cregit-Linux how code gets into the kernel

Release 4.7 kernel/time/timekeeping.c

Directory: kernel/time
/*
 *  linux/kernel/time/timekeeping.c
 *
 *  Kernel timekeeping code and accessor functions
 *
 *  This code was moved from linux/kernel/timer.c.
 *  Please see that file for copyright and history logs.
 *
 */

#include <linux/timekeeper_internal.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/syscore_ops.h>
#include <linux/clocksource.h>
#include <linux/jiffies.h>
#include <linux/time.h>
#include <linux/tick.h>
#include <linux/stop_machine.h>
#include <linux/pvclock_gtod.h>
#include <linux/compiler.h>

#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)

/*
 * The most important data for readout fits into a single 64 byte
 * cache line.
 */
static struct {
	
seqcount_t		seq;
	
struct timekeeper	timekeeper;
} 
tk_core ____cacheline_aligned;

static DEFINE_RAW_SPINLOCK(timekeeper_lock);

static struct timekeeper shadow_timekeeper;

/**
 * struct tk_fast - NMI safe timekeeper
 * @seq:        Sequence counter for protecting updates. The lowest bit
 *              is the index for the tk_read_base array
 * @base:       tk_read_base array. Access is indexed by the lowest bit of
 *              @seq.
 *
 * See @update_fast_timekeeper() below.
 */

struct tk_fast {
	
seqcount_t		seq;
	
struct tk_read_base	base[2];
};


static struct tk_fast tk_fast_mono ____cacheline_aligned;

static struct tk_fast tk_fast_raw  ____cacheline_aligned;

/* flag for if timekeeping is suspended */

int __read_mostly timekeeping_suspended;


static inline void tk_normalize_xtime(struct timekeeper *tk) { while (tk->tkr_mono.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_mono.shift)) { tk->tkr_mono.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_mono.shift; tk->xtime_sec++; } }

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static inline struct timespec64 tk_xtime(struct timekeeper *tk) { struct timespec64 ts; ts.tv_sec = tk->xtime_sec; ts.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); return ts; }

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static void tk_set_xtime(struct timekeeper *tk, const struct timespec64 *ts) { tk->xtime_sec = ts->tv_sec; tk->tkr_mono.xtime_nsec = (u64)ts->tv_nsec << tk->tkr_mono.shift; }

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static void tk_xtime_add(struct timekeeper *tk, const struct timespec64 *ts) { tk->xtime_sec += ts->tv_sec; tk->tkr_mono.xtime_nsec += (u64)ts->tv_nsec << tk->tkr_mono.shift; tk_normalize_xtime(tk); }

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static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm) { struct timespec64 tmp; /* * Verify consistency of: offset_real = -wall_to_monotonic * before modifying anything */ set_normalized_timespec64(&tmp, -tk->wall_to_monotonic.tv_sec, -tk->wall_to_monotonic.tv_nsec); WARN_ON_ONCE(tk->offs_real.tv64 != timespec64_to_ktime(tmp).tv64); tk->wall_to_monotonic = wtm; set_normalized_timespec64(&tmp, -wtm.tv_sec, -wtm.tv_nsec); tk->offs_real = timespec64_to_ktime(tmp); tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0)); }

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static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta) { tk->offs_boot = ktime_add(tk->offs_boot, delta); }

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#ifdef CONFIG_DEBUG_TIMEKEEPING #define WARNING_FREQ (HZ*300) /* 5 minute rate-limiting */
static void timekeeping_check_update(struct timekeeper *tk, cycle_t offset) { cycle_t max_cycles = tk->tkr_mono.clock->max_cycles; const char *name = tk->tkr_mono.clock->name; if (offset > max_cycles) { printk_deferred("WARNING: timekeeping: Cycle offset (%lld) is larger than allowed by the '%s' clock's max_cycles value (%lld): time overflow danger\n", offset, name, max_cycles); printk_deferred(" timekeeping: Your kernel is sick, but tries to cope by capping time updates\n"); } else { if (offset > (max_cycles >> 1)) { printk_deferred("INFO: timekeeping: Cycle offset (%lld) is larger than the '%s' clock's 50%% safety margin (%lld)\n", offset, name, max_cycles >> 1); printk_deferred(" timekeeping: Your kernel is still fine, but is feeling a bit nervous\n"); } } if (tk->underflow_seen) { if (jiffies - tk->last_warning > WARNING_FREQ) { printk_deferred("WARNING: Underflow in clocksource '%s' observed, time update ignored.\n", name); printk_deferred(" Please report this, consider using a different clocksource, if possible.\n"); printk_deferred(" Your kernel is probably still fine.\n"); tk->last_warning = jiffies; } tk->underflow_seen = 0; } if (tk->overflow_seen) { if (jiffies - tk->last_warning > WARNING_FREQ) { printk_deferred("WARNING: Overflow in clocksource '%s' observed, time update capped.\n", name); printk_deferred(" Please report this, consider using a different clocksource, if possible.\n"); printk_deferred(" Your kernel is probably still fine.\n"); tk->last_warning = jiffies; } tk->overflow_seen = 0; } }

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static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr) { struct timekeeper *tk = &tk_core.timekeeper; cycle_t now, last, mask, max, delta; unsigned int seq; /* * Since we're called holding a seqlock, the data may shift * under us while we're doing the calculation. This can cause * false positives, since we'd note a problem but throw the * results away. So nest another seqlock here to atomically * grab the points we are checking with. */ do { seq = read_seqcount_begin(&tk_core.seq); now = tkr->read(tkr->clock); last = tkr->cycle_last; mask = tkr->mask; max = tkr->clock->max_cycles; } while (read_seqcount_retry(&tk_core.seq, seq)); delta = clocksource_delta(now, last, mask); /* * Try to catch underflows by checking if we are seeing small * mask-relative negative values. */ if (unlikely((~delta & mask) < (mask >> 3))) { tk->underflow_seen = 1; delta = 0; } /* Cap delta value to the max_cycles values to avoid mult overflows */ if (unlikely(delta > max)) { tk->overflow_seen = 1; delta = tkr->clock->max_cycles; } return delta; }

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#else
static inline void timekeeping_check_update(struct timekeeper *tk, cycle_t offset) { }

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static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr) { cycle_t cycle_now, delta; /* read clocksource */ cycle_now = tkr->read(tkr->clock); /* calculate the delta since the last update_wall_time */ delta = clocksource_delta(cycle_now, tkr->cycle_last, tkr->mask); return delta; }

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#endif /** * 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 * pair and interval request. * * Unless you're the timekeeping code, you should not be using this! */
static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock) { cycle_t interval; u64 tmp, ntpinterval; struct clocksource *old_clock; ++tk->cs_was_changed_seq; old_clock = tk->tkr_mono.clock; tk->tkr_mono.clock = clock; tk->tkr_mono.read = clock->read; tk->tkr_mono.mask = clock->mask; tk->tkr_mono.cycle_last = tk->tkr_mono.read(clock); tk->tkr_raw.clock = clock; tk->tkr_raw.read = clock->read; tk->tkr_raw.mask = clock->mask; tk->tkr_raw.cycle_last = tk->tkr_mono.cycle_last; /* Do the ns -> cycle conversion first, using original mult */ tmp = NTP_INTERVAL_LENGTH; tmp <<= clock->shift; ntpinterval = tmp; tmp += clock->mult/2; do_div(tmp, clock->mult); if (tmp == 0) tmp = 1; interval = (cycle_t) tmp; tk->cycle_interval = interval; /* Go back from cycles -> shifted ns */ tk->xtime_interval = (u64) interval * clock->mult; tk->xtime_remainder = ntpinterval - tk->xtime_interval; tk->raw_interval = ((u64) interval * clock->mult) >> 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->tkr_mono.xtime_nsec >>= -shift_change; else tk->tkr_mono.xtime_nsec <<= shift_change; } tk->tkr_raw.xtime_nsec = 0; tk->tkr_mono.shift = clock->shift; tk->tkr_raw.shift = clock->shift; tk->ntp_error = 0; tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; tk->ntp_tick = ntpinterval << tk->ntp_error_shift; /* * The timekeeper keeps its own mult values for the currently * active clocksource. These value will be adjusted via NTP * to counteract clock drifting. */ tk->tkr_mono.mult = clock->mult; tk->tkr_raw.mult = clock->mult; tk->ntp_err_mult = 0; }

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kasper pedersenkasper pedersen123.47%17.14%
christopher s. hallchristopher s. hall51.45%17.14%
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/* Timekeeper helper functions. */ #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
static u32 default_arch_gettimeoffset(void) { return 0; }

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u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset; #else
static inline u32 arch_gettimeoffset(void) { return 0; }

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#endif
static inline s64 timekeeping_delta_to_ns(struct tk_read_base *tkr, cycle_t delta) { s64 nsec; nsec = delta * tkr->mult + tkr->xtime_nsec; nsec >>= tkr->shift; /* If arch requires, add in get_arch_timeoffset() */ return nsec + arch_gettimeoffset(); }

