ntp: Add ntp_lock to replace xtime_locking
Use a ntp_lock spin lock to replace xtime_lock locking in ntp.c CC: Thomas Gleixner <tglx@linutronix.de> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: Richard Cochran <richardcochran@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
John Stultz
Родитель
ea7cf49a76
Коммит
bd3312681f
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@ -22,6 +22,9 @@
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* NTP timekeeping variables:
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*/
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DEFINE_SPINLOCK(ntp_lock);
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/* USER_HZ period (usecs): */
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unsigned long tick_usec = TICK_USEC;
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@ -133,7 +136,7 @@ static inline void pps_reset_freq_interval(void)
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/**
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* pps_clear - Clears the PPS state variables
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*
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* Must be called while holding a write on the xtime_lock
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* Must be called while holding a write on the ntp_lock
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*/
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static inline void pps_clear(void)
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{
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@ -149,7 +152,7 @@ static inline void pps_clear(void)
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* the last PPS signal. When it reaches 0, indicate that PPS signal is
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* missing.
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*
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* Must be called while holding a write on the xtime_lock
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* Must be called while holding a write on the ntp_lock
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*/
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static inline void pps_dec_valid(void)
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{
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@ -341,11 +344,13 @@ static void ntp_update_offset(long offset)
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/**
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* ntp_clear - Clears the NTP state variables
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*
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* Must be called while holding a write on the xtime_lock
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*/
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void ntp_clear(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&ntp_lock, flags);
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time_adjust = 0; /* stop active adjtime() */
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time_status |= STA_UNSYNC;
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time_maxerror = NTP_PHASE_LIMIT;
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@ -358,12 +363,20 @@ void ntp_clear(void)
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/* Clear PPS state variables */
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pps_clear();
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spin_unlock_irqrestore(&ntp_lock, flags);
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}
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u64 ntp_tick_length(void)
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{
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return tick_length;
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unsigned long flags;
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s64 ret;
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spin_lock_irqsave(&ntp_lock, flags);
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ret = tick_length;
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spin_unlock_irqrestore(&ntp_lock, flags);
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return ret;
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}
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@ -375,14 +388,15 @@ u64 ntp_tick_length(void)
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static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
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{
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enum hrtimer_restart res = HRTIMER_NORESTART;
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unsigned long flags;
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int leap = 0;
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write_seqlock(&xtime_lock);
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spin_lock_irqsave(&ntp_lock, flags);
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switch (time_state) {
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case TIME_OK:
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break;
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case TIME_INS:
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timekeeping_leap_insert(-1);
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leap = -1;
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time_state = TIME_OOP;
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printk(KERN_NOTICE
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"Clock: inserting leap second 23:59:60 UTC\n");
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@ -390,7 +404,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
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res = HRTIMER_RESTART;
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break;
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case TIME_DEL:
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timekeeping_leap_insert(1);
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leap = 1;
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time_tai--;
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time_state = TIME_WAIT;
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printk(KERN_NOTICE
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@ -405,8 +419,14 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
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time_state = TIME_OK;
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break;
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}
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spin_unlock_irqrestore(&ntp_lock, flags);
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write_sequnlock(&xtime_lock);
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/*
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* We have to call this outside of the ntp_lock to keep
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* the proper locking hierarchy
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*/
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if (leap)
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timekeeping_leap_insert(leap);
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return res;
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}
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@ -422,6 +442,9 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
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void second_overflow(void)
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{
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s64 delta;
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unsigned long flags;
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spin_lock_irqsave(&ntp_lock, flags);
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/* Bump the maxerror field */
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time_maxerror += MAXFREQ / NSEC_PER_USEC;
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@ -441,23 +464,25 @@ void second_overflow(void)
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pps_dec_valid();
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if (!time_adjust)
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return;
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goto out;
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if (time_adjust > MAX_TICKADJ) {
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time_adjust -= MAX_TICKADJ;
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tick_length += MAX_TICKADJ_SCALED;
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return;
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goto out;
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}
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if (time_adjust < -MAX_TICKADJ) {
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time_adjust += MAX_TICKADJ;
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tick_length -= MAX_TICKADJ_SCALED;
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return;
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goto out;
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}
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tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
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<< NTP_SCALE_SHIFT;
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time_adjust = 0;
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out:
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spin_unlock_irqrestore(&ntp_lock, flags);
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}
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#ifdef CONFIG_GENERIC_CMOS_UPDATE
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@ -681,7 +706,7 @@ int do_adjtimex(struct timex *txc)
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getnstimeofday(&ts);
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write_seqlock_irq(&xtime_lock);
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spin_lock_irq(&ntp_lock);
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if (txc->modes & ADJ_ADJTIME) {
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long save_adjust = time_adjust;
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@ -723,7 +748,7 @@ int do_adjtimex(struct timex *txc)
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/* fill PPS status fields */
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pps_fill_timex(txc);
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write_sequnlock_irq(&xtime_lock);
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spin_unlock_irq(&ntp_lock);
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txc->time.tv_sec = ts.tv_sec;
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txc->time.tv_usec = ts.tv_nsec;
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@ -921,7 +946,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
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pts_norm = pps_normalize_ts(*phase_ts);
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write_seqlock_irqsave(&xtime_lock, flags);
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spin_lock_irqsave(&ntp_lock, flags);
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/* clear the error bits, they will be set again if needed */
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time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
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@ -934,7 +959,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
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* just start the frequency interval */
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if (unlikely(pps_fbase.tv_sec == 0)) {
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pps_fbase = *raw_ts;
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write_sequnlock_irqrestore(&xtime_lock, flags);
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spin_unlock_irqrestore(&ntp_lock, flags);
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return;
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}
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@ -949,7 +974,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
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time_status |= STA_PPSJITTER;
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/* restart the frequency calibration interval */
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pps_fbase = *raw_ts;
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write_sequnlock_irqrestore(&xtime_lock, flags);
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spin_unlock_irqrestore(&ntp_lock, flags);
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pr_err("hardpps: PPSJITTER: bad pulse\n");
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return;
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}
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@ -966,7 +991,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
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hardpps_update_phase(pts_norm.nsec);
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write_sequnlock_irqrestore(&xtime_lock, flags);
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spin_unlock_irqrestore(&ntp_lock, flags);
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}
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EXPORT_SYMBOL(hardpps);
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