1 files changed, 64 insertions, 21 deletions

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index f6117a4c7cb8..6e039b144daf 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -22,13 +22,16 @@
  * 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;
@@ -49,7 +52,7 @@ 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 +136,7 @@ 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 +152,7 @@ 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 +236,17 @@ 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 +289,7 @@ 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 +344,13 @@ 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;
@@ -347,8 +363,23 @@ 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
@@ -357,14 +388,15 @@ void ntp_clear(void)
 static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
 {
         enum hrtimer_restart res = HRTIMER_NORESTART;
+        unsigned long flags;
+        int leap = 0;
 
-        write_seqlock(&xtime_lock);
-
+        spin_lock_irqsave(&ntp_lock, flags);
         switch (time_state) {
         case TIME_OK:
                 break;
         case TIME_INS:
-                timekeeping_leap_insert(-1);
+                leap = -1;
                 time_state = TIME_OOP;
                 printk(KERN_NOTICE
                         "Clock: inserting leap second 23:59:60 UTC\n");
@@ -372,7 +404,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
                 res = HRTIMER_RESTART;
                 break;
         case TIME_DEL:
-                timekeeping_leap_insert(1);
+                leap = 1;
                 time_tai--;
                 time_state = TIME_WAIT;
                 printk(KERN_NOTICE
@@ -387,8 +419,14 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
                         time_state = TIME_OK;
                 break;
         }
+        spin_unlock_irqrestore(&ntp_lock, flags);
 
-        write_sequnlock(&xtime_lock);
+        /*
+         * We have to call this outside of the ntp_lock to keep
+         * the proper locking hierarchy
+         */
+        if (leap)
+                timekeeping_leap_insert(leap);
 
         return res;
 }
@@ -404,6 +442,9 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
 void second_overflow(void)
 {
         s64 delta;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ntp_lock, flags);
 
         /* Bump the maxerror field */
         time_maxerror += MAXFREQ / NSEC_PER_USEC;
@@ -423,23 +464,25 @@ 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);
 }
 
 #ifdef CONFIG_GENERIC_CMOS_UPDATE
@@ -663,7 +706,7 @@ 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 +748,7 @@ 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 +946,7 @@ 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 +959,7 @@ 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 +974,7 @@ 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 +991,7 @@ 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);