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christopher s. hallchristopher s. hall716.28%110.00%
stephen warrenstephen warren12.33%110.00%
Total43100.00%10100.00%


static inline s64 timekeeping_get_ns(struct tk_read_base *tkr) { cycle_t delta; delta = timekeeping_get_delta(tkr); return timekeeping_delta_to_ns(tkr, delta); }

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static inline s64 timekeeping_cycles_to_ns(struct tk_read_base *tkr, cycle_t cycles) { cycle_t delta; /* calculate the delta since the last update_wall_time */ delta = clocksource_delta(cycles, tkr->cycle_last, tkr->mask); return timekeeping_delta_to_ns(tkr, delta); }

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/** * update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper. * @tkr: Timekeeping readout base from which we take the update * * We want to use this from any context including NMI and tracing / * instrumenting the timekeeping code itself. * * Employ the latch technique; see @raw_write_seqcount_latch. * * So if a NMI hits the update of base[0] then it will use base[1] * which is still consistent. In the worst case this can result is a * slightly wrong timestamp (a few nanoseconds). See * @ktime_get_mono_fast_ns. */
static void update_fast_timekeeper(struct tk_read_base *tkr, struct tk_fast *tkf) { struct tk_read_base *base = tkf->base; /* Force readers off to base[1] */ raw_write_seqcount_latch(&tkf->seq); /* Update base[0] */ memcpy(base, tkr, sizeof(*base)); /* Force readers back to base[0] */ raw_write_seqcount_latch(&tkf->seq); /* Update base[1] */ memcpy(base + 1, base, sizeof(*base)); }

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/** * ktime_get_mono_fast_ns - Fast NMI safe access to clock monotonic * * This timestamp is not guaranteed to be monotonic across an update. * The timestamp is calculated by: * * now = base_mono + clock_delta * slope * * So if the update lowers the slope, readers who are forced to the * not yet updated second array are still using the old steeper slope. * * tmono * ^ * | o n * | o n * | u * | o * |o * |12345678---> reader order * * o = old slope * u = update * n = new slope * * So reader 6 will observe time going backwards versus reader 5. * * While other CPUs are likely to be able observe that, the only way * for a CPU local observation is when an NMI hits in the middle of * the update. Timestamps taken from that NMI context might be ahead * of the following timestamps. Callers need to be aware of that and * deal with it. */
static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf) { struct tk_read_base *tkr; unsigned int seq; u64 now; do { seq = raw_read_seqcount_latch(&tkf->seq); tkr = tkf->base + (seq & 0x01); now = ktime_to_ns(tkr->base) + timekeeping_get_ns(tkr); } while (read_seqcount_retry(&tkf->seq, seq)); return now; }

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u64 ktime_get_mono_fast_ns(void) { return __ktime_get_fast_ns(&tk_fast_mono); }

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EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns);
u64 ktime_get_raw_fast_ns(void) { return __ktime_get_fast_ns(&tk_fast_raw); }

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EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); /* Suspend-time cycles value for halted fast timekeeper. */ static cycle_t cycles_at_suspend;
static cycle_t dummy_clock_read(struct clocksource *cs) { return cycles_at_suspend; }

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/** * halt_fast_timekeeper - Prevent fast timekeeper from accessing clocksource. * @tk: Timekeeper to snapshot. * * It generally is unsafe to access the clocksource after timekeeping has been * suspended, so take a snapshot of the readout base of @tk and use it as the * fast timekeeper's readout base while suspended. It will return the same * number of cycles every time until timekeeping is resumed at which time the * proper readout base for the fast timekeeper will be restored automatically. */
static void halt_fast_timekeeper(struct timekeeper *tk) { static struct tk_read_base tkr_dummy; struct tk_read_base *tkr = &tk->tkr_mono; memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); cycles_at_suspend = tkr->read(tkr->clock); tkr_dummy.read = dummy_clock_read; update_fast_timekeeper(&tkr_dummy, &tk_fast_mono); tkr = &tk->tkr_raw; memcpy(&tkr_dummy, tkr, sizeof(tkr_dummy)); tkr_dummy.read = dummy_clock_read; update_fast_timekeeper(&tkr_dummy, &tk_fast_raw); }

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#ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
static inline void update_vsyscall(struct timekeeper *tk) { struct timespec xt, wm; xt = timespec64_to_timespec(tk_xtime(tk)); wm = timespec64_to_timespec(tk->wall_to_monotonic); update_vsyscall_old(&xt, &wm, tk->tkr_mono.clock, tk->tkr_mono.mult, tk->tkr_mono.cycle_last); }

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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->tkr_mono.xtime_nsec & ((1ULL << tk->tkr_mono.shift) - 1); tk->tkr_mono.xtime_nsec -= remainder; tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift; tk->ntp_error += remainder << tk->ntp_error_shift; tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift; }

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#else #define old_vsyscall_fixup(tk) #endif 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); }

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/** * pvclock_gtod_register_notifier - register a pvclock timedata update listener */
int pvclock_gtod_register_notifier(struct notifier_block *nb) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long flags; int ret; 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; }

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EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier); /** * pvclock_gtod_unregister_notifier - unregister a pvclock * timedata update listener */
int pvclock_gtod_unregister_notifier(struct notifier_block *nb) { unsigned long flags; int ret; raw_spin_lock_irqsave(&timekeeper_lock, flags); ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); return ret; }

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EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); /* * tk_update_leap_state - helper to update the next_leap_ktime */
static inline void tk_update_leap_state(struct timekeeper *tk) { tk->next_leap_ktime = ntp_get_next_leap(); if (tk->next_leap_ktime.tv64 != KTIME_MAX) /* Convert to monotonic time */ tk->next_leap_ktime = ktime_sub(tk->next_leap_ktime, tk->offs_real); }

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/* * Update the ktime_t based scalar nsec members of the timekeeper */
static inline void tk_update_ktime_data(struct timekeeper *tk) { u64 seconds; u32 nsec; /* * The xtime based monotonic readout is: * nsec = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec + now(); * The ktime based monotonic readout is: * nsec = base_mono + now(); * ==> base_mono = (xtime_sec + wtm_sec) * 1e9 + wtm_nsec */ seconds = (u64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec); nsec = (u32) tk->wall_to_monotonic.tv_nsec; tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec); /* Update the monotonic raw base */ tk->tkr_raw.base = timespec64_to_ktime(tk->raw_time); /* * The sum of the nanoseconds portions of xtime and * wall_to_monotonic can be greater/equal one second. Take * this into account before updating tk->ktime_sec. */ nsec += (u32)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); if (nsec >= NSEC_PER_SEC) seconds++; tk->ktime_sec = seconds; }

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/* must hold timekeeper_lock */
static void timekeeping_update(struct timekeeper *tk, unsigned int action) { if (action & TK_CLEAR_NTP) { tk->ntp_error = 0; ntp_clear(); } tk_update_leap_state(tk); tk_update_ktime_data(tk); update_vsyscall(tk); update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET); update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono); update_fast_timekeeper(&tk->tkr_raw, &tk_fast_raw); if (action & TK_CLOCK_WAS_SET) tk->clock_was_set_seq++; /* * The mirroring of the data to the shadow-timekeeper needs * to happen last here to ensure we don't over-write the * timekeeper structure on the next update with stale data */ if (action & TK_MIRROR) memcpy(&shadow_timekeeper, &tk_core.timekeeper, sizeof(tk_core.timekeeper)); }

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david vrabeldavid vrabel108.77%213.33%
marcelo tosattimarcelo tosatti54.39%16.67%
rafael j. wysockirafael j. wysocki21.75%16.67%
Total114100.00%15100.00%

/** * timekeeping_forward_now - update clock to the current time * * Forward the current clock to update its state since the last call to * update_wall_time(). This is useful before significant clock changes, * as it avoids having to deal with this time offset explicitly. */
static void timekeeping_forward_now(struct timekeeper *tk) { struct clocksource *clock = tk->tkr_mono.clock; cycle_t cycle_now, delta; s64 nsec; cycle_now = tk->tkr_mono.read(clock); delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask); tk->tkr_mono.cycle_last = cycle_now; tk->tkr_raw.cycle_last = cycle_now; tk->tkr_mono.xtime_nsec += delta * tk->tkr_mono.mult; /* If arch requires, add in get_arch_timeoffset() */ tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift; tk_normalize_xtime(tk); nsec = clocksource_cyc2ns(delta, tk->tkr_raw.mult, tk->tkr_raw.shift); timespec64_add_ns(&tk->raw_time, nsec); }

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PersonTokensPropCommitsCommitProp
john stultzjohn stultz5739.86%630.00%
thomas gleixnerthomas gleixner3423.78%630.00%
peter zijlstrapeter zijlstra2316.08%210.00%
martin schwidefskymartin schwidefsky1812.59%315.00%
roman zippelroman zippel74.90%15.00%
andreas schwabandreas schwab32.10%15.00%
stephen warrenstephen warren10.70%15.00%
Total143100.00%20100.00%

