hrtimer: Cleanup direct access to wall_to_monotonic

Provides an accessor function to replace hrtimer.c's
direct access of wall_to_monotonic.

This will allow wall_to_monotonic to be made static as
planned in Documentation/feature-removal-schedule.txt

Signed-off-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-9-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/linux/time.h

@@ -126,7 +126,8 @@ extern int timekeeping_suspended;
 
 unsigned long get_seconds(void);
 struct timespec current_kernel_time(void);
-struct timespec __current_kernel_time(void); /* does not hold xtime_lock */
+struct timespec __current_kernel_time(void); /* does not take xtime_lock */
+struct timespec __get_wall_to_monotonic(void); /* does not take xtime_lock */
 struct timespec get_monotonic_coarse(void);
 
 #define CURRENT_TIME		(current_kernel_time())

kernel/hrtimer.c

@@ -90,7 +90,7 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base)
 	do {
 		seq = read_seqbegin(&xtime_lock);
 		xts = __current_kernel_time();
-		tom = wall_to_monotonic;
+		tom = __get_wall_to_monotonic();
 	} while (read_seqretry(&xtime_lock, seq));
 
 	xtim = timespec_to_ktime(xts);
@@ -612,7 +612,7 @@ static int hrtimer_reprogram(struct hrtimer *timer,
 static void retrigger_next_event(void *arg)
 {
 	struct hrtimer_cpu_base *base;
-	struct timespec realtime_offset;
+	struct timespec realtime_offset, wtm;
 	unsigned long seq;
 
 	if (!hrtimer_hres_active())
@@ -620,10 +620,9 @@ static void retrigger_next_event(void *arg)
 
 	do {
 		seq = read_seqbegin(&xtime_lock);
-		set_normalized_timespec(&realtime_offset,
-					-wall_to_monotonic.tv_sec,
-					-wall_to_monotonic.tv_nsec);
+		wtm = __get_wall_to_monotonic();
 	} while (read_seqretry(&xtime_lock, seq));
+	set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec);
 
 	base = &__get_cpu_var(hrtimer_bases);
 

kernel/time/timekeeping.c

@@ -858,6 +858,11 @@ struct timespec __current_kernel_time(void)
 	return xtime;
 }
 
+struct timespec __get_wall_to_monotonic(void)
+{
+	return wall_to_monotonic;
+}
+
 struct timespec current_kernel_time(void)
 {
 	struct timespec now;