linux-kernel - [PATCH 6/8] time: Move arch_gettimeoffset() usage into timekeeping_get

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Date:	Fri, 13 Jul 2012 01:21:55 -0400
From:	John Stultz <john.stultz@...aro.org>
To:	Linux Kernel <linux-kernel@...r.kernel.org>
Cc:	John Stultz <john.stultz@...aro.org>,
	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Richard Cochran <richardcochran@...il.com>,
	Prarit Bhargava <prarit@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	John Stultz <johnstul@...ibm.com>
Subject: [PATCH 6/8] time: Move arch_gettimeoffset() usage into timekeeping_get_ns()

Since we call arch_gettimeoffset() in all the accessor
functions, move arch_gettimeoffset() calls into
timekeeping_get_ns() and timekeeping_get_ns_raw() to simplify
the code.

This also makes the code easier to maintain as we don't have to
worry about forgetting the arch_gettimeoffset() as has happened
in the past.

CC: Ingo Molnar <mingo@...nel.org>
CC: Peter Zijlstra <a.p.zijlstra@...llo.nl>
CC: Richard Cochran <richardcochran@...il.com>
CC: Prarit Bhargava <prarit@...hat.com>
CC: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: John Stultz <johnstul@...ibm.com>
---
 kernel/time/timekeeping.c |   32 +++++++++++++-------------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 5ffb2b6..dd119355 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -195,13 +195,18 @@ static inline s64 timekeeping_get_ns(void)
 	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
 
 	nsec = cycle_delta * timekeeper.mult + timekeeper.xtime_nsec;
-	return nsec >> timekeeper.shift;
+	nsec >>= timekeeper.shift;
+
+	/* If arch requires, add in gettimeoffset() */
+	nsec += arch_gettimeoffset();
+	return nsec;
 }
 
 static inline s64 timekeeping_get_ns_raw(void)
 {
 	cycle_t cycle_now, cycle_delta;
 	struct clocksource *clock;
+	s64 nsec;
 
 	/* read clocksource: */
 	clock = timekeeper.clock;
@@ -210,8 +215,13 @@ static inline s64 timekeeping_get_ns_raw(void)
 	/* calculate the delta since the last update_wall_time: */
 	cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
 
-	/* return delta convert to nanoseconds. */
-	return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
+	/* convert delta to nanoseconds. */
+	nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
+
+	/* If arch requires, add in gettimeoffset() */
+	nsec += arch_gettimeoffset();
+	return nsec;
+
 }
 
 static void update_rt_offset(void)
@@ -286,9 +296,6 @@ void getnstimeofday(struct timespec *ts)
 		ts->tv_sec = timekeeper.xtime_sec;
 		ts->tv_nsec = timekeeping_get_ns();
 
-		/* If arch requires, add in gettimeoffset() */
-		nsecs += arch_gettimeoffset();
-
 	} while (read_seqretry(&timekeeper.lock, seq));
 
 	timespec_add_ns(ts, nsecs);
@@ -308,8 +315,6 @@ ktime_t ktime_get(void)
 				timekeeper.wall_to_monotonic.tv_sec;
 		nsecs = timekeeping_get_ns() +
 				timekeeper.wall_to_monotonic.tv_nsec;
-		/* If arch requires, add in gettimeoffset() */
-		nsecs += arch_gettimeoffset();
 
 	} while (read_seqretry(&timekeeper.lock, seq));
 	/*
@@ -340,8 +345,6 @@ void ktime_get_ts(struct timespec *ts)
 		ts->tv_sec = timekeeper.xtime_sec;
 		ts->tv_nsec = timekeeping_get_ns();
 		tomono = timekeeper.wall_to_monotonic;
-		/* If arch requires, add in gettimeoffset() */
-		ts->tv_nsec += arch_gettimeoffset();
 
 	} while (read_seqretry(&timekeeper.lock, seq));
 
@@ -369,8 +372,6 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
 	WARN_ON_ONCE(timekeeping_suspended);
 
 	do {
-		u32 arch_offset;
-
 		seq = read_seqbegin(&timekeeper.lock);
 
 		*ts_raw = timekeeper.raw_time;
@@ -380,11 +381,6 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
 		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(&timekeeper.lock, seq));
 
 	timespec_add_ns(ts_raw, nsecs_raw);
@@ -1342,8 +1338,6 @@ ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
 
 		secs = timekeeper.xtime_sec;
 		nsecs = timekeeping_get_ns();
-		/* If arch requires, add in gettimeoffset() */
-		nsecs += arch_gettimeoffset();
 
 		*offs_real = timekeeper.offs_real;
 		*offs_boot = timekeeper.offs_boot;
-- 
1.7.9.5

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