/** * __getnstimeofday64 - Returns the time of day in a timespec64. * @ts: pointer to the timespec to be set * * Updates the time of day in the timespec. * Returns 0 on success, or -ve when suspended (timespec will be undefined). */
int __getnstimeofday64(struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long seq; s64 nsecs = 0; do { seq = read_seqcount_begin(&tk_core.seq); ts->tv_sec = tk->xtime_sec; nsecs = timekeeping_get_ns(&tk->tkr_mono); } while (read_seqcount_retry(&tk_core.seq, seq)); ts->tv_nsec = 0; timespec64_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; }

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PersonTokensPropCommitsCommitProp
john stultzjohn stultz6766.34%541.67%
kees cookkees cook1716.83%18.33%
thomas gleixnerthomas gleixner1514.85%433.33%
martin schwidefskymartin schwidefsky10.99%18.33%
peter zijlstrapeter zijlstra10.99%18.33%
Total101100.00%12100.00%

EXPORT_SYMBOL(__getnstimeofday64); /** * getnstimeofday64 - Returns the time of day in a timespec64. * @ts: pointer to the timespec64 to be set * * Returns the time of day in a timespec64 (WARN if suspended). */
void getnstimeofday64(struct timespec64 *ts) { WARN_ON(__getnstimeofday64(ts)); }

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PersonTokensPropCommitsCommitProp
kees cookkees cook1477.78%133.33%
thomas gleixnerthomas gleixner316.67%133.33%
john stultzjohn stultz15.56%133.33%
Total18100.00%3100.00%

EXPORT_SYMBOL(getnstimeofday64);
ktime_t ktime_get(void) { struct timekeeper *tk = &tk_core.timekeeper; unsigned int seq; ktime_t base; s64 nsecs; WARN_ON(timekeeping_suspended); do { seq = read_seqcount_begin(&tk_core.seq); base = tk->tkr_mono.base; nsecs = timekeeping_get_ns(&tk->tkr_mono); } while (read_seqcount_retry(&tk_core.seq, seq)); return ktime_add_ns(base, nsecs); }

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PersonTokensPropCommitsCommitProp
martin schwidefskymartin schwidefsky4857.14%110.00%
thomas gleixnerthomas gleixner1922.62%550.00%
john stultzjohn stultz1416.67%330.00%
peter zijlstrapeter zijlstra33.57%110.00%
Total84100.00%10100.00%

EXPORT_SYMBOL_GPL(ktime_get);
u32 ktime_get_resolution_ns(void) { struct timekeeper *tk = &tk_core.timekeeper; unsigned int seq; u32 nsecs; WARN_ON(timekeeping_suspended); do { seq = read_seqcount_begin(&tk_core.seq); nsecs = tk->tkr_mono.mult >> tk->tkr_mono.shift; } while (read_seqcount_retry(&tk_core.seq, seq)); return nsecs; }

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harald geyerharald geyer72100.00%1100.00%
Total72100.00%1100.00%

EXPORT_SYMBOL_GPL(ktime_get_resolution_ns); static ktime_t *offsets[TK_OFFS_MAX] = { [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real, [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot, [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai, };
ktime_t ktime_get_with_offset(enum tk_offsets offs) { struct timekeeper *tk = &tk_core.timekeeper; unsigned int seq; ktime_t base, *offset = offsets[offs]; s64 nsecs; WARN_ON(timekeeping_suspended); do { seq = read_seqcount_begin(&tk_core.seq); base = ktime_add(tk->tkr_mono.base, *offset); nsecs = timekeeping_get_ns(&tk->tkr_mono); } while (read_seqcount_retry(&tk_core.seq, seq)); return ktime_add_ns(base, nsecs); }

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thomas gleixnerthomas gleixner9797.00%375.00%
peter zijlstrapeter zijlstra33.00%125.00%
Total100100.00%4100.00%

EXPORT_SYMBOL_GPL(ktime_get_with_offset); /** * ktime_mono_to_any() - convert mononotic time to any other time * @tmono: time to convert. * @offs: which offset to use */
ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs) { ktime_t *offset = offsets[offs]; unsigned long seq; ktime_t tconv; do { seq = read_seqcount_begin(&tk_core.seq); tconv = ktime_add(tmono, *offset); } while (read_seqcount_retry(&tk_core.seq, seq)); return tconv; }

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thomas gleixnerthomas gleixner67100.00%1100.00%
Total67100.00%1100.00%

EXPORT_SYMBOL_GPL(ktime_mono_to_any); /** * ktime_get_raw - Returns the raw monotonic time in ktime_t format */
ktime_t ktime_get_raw(void) { struct timekeeper *tk = &tk_core.timekeeper; unsigned int seq; ktime_t base; s64 nsecs; do { seq = read_seqcount_begin(&tk_core.seq); base = tk->tkr_raw.base; nsecs = timekeeping_get_ns(&tk->tkr_raw); } while (read_seqcount_retry(&tk_core.seq, seq)); return ktime_add_ns(base, nsecs); }

Contributors

PersonTokensPropCommitsCommitProp
thomas gleixnerthomas gleixner7291.14%150.00%
peter zijlstrapeter zijlstra78.86%150.00%
Total79100.00%2100.00%

EXPORT_SYMBOL_GPL(ktime_get_raw); /** * ktime_get_ts64 - get the monotonic clock in timespec64 format * @ts: pointer to timespec variable * * The function calculates the monotonic clock from the realtime * clock and the wall_to_monotonic offset and stores the result * in normalized timespec64 format in the variable pointed to by @ts. */
void ktime_get_ts64(struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; struct timespec64 tomono; s64 nsec; unsigned int seq; WARN_ON(timekeeping_suspended); do { seq = read_seqcount_begin(&tk_core.seq); ts->tv_sec = tk->xtime_sec; nsec = timekeeping_get_ns(&tk->tkr_mono); tomono = tk->wall_to_monotonic; } while (read_seqcount_retry(&tk_core.seq, seq)); ts->tv_sec += tomono.tv_sec; ts->tv_nsec = 0; timespec64_add_ns(ts, nsec + tomono.tv_nsec); }

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PersonTokensPropCommitsCommitProp
martin schwidefskymartin schwidefsky5549.55%216.67%
john stultzjohn stultz3430.63%541.67%
thomas gleixnerthomas gleixner2118.92%433.33%
peter zijlstrapeter zijlstra10.90%18.33%
Total111100.00%12100.00%

EXPORT_SYMBOL_GPL(ktime_get_ts64); /** * ktime_get_seconds - Get the seconds portion of CLOCK_MONOTONIC * * Returns the seconds portion of CLOCK_MONOTONIC with a single non * serialized read. tk->ktime_sec is of type 'unsigned long' so this * works on both 32 and 64 bit systems. On 32 bit systems the readout * covers ~136 years of uptime which should be enough to prevent * premature wrap arounds. */
time64_t ktime_get_seconds(void) { struct timekeeper *tk = &tk_core.timekeeper; WARN_ON(timekeeping_suspended); return tk->ktime_sec; }

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heena sirwaniheena sirwani27100.00%1100.00%
Total27100.00%1100.00%

EXPORT_SYMBOL_GPL(ktime_get_seconds); /** * ktime_get_real_seconds - Get the seconds portion of CLOCK_REALTIME * * Returns the wall clock seconds since 1970. This replaces the * get_seconds() interface which is not y2038 safe on 32bit systems. * * For 64bit systems the fast access to tk->xtime_sec is preserved. On * 32bit systems the access must be protected with the sequence * counter to provide "atomic" access to the 64bit tk->xtime_sec * value. */
time64_t ktime_get_real_seconds(void) { struct timekeeper *tk = &tk_core.timekeeper; time64_t seconds; unsigned int seq; if (IS_ENABLED(CONFIG_64BIT)) return tk->xtime_sec; do { seq = read_seqcount_begin(&tk_core.seq); seconds = tk->xtime_sec; } while (read_seqcount_retry(&tk_core.seq, seq)); return seconds; }

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heena sirwaniheena sirwani71100.00%1100.00%
Total71100.00%1100.00%

EXPORT_SYMBOL_GPL(ktime_get_real_seconds); /** * __ktime_get_real_seconds - The same as ktime_get_real_seconds * but without the sequence counter protect. This internal function * is called just when timekeeping lock is already held. */
time64_t __ktime_get_real_seconds(void) { struct timekeeper *tk = &tk_core.timekeeper; return tk->xtime_sec; }

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dengchaodengchao22100.00%1100.00%
Total22100.00%1100.00%

