(&timekeeper_seq); - nsecs_raw = timekeeping_get_ns_raw(); - nsecs_real = timekeeping_get_ns(); + *ts_raw = tk->raw_time; + ts_real->tv_sec = tk->xtime_sec; + ts_real->tv_nsec = 0; - /* If arch requires, add in gettimeoffset() */ - arch_offset = arch_gettimeoffset(); - nsecs_raw += arch_offset; - nsecs_real += arch_offset; + nsecs_raw = timekeeping_get_ns_raw(tk); + nsecs_real = timekeeping_get_ns(tk); - } while (read_seqretry(&xtime_lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); timespec_add_ns(ts_raw, nsecs_raw); timespec_add_ns(ts_real, nsecs_real); @@ -349,8 +485,8 @@ void do_gettimeofday(struct timeval *tv) tv->tv_sec = now.tv_sec; tv->tv_usec = now.tv_nsec/1000; } - EXPORT_SYMBOL(do_gettimeofday); + /** * do_settimeofday - Sets the time of day * @tv: pointer to the timespec variable containing the new time @@ -359,39 +495,38 @@ 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) + if (!timespec_valid_strict(tv)) return -EINVAL; - write_seqlock_irqsave(&xtime_lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); - timekeeping_forward_now(); + timekeeping_forward_now(tk); - ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec; - ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec; - wall_to_monotonic = timespec_sub(wall_to_monotonic, ts_delta); + xt = tk_xtime(tk); + ts_delta.tv_sec = tv->tv_sec - xt.tv_sec; + ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec; - xtime = *tv; + tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta)); - timekeeper.ntp_error = 0; - ntp_clear(); + tk_set_xtime(tk, tv); - update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, - timekeeper.mult); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); - write_sequnlock_irqrestore(&xtime_lock, flags); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); /* signal hrtimers about time change */ clock_was_set(); return 0; } - EXPORT_SYMBOL(do_settimeofday); - /** * timekeeping_inject_offset - Adds or subtracts from the current time. * @tv: pointer to the timespec variable containing the offset @@ -400,33 +535,89 @@ EXPORT_SYMBOL(do_settimeofday); */ int timekeeping_inject_offset(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; unsigned long flags; + struct timespec tmp; + int ret = 0; if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC) return -EINVAL; - write_seqlock_irqsave(&xtime_lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); - timekeeping_forward_now(); + timekeeping_forward_now(tk); - xtime = timespec_add(xtime, *ts); - wall_to_monotonic = timespec_sub(wall_to_monotonic, *ts); + /* Make sure the proposed value is valid */ + tmp = timespec_add(tk_xtime(tk), *ts); + if (!timespec_valid_strict(&tmp)) { + ret = -EINVAL; + goto error; + } - timekeeper.ntp_error = 0; - ntp_clear(); + tk_xtime_add(tk, ts); + tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts)); - update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, - timekeeper.mult); +error: /* even if we error out, we forwarded the time, so call update */ + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); - write_sequnlock_irqrestore(&xtime_lock, flags); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); /* signal hrtimers about time change */ clock_was_set(); - return 0; + return ret; } EXPORT_SYMBOL(timekeeping_inject_offset); + +/** + * timekeeping_get_tai_offset - Returns current TAI offset from UTC + * + */ +s32 timekeeping_get_tai_offset(void) +{ + struct timekeeper *tk = &timekeeper; + unsigned int seq; + s32 ret; + + do { + seq = read_seqcount_begin(&timekeeper_seq); + ret = tk->tai_offset; + } while (read_seqcount_retry(&timekeeper_seq, seq)); + + return ret; +} + +/** + * __timekeeping_set_tai_offset - Lock free worker function + * + */ +static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset) +{ + tk->tai_offset = tai_offset; + tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0)); +} + +/** + * timekeeping_set_tai_offset - Sets the current TAI offset from UTC + * + */ +void timekeeping_set_tai_offset(s32 tai_offset) +{ + struct timekeeper *tk = &timekeeper; + unsigned long flags; + + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); + __timekeeping_set_tai_offset(tk, tai_offset); + timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + clock_was_set(); +} + /** * change_clocksource - Swaps clocksources if a new one is available * @@ -434,17 +625,36 @@ 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; - timekeeping_forward_now(); - if (!new->enable || new->enable(new) == 0) { - old = timekeeper.clock; - timekeeper_setup_internals(new); - if (old->disable) - old->disable(old); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); + + timekeeping_forward_now(tk); + /* + * If the cs is in module, get a module reference. Succeeds + * for built-in code (owner == NULL) as well. + */ + if (try_module_get(new->owner)) { + if (!new->enable || new->enable(new) == 0) { + old = tk->clock; + tk_setup_internals(tk, new); + if (old->disable) + old->disable(old); + module_put(old->owner); + } else { + module_put(new->owner); + } } + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); + + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + return 0; } @@ -455,12 +665,15 @@ static int change_clocksource(void *data) * This function is called from clocksource.c after a new, better clock * source has been registered. The caller holds the clocksource_mutex. */ -void timekeeping_notify(struct clocksource *clock) +int timekeeping_notify(struct clocksource *clock) { - if (timekeeper.clock == clock) - return; + struct timekeeper *tk = &timekeeper; + + if (tk->clock == clock) + return 0; stop_machine(change_clocksource, clock, NULL); tick_clock_notify(); + return tk->clock == clock ? 0 : -1; } /** @@ -486,48 +699,57 @@ EXPORT_SYMBOL_GPL(ktime_get_real); */ void getrawmonotonic(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; unsigned long seq; s64 nsecs; do { - seq = read_seqbegin(&xtime_lock); - nsecs = timekeeping_get_ns_raw(); - *ts = raw_time; + seq = read_seqcount_begin(&timekeeper_seq); + nsecs = timekeeping_get_ns_raw(tk); + *ts = tk->raw_time; - } while (read_seqretry(&xtime_lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); timespec_add_ns(ts, nsecs); } EXPORT_SYMBOL(getrawmonotonic); - /** * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres */ int timekeeping_valid_for_hres(void) { + struct timekeeper *tk = &timekeeper; unsigned long seq; int ret; do { - seq = read_seqbegin(&xtime_lock); + seq = read_seqcount_begin(&timekeeper_seq); - ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; + ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; - } while (read_seqretry(&xtime_lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, seq)); return ret; } /** * timekeeping_max_deferment - Returns max time the clocksource can be deferred - * - * Caller must observe xtime_lock via read_seqbegin/read_seqretry to - * ensure that the clocksource does not change! */ u64 timekeeping_max_deferment(void) { - return timekeeper.clock->max_idle_ns; + struct timekeeper *tk = &timekeeper; + unsigned long seq; + u64 ret; + + do { + seq = read_seqcount_begin(&timekeeper_seq); + + ret = tk->clock->max_idle_ns; + + } while (read_seqcount_retry(&timekeeper_seq, seq)); + + return ret; } /** @@ -539,7 +761,7 @@ u64 timekeeping_max_deferment(void) * * XXX - Do be sure to remove it once all arches implement it. */ -void __attribute__((weak)) read_persistent_clock(struct timespec *ts) +void __weak read_persistent_clock(struct timespec *ts) { ts->tv_sec = 0; ts->tv_nsec = 0; @@ -554,7 +776,7 @@ void __attribute__((weak)) read_persistent_clock(struct timespec *ts) * * XXX - Do be sure to remove it once all arches implement it. */ -void __attribute__((weak)) read_boot_clock(struct timespec *ts) +void __weak read_boot_clock(struct timespec *ts) { ts->tv_sec = 0; ts->tv_nsec = 0; @@ -565,35 +787,55 @@ void __attribute__((weak)) read_boot_clock(struct timespec *ts) */ void __init timekeeping_init(void) { + struct timekeeper *tk = &timekeeper; struct clocksource *clock; unsigned long flags; - struct timespec now, boot; + struct timespec now, boot, tmp; read_persistent_clock(&now); - read_boot_clock(&boot); - write_seqlock_irqsave(&xtime_lock, flags); + if (!timespec_valid_strict(&now)) { + pr_warn("WARNING: Persistent clock returned invalid value!