From cc244ddae6d4c6902ac9d7d64023534f8c44a7eb Mon Sep 17 00:00:00 2001 From: John Stultz Date: Thu, 3 May 2012 12:30:07 -0700 Subject: [PATCH] timekeeping: Move TAI managment into timekeeping core from ntp Currently NTP manages the TAI offset. Since there's plans for a CLOCK_TAI clockid, push the TAI management into the timekeeping core. CC: Thomas Gleixner CC: Eric Dumazet CC: Richard Cochran Signed-off-by: John Stultz --- include/linux/time.h | 2 ++ include/linux/timekeeper_internal.h | 3 ++ kernel/time/ntp.c | 18 ++++++------ kernel/time/timekeeping.c | 44 +++++++++++++++++++++++++++++ 4 files changed, 59 insertions(+), 8 deletions(-) diff --git a/include/linux/time.h b/include/linux/time.h index d4835dfdf25e..47210a175e78 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -181,6 +181,8 @@ extern struct timespec timespec_trunc(struct timespec t, unsigned gran); extern int timekeeping_valid_for_hres(void); extern u64 timekeeping_max_deferment(void); extern int timekeeping_inject_offset(struct timespec *ts); +extern s32 timekeeping_get_tai_offset(void); +extern void timekeeping_set_tai_offset(s32 tai_offset); struct tms; extern void do_sys_times(struct tms *); diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index e1d558e237ec..ff94f436f8b7 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -62,6 +62,9 @@ struct timekeeper { ktime_t offs_boot; /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */ struct timespec raw_time; + /* The current UTC to TAI offset in seconds */ + s32 tai_offset; + /* Seqlock for all timekeeper values */ seqlock_t lock; }; diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 072bb066bb7d..59e2749be0fa 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -53,9 +53,6 @@ static int time_state = TIME_OK; /* clock status bits: */ static int time_status = STA_UNSYNC; -/* TAI offset (secs): */ -static long time_tai; - /* time adjustment (nsecs): */ static s64 time_offset; @@ -415,7 +412,6 @@ int second_overflow(unsigned long secs) else if (secs % 86400 == 0) { leap = -1; time_state = TIME_OOP; - time_tai++; printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n"); } @@ -425,7 +421,6 @@ int second_overflow(unsigned long secs) time_state = TIME_OK; else if ((secs + 1) % 86400 == 0) { leap = 1; - time_tai--; time_state = TIME_WAIT; printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n"); @@ -579,7 +574,9 @@ static inline void process_adj_status(struct timex *txc, struct timespec *ts) * Called with ntp_lock held, so we can access and modify * all the global NTP state: */ -static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts) +static inline void process_adjtimex_modes(struct timex *txc, + struct timespec *ts, + s32 *time_tai) { if (txc->modes & ADJ_STATUS) process_adj_status(txc, ts); @@ -613,7 +610,7 @@ static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts } if (txc->modes & ADJ_TAI && txc->constant > 0) - time_tai = txc->constant; + *time_tai = txc->constant; if (txc->modes & ADJ_OFFSET) ntp_update_offset(txc->offset); @@ -632,6 +629,7 @@ static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts int do_adjtimex(struct timex *txc) { struct timespec ts; + u32 time_tai, orig_tai; int result; /* Validate the data before disabling interrupts */ @@ -671,6 +669,7 @@ int do_adjtimex(struct timex *txc) } getnstimeofday(&ts); + orig_tai = time_tai = timekeeping_get_tai_offset(); raw_spin_lock_irq(&ntp_lock); @@ -687,7 +686,7 @@ int do_adjtimex(struct timex *txc) /* If there are input parameters, then process them: */ if (txc->modes) - process_adjtimex_modes(txc, &ts); + process_adjtimex_modes(txc, &ts, &time_tai); txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ, NTP_SCALE_SHIFT); @@ -716,6 +715,9 @@ int do_adjtimex(struct timex *txc) raw_spin_unlock_irq(&ntp_lock); + if (time_tai != orig_tai) + timekeeping_set_tai_offset(time_tai); + txc->time.tv_sec = ts.tv_sec; txc->time.tv_usec = ts.tv_nsec; if (!(time_status & STA_NANO)) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 0355f125d585..937098aab498 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -513,6 +513,48 @@ error: /* even if we error out, we forwarded the time, so call update */ } EXPORT_SYMBOL(timekeeping_inject_offset); + +/** + * timekeeping_get_tai_offset - Returns current TAI offset from UTC + * + */ +s32 timekeeping_get_tai_offset(void) +{ + struct timekeeper *tk = &timekeeper; + unsigned int seq; + s32 ret; + + do { + seq = read_seqbegin(&tk->lock); + ret = tk->tai_offset; + } while (read_seqretry(&tk->lock, seq)); + + return ret; +} + +/** + * __timekeeping_set_tai_offset - Lock free worker function + * + */ +void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset) +{ + tk->tai_offset = tai_offset; +} + +/** + * timekeeping_set_tai_offset - Sets the current TAI offset from UTC + * + */ +void timekeeping_set_tai_offset(s32 tai_offset) +{ + struct timekeeper *tk = &timekeeper; + unsigned long flags; + + write_seqlock_irqsave(&tk->lock, flags); + __timekeeping_set_tai_offset(tk, tai_offset); + write_sequnlock_irqrestore(&tk->lock, flags); +} + /** * change_clocksource - Swaps clocksources if a new one is available * @@ -1143,6 +1185,8 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk) tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts)); + __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); + clock_was_set_delayed(); } } -- 2.34.1