/** * ktime_get_snapshot - snapshots the realtime/monotonic raw clocks with counter * @systime_snapshot: pointer to struct receiving the system time snapshot */
void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long seq; ktime_t base_raw; ktime_t base_real; s64 nsec_raw; s64 nsec_real; cycle_t now; WARN_ON_ONCE(timekeeping_suspended); do { seq = read_seqcount_begin(&tk_core.seq); now = tk->tkr_mono.read(tk->tkr_mono.clock); systime_snapshot->cs_was_changed_seq = tk->cs_was_changed_seq; systime_snapshot->clock_was_set_seq = tk->clock_was_set_seq; base_real = ktime_add(tk->tkr_mono.base, tk_core.timekeeper.offs_real); base_raw = tk->tkr_raw.base; nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, now); nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, now); } while (read_seqcount_retry(&tk_core.seq, seq)); systime_snapshot->cycles = now; systime_snapshot->real = ktime_add_ns(base_real, nsec_real); systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw); }

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christopher s. hallchristopher s. hall178100.00%3100.00%
Total178100.00%3100.00%

EXPORT_SYMBOL_GPL(ktime_get_snapshot); /* Scale base by mult/div checking for overflow */
static int scale64_check_overflow(u64 mult, u64 div, u64 *base) { u64 tmp, rem; tmp = div64_u64_rem(*base, div, &rem); if (((int)sizeof(u64)*8 - fls64(mult) < fls64(tmp)) || ((int)sizeof(u64)*8 - fls64(mult) < fls64(rem))) return -EOVERFLOW; tmp *= mult; rem *= mult; do_div(rem, div); *base = tmp + rem; return 0; }

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PersonTokensPropCommitsCommitProp
christopher s. hallchristopher s. hall109100.00%1100.00%
Total109100.00%1100.00%

/** * adjust_historical_crosststamp - adjust crosstimestamp previous to current interval * @history: Snapshot representing start of history * @partial_history_cycles: Cycle offset into history (fractional part) * @total_history_cycles: Total history length in cycles * @discontinuity: True indicates clock was set on history period * @ts: Cross timestamp that should be adjusted using * partial/total ratio * * Helper function used by get_device_system_crosststamp() to correct the * crosstimestamp corresponding to the start of the current interval to the * system counter value (timestamp point) provided by the driver. The * total_history_* quantities are the total history starting at the provided * reference point and ending at the start of the current interval. The cycle * count between the driver timestamp point and the start of the current * interval is partial_history_cycles. */
static int adjust_historical_crosststamp(struct system_time_snapshot *history, cycle_t partial_history_cycles, cycle_t total_history_cycles, bool discontinuity, struct system_device_crosststamp *ts) { struct timekeeper *tk = &tk_core.timekeeper; u64 corr_raw, corr_real; bool interp_forward; int ret; if (total_history_cycles == 0 || partial_history_cycles == 0) return 0; /* Interpolate shortest distance from beginning or end of history */ interp_forward = partial_history_cycles > total_history_cycles/2 ? true : false; partial_history_cycles = interp_forward ? total_history_cycles - partial_history_cycles : partial_history_cycles; /* * Scale the monotonic raw time delta by: * partial_history_cycles / total_history_cycles */ corr_raw = (u64)ktime_to_ns( ktime_sub(ts->sys_monoraw, history->raw)); ret = scale64_check_overflow(partial_history_cycles, total_history_cycles, &corr_raw); if (ret) return ret; /* * If there is a discontinuity in the history, scale monotonic raw * correction by: * mult(real)/mult(raw) yielding the realtime correction * Otherwise, calculate the realtime correction similar to monotonic * raw calculation */ if (discontinuity) { corr_real = mul_u64_u32_div (corr_raw, tk->tkr_mono.mult, tk->tkr_raw.mult); } else { corr_real = (u64)ktime_to_ns( ktime_sub(ts->sys_realtime, history->real)); ret = scale64_check_overflow(partial_history_cycles, total_history_cycles, &corr_real); if (ret) return ret; } /* Fixup monotonic raw and real time time values */ if (interp_forward) { ts->sys_monoraw = ktime_add_ns(history->raw, corr_raw); ts->sys_realtime = ktime_add_ns(history->real, corr_real); } else { ts->sys_monoraw = ktime_sub_ns(ts->sys_monoraw, corr_raw); ts->sys_realtime = ktime_sub_ns(ts->sys_realtime, corr_real); } return 0; }

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christopher s. hallchristopher s. hall253100.00%1100.00%
Total253100.00%1100.00%

/* * cycle_between - true if test occurs chronologically between before and after */
static bool cycle_between(cycle_t before, cycle_t test, cycle_t after) { if (test > before && test < after) return true; if (test < before && before > after) return true; return false; }

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christopher s. hallchristopher s. hall44100.00%1100.00%
Total44100.00%1100.00%

/** * get_device_system_crosststamp - Synchronously capture system/device timestamp * @get_time_fn: Callback to get simultaneous device time and * system counter from the device driver * @ctx: Context passed to get_time_fn() * @history_begin: Historical reference point used to interpolate system * time when counter provided by the driver is before the current interval * @xtstamp: Receives simultaneously captured system and device time * * Reads a timestamp from a device and correlates it to system time */
int get_device_system_crosststamp(int (*get_time_fn) (ktime_t *device_time, struct system_counterval_t *sys_counterval, void *ctx), void *ctx, struct system_time_snapshot *history_begin, struct system_device_crosststamp *xtstamp) { struct system_counterval_t system_counterval; struct timekeeper *tk = &tk_core.timekeeper; cycle_t cycles, now, interval_start; unsigned int clock_was_set_seq = 0; ktime_t base_real, base_raw; s64 nsec_real, nsec_raw; u8 cs_was_changed_seq; unsigned long seq; bool do_interp; int ret; do { seq = read_seqcount_begin(&tk_core.seq); /* * Try to synchronously capture device time and a system * counter value calling back into the device driver */ ret = get_time_fn(&xtstamp->device, &system_counterval, ctx); if (ret) return ret; /* * Verify that the clocksource associated with the captured * system counter value is the same as the currently installed * timekeeper clocksource */ if (tk->tkr_mono.clock != system_counterval.cs) return -ENODEV; cycles = system_counterval.cycles; /* * Check whether the system counter value provided by the * device driver is on the current timekeeping interval. */ now = tk->tkr_mono.read(tk->tkr_mono.clock); interval_start = tk->tkr_mono.cycle_last; if (!cycle_between(interval_start, cycles, now)) { clock_was_set_seq = tk->clock_was_set_seq; cs_was_changed_seq = tk->cs_was_changed_seq; cycles = interval_start; do_interp = true; } else { do_interp = false; } base_real = ktime_add(tk->tkr_mono.base, tk_core.timekeeper.offs_real); base_raw = tk->tkr_raw.base; nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, system_counterval.cycles); nsec_raw = timekeeping_cycles_to_ns(&tk->tkr_raw, system_counterval.cycles); } while (read_seqcount_retry(&tk_core.seq, seq)); xtstamp->sys_realtime = ktime_add_ns(base_real, nsec_real); xtstamp->sys_monoraw = ktime_add_ns(base_raw, nsec_raw); /* * Interpolate if necessary, adjusting back from the start of the * current interval */ if (do_interp) { cycle_t partial_history_cycles, total_history_cycles; bool discontinuity; /* * Check that the counter value occurs after the provided * history reference and that the history doesn't cross a * clocksource change */ if (!history_begin || !cycle_between(history_begin->cycles, system_counterval.cycles, cycles) || history_begin->cs_was_changed_seq != cs_was_changed_seq) return -EINVAL; partial_history_cycles = cycles - system_counterval.cycles; total_history_cycles = cycles - history_begin->cycles; discontinuity = history_begin->clock_was_set_seq != clock_was_set_seq; ret = adjust_historical_crosststamp(history_begin, partial_history_cycles, total_history_cycles, discontinuity, xtstamp); if (ret) return ret; } return 0; }

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christopher s. hallchristopher s. hall39399.49%266.67%
ingo molnaringo molnar20.51%133.33%
Total395100.00%3100.00%

EXPORT_SYMBOL_GPL(get_device_system_crosststamp); /** * do_gettimeofday - Returns the time of day in a timeval * @tv: pointer to the timeval to be set * * NOTE: Users should be converted to using getnstimeofday() */
void do_gettimeofday(struct timeval *tv) { struct timespec64 now; getnstimeofday64(&now); tv->tv_sec = now.tv_sec; tv->tv_usec = now.tv_nsec/1000; }

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john stultzjohn stultz3694.74%150.00%
thomas gleixnerthomas gleixner25.26%150.00%
Total38100.00%2100.00%