\n" + " Check your CMOS/BIOS settings.\n"); + now.tv_sec = 0; + now.tv_nsec = 0; + } else if (now.tv_sec || now.tv_nsec) + persistent_clock_exist = true; + + read_boot_clock(&boot); + if (!timespec_valid_strict(&boot)) { + pr_warn("WARNING: Boot clock returned invalid value!\n" + " Check your CMOS/BIOS settings.\n"); + boot.tv_sec = 0; + boot.tv_nsec = 0; + } + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); ntp_init(); clock = clocksource_default_clock(); if (clock->enable) clock->enable(clock); - timekeeper_setup_internals(clock); - - xtime.tv_sec = now.tv_sec; - xtime.tv_nsec = now.tv_nsec; - raw_time.tv_sec = 0; - raw_time.tv_nsec = 0; - if (boot.tv_sec == 0 && boot.tv_nsec == 0) { - boot.tv_sec = xtime.tv_sec; - boot.tv_nsec = xtime.tv_nsec; - } - set_normalized_timespec(&wall_to_monotonic, - -boot.tv_sec, -boot.tv_nsec); - total_sleep_time.tv_sec = 0; - total_sleep_time.tv_nsec = 0; - write_sequnlock_irqrestore(&xtime_lock, flags); + tk_setup_internals(tk, clock); + + tk_set_xtime(tk, &now); + tk->raw_time.tv_sec = 0; + tk->raw_time.tv_nsec = 0; + if (boot.tv_sec == 0 && boot.tv_nsec == 0) + boot = tk_xtime(tk); + + set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec); + tk_set_wall_to_mono(tk, tmp); + + tmp.tv_sec = 0; + tmp.tv_nsec = 0; + tk_set_sleep_time(tk, tmp); + + memcpy(&shadow_timekeeper, &timekeeper, sizeof(timekeeper)); + + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); } /* time in seconds when suspend began */ @@ -606,20 +848,21 @@ 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"); + if (!timespec_valid_strict(delta)) { + printk_deferred(KERN_WARNING + "__timekeeping_inject_sleeptime: Invalid " + "sleep delta value!\n"); return; } - - xtime = timespec_add(xtime, *delta); - wall_to_monotonic = timespec_sub(wall_to_monotonic, *delta); - total_sleep_time = timespec_add(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)); + tk_debug_account_sleep_time(delta); } - /** * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values * @delta: pointer to a timespec delta value @@ -632,31 +875,32 @@ 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; - /* Make sure we don't set the clock twice */ - read_persistent_clock(&ts); - if (!(ts.tv_sec == 0 && ts.tv_nsec == 0)) + /* + * Make sure we don't set the clock twice, as timekeeping_resume() + * already did it + */ + if (has_persistent_clock()) return; - write_seqlock_irqsave(&xtime_lock, flags); - timekeeping_forward_now(); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); + + timekeeping_forward_now(tk); - __timekeeping_inject_sleeptime(delta); + __timekeeping_inject_sleeptime(tk, delta); - timekeeper.ntp_error = 0; - ntp_clear(); - update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, - timekeeper.mult); + timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); - write_sequnlock_irqrestore(&xtime_lock, flags); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); /* signal hrtimers about time change */ clock_was_set(); } - /** * timekeeping_resume - Resumes the generic timekeeping subsystem. * @@ -666,24 +910,73 @@ void timekeeping_inject_sleeptime(struct timespec *delta) */ static void timekeeping_resume(void) { + struct timekeeper *tk = &timekeeper; + struct clocksource *clock = tk->clock; unsigned long flags; - struct timespec ts; + struct timespec ts_new, ts_delta; + cycle_t cycle_now, cycle_delta; + bool suspendtime_found = false; - read_persistent_clock(&ts); + read_persistent_clock(&ts_new); + clockevents_resume(); clocksource_resume(); - write_seqlock_irqsave(&xtime_lock, flags); + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); + + /* + * After system resumes, we need to calculate the suspended time and + * compensate it for the OS time. There are 3 sources that could be + * used: Nonstop clocksource during