x86, vdso: __vdso_clock_gettime() cleanup

This patch is a small code cleanup for the __vdso_clock_gettime() function.

It removes the unneeded return values from do_monotonic_coarse() and
do_realtime_coarse() and add a fallback label for doing the kernel
gettimeofday() system call.

Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-5-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 14 insertions, 13 deletions

diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index bbc80657050f..fd074dd19a4a 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -209,7 +209,7 @@ notrace static int do_monotonic(struct timespec *ts)
         return mode;
 }
 
-notrace static int do_realtime_coarse(struct timespec *ts)
+notrace static void do_realtime_coarse(struct timespec *ts)
 {
         unsigned long seq;
         do {
@@ -217,10 +217,9 @@ notrace static int do_realtime_coarse(struct timespec *ts)
                 ts->tv_sec = gtod->wall_time_coarse.tv_sec;
                 ts->tv_nsec = gtod->wall_time_coarse.tv_nsec;
         } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
-        return 0;
 }
 
-notrace static int do_monotonic_coarse(struct timespec *ts)
+notrace static void do_monotonic_coarse(struct timespec *ts)
 {
         unsigned long seq;
         do {
@@ -228,30 +227,32 @@ notrace static int do_monotonic_coarse(struct timespec *ts)
                 ts->tv_sec = gtod->monotonic_time_coarse.tv_sec;
                 ts->tv_nsec = gtod->monotonic_time_coarse.tv_nsec;
         } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
-
-        return 0;
 }
 
 notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
 {
-        int ret = VCLOCK_NONE;
-
         switch (clock) {
         case CLOCK_REALTIME:
-                ret = do_realtime(ts);
+                if (do_realtime(ts) == VCLOCK_NONE)
+                        goto fallback;
                 break;
         case CLOCK_MONOTONIC:
-                ret = do_monotonic(ts);
+                if (do_monotonic(ts) == VCLOCK_NONE)
+                        goto fallback;
                 break;
         case CLOCK_REALTIME_COARSE:
-                return do_realtime_coarse(ts);
+                do_realtime_coarse(ts);
+                break;
         case CLOCK_MONOTONIC_COARSE:
-                return do_monotonic_coarse(ts);
+                do_monotonic_coarse(ts);
+                break;
+        default:
+                goto fallback;
         }
 
-        if (ret == VCLOCK_NONE)
-                return vdso_fallback_gettime(clock, ts);
         return 0;
+fallback:
+        return vdso_fallback_gettime(clock, ts);
 }
 int clock_gettime(clockid_t, struct timespec *)
         __attribute__((weak, alias("__vdso_clock_gettime")));