EXPORT_SYMBOL(do_gettimeofday); /** * do_settimeofday64 - Sets the time of day. * @ts: pointer to the timespec64 variable containing the new time * * Sets the time of day to the new time and update NTP and notify hrtimers */
int do_settimeofday64(const struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; struct timespec64 ts_delta, xt; unsigned long flags; int ret = 0; if (!timespec64_valid_strict(ts)) return -EINVAL; raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.seq); timekeeping_forward_now(tk); xt = tk_xtime(tk); ts_delta.tv_sec = ts->tv_sec - xt.tv_sec; ts_delta.tv_nsec = ts->tv_nsec - xt.tv_nsec; if (timespec64_compare(&tk->wall_to_monotonic, &ts_delta) > 0) { ret = -EINVAL; goto out; } tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta)); tk_set_xtime(tk, ts); out: timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); /* signal hrtimers about time change */ clock_was_set(); return ret; }

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john stultzjohn stultz9652.75%945.00%
wang yanqingwang yanqing3318.13%15.00%
thomas gleixnerthomas gleixner2312.64%420.00%
roman zippelroman zippel158.24%15.00%
pang xunleipang xunlei84.40%15.00%
david vrabeldavid vrabel52.75%210.00%
martin schwidefskymartin schwidefsky10.55%15.00%
richard cochranrichard cochran10.55%15.00%
Total182100.00%20100.00%

EXPORT_SYMBOL(do_settimeofday64); /** * timekeeping_inject_offset - Adds or subtracts from the current time. * @tv: pointer to the timespec variable containing the offset * * Adds or subtracts an offset value from the current time. */
int timekeeping_inject_offset(struct timespec *ts) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long flags; struct timespec64 ts64, tmp; int ret = 0; if (!timespec_inject_offset_valid(ts)) return -EINVAL; ts64 = timespec_to_timespec64(*ts); raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.seq); timekeeping_forward_now(tk); /* Make sure the proposed value is valid */ tmp = timespec64_add(tk_xtime(tk), ts64); if (timespec64_compare(&tk->wall_to_monotonic, &ts64) > 0 || !timespec64_valid_strict(&tmp)) { ret = -EINVAL; goto error; } tk_xtime_add(tk, &ts64); tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts64)); 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_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); /* signal hrtimers about time change */ clock_was_set(); return ret; }

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PersonTokensPropCommitsCommitProp
john stultzjohn stultz13977.22%1058.82%
thomas gleixnerthomas gleixner2312.78%423.53%
wang yanqingwang yanqing137.22%15.88%
david vrabeldavid vrabel52.78%211.76%
Total180100.00%17100.00%

EXPORT_SYMBOL(timekeeping_inject_offset); /** * timekeeping_get_tai_offset - Returns current TAI offset from UTC * */
s32 timekeeping_get_tai_offset(void) { struct timekeeper *tk = &tk_core.timekeeper; unsigned int seq; s32 ret; do { seq = read_seqcount_begin(&tk_core.seq); ret = tk->tai_offset; } while (read_seqcount_retry(&tk_core.seq, seq)); return ret; }

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john stultzjohn stultz4983.05%133.33%
thomas gleixnerthomas gleixner1016.95%266.67%
Total59100.00%3100.00%

/** * __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)); }

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john stultzjohn stultz3797.37%375.00%
fengguang wufengguang wu12.63%125.00%
Total38100.00%4100.00%

/** * timekeeping_set_tai_offset - Sets the current TAI offset from UTC * */
void timekeeping_set_tai_offset(s32 tai_offset) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long flags; raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.seq); __timekeeping_set_tai_offset(tk, tai_offset); timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); clock_was_set(); }

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john stultzjohn stultz5169.86%350.00%
thomas gleixnerthomas gleixner2230.14%350.00%
Total73100.00%6100.00%

/** * change_clocksource - Swaps clocksources if a new one is available * * Accumulates current time interval and initializes new clocksource */
static int change_clocksource(void *data) { struct timekeeper *tk = &tk_core.timekeeper; struct clocksource *new, *old; unsigned long flags; new = (struct clocksource *) data; raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.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->tkr_mono.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(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); return 0; }

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john stultzjohn stultz5432.34%423.53%
thomas gleixnerthomas gleixner5331.74%635.29%
martin schwidefskymartin schwidefsky3722.16%317.65%
magnus dammmagnus damm1710.18%15.88%
david vrabeldavid vrabel52.99%211.76%
peter zijlstrapeter zijlstra10.60%15.88%
Total167100.00%17100.00%

/** * timekeeping_notify - Install a new clock source * @clock: pointer to the clock source * * This function is called from clocksource.c after a new, better clock * source has been registered. The caller holds the clocksource_mutex. */
int timekeeping_notify(struct clocksource *clock) { struct timekeeper *tk = &tk_core.timekeeper; if (tk->tkr_mono.clock == clock) return 0; stop_machine(change_clocksource, clock, NULL); tick_clock_notify(); return tk->tkr_mono.clock == clock ? 0 : -1; }

Contributors

PersonTokensPropCommitsCommitProp
martin schwidefskymartin schwidefsky2338.98%114.29%
thomas gleixnerthomas gleixner2033.90%342.86%
john stultzjohn stultz1423.73%228.57%
peter zijlstrapeter zijlstra23.39%114.29%
Total59100.00%7100.00%

/** * getrawmonotonic64 - Returns the raw monotonic time in a timespec * @ts: pointer to the timespec64 to be set * * Returns the raw monotonic time (completely un-modified by ntp) */
void getrawmonotonic64(struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; struct timespec64 ts64; unsigned long seq; s64 nsecs; do { seq = read_seqcount_begin(&tk_core.seq); nsecs = timekeeping_get_ns(&tk->tkr_raw); ts64 = tk->raw_time; } while (read_seqcount_retry(&tk_core.seq, seq)); timespec64_add_ns(&ts64, nsecs); *ts = ts64; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz7283.72%562.50%
thomas gleixnerthomas gleixner1011.63%225.00%
peter zijlstrapeter zijlstra44.65%112.50%
Total86100.00%8100.00%

EXPORT_SYMBOL(getrawmonotonic64); /** * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres */
int timekeeping_valid_for_hres(void) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long seq; int ret; do { seq = read_seqcount_begin(&tk_core.seq); ret = tk->tkr_mono.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; } while (read_seqcount_retry(&tk_core.seq, seq)); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz5280.00%228.57%
thomas gleixnerthomas gleixner1116.92%342.86%
peter zijlstrapeter zijlstra11.54%114.29%
li zefanli zefan11.54%114.29%
Total65100.00%7100.00%

/** * timekeeping_max_deferment - Returns max time the clocksource can be deferred */
u64 timekeeping_max_deferment(void) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long seq; u64 ret; do { seq = read_seqcount_begin(&tk_core.seq); ret = tk->tkr_mono.clock->max_idle_ns; } while (read_seqcount_retry(&tk_core.seq, seq)); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz4063.49%228.57%
jon hunterjon hunter1117.46%114.29%
thomas gleixnerthomas gleixner1117.46%342.86%
peter zijlstrapeter zijlstra11.59%114.29%
Total63100.00%7100.00%

/** * read_persistent_clock - Return time from the persistent clock. * * Weak dummy function for arches that do not yet support it. * Reads the time from the battery backed persistent clock. * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. * * XXX - Do be sure to remove it once all arches implement it. */
void __weak read_persistent_clock(struct timespec *ts) { ts->tv_sec = 0; ts->tv_nsec = 0; }

Contributors

PersonTokensPropCommitsCommitProp
martin schwidefskymartin schwidefsky1460.87%133.33%
gideon israel dsouzagideon israel dsouza521.74%133.33%
john stultzjohn stultz417.39%133.33%
Total23100.00%3100.00%


void __weak read_persistent_clock64(struct timespec64 *ts64) { struct timespec ts; read_persistent_clock(&ts); *ts64 = timespec_to_timespec64(ts); }

Contributors

PersonTokensPropCommitsCommitProp
pang xunleipang xunlei29100.00%1100.00%
Total29100.00%1100.00%

/** * read_boot_clock64 - Return time of the system start. * * Weak dummy function for arches that do not yet support it. * Function to read the exact time the system has been started. * Returns a timespec64 with tv_sec=0 and tv_nsec=0 if unsupported. * * XXX - Do be sure to remove it once all arches implement it. */
void __weak read_boot_clock64(struct timespec64 *ts) { ts->tv_sec = 0; ts->tv_nsec = 0; }

Contributors

PersonTokensPropCommitsCommitProp
martin schwidefskymartin schwidefsky1669.57%133.33%
gideon israel dsouzagideon israel dsouza521.74%133.33%
pang xunleipang xunlei28.70%133.33%
Total23100.00%3100.00%