suspend, persistent clock and rtc + * device. + * + * One specific platform may have 1 or 2 or all of them, and the + * preference will be: + * suspend-nonstop clocksource -> persistent clock -> rtc + * The less preferred source will only be tried if there is no better + * usable source. The rtc part is handled separately in rtc core code. + */ + cycle_now = clock->read(clock); + if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) && + cycle_now > clock->cycle_last) { + u64 num, max = ULLONG_MAX; + u32 mult = clock->mult; + u32 shift = clock->shift; + s64 nsec = 0; + + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { - ts = timespec_sub(ts, timekeeping_suspend_time); - __timekeeping_inject_sleeptime(&ts); + /* + * "cycle_delta * mutl" may cause 64 bits overflow, if the + * suspended time is too long. In that case we need do the + * 64 bits math carefully + */ + do_div(max, mult); + if (cycle_delta > max) { + num = div64_u64(cycle_delta, max); + nsec = (((u64) max * mult) >> shift) * num; + cycle_delta -= num * max; + } + nsec += ((u64) cycle_delta * mult) >> shift; + + ts_delta = ns_to_timespec(nsec); + suspendtime_found = true; + } else if (timespec_compare(&ts_new, &timekeeping_suspend_time) > 0) { + ts_delta = timespec_sub(ts_new, timekeeping_suspend_time); + suspendtime_found = true; } - /* re-base the last cycle value */ - timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); - timekeeper.ntp_error = 0; + + if (suspendtime_found) + __timekeeping_inject_sleeptime(tk, &ts_delta); + + /* Re-base the last cycle value */ + tk->cycle_last = clock->cycle_last = cycle_now; + tk->ntp_error = 0; timekeeping_suspended = 0; - write_sequnlock_irqrestore(&xtime_lock, flags); + timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); touch_softlockup_watchdog(); @@ -695,14 +988,24 @@ 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(&xtime_lock, flags); - timekeeping_forward_now(); + /* + * On some systems the persistent_clock can not be detected at + * timekeeping_init by its return value, so if we see a valid + * value returned, update the persistent_clock_exists flag. + */ + if (timekeeping_suspend_time.tv_sec || timekeeping_suspend_time.tv_nsec) + persistent_clock_exist = true; + + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); + timekeeping_forward_now(tk); timekeeping_suspended = 1; /* @@ -711,7 +1014,7 @@ 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(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) { /* @@ -724,10 +1027,14 @@ static int timekeeping_suspend(void) timekeeping_suspend_time = timespec_add(timekeeping_suspend_time, delta_delta); } - write_sequnlock_irqrestore(&xtime_lock, flags); + + timekeeping_update(tk, TK_MIRROR); + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL); clocksource_suspend(); + clockevents_suspend(); return 0; } @@ -750,7 +1057,8 @@ 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; @@ -766,7 +1074,7 @@ static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval, * here. This is tuned so that an error of about 1 msec is adjusted * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). */ - error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); + error2 = tk->ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); error2 = abs(error2); for (look_ahead = 0; error2 > 0; look_ahead++) error2 >>= 2; @@ -775,8 +1083,8 @@ static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval, * Now calculate the error in (1 << look_ahead) ticks, but first * remove the single look ahead already included in the error. */ - tick_error = tick_length >> (timekeeper.ntp_error_shift + 1); - tick_error -= timekeeper.xtime_interval >> 1; + tick_error = ntp_tick_length() >> (tk->ntp_error_shift + 1); + tick_error -= tk->xtime_interval >> 1; error = ((error - tick_error) >> look_ahead) + tick_error; /* Finally calculate the adjustment shift value. */ @@ -801,13 +1109,13 @@ 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; /* - * The point of this is to check if the error is greater then half + * 