Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / kernel / time / timekeeping.c

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 49010d822f725b47726742fa7e1b45aad076ef90..d27c7562902cbe3aa2472292bd813c1eee8c1ecb 100644 (file)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -32,6 +32,8 @@ struct timekeeper {
        cycle_t cycle_interval;
        /* Number of clock shifted nano seconds in one NTP interval. */
        u64     xtime_interval;
+       /* shifted nano seconds left over when rounding cycle_interval */
+       s64     xtime_remainder;
        /* Raw nano seconds accumulated per NTP interval. */
        u32     raw_interval;
 
@@ -47,7 +49,7 @@ struct timekeeper {
        u32     mult;
 };
 
-struct timekeeper timekeeper;
+static struct timekeeper timekeeper;
 
 /**
  * timekeeper_setup_internals - Set up internals to use clocksource clock.
@@ -62,7 +64,7 @@ struct timekeeper timekeeper;
 static void timekeeper_setup_internals(struct clocksource *clock)
 {
        cycle_t interval;
-       u64 tmp;
+       u64 tmp, ntpinterval;
 
        timekeeper.clock = clock;
        clock->cycle_last = clock->read(clock);
@@ -70,6 +72,7 @@ static void timekeeper_setup_internals(struct clocksource *clock)
        /* 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)
@@ -80,6 +83,7 @@ static void timekeeper_setup_internals(struct clocksource *clock)
 
        /* Go back from cycles -> shifted ns */
        timekeeper.xtime_interval = (u64) interval * clock->mult;
+       timekeeper.xtime_remainder = ntpinterval - timekeeper.xtime_interval;
        timekeeper.raw_interval =
                ((u64) interval * clock->mult) >> clock->shift;
 
@@ -160,7 +164,7 @@ static struct timespec total_sleep_time;
 /*
  * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock.
  */
-struct timespec raw_time;
+static struct timespec raw_time;
 
 /* flag for if timekeeping is suspended */
 int __read_mostly timekeeping_suspended;
@@ -284,6 +288,49 @@ void ktime_get_ts(struct timespec *ts)
 }
 EXPORT_SYMBOL_GPL(ktime_get_ts);
 
+#ifdef CONFIG_NTP_PPS
+
+/**
+ * getnstime_raw_and_real - get day and raw monotonic time in timespec format
+ * @ts_raw:    pointer to the timespec to be set to raw monotonic time
+ * @ts_real:   pointer to the timespec to be set to the time of day
+ *
+ * This function reads both the time of day and raw monotonic time at the
+ * same time atomically and stores the resulting timestamps in timespec
+ * format.
+ */
+void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
+{
+       unsigned long seq;
+       s64 nsecs_raw, nsecs_real;
+
+       WARN_ON_ONCE(timekeeping_suspended);
+
+       do {
+               u32 arch_offset;
+
+               seq = read_seqbegin(&xtime_lock);
+
+               *ts_raw = raw_time;
+               *ts_real = xtime;
+
+               nsecs_raw = timekeeping_get_ns_raw();
+               nsecs_real = timekeeping_get_ns();
+
+               /* If arch requires, add in gettimeoffset() */
+               arch_offset = arch_gettimeoffset();
+               nsecs_raw += arch_offset;
+               nsecs_real += arch_offset;
+
+       } while (read_seqretry(&xtime_lock, seq));
+
+       timespec_add_ns(ts_raw, nsecs_raw);
+       timespec_add_ns(ts_real, nsecs_real);
+}
+EXPORT_SYMBOL(getnstime_raw_and_real);
+
+#endif /* CONFIG_NTP_PPS */
+
 /**
  * do_gettimeofday - Returns the time of day in a timeval
  * @tv:                pointer to the timeval to be set
@@ -719,7 +766,8 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
 
        /* Accumulate error between NTP and clock interval */
        timekeeper.ntp_error += tick_length << shift;
-       timekeeper.ntp_error -= timekeeper.xtime_interval <<
+       timekeeper.ntp_error -=
+           (timekeeper.xtime_interval + timekeeper.xtime_remainder) <<
                                (timekeeper.ntp_error_shift + shift);
 
        return offset;