/* Flag for if timekeeping_resume() has injected sleeptime */ static bool sleeptime_injected; /* Flag for if there is a persistent clock on this platform */ static bool persistent_clock_exists; /* * timekeeping_init - Initializes the clocksource and common timekeeping values */
void __init timekeeping_init(void) { struct timekeeper *tk = &tk_core.timekeeper; struct clocksource *clock; unsigned long flags; struct timespec64 now, boot, tmp; read_persistent_clock64(&now); if (!timespec64_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_exists = true; read_boot_clock64(&boot); if (!timespec64_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(&tk_core.seq); ntp_init(); clock = clocksource_default_clock(); if (clock->enable) clock->enable(clock); 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_timespec64(&tmp, -boot.tv_sec, -boot.tv_nsec); tk_set_wall_to_mono(tk, tmp); timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz14355.64%934.62%
martin schwidefskymartin schwidefsky6123.74%519.23%
thomas gleixnerthomas gleixner3212.45%726.92%
feng tangfeng tang145.45%13.85%
magnus dammmagnus damm41.56%13.85%
pang xunleipang xunlei31.17%311.54%
Total257100.00%26100.00%

/* time in seconds when suspend began for persistent clock */ static struct timespec64 timekeeping_suspend_time; /** * __timekeeping_inject_sleeptime - Internal function to add sleep interval * @delta: pointer to a timespec delta value * * Takes a timespec offset measuring a suspend interval and properly * adds the sleep offset to the timekeeping variables. */
static void __timekeeping_inject_sleeptime(struct timekeeper *tk, struct timespec64 *delta) { if (!timespec64_valid_strict(delta)) { printk_deferred(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid " "sleep delta value!\n"); return; } tk_xtime_add(tk, delta); tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *delta)); tk_update_sleep_time(tk, timespec64_to_ktime(*delta)); tk_debug_account_sleep_time(delta); }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz6387.50%872.73%
colin crosscolin cross56.94%19.09%
thomas gleixnerthomas gleixner45.56%218.18%
Total72100.00%11100.00%

#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE) /** * We have three kinds of time sources to use for sleep time * injection, the preference order is: * 1) non-stop clocksource * 2) persistent clock (ie: RTC accessible when irqs are off) * 3) RTC * * 1) and 2) are used by timekeeping, 3) by RTC subsystem. * If system has neither 1) nor 2), 3) will be used finally. * * * If timekeeping has injected sleeptime via either 1) or 2), * 3) becomes needless, so in this case we don't need to call * rtc_resume(), and this is what timekeeping_rtc_skipresume() * means. */
bool timekeeping_rtc_skipresume(void) { return sleeptime_injected; }

Contributors

PersonTokensPropCommitsCommitProp
pang xunleipang xunlei10100.00%1100.00%
Total10100.00%1100.00%

/** * 1) can be determined whether to use or not only when doing * timekeeping_resume() which is invoked after rtc_suspend(), * so we can't skip rtc_suspend() surely if system has 1). * * But if system has 2), 2) will definitely be used, so in this * case we don't need to call rtc_suspend(), and this is what * timekeeping_rtc_skipsuspend() means. */
bool timekeeping_rtc_skipsuspend(void) { return persistent_clock_exists; }

Contributors

PersonTokensPropCommitsCommitProp
pang xunleipang xunlei10100.00%1100.00%
Total10100.00%1100.00%

/** * timekeeping_inject_sleeptime64 - Adds suspend interval to timeekeeping values * @delta: pointer to a timespec64 delta value * * This hook is for architectures that cannot support read_persistent_clock64 * because their RTC/persistent clock is only accessible when irqs are enabled. * and also don't have an effective nonstop clocksource. * * This function should only be called by rtc_resume(), and allows * a suspend offset to be injected into the timekeeping values. */
void timekeeping_inject_sleeptime64(struct timespec64 *delta) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long flags; raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.seq); timekeeping_forward_now(tk); __timekeeping_inject_sleeptime(tk, delta); timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); /* signal hrtimers about time change */ clock_was_set(); }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz5262.65%541.67%
thomas gleixnerthomas gleixner2327.71%433.33%
david vrabeldavid vrabel56.02%216.67%
pang xunleipang xunlei33.61%18.33%
Total83100.00%12100.00%

#endif /** * timekeeping_resume - Resumes the generic timekeeping subsystem. */
void timekeeping_resume(void) { struct timekeeper *tk = &tk_core.timekeeper; struct clocksource *clock = tk->tkr_mono.clock; unsigned long flags; struct timespec64 ts_new, ts_delta; cycle_t cycle_now, cycle_delta; sleeptime_injected = false; read_persistent_clock64(&ts_new); clockevents_resume(); clocksource_resume(); raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.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 = tk->tkr_mono.read(clock); if ((clock->flags & CLOCK_SOURCE_SUSPEND_NONSTOP) && cycle_now > tk->tkr_mono.cycle_last) { u64 num, max = ULLONG_MAX; u32 mult = clock->mult; u32 shift = clock->shift; s64 nsec = 0; cycle_delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask); /* * "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_timespec64(nsec); sleeptime_injected = true; } else if (timespec64_compare(&ts_new, &timekeeping_suspend_time) > 0) { ts_delta = timespec64_sub(ts_new, timekeeping_suspend_time); sleeptime_injected = true; } if (sleeptime_injected) __timekeeping_inject_sleeptime(tk, &ts_delta); /* Re-base the last cycle value */ tk->tkr_mono.cycle_last = cycle_now; tk->tkr_raw.cycle_last = cycle_now; tk->ntp_error = 0; timekeeping_suspended = 0; timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); touch_softlockup_watchdog(); tick_resume(); hrtimers_resume(); }

Contributors

PersonTokensPropCommitsCommitProp
feng tangfeng tang16450.31%13.12%
john stultzjohn stultz6018.40%721.88%
thomas gleixnerthomas gleixner5115.64%1237.50%
martin schwidefskymartin schwidefsky206.13%26.25%
peter zijlstrapeter zijlstra144.29%26.25%
pang xunleipang xunlei72.15%26.25%
rafael j. wysockirafael j. wysocki51.53%26.25%
david vrabeldavid vrabel30.92%26.25%
tomas janousektomas janousek10.31%13.12%
ingo molnaringo molnar10.31%13.12%
Total326100.00%32100.00%


int timekeeping_suspend(void) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long flags; struct timespec64 delta, delta_delta; static struct timespec64 old_delta; read_persistent_clock64(&timekeeping_suspend_time); /* * 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_exists = true; raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.seq); timekeeping_forward_now(tk); timekeeping_suspended = 1; if (persistent_clock_exists) { /* * To avoid drift caused by repeated suspend/resumes, * which each can add ~1 second drift error, * try to compensate so the difference in system time * and persistent_clock time stays close to constant. */ delta = timespec64_sub(tk_xtime(tk), timekeeping_suspend_time); delta_delta = timespec64_sub(delta, old_delta); if (abs(delta_delta.tv_sec) >= 2) { /* * if delta_delta is too large, assume time correction * has occurred and set old_delta to the current delta. */ old_delta = delta; } else { /* Otherwise try to adjust old_system to compensate */ timekeeping_suspend_time = timespec64_add(timekeeping_suspend_time, delta_delta); } } timekeeping_update(tk, TK_MIRROR); halt_fast_timekeeper(tk); write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); tick_suspend(); clocksource_suspend(); clockevents_suspend(); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz11062.15%936.00%
thomas gleixnerthomas gleixner2614.69%624.00%
zoran markoviczoran markovic147.91%14.00%
pang xunleipang xunlei105.65%312.00%
rafael j. wysockirafael j. wysocki95.08%312.00%
martin schwidefskymartin schwidefsky52.82%28.00%
magnus dammmagnus damm31.69%14.00%
Total177100.00%25100.00%

/* sysfs resume/suspend bits for timekeeping */ static struct syscore_ops timekeeping_syscore_ops = { .resume = timekeeping_resume, .suspend = timekeeping_suspend, };
static int __init timekeeping_init_ops(void) { register_syscore_ops(&timekeeping_syscore_ops); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz1477.78%150.00%
rafael j. wysockirafael j. wysocki422.22%150.00%
Total18100.00%2100.00%

