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authorIngo Molnar <mingo@kernel.org>2012-04-14 13:18:27 +0200
committerIngo Molnar <mingo@kernel.org>2012-04-14 13:19:04 +0200
commit6ac1ef482d7ae0c690f1640bf6eb818ff9a2d91e (patch)
tree021cc9f6b477146fcebe6f3be4752abfa2ba18a9 /kernel/time/ntp.c
parent682968e0c425c60f0dde37977e5beb2b12ddc4cc (diff)
parenta385ec4f11bdcf81af094c03e2444ee9b7fad2e5 (diff)
Merge branch 'perf/core' into perf/uprobes
Merge in latest upstream (and the latest perf development tree), to prepare for tooling changes, and also to pick up v3.4 MM changes that the uprobes code needs to take care of. Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/time/ntp.c')
-rw-r--r--kernel/time/ntp.c191
1 files changed, 92 insertions, 99 deletions
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index f6117a4c7cb..f03fd83b170 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -22,17 +22,18 @@
* NTP timekeeping variables:
*/
+DEFINE_SPINLOCK(ntp_lock);
+
+
/* USER_HZ period (usecs): */
unsigned long tick_usec = TICK_USEC;
/* ACTHZ period (nsecs): */
unsigned long tick_nsec;
-u64 tick_length;
+static u64 tick_length;
static u64 tick_length_base;
-static struct hrtimer leap_timer;
-
#define MAX_TICKADJ 500LL /* usecs */
#define MAX_TICKADJ_SCALED \
(((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
@@ -49,7 +50,7 @@ static struct hrtimer leap_timer;
static int time_state = TIME_OK;
/* clock status bits: */
-int time_status = STA_UNSYNC;
+static int time_status = STA_UNSYNC;
/* TAI offset (secs): */
static long time_tai;
@@ -133,7 +134,7 @@ static inline void pps_reset_freq_interval(void)
/**
* pps_clear - Clears the PPS state variables
*
- * Must be called while holding a write on the xtime_lock
+ * Must be called while holding a write on the ntp_lock
*/
static inline void pps_clear(void)
{
@@ -149,7 +150,7 @@ static inline void pps_clear(void)
* the last PPS signal. When it reaches 0, indicate that PPS signal is
* missing.
*
- * Must be called while holding a write on the xtime_lock
+ * Must be called while holding a write on the ntp_lock
*/
static inline void pps_dec_valid(void)
{
@@ -233,6 +234,17 @@ static inline void pps_fill_timex(struct timex *txc)
#endif /* CONFIG_NTP_PPS */
+
+/**
+ * ntp_synced - Returns 1 if the NTP status is not UNSYNC
+ *
+ */
+static inline int ntp_synced(void)
+{
+ return !(time_status & STA_UNSYNC);
+}
+
+
/*
* NTP methods:
*/
@@ -275,7 +287,7 @@ static inline s64 ntp_update_offset_fll(s64 offset64, long secs)
time_status |= STA_MODE;
- return div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
+ return div64_long(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
}
static void ntp_update_offset(long offset)
@@ -330,11 +342,13 @@ static void ntp_update_offset(long offset)
/**
* ntp_clear - Clears the NTP state variables
- *
- * Must be called while holding a write on the xtime_lock
*/
void ntp_clear(void)
{
+ unsigned long flags;
+
+ spin_lock_irqsave(&ntp_lock, flags);
+
time_adjust = 0; /* stop active adjtime() */
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
@@ -347,63 +361,81 @@ void ntp_clear(void)
/* Clear PPS state variables */
pps_clear();
+ spin_unlock_irqrestore(&ntp_lock, flags);
+
+}
+
+
+u64 ntp_tick_length(void)
+{
+ unsigned long flags;
+ s64 ret;
+
+ spin_lock_irqsave(&ntp_lock, flags);
+ ret = tick_length;
+ spin_unlock_irqrestore(&ntp_lock, flags);
+ return ret;
}
+
/*
- * Leap second processing. If in leap-insert state at the end of the
- * day, the system clock is set back one second; if in leap-delete
- * state, the system clock is set ahead one second.
+ * this routine handles the overflow of the microsecond field
+ *
+ * The tricky bits of code to handle the accurate clock support
+ * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
+ * They were originally developed for SUN and DEC kernels.
+ * All the kudos should go to Dave for this stuff.
+ *
+ * Also handles leap second processing, and returns leap offset
*/
-static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
+int second_overflow(unsigned long secs)
{
- enum hrtimer_restart res = HRTIMER_NORESTART;
+ s64 delta;
+ int leap = 0;
+ unsigned long flags;
- write_seqlock(&xtime_lock);
+ spin_lock_irqsave(&ntp_lock, flags);
+ /*
+ * Leap second processing. If in leap-insert state at the end of the
+ * day, the system clock is set back one second; if in leap-delete
+ * state, the system clock is set ahead one second.
+ */
switch (time_state) {
case TIME_OK:
+ if (time_status & STA_INS)
+ time_state = TIME_INS;
+ else if (time_status & STA_DEL)
+ time_state = TIME_DEL;
break;
case TIME_INS:
- timekeeping_leap_insert(-1);
- time_state = TIME_OOP;
- printk(KERN_NOTICE
- "Clock: inserting leap second 23:59:60 UTC\n");
- hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC);
- res = HRTIMER_RESTART;
+ if (secs % 86400 == 0) {
+ leap = -1;
+ time_state = TIME_OOP;
+ printk(KERN_NOTICE
+ "Clock: inserting leap second 23:59:60 UTC\n");
+ }
break;
case TIME_DEL:
- timekeeping_leap_insert(1);
- time_tai--;
- time_state = TIME_WAIT;
- printk(KERN_NOTICE
- "Clock: deleting leap second 23:59:59 UTC\n");
+ 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");
+ }
break;
case TIME_OOP:
time_tai++;
time_state = TIME_WAIT;
- /* fall through */
+ break;
+
case TIME_WAIT:
if (!(time_status & (STA_INS | STA_DEL)))
time_state = TIME_OK;
break;
}
- write_sequnlock(&xtime_lock);
-
- return res;
-}
-
-/*
- * this routine handles the overflow of the microsecond field
- *
- * The tricky bits of code to handle the accurate clock support
- * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
- * They were originally developed for SUN and DEC kernels.
