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>

diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index bbc80657050f289e7df6581de5b8101e9dba5db1..fd074dd19a4a8a99d066c510c5e797fbbfb81170 100644 (file)
--- 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")));