x86/vdso: Collapse coarse functions

do_realtime_coarse() and do_monotonic_coarse() are now the same except for
the storage array index. Hand the index in as an argument and collapse the
functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Matt Rickard <matt@softrans.com.au>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: devel@linuxdriverproject.org
Cc: virtualization@lists.linux-foundation.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Juergen Gross <jgross@suse.com>
Link: https://lkml.kernel.org/r/20180917130707.490733779@linutronix.de

arch/x86/entry/vdso/vclock_gettime.c

@@ -227,21 +227,9 @@ notrace static int do_hres(clockid_t clk, struct timespec *ts)
 	return mode;
 }
 
-notrace static void do_realtime_coarse(struct timespec *ts)
+notrace static void do_coarse(clockid_t clk, struct timespec *ts)
 {
-	struct vgtod_ts *base = &gtod->basetime[CLOCK_REALTIME_COARSE];
-	unsigned int seq;
-
-	do {
-		seq = gtod_read_begin(gtod);
-		ts->tv_sec = base->sec;
-		ts->tv_nsec = base->nsec;
-	} while (unlikely(gtod_read_retry(gtod, seq)));
-}
-
-notrace static void do_monotonic_coarse(struct timespec *ts)
-{
-	struct vgtod_ts *base = &gtod->basetime[CLOCK_MONOTONIC_COARSE];
+	struct vgtod_ts *base = &gtod->basetime[clk];
 	unsigned int seq;
 
 	do {
@@ -263,10 +251,10 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
 			goto fallback;
 		break;
 	case CLOCK_REALTIME_COARSE:
-		do_realtime_coarse(ts);
+		do_coarse(CLOCK_REALTIME_COARSE, ts);
 		break;
 	case CLOCK_MONOTONIC_COARSE:
-		do_monotonic_coarse(ts);
+		do_coarse(CLOCK_MONOTONIC_COARSE, ts);
 		break;
 	default:
 		goto fallback;