- * All the kudos should go to Dave for this stuff.
- */
-void second_overflow(void)
-{
- s64 delta;
/* Bump the maxerror field */
time_maxerror += MAXFREQ / NSEC_PER_USEC;
@@ -423,30 +455,34 @@ void second_overflow(void)
pps_dec_valid();
if (!time_adjust)
- return;
+ goto out;
if (time_adjust > MAX_TICKADJ) {
time_adjust -= MAX_TICKADJ;
tick_length += MAX_TICKADJ_SCALED;
- return;
+ goto out;
}
if (time_adjust < -MAX_TICKADJ) {
time_adjust += MAX_TICKADJ;
tick_length -= MAX_TICKADJ_SCALED;
- return;
+ goto out;
}
tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
<< NTP_SCALE_SHIFT;
time_adjust = 0;
+
+
+
+out:
+ spin_unlock_irqrestore(&ntp_lock, flags);
+
+ return leap;
}
#ifdef CONFIG_GENERIC_CMOS_UPDATE
-/* Disable the cmos update - used by virtualization and embedded */
-int no_sync_cmos_clock __read_mostly;
-
static void sync_cmos_clock(struct work_struct *work);
static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock);
@@ -493,35 +529,13 @@ static void sync_cmos_clock(struct work_struct *work)
static void notify_cmos_timer(void)
{
- if (!no_sync_cmos_clock)
- schedule_delayed_work(&sync_cmos_work, 0);
+ schedule_delayed_work(&sync_cmos_work, 0);
}
#else
static inline void notify_cmos_timer(void) { }
#endif
-/*
- * Start the leap seconds timer:
- */
-static inline void ntp_start_leap_timer(struct timespec *ts)
-{
- long now = ts->tv_sec;
-
- if (time_status & STA_INS) {
- time_state = TIME_INS;
- now += 86400 - now % 86400;
- hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
-
- return;
- }
-
- if (time_status & STA_DEL) {
- time_state = TIME_DEL;
- now += 86400 - (now + 1) % 86400;
- hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
- }
-}
/*
* Propagate a new txc->status value into the NTP state:
@@ -546,22 +560,6 @@ static inline void process_adj_status(struct timex *txc, struct timespec *ts)
time_status &= STA_RONLY;
time_status |= txc->status & ~STA_RONLY;
- switch (time_state) {
- case TIME_OK:
- ntp_start_leap_timer(ts);
- break;
- case TIME_INS:
- case TIME_DEL:
- time_state = TIME_OK;
- ntp_start_leap_timer(ts);
- case TIME_WAIT:
- if (!(time_status & (STA_INS | STA_DEL)))
- time_state = TIME_OK;
- break;
- case TIME_OOP:
- hrtimer_restart(&leap_timer);
- break;
- }
}
/*
* Called with the xtime lock held, so we can access and modify
@@ -643,9 +641,6 @@ int do_adjtimex(struct timex *txc)
(txc->tick < 900000/USER_HZ ||
txc->tick > 1100000/USER_HZ))
return -EINVAL;
-
- if (txc->modes & ADJ_STATUS && time_state != TIME_OK)
- hrtimer_cancel(&leap_timer);
}
if (txc->modes & ADJ_SETOFFSET) {
@@ -663,7 +658,7 @@ int do_adjtimex(struct timex *txc)
getnstimeofday(&ts);
- write_seqlock_irq(&xtime_lock);
+ spin_lock_irq(&ntp_lock);
if (txc->modes & ADJ_ADJTIME) {
long save_adjust = time_adjust;
@@ -705,7 +700,7 @@ int do_adjtimex(struct timex *txc)
/* fill PPS status fields */
pps_fill_timex(txc);
- write_sequnlock_irq(&xtime_lock);
+ spin_unlock_irq(&ntp_lock);
txc->time.tv_sec = ts.tv_sec;
txc->time.tv_usec = ts.tv_nsec;
@@ -903,7 +898,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
pts_norm = pps_normalize_ts(*phase_ts);
- write_seqlock_irqsave(&xtime_lock, flags);
+ spin_lock_irqsave(&ntp_lock, flags);
/* clear the error bits, they will be set again if needed */
time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
@@ -916,7 +911,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
* just start the frequency interval */
if (unlikely(pps_fbase.tv_sec == 0)) {
pps_fbase = *raw_ts;
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ spin_unlock_irqrestore(&ntp_lock, flags);
return;
}
@@ -931,7 +926,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
time_status |= STA_PPSJITTER;
/* restart the frequency calibration interval */
pps_fbase = *raw_ts;
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ spin_unlock_irqrestore(&ntp_lock, flags);
pr_err("hardpps: PPSJITTER: bad pulse\n");
return;
}
@@ -948,7 +943,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
hardpps_update_phase(pts_norm.nsec);
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ spin_unlock_irqrestore(&ntp_lock, flags);
}
EXPORT_SYMBOL(hardpps);
@@ -967,6 +962,4 @@ __setup("ntp_tick_adj=", ntp_tick_adj_setup);
void __init ntp_init(void)
{
ntp_clear();
- hrtimer_init(&leap_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
- leap_timer.function = ntp_leap_second;
}