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. @@ -815,52 +1123,46 @@ static void timekeeping_adjust(s64 offset) * 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 then half an interval. + * 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); + error = tk->ntp_error >> (tk->ntp_error_shift - 1); if (error > interval) { /* * We now divide error by 4(via shift), which checks if - * the error is greater then twice the interval. + * 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; + 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; + } + } - WARN_ONCE(timekeeper.clock->maxadj && - (timekeeper.mult + adj > timekeeper.clock->mult + - timekeeper.clock->maxadj), - "Adjusting %s more then 11%% (%ld vs %ld)\n", - timekeeper.clock->name, (long)timekeeper.mult + adj, - (long)timekeeper.clock->mult + - timekeeper.clock->maxadj); + if (unlikely(tk->clock->maxadj && + (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) { + printk_deferred_once(KERN_WARNING + "Adjusting %s more than 11%% (%ld vs %ld)\n", + tk->clock->name, (long)tk->mult + adj, + (long)tk->clock->mult + tk->clock->maxadj); + } /* * So the following can be confusing. * @@ -910,13 +1212,72 @@ 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 unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk) +{ + u64 nsecps = (u64)NSEC_PER_SEC << tk->shift; + unsigned int clock_set = 0; + + while (tk->xtime_nsec >= nsecps) { + int leap; + + tk->xtime_nsec -= nsecps; + tk->xtime_sec++; + + /* Figure out if its a leap sec and apply if needed */ + leap = second_overflow(tk->xtime_sec); + if (unlikely(leap)) { + struct timespec ts; + + tk->xtime_sec += leap; + + ts.tv_sec = leap; + ts.tv_nsec = 0; + tk_set_wall_to_mono(tk, + timespec_sub(tk->wall_to_monotonic, ts)); + + __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); + + clock_set = TK_CLOCK_WAS_SET; + } + } + return clock_set; +} /** * logarithmic_accumulation - shifted accumulation of cycles @@ -927,137 +1288,157 @@ static void timekeeping_adjust(s64 offset) * * Returns the unconsumed cycles. */ -static cycle_t logarithmic_accumulation(cycle_t offset, int shift) +static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, + u32 shift, + unsigned int *clock_set) { - u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift; + cycle_t interval = tk->cycle_interval << shift; u64 raw_nsecs; /* If the offset is smaller then a shifted interval, do nothing */ - if (offset < timekeeper.cycle_interval<<shift) + if (offset < interval) return offset; /* Accumulate one shifted interval */ - offset -= timekeeper.cycle_interval << shift; - timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift; - - timekeeper.xtime_nsec += timekeeper.xtime_interval << shift; - while (timekeeper.xtime_nsec >= nsecps) { - timekeeper.xtime_nsec -= nsecps; - xtime.tv_sec++; - second_overflow(); - } + offset -= interval; + tk->cycle_last += interval; + + tk->xtime_nsec += tk->xtime_interval << shift; + *clock_set |= accumulate_nsecs_to_secs(tk); /* Accumulate raw time */ - raw_nsecs = timekeeper.raw_interval << shift; - raw_nsecs += raw_time.tv_nsec; + raw_nsecs = (u64)tk->raw_interval << shift; + raw_nsecs += tk->raw_time.tv_nsec; if (raw_nsecs >= NSEC_PER_SEC) { u64 raw_secs = raw_nsecs; raw_nsecs = do_div(raw_secs, NSEC_PER_SEC); - raw_time.tv_sec += raw_secs; + tk->raw_time.tv_sec += raw_secs; } - raw_time.tv_nsec = raw_nsecs; + tk->raw_time.tv_nsec = raw_nsecs; /* Accumulate error between NTP and clock interval */ - timekeeper.ntp_error += tick_length << shift; - timekeeper.ntp_error -= - (timekeeper.xtime_interval + timekeeper.