[PATCH 08/11] timekeeping: Provide internal function __ktime_get_real_seconds

[John Stultz <john.stultz@linaro.org>]

From: DengChao <chao.deng@linaro.org>

In order to fix Y2038 issues in the ntp code we will need replace
get_seconds() with ktime_get_real_seconds() but as the ntp code uses
the timekeeping lock which is also used by ktime_get_real_seconds(),
we need a version without locking.
Add a new function __ktime_get_real_seconds() in timekeeping to
do this.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: DengChao <chao.deng@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 kernel/time/timekeeping.c          | 13 +++++++++++++
 kernel/time/timekeeping_internal.h |  2 ++
 2 files changed, 15 insertions(+)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index d9249da..21cc239 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -845,6 +845,19 @@ time64_t ktime_get_real_seconds(void)
 }
 EXPORT_SYMBOL_GPL(ktime_get_real_seconds);
 
+/**
+ * __ktime_get_real_seconds - The same as ktime_get_real_seconds
+ * but without the sequence counter protect. This internal function
+ * is called just when timekeeping lock is already held.
+ */
+time64_t __ktime_get_real_seconds(void)
+{
+	struct timekeeper *tk = &tk_core.timekeeper;
+
+	return tk->xtime_sec;
+}
+
+
 #ifdef CONFIG_NTP_PPS
 
 /**
diff --git a/kernel/time/timekeeping_internal.h b/kernel/time/timekeeping_internal.h
index 4ea005a..e20466f 100644
--- a/kernel/time/timekeeping_internal.h
+++ b/kernel/time/timekeeping_internal.h
@@ -26,4 +26,6 @@ static inline cycle_t clocksource_delta(cycle_t now, cycle_t last, cycle_t mask)
 }
 #endif
 
+extern time64_t __ktime_get_real_seconds(void);
+
 #endif /* _TIMEKEEPING_INTERNAL_H */
-- 
1.9.1