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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-12 22:17:48 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-12 22:17:48 +0900
commit03d3602a833715f83ea53b9feb078b9c4c5f6c1a (patch)
tree7b63ec6753dd65e61392017e1aba2ee1e6b4bcd1 /kernel/time/timekeeping.c
parent0588f1f934791b79d0a1e9b327be9b6eb361d2b8 (diff)
parent5b3900cd409466c0070b234d941650685ad0c791 (diff)
downloadlinaro-lsk-03d3602a833715f83ea53b9feb078b9c4c5f6c1a.tar.gz
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core update from Thomas Gleixner: - Bug fixes (one for a longstanding dead loop issue) - Rework of time related vsyscalls - Alarm timer updates - Jiffies updates to remove compile time dependencies * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timekeeping: Cast raw_interval to u64 to avoid shift overflow timers: Fix endless looping between cascade() and internal_add_timer() time/jiffies: bring back unconditional LATCH definition time: Convert x86_64 to using new update_vsyscall time: Only do nanosecond rounding on GENERIC_TIME_VSYSCALL_OLD systems time: Introduce new GENERIC_TIME_VSYSCALL time: Convert CONFIG_GENERIC_TIME_VSYSCALL to CONFIG_GENERIC_TIME_VSYSCALL_OLD time: Move update_vsyscall definitions to timekeeper_internal.h time: Move timekeeper structure to timekeeper_internal.h for vsyscall changes jiffies: Remove compile time assumptions about CLOCK_TICK_RATE jiffies: Kill unused TICK_USEC_TO_NSEC alarmtimer: Rename alarmtimer_remove to alarmtimer_dequeue alarmtimer: Remove unused helpers & defines alarmtimer: Use hrtimer per-alarm instead of per-base alarmtimer: Implement minimum alarm interval for allowing suspend
Diffstat (limited to 'kernel/time/timekeeping.c')
-rw-r--r--kernel/time/timekeeping.c117
1 files changed, 34 insertions, 83 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 5ce06a3fa91..e424970bb56 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -8,6 +8,7 @@
*
*/
+#include <linux/timekeeper_internal.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
@@ -21,61 +22,6 @@
#include <linux/tick.h>
#include <linux/stop_machine.h>
-/* Structure holding internal timekeeping values. */
-struct timekeeper {
- /* Current clocksource used for timekeeping. */
- struct clocksource *clock;
- /* NTP adjusted clock multiplier */
- u32 mult;
- /* The shift value of the current clocksource. */
- u32 shift;
- /* Number of clock cycles in one NTP interval. */
- 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;
-
- /* Current CLOCK_REALTIME time in seconds */
- u64 xtime_sec;
- /* Clock shifted nano seconds */
- u64 xtime_nsec;
-
- /* Difference between accumulated time and NTP time in ntp
- * shifted nano seconds. */
- s64 ntp_error;
- /* Shift conversion between clock shifted nano seconds and
- * ntp shifted nano seconds. */
- u32 ntp_error_shift;
-
- /*
- * wall_to_monotonic is what we need to add to xtime (or xtime corrected
- * for sub jiffie times) to get to monotonic time. Monotonic is pegged
- * at zero at system boot time, so wall_to_monotonic will be negative,
- * however, we will ALWAYS keep the tv_nsec part positive so we can use
- * the usual normalization.
- *
- * wall_to_monotonic is moved after resume from suspend for the
- * monotonic time not to jump. We need to add total_sleep_time to
- * wall_to_monotonic to get the real boot based time offset.
- *
- * - wall_to_monotonic is no longer the boot time, getboottime must be
- * used instead.
- */
- struct timespec wall_to_monotonic;
- /* Offset clock monotonic -> clock realtime */
- ktime_t offs_real;
- /* time spent in suspend */
- struct timespec total_sleep_time;
- /* Offset clock monotonic -> clock boottime */
- ktime_t offs_boot;
- /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
- struct timespec raw_time;
- /* Seqlock for all timekeeper values */
- seqlock_t lock;
-};
static struct timekeeper timekeeper;
@@ -96,15 +42,6 @@ static inline void tk_normalize_xtime(struct timekeeper *tk)
}
}
-static struct timespec tk_xtime(struct timekeeper *tk)
-{
- struct timespec ts;
-
- ts.tv_sec = tk->xtime_sec;
- ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift);
- return ts;
-}
-
static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts)
{
tk->xtime_sec = ts->tv_sec;
@@ -246,14 +183,11 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
/* must hold write on timekeeper.lock */
static void timekeeping_update(struct timekeeper *tk, bool clearntp)
{
- struct timespec xt;
-
if (clearntp) {
tk->ntp_error = 0;
ntp_clear();
}
- xt = tk_xtime(tk);
- update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
+ update_vsyscall(tk);
}
/**
@@ -1113,7 +1047,7 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
accumulate_nsecs_to_secs(tk);
/* Accumulate raw time */
- raw_nsecs = tk->raw_interval << shift;
+ raw_nsecs = (u64)tk->raw_interval << shift;
raw_nsecs += tk->raw_time.tv_nsec;
if (raw_nsecs >= NSEC_PER_SEC) {
u64 raw_secs = raw_nsecs;
@@ -1130,6 +1064,33 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
return offset;
}
+#ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
+static inline void old_vsyscall_fixup(struct timekeeper *tk)
+{
+ s64 remainder;
+
+ /*
+ * Store only full nanoseconds into xtime_nsec after rounding
+ * it up and add the remainder to the error difference.
+ * XXX - This is necessary to avoid small 1ns inconsistnecies caused
+ * by truncating the remainder in vsyscalls. However, it causes
+ * additional work to be done in timekeeping_adjust(). Once
+ * the vsyscall implementations are converted to use xtime_nsec
+ * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
+ * users are removed, this can be killed.
+ */
+ remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
+ tk->xtime_nsec -= remainder;
+ tk->xtime_nsec += 1ULL << tk->shift;
+ tk->ntp_error += remainder << tk->ntp_error_shift;
+
+}
+#else
+#define old_vsyscall_fixup(tk)
+#endif
+
+
+
/**
* update_wall_time - Uses the current clocksource to increment the wall time
*
@@ -1141,7 +1102,6 @@ static void update_wall_time(void)
cycle_t offset;
int shift = 0, maxshift;
unsigned long flags;
- s64 remainder;
write_seqlock_irqsave(&tk->lock, flags);
@@ -1183,20 +1143,11 @@ static void update_wall_time(void)
/* correct the clock when NTP error is too big */
timekeeping_adjust(tk, offset);
-
/*
- * Store only full nanoseconds into xtime_nsec after rounding
- * it up and add the remainder to the error difference.
- * XXX - This is necessary to avoid small 1ns inconsistnecies caused
- * by truncating the remainder in vsyscalls. However, it causes
- * additional work to be done in timekeeping_adjust(). Once
- * the vsyscall implementations are converted to use xtime_nsec
- * (shifted nanoseconds), this can be killed.
- */
- remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
- tk->xtime_nsec -= remainder;
- tk->xtime_nsec += 1ULL << tk->shift;
- tk->ntp_error += remainder << tk->ntp_error_shift;
+ * XXX This can be killed once everyone converts
+ * to the new update_vsyscall.
+ */
+ old_vsyscall_fixup(tk);
/*
* Finally, make sure that after the rounding