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; } +#ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD +static inline void old_vsyscall_fixup(struct timekeeper *tk) +{ + s64 remainder; + + /* + * Store only full nanoseconds into xtime_nsec after rounding + * it up and add the remainder to the error difference. + * XXX - This is necessary to avoid small 1ns inconsistnecies caused + * by truncating the remainder in vsyscalls. However, it causes + * additional work to be done in timekeeping_adjust(). Once + * the vsyscall implementations are converted to use xtime_nsec + * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD + * users are removed, this can be killed. + */ + remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1); + tk->xtime_nsec -= remainder; + tk->xtime_nsec += 1ULL << tk->shift; + tk->ntp_error += remainder << tk->ntp_error_shift; + tk->ntp_error -= (1ULL << tk->shift) << tk->ntp_error_shift; +} +#else +#define old_vsyscall_fixup(tk) +#endif + + /** * update_wall_time - Uses the current clocksource to increment the wall time * - * Called from the timer interrupt, must hold a write on xtime_lock. */ -static void update_wall_time(void) +void update_wall_time(void) { struct clocksource *clock; + struct timekeeper *real_tk = &timekeeper; + struct timekeeper *tk = &shadow_timekeeper; cycle_t offset; int shift = 0, maxshift; + unsigned int clock_set = 0; + unsigned long flags; + + raw_spin_lock_irqsave(&timekeeper_lock, flags); /* Make sure we're fully resumed: */ if (unlikely(timekeeping_suspended)) - return; + goto out; - clock = timekeeper.clock; + clock = real_tk->clock; #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET - offset = timekeeper.cycle_interval; + offset = real_tk->cycle_interval; #else offset = (clock->read(clock) - clock->cycle_last) & clock->mask; #endif - timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; + + /* Check if there's really nothing to do */ + if (offset < real_tk->cycle_interval) + goto out; /* * With NO_HZ we may have to accumulate many cycle_intervals * (think "ticks") worth of time at once. To do this efficiently, * we calculate the largest doubling multiple of cycle_intervals - * that is smaller then the offset. We then accumulate that + * that is smaller than the offset. We then accumulate that * chunk in one go, and then try to consume the next smaller * doubled multiple. */ - shift = ilog2(offset) - ilog2(timekeeper.cycle_interval); + shift = ilog2(offset) - ilog2(tk->cycle_interval); shift = max(0, shift); - /* Bound shift to one less then what overflows tick_length */ - maxshift = (8*sizeof(tick_length) - (ilog2(tick_length)+1)) - 1; + /* Bound shift to one less than what overflows tick_length */ + maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1; shift = min(shift, maxshift); - while (offset >= timekeeper.cycle_interval) { - offset = logarithmic_accumulation(offset, shift); - if(offset < timekeeper.cycle_interval<<shift) + while (offset >= tk->cycle_interval) { + offset = logarithmic_accumulation(tk, offset, shift, + &clock_set); + if (offset < tk->cycle_interval<<shift) shift--; } /* correct the clock when NTP error is too big */ - timekeeping_adjust(offset); + timekeeping_adjust(tk, offset); /* - * Since in the loop above, we accumulate any amount of time - * in xtime_nsec over a second into xtime.tv_sec, its possible for - * xtime_nsec to be fairly small after the loop. Further, if we're - * slightly speeding the clocksource up in timekeeping_adjust(), - * its possible the required corrective factor to xtime_nsec could - * cause it to underflow. - * - * Now, we cannot simply roll the accumulated second back, since - * the NTP subsystem has been notified via second_overflow. So - * instead we push xtime_nsec forward by the amount we underflowed, - * and add that amount into the error. - * - * We'll correct this error next time through this function, when - * xtime_nsec is not as small. + * XXX This can be killed once everyone converts + * to the new update_vsyscall. */ - if (unlikely((s64)timekeeper.xtime_nsec < 0)) { - s64 neg = -(s64)timekeeper.xtime_nsec; - timekeeper.xtime_nsec = 0; - timekeeper.ntp_error += neg << timekeeper.ntp_error_shift; - } - + old_vsyscall_fixup(tk); /* - * Store full nanoseconds into xtime after rounding it up and - * add the remainder to the error difference. + * Finally, make sure that after the rounding + * xtime_nsec isn't larger than NSEC_PER_SEC */ - xtime.tv_nsec = ((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1; - timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift; - timekeeper.ntp_error += timekeeper.xtime_nsec << - timekeeper.ntp_error_shift; + clock_set |= accumulate_nsecs_to_secs(tk); + write_seqcount_begin(&timekeeper_seq); + /* Update clock->cycle_last with the new value */ + clock->cycle_last = tk->cycle_last; /* - * Finally, make sure that after the rounding - * xtime.tv_nsec isn't larger then NSEC_PER_SEC + * Update the real timekeeper. + * + * We could avoid this memcpy by switching pointers, but that + * requires changes to all other timekeeper usage sites as + * well, i.e. move the timekeeper pointer getter into the + * spinlocked/seqcount protected sections. And we trade this + * memcpy under the timekeeper_seq against one before we start + * updating. */ - if (unlikely(xtime.tv_nsec >= NSEC_PER_SEC)) { - xtime.tv_nsec -= NSEC_PER_SEC; - xtime.tv_sec++; - second_overflow(); - } - - /* check to see if there is a new clocksource to use */ - update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock, - timekeeper.mult); + memcpy(real_tk, tk, sizeof(*tk)); + timekeeping_update(real_tk, clock_set); + write_seqcount_end(&timekeeper_seq); +out: + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + if (clock_set) + /* Have to call _delayed version, since in irq context*/ + clock_was_set_delayed(); } /** @@ -1073,16 +1454,18 @@ static void update_wall_time(void) */ void getboottime(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; struct timespec boottime = { - .tv_sec = wall_to_monotonic.tv_sec + total_sleep_time.tv_sec, - .tv_nsec = wall_to_monotonic.tv_nsec + total_sleep_time.tv_nsec + .tv_sec = tk->wall_to_monotonic.tv_sec + + tk->total_sleep_time.tv_sec, + .tv_nsec = tk->wall_to_monotonic.tv_nsec + + tk->total_sleep_time.tv_nsec }; set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); } EXPORT_SYMBOL_GPL(getboottime); - /** * get_monotonic_boottime - Returns monotonic time since boot * @ts: pointer to the timespec to be set @@ -1094,23 +1477,25 @@ EXPORT_SYMBOL_GPL(getboottime); */ void get_monotonic_boottime(struct timespec *ts) { + struct timekeeper *tk = &timekeeper; struct timespec tomono, sleep; + s64 nsec; 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(); + seq = read_seqcount_begin(&timekeeper_seq); + ts->tv_sec = tk->xtime_sec; + nsec = timekeeping_get_ns(tk); + tomono = tk->wall_to_monotonic; + sleep = tk->total_sleep_time; - } while (read_seqretry(&xtime_lock, seq)); + } while (read_seqcount_retry(&timekeeper_seq, 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_sec += tomono.tv_sec + sleep.tv_sec; + ts->tv_nsec = 0; + timespec_add_ns(ts, nsec + tomono.tv_nsec + sleep.tv_nsec); } EXPORT_SYMBOL_GPL(get_monotonic_boottime); @@ -1137,31 +1522,38 @@ EXPORT_SYMBOL_GPL(ktime_get_boottime); */ void monotonic_to_bootbased(struct timespec *ts) { - *ts = timespec_add(*ts, total_sleep_time); + struct timekeeper *tk = &timekeeper; + + *ts = timespec_add(*ts, tk->total_sleep_time); } EXPORT_SYMBOL_GPL(monotonic_to_bootbased); unsigned long get_seconds(void) { - return xtime.tv_sec; + struct timekeeper *tk = &timekeeper; + + return tk->xtime_sec; } EXPORT_SYMBOL(get_seconds); struct timespec __current_kernel_time(void) { - return xtime; + struct timekeeper *tk = &timekeeper; + + return tk_xtime(tk); } struct timespec current_kernel_time(void) { + struct timekeeper *tk = &timekeeper; struct timespec now; unsigned long seq; do { - seq = read_seqbegin(&xtime_lock); + seq = read_seqcount_begin(&timekeeper_seq); - now = xtime; - } while (read_seqretry(&xtime_lock, seq)); + now = tk_xtime(tk); + } while (read_seqcount_retry(&timekeeper_seq, seq)); return now; } @@ -1169,15 +1561,16 @@ 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(&xtime_lock); + seq = read_seqcount_begin(&timekeeper_seq); - now = xtime; - mono = wall_to_monotonic; - } while (read_seqretry(&xtime_lock, seq)); + now = tk_xtime(tk); + mono = tk->wall_to_monotonic; + } while (read_seqcount_retry(&timekeeper_seq, seq)); set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, now.tv_nsec + mono.tv_nsec); @@ -1185,14 +1578,11 @@ struct timespec get_monotonic_coarse(void) } /* - * 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... + * Must hold jiffies_lock */ void do_timer(unsigned long ticks) { jiffies_64 += ticks; - update_wall_time(); calc_global_load(ticks); } @@ -1206,30 +1596,138 @@ 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(&xtime_lock); - *xtim = xtime; - *wtom = wall_to_monotonic; - *sleep = total_sleep_time; - } while (read_seqretry(&xtime_lock, seq)); + seq = read_seqcount_begin(&timekeeper_seq); + *xtim = tk_xtime(tk); + *wtom = tk->wall_to_monotonic; + *sleep = tk->total_sleep_time; + } while (read_seqcount_retry(&timekeeper_seq, seq)); } +#ifdef CONFIG_HIGH_RES_TIMERS +/** + * ktime_get_update_offsets - hrtimer helper + * @offs_real: pointer to storage for monotonic -> realtime offset + * @offs_boot: pointer to storage for monotonic -> boottime offset + * @offs_tai: pointer to storage for monotonic -> clock tai offset + * + * Returns current monotonic time and updates the offsets + * Called from hrtimer_interrupt() or retrigger_next_event() + */ +ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot, + ktime_t *offs_tai) +{ + struct timekeeper *tk = &timekeeper; + ktime_t now; + unsigned int seq; + u64 secs, nsecs; + + do { + seq = read_seqcount_begin(&timekeeper_seq); + + secs = tk->xtime_sec; + nsecs = timekeeping_get_ns(tk); + + *offs_real = tk->offs_real; + *offs_boot = tk->offs_boot; + *offs_tai = tk->offs_tai; + } while (read_seqcount_retry(&timekeeper_seq, seq)); + + now = ktime_add_ns(ktime_set(secs, 0), nsecs); + now = ktime_sub(now, *offs_real); + return now; +} +#endif + /** * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format */ ktime_t ktime_get_monotonic_offset(void) { + struct timekeeper *tk = &timekeeper; unsigned long seq; struct timespec wtom; do { - seq = read_seqbegin(&xtime_lock); - wtom = wall_to_monotonic; - } while (read_seqretry(&xtime_lock, seq)); + seq = read_seqcount_begin(&timekeeper_seq); + wtom = tk->wall_to_monotonic; + } while (read_seqcount_retry(&timekeeper_seq, seq)); + return timespec_to_ktime(wtom); } +EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset); + +/** + * do_adjtimex() - Accessor function to NTP __do_adjtimex function + */ +int do_adjtimex(struct timex *txc) +{ + struct timekeeper *tk = &timekeeper; + unsigned long flags; + struct timespec ts; + s32 orig_tai, tai; + int ret; + + /* Validate the data before disabling interrupts */ + ret = ntp_validate_timex(txc); + if (ret) + return ret; + + if (txc->modes & ADJ_SETOFFSET) { + struct timespec delta; + delta.tv_sec = txc->time.tv_sec; + delta.tv_nsec = txc->time.tv_usec; + if (!(txc->modes & ADJ_NANO)) + delta.tv_nsec *= 1000; + ret = timekeeping_inject_offset(&delta); + if (ret) + return ret; + } + + getnstimeofday(&ts); + + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); + + orig_tai = tai = tk->tai_offset; + ret = __do_adjtimex(txc, &ts, &tai); + + if (tai != orig_tai) { + __timekeeping_set_tai_offset(tk, tai); + timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); + } + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + + if (tai != orig_tai) + clock_was_set(); + + ntp_notify_cmos_timer(); + + return ret; +} + +#ifdef CONFIG_NTP_PPS +/** + * hardpps() - Accessor function to NTP __hardpps function + */ +void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&timekeeper_lock, flags); + write_seqcount_begin(&timekeeper_seq); + + __hardpps(phase_ts, raw_ts); + + write_seqcount_end(&timekeeper_seq); + raw_spin_unlock_irqrestore(&timekeeper_lock, flags); +} +EXPORT_SYMBOL(hardpps); +#endif /** * xtime_update() - advances the timekeeping infrastructure @@ -1239,7 +1737,8 @@ ktime_t ktime_get_monotonic_offset(void) */ void xtime_update(unsigned long ticks) { - write_seqlock(&xtime_lock); + write_seqlock(&jiffies_lock); do_timer(ticks); - write_sequnlock(&xtime_lock); + write_sequnlock(&jiffies_lock); + update_wall_time(); } |