device_initcall(timekeeping_init_ops); /* * Apply a multiplier adjustment to the timekeeper */
static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk, s64 offset, bool negative, int adj_scale) { s64 interval = tk->cycle_interval; s32 mult_adj = 1; if (negative) { mult_adj = -mult_adj; interval = -interval; offset = -offset; } mult_adj <<= adj_scale; interval <<= adj_scale; offset <<= adj_scale; /* * So the following can be confusing. * * To keep things simple, lets assume mult_adj == 1 for now. * * When mult_adj != 1, remember that the interval and offset values * have been appropriately scaled so the math is the same. * * The basic idea here is that we're increasing the multiplier * by one, this causes the xtime_interval to be incremented by * one cycle_interval. This is because: * xtime_interval = cycle_interval * mult * So if mult is being incremented by one: * xtime_interval = cycle_interval * (mult + 1) * Its the same as: * xtime_interval = (cycle_interval * mult) + cycle_interval * Which can be shortened to: * xtime_interval += cycle_interval * * So offset stores the non-accumulated cycles. Thus the current * time (in shifted nanoseconds) is: * now = (offset * adj) + xtime_nsec * Now, even though we're adjusting the clock frequency, we have * to keep time consistent. In other words, we can't jump back * in time, and we also want to avoid jumping forward in time. * * So given the same offset value, we need the time to be the same * both before and after the freq adjustment. * now = (offset * adj_1) + xtime_nsec_1 * now = (offset * adj_2) + xtime_nsec_2 * So: * (offset * adj_1) + xtime_nsec_1 = * (offset * adj_2) + xtime_nsec_2 * And we know: * adj_2 = adj_1 + 1 * So: * (offset * adj_1) + xtime_nsec_1 = * (offset * (adj_1+1)) + xtime_nsec_2 * (offset * adj_1) + xtime_nsec_1 = * (offset * adj_1) + offset + xtime_nsec_2 * Canceling the sides: * xtime_nsec_1 = offset + xtime_nsec_2 * Which gives us: * xtime_nsec_2 = xtime_nsec_1 - offset * Which simplfies to: * xtime_nsec -= offset * * XXX - TODO: Doc ntp_error calculation. */ if ((mult_adj > 0) && (tk->tkr_mono.mult + mult_adj < mult_adj)) { /* NTP adjustment caused clocksource mult overflow */ WARN_ON_ONCE(1); return; } tk->tkr_mono.mult += mult_adj; tk->xtime_interval += interval; tk->tkr_mono.xtime_nsec -= offset; tk->ntp_error -= (interval - offset) << tk->ntp_error_shift; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz10982.58%466.67%
pang xunleipang xunlei2015.15%116.67%
peter zijlstrapeter zijlstra32.27%116.67%
Total132100.00%6100.00%

/* * Calculate the multiplier adjustment needed to match the frequency * specified by NTP */
static __always_inline void timekeeping_freqadjust(struct timekeeper *tk, s64 offset) { s64 interval = tk->cycle_interval; s64 xinterval = tk->xtime_interval; u32 base = tk->tkr_mono.clock->mult; u32 max = tk->tkr_mono.clock->maxadj; u32 cur_adj = tk->tkr_mono.mult; s64 tick_error; bool negative; u32 adj_scale; /* Remove any current error adj from freq calculation */ if (tk->ntp_err_mult) xinterval -= tk->cycle_interval; tk->ntp_tick = ntp_tick_length(); /* Calculate current error per tick */ tick_error = ntp_tick_length() >> tk->ntp_error_shift; tick_error -= (xinterval + tk->xtime_remainder); /* Don't worry about correcting it if its small */ if (likely((tick_error >= 0) && (tick_error <= interval))) return; /* preserve the direction of correction */ negative = (tick_error < 0); /* If any adjustment would pass the max, just return */ if (negative && (cur_adj - 1) <= (base - max)) return; if (!negative && (cur_adj + 1) >= (base + max)) return; /* * Sort out the magnitude of the correction, but * avoid making so large a correction that we go * over the max adjustment. */ adj_scale = 0; tick_error = abs(tick_error); while (tick_error > interval) { u32 adj = 1 << (adj_scale + 1); /* Check if adjustment gets us within 1 unit from the max */ if (negative && (cur_adj - adj) <= (base - max)) break; if (!negative && (cur_adj + adj) >= (base + max)) break; adj_scale++; tick_error >>= 1; } /* scale the corrections */ timekeeping_apply_adjustment(tk, offset, negative, adj_scale); }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz25799.23%571.43%
andrew mortonandrew morton10.39%114.29%
martin schwidefskymartin schwidefsky10.39%114.29%
Total259100.00%7100.00%

/* * Adjust the timekeeper's multiplier to the correct frequency * and also to reduce the accumulated error value. */
static void timekeeping_adjust(struct timekeeper *tk, s64 offset) { /* Correct for the current frequency error */ timekeeping_freqadjust(tk, offset); /* Next make a small adjustment to fix any cumulative error */ if (!tk->ntp_err_mult && (tk->ntp_error > 0)) { tk->ntp_err_mult = 1; timekeeping_apply_adjustment(tk, offset, 0, 0); } else if (tk->ntp_err_mult && (tk->ntp_error <= 0)) { /* Undo any existing error adjustment */ timekeeping_apply_adjustment(tk, offset, 1, 0); tk->ntp_err_mult = 0; } if (unlikely(tk->tkr_mono.clock->maxadj && (abs(tk->tkr_mono.mult - tk->tkr_mono.clock->mult) > tk->tkr_mono.clock->maxadj))) { printk_once(KERN_WARNING "Adjusting %s more than 11%% (%ld vs %ld)\n", tk->tkr_mono.clock->name, (long)tk->tkr_mono.mult, (long)tk->tkr_mono.clock->mult + tk->tkr_mono.clock->maxadj); } /* * 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->tkr_mono.xtime_nsec < 0)) { s64 neg = -(s64)tk->tkr_mono.xtime_nsec; tk->tkr_mono.xtime_nsec = 0; tk->ntp_error += neg << tk->ntp_error_shift; } }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz19787.17%660.00%
peter zijlstrapeter zijlstra114.87%110.00%
thomas gleixnerthomas gleixner114.87%110.00%
pang xunleipang xunlei52.21%110.00%
ingo molnaringo molnar20.88%110.00%
Total226100.00%10100.00%

/** * accumulate_nsecs_to_secs - Accumulates nsecs into secs * * Helper function that accumulates the nsecs greater than 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->tkr_mono.shift; unsigned int clock_set = 0; while (tk->tkr_mono.xtime_nsec >= nsecps) { int leap; tk->tkr_mono.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 timespec64 ts; tk->xtime_sec += leap; ts.tv_sec = leap; ts.tv_nsec = 0; tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts)); __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); clock_set = TK_CLOCK_WAS_SET; } } return clock_set; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz10679.10%763.64%
david vrabeldavid vrabel128.96%19.09%
martin schwidefskymartin schwidefsky107.46%19.09%
peter zijlstrapeter zijlstra32.24%19.09%
thomas gleixnerthomas gleixner32.24%19.09%
Total134100.00%11100.00%

/** * logarithmic_accumulation - shifted accumulation of cycles * * This functions accumulates a shifted interval of cycles into * into a shifted interval nanoseconds. Allows for O(log) accumulation * loop. * * Returns the unconsumed cycles. */
static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, u32 shift, unsigned int *clock_set) { cycle_t interval = tk->cycle_interval << shift; u64 raw_nsecs; /* If the offset is smaller than a shifted interval, do nothing */ if (offset < interval) return offset; /* Accumulate one shifted interval */ offset -= interval; tk->tkr_mono.cycle_last += interval; tk->tkr_raw.cycle_last += interval; tk->tkr_mono.xtime_nsec += tk->xtime_interval << shift; *clock_set |= accumulate_nsecs_to_secs(tk); /* Accumulate raw time */ 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); tk->raw_time.tv_sec += raw_secs; } tk->raw_time.tv_nsec = raw_nsecs; /* Accumulate error between NTP and clock interval */ tk->ntp_error += tk->ntp_tick << shift; tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) << (tk->ntp_error_shift + shift); return offset; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz12167.60%945.00%
jason wesseljason wessel1810.06%15.00%
thomas gleixnerthomas gleixner147.82%210.00%
peter zijlstrapeter zijlstra105.59%210.00%
roman zippelroman zippel52.79%15.00%
kasper pedersenkasper pedersen42.23%15.00%
martin schwidefskymartin schwidefsky31.68%210.00%
dan carpenterdan carpenter31.68%15.00%
zhen leizhen lei10.56%15.00%
Total179100.00%20100.00%

/** * update_wall_time - Uses the current clocksource to increment the wall time * */
void update_wall_time(void) { struct timekeeper *real_tk = &tk_core.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)) goto out; #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET offset = real_tk->cycle_interval; #else offset = clocksource_delta(tk->tkr_mono.read(tk->tkr_mono.clock), tk->tkr_mono.cycle_last, tk->tkr_mono.mask); #endif /* Check if there's really nothing to do */ if (offset < real_tk->cycle_interval) goto out; /* Do some additional sanity checking */ timekeeping_check_update(real_tk, offset); /* * With NO_HZ we may have to accumulate many cycle_intervals * (think "ticks") worth of time at once. To do this efficiently, * we calculate the largest doubling multiple of cycle_intervals * that is smaller than the offset. We then accumulate that * chunk in one go, and then try to consume the next smaller * doubled multiple. */ shift = ilog2(offset) - ilog2(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 >= 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(tk, offset); /* * XXX This can be killed once everyone converts * to the new update_vsyscall. */ old_vsyscall_fixup(tk); /* * Finally, make sure that after the rounding * xtime_nsec isn't larger than NSEC_PER_SEC */ clock_set |= accumulate_nsecs_to_secs(tk); write_seqcount_begin(&tk_core.seq); /* * 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 tk_core.seq against one before we start * updating. */ timekeeping_update(tk, clock_set); memcpy(real_tk, tk, sizeof(*tk)); /* The memcpy must come last. Do not put anything here! */ write_seqcount_end(&tk_core.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(); }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz22275.51%1957.58%
thomas gleixnerthomas gleixner6120.75%927.27%
peter zijlstrapeter zijlstra41.36%13.03%
david vrabeldavid vrabel31.02%13.03%
jim cromiejim cromie20.68%13.03%
roman zippelroman zippel10.34%13.03%
martin schwidefskymartin schwidefsky10.34%13.03%
Total294100.00%33100.00%

