commit 3a97837784acbf9fed699fc04d1799b0eb742fdf
author Thomas Gleixner <tglx@linutronix.de> Wed Jul 16 21:05:10 2014 +0000
committer John Stultz <john.stultz@linaro.org> Wed Jul 23 15:01:51 2014 -0700
tree 12297634077b24bcc6a01b779205043fc2a2a1f1
parent 6438e0ddc870f282f7ad46c050c211063a574687

clocksource: Make delta calculation a function

We want to move the TSC sanity check into core code to make NMI safe
accessors to clock monotonic[_raw] possible. For this we need to
sanity check the delta calculation. Create a helper function and
convert all sites to use it.

[ Build fix from jstultz ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>

kernel/time/clocksource.c

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index ba3e502..2e949cc 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -32,6 +32,7 @@
 #include <linux/kthread.h>
 
 #include "tick-internal.h"
+#include "timekeeping_internal.h"
 
 void timecounter_init(struct timecounter *tc,
 		      const struct cyclecounter *cc,
@@ -249,7 +250,7 @@
 static void clocksource_watchdog(unsigned long data)
 {
 	struct clocksource *cs;
-	cycle_t csnow, wdnow;
+	cycle_t csnow, wdnow, delta;
 	int64_t wd_nsec, cs_nsec;
 	int next_cpu, reset_pending;
 
@@ -282,11 +283,12 @@
 			continue;
 		}
 
-		wd_nsec = clocksource_cyc2ns((wdnow - cs->wd_last) & watchdog->mask,
-					     watchdog->mult, watchdog->shift);
+		delta = clocksource_delta(wdnow, cs->wd_last, watchdog->mask);
+		wd_nsec = clocksource_cyc2ns(delta, watchdog->mult,
+					     watchdog->shift);
 
-		cs_nsec = clocksource_cyc2ns((csnow - cs->cs_last) &
-					     cs->mask, cs->mult, cs->shift);
+		delta = clocksource_delta(csnow, cs->cs_last, cs->mask);
+		cs_nsec = clocksource_cyc2ns(delta, cs->mult, cs->shift);
 		cs->cs_last = csnow;
 		cs->wd_last = wdnow;