/** * getboottime64 - Return the real time of system boot. * @ts: pointer to the timespec64 to be set * * Returns the wall-time of boot in a timespec64. * * This is based on the wall_to_monotonic offset and the total suspend * time. Calls to settimeofday will affect the value returned (which * basically means that however wrong your real time clock is at boot time, * you get the right time here). */
void getboottime64(struct timespec64 *ts) { struct timekeeper *tk = &tk_core.timekeeper; ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot); *ts = ktime_to_timespec64(t); }

Contributors

PersonTokensPropCommitsCommitProp
thomas gleixnerthomas gleixner1433.33%228.57%
john stultzjohn stultz1433.33%228.57%
tomas janousektomas janousek1126.19%114.29%
hiroshi shimamotohiroshi shimamoto24.76%114.29%
martin schwidefskymartin schwidefsky12.38%114.29%
Total42100.00%7100.00%

EXPORT_SYMBOL_GPL(getboottime64);
unsigned long get_seconds(void) { struct timekeeper *tk = &tk_core.timekeeper; return tk->xtime_sec; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz2191.30%480.00%
thomas gleixnerthomas gleixner28.70%120.00%
Total23100.00%5100.00%

EXPORT_SYMBOL(get_seconds);
struct timespec __current_kernel_time(void) { struct timekeeper *tk = &tk_core.timekeeper; return timespec64_to_timespec(tk_xtime(tk)); }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz2592.59%480.00%
thomas gleixnerthomas gleixner27.41%120.00%
Total27100.00%5100.00%


struct timespec64 current_kernel_time64(void) { struct timekeeper *tk = &tk_core.timekeeper; struct timespec64 now; unsigned long seq; do { seq = read_seqcount_begin(&tk_core.seq); now = tk_xtime(tk); } while (read_seqcount_retry(&tk_core.seq, seq)); return now; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz5080.65%457.14%
thomas gleixnerthomas gleixner1016.13%228.57%
baolin wangbaolin wang23.23%114.29%
Total62100.00%7100.00%

EXPORT_SYMBOL(current_kernel_time64);
struct timespec64 get_monotonic_coarse64(void) { struct timekeeper *tk = &tk_core.timekeeper; struct timespec64 now, mono; unsigned long seq; do { seq = read_seqcount_begin(&tk_core.seq); now = tk_xtime(tk); mono = tk->wall_to_monotonic; } while (read_seqcount_retry(&tk_core.seq, seq)); set_normalized_timespec64(&now, now.tv_sec + mono.tv_sec, now.tv_nsec + mono.tv_nsec); return now; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz8289.13%571.43%
thomas gleixnerthomas gleixner1010.87%228.57%
Total92100.00%7100.00%

/* * Must hold jiffies_lock */
void do_timer(unsigned long ticks) { jiffies_64 += ticks; calc_global_load(ticks); }

Contributors

PersonTokensPropCommitsCommitProp
torben hohntorben hohn18100.00%1100.00%
Total18100.00%1100.00%

/** * ktime_get_update_offsets_now - hrtimer helper * @cwsseq: pointer to check and store the clock was set sequence number * @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 if the * sequence number in @cwsseq and timekeeper.clock_was_set_seq are * different. * * Called from hrtimer_interrupt() or retrigger_next_event() */
ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real, ktime_t *offs_boot, ktime_t *offs_tai) { struct timekeeper *tk = &tk_core.timekeeper; unsigned int seq; ktime_t base; u64 nsecs; do { seq = read_seqcount_begin(&tk_core.seq); base = tk->tkr_mono.base; nsecs = timekeeping_get_ns(&tk->tkr_mono); base = ktime_add_ns(base, nsecs); if (*cwsseq != tk->clock_was_set_seq) { *cwsseq = tk->clock_was_set_seq; *offs_real = tk->offs_real; *offs_boot = tk->offs_boot; *offs_tai = tk->offs_tai; } /* Handle leapsecond insertion adjustments */ if (unlikely(base.tv64 >= tk->next_leap_ktime.tv64)) *offs_real = ktime_sub(tk->offs_real, ktime_set(1, 0)); } while (read_seqcount_retry(&tk_core.seq, seq)); return base; }

Contributors

PersonTokensPropCommitsCommitProp
thomas gleixnerthomas gleixner9656.47%753.85%
john stultzjohn stultz7141.76%538.46%
peter zijlstrapeter zijlstra31.76%17.69%
Total170100.00%13100.00%

/** * do_adjtimex() - Accessor function to NTP __do_adjtimex function */
int do_adjtimex(struct timex *txc) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long flags; struct timespec64 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; } getnstimeofday64(&ts); raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.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); } tk_update_leap_state(tk); write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); if (tai != orig_tai) clock_was_set(); ntp_notify_cmos_timer(); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz20693.64%1280.00%
thomas gleixnerthomas gleixner94.09%213.33%
david vrabeldavid vrabel52.27%16.67%
Total220100.00%15100.00%

#ifdef CONFIG_NTP_PPS /** * hardpps() - Accessor function to NTP __hardpps function */
void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts) { unsigned long flags; raw_spin_lock_irqsave(&timekeeper_lock, flags); write_seqcount_begin(&tk_core.seq); __hardpps(phase_ts, raw_ts); write_seqcount_end(&tk_core.seq); raw_spin_unlock_irqrestore(&timekeeper_lock, flags); }

Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz5286.67%250.00%
thomas gleixnerthomas gleixner610.00%125.00%
arnd bergmannarnd bergmann23.33%125.00%
Total60100.00%4100.00%

EXPORT_SYMBOL(hardpps); #endif /** * xtime_update() - advances the timekeeping infrastructure * @ticks: number of ticks, that have elapsed since the last call. * * Must be called with interrupts disabled. */
void xtime_update(unsigned long ticks) { write_seqlock(&jiffies_lock); do_timer(ticks); write_sequnlock(&jiffies_lock); update_wall_time(); }

Contributors

PersonTokensPropCommitsCommitProp
torben hohntorben hohn2482.76%133.33%
john stultzjohn stultz517.24%266.67%
Total29100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
john stultzjohn stultz382145.37%7838.81%
thomas gleixnerthomas gleixner150117.82%4321.39%
christopher s. hallchristopher s. hall107612.78%52.49%
martin schwidefskymartin schwidefsky4775.66%104.98%
peter zijlstrapeter zijlstra3213.81%62.99%
feng tangfeng tang1782.11%21.00%
heena sirwaniheena sirwani1571.86%21.00%
marcelo tosattimarcelo tosatti1411.67%10.50%
pang xunleipang xunlei1371.63%104.98%
rafael j. wysockirafael j. wysocki1071.27%41.99%
harald geyerharald geyer770.91%10.50%
david vrabeldavid vrabel710.84%21.00%
wang yanqingwang yanqing460.55%10.50%
torben hohntorben hohn430.51%21.00%
kees cookkees cook350.42%10.50%
stephen warrenstephen warren290.34%10.50%
roman zippelroman zippel280.33%21.00%
magnus dammmagnus damm240.28%21.00%
dengchaodengchao230.27%10.50%
jason wesseljason wessel180.21%10.50%
kasper pedersenkasper pedersen160.19%10.50%
zoran markoviczoran markovic140.17%10.50%
gideon israel dsouzagideon israel dsouza130.15%10.50%
tomas janousektomas janousek120.14%10.50%
jon hunterjon hunter110.13%10.50%
colin crosscolin cross80.09%10.50%
ingo molnaringo molnar50.06%31.49%
jason wangjason wang40.05%10.50%
andreas schwabandreas schwab30.04%10.50%
baolin wangbaolin wang30.04%10.50%
dan carpenterdan carpenter30.04%10.50%
alexey dobriyanalexey dobriyan30.04%10.50%
arnd bergmannarnd bergmann20.02%10.50%
li zefanli zefan20.02%10.50%
zhen leizhen lei20.02%10.50%
jim cromiejim cromie20.02%10.50%
hiroshi shimamotohiroshi shimamoto20.02%10.50%
masanari iidamasanari iida10.01%10.50%
wang yijingwang yijing10.01%10.50%
andrew mortonandrew morton10.01%10.50%
geert uytterhoevengeert uytterhoeven10.01%10.50%
h hartley sweetenh hartley sweeten10.01%10.50%
fengguang wufengguang wu10.01%10.50%
richard cochranrichard cochran10.01%10.50%
Total8422100.00%201100.00%
Directory: kernel/time
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