1 files changed, 67 insertions, 68 deletions

diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 6bc0e723b6e8..885eff49d6ab 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -70,100 +70,98 @@ notrace static long vdso_fallback_gettime(long clock, struct timespec *ts)
         return ret;
 }
 
+notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
+{
+        long ret;
+
+        asm("syscall" : "=a" (ret) :
+            "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory");
+        return ret;
+}
+
+
 notrace static inline long vgetns(void)
 {
         long v;
         cycles_t cycles;
         if (gtod->clock.vclock_mode == VCLOCK_TSC)
                 cycles = vread_tsc();
-        else
+        else if (gtod->clock.vclock_mode == VCLOCK_HPET)
                 cycles = vread_hpet();
+        else
+                return 0;
         v = (cycles - gtod->clock.cycle_last) & gtod->clock.mask;
         return (v * gtod->clock.mult) >> gtod->clock.shift;
 }
 
-notrace static noinline int do_realtime(struct timespec *ts)
+/* Code size doesn't matter (vdso is 4k anyway) and this is faster. */
+notrace static int __always_inline do_realtime(struct timespec *ts)
 {
         unsigned long seq, ns;
+        int mode;
+
         do {
-                seq = read_seqbegin(&gtod->lock);
+                seq = read_seqcount_begin(&gtod->seq);
+                mode = gtod->clock.vclock_mode;
                 ts->tv_sec = gtod->wall_time_sec;
                 ts->tv_nsec = gtod->wall_time_nsec;
                 ns = vgetns();
-        } while (unlikely(read_seqretry(&gtod->lock, seq)));
+        } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
+
         timespec_add_ns(ts, ns);
-        return 0;
+        return mode;
 }
 
-notrace static noinline int do_monotonic(struct timespec *ts)
+notrace static int do_monotonic(struct timespec *ts)
 {
-        unsigned long seq, ns, secs;
+        unsigned long seq, ns;
+        int mode;
+
         do {
-                seq = read_seqbegin(&gtod->lock);
-                secs = gtod->wall_time_sec;
-                ns = gtod->wall_time_nsec + vgetns();
-                secs += gtod->wall_to_monotonic.tv_sec;
-                ns += gtod->wall_to_monotonic.tv_nsec;
-        } while (unlikely(read_seqretry(&gtod->lock, seq)));
-
-        /* wall_time_nsec, vgetns(), and wall_to_monotonic.tv_nsec
-         * are all guaranteed to be nonnegative.
-         */
-        while (ns >= NSEC_PER_SEC) {
-                ns -= NSEC_PER_SEC;
-                ++secs;
-        }
-        ts->tv_sec = secs;
-        ts->tv_nsec = ns;
+                seq = read_seqcount_begin(&gtod->seq);
+                mode = gtod->clock.vclock_mode;
+                ts->tv_sec = gtod->monotonic_time_sec;
+                ts->tv_nsec = gtod->monotonic_time_nsec;
+                ns = vgetns();
+        } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
+        timespec_add_ns(ts, ns);
 
-        return 0;
+        return mode;
 }
 
-notrace static noinline int do_realtime_coarse(struct timespec *ts)
+notrace static int do_realtime_coarse(struct timespec *ts)
 {
         unsigned long seq;
         do {
-                seq = read_seqbegin(&gtod->lock);
+                seq = read_seqcount_begin(&gtod->seq);
                 ts->tv_sec = gtod->wall_time_coarse.tv_sec;
                 ts->tv_nsec = gtod->wall_time_coarse.tv_nsec;
-        } while (unlikely(read_seqretry(&gtod->lock, seq)));
+        } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
         return 0;
 }
 
-notrace static noinline int do_monotonic_coarse(struct timespec *ts)
+notrace static int do_monotonic_coarse(struct timespec *ts)
 {
-        unsigned long seq, ns, secs;
+        unsigned long seq;
         do {
-                seq = read_seqbegin(&gtod->lock);
-                secs = gtod->wall_time_coarse.tv_sec;
-                ns = gtod->wall_time_coarse.tv_nsec;
-                secs += gtod->wall_to_monotonic.tv_sec;
-                ns += gtod->wall_to_monotonic.tv_nsec;
-        } while (unlikely(read_seqretry(&gtod->lock, seq)));
-
-        /* wall_time_nsec and wall_to_monotonic.tv_nsec are
-         * guaranteed to be between 0 and NSEC_PER_SEC.
-         */
-        if (ns >= NSEC_PER_SEC) {
-                ns -= NSEC_PER_SEC;
-                ++secs;
-        }
-        ts->tv_sec = secs;
-        ts->tv_nsec = ns;
+                seq = read_seqcount_begin(&gtod->seq);
+                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:
-                if (likely(gtod->clock.vclock_mode != VCLOCK_NONE))
-                        return do_realtime(ts);
+                ret = do_realtime(ts);
                 break;
         case CLOCK_MONOTONIC:
-                if (likely(gtod->clock.vclock_mode != VCLOCK_NONE))
-                        return do_monotonic(ts);
+                ret = do_monotonic(ts);
                 break;
         case CLOCK_REALTIME_COARSE:
                 return do_realtime_coarse(ts);
@@ -171,32 +169,33 @@ notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
                 return do_monotonic_coarse(ts);
         }
 
-        return vdso_fallback_gettime(clock, ts);
+        if (ret == VCLOCK_NONE)
+                return vdso_fallback_gettime(clock, ts);
+        return 0;
 }
 int clock_gettime(clockid_t, struct timespec *)
         __attribute__((weak, alias("__vdso_clock_gettime")));
 
 notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
 {
-        long ret;
-        if (likely(gtod->clock.vclock_mode != VCLOCK_NONE)) {
-                if (likely(tv != NULL)) {
-                        BUILD_BUG_ON(offsetof(struct timeval, tv_usec) !=
-                                     offsetof(struct timespec, tv_nsec) ||
-                                     sizeof(*tv) != sizeof(struct timespec));
-                        do_realtime((struct timespec *)tv);
-                        tv->tv_usec /= 1000;
-                }
-                if (unlikely(tz != NULL)) {
-                        /* Avoid memcpy. Some old compilers fail to inline it */
-                        tz->tz_minuteswest = gtod->sys_tz.tz_minuteswest;
-                        tz->tz_dsttime = gtod->sys_tz.tz_dsttime;
-                }
-                return 0;
+        long ret = VCLOCK_NONE;
+
+        if (likely(tv != NULL)) {
+                BUILD_BUG_ON(offsetof(struct timeval, tv_usec) !=
+                             offsetof(struct timespec, tv_nsec) ||
+                             sizeof(*tv) != sizeof(struct timespec));
+                ret = do_realtime((struct timespec *)tv);
+                tv->tv_usec /= 1000;
         }
-        asm("syscall" : "=a" (ret) :
-            "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory");
-        return ret;
+        if (unlikely(tz != NULL)) {
+                /* Avoid memcpy. Some old compilers fail to inline it */
+                tz->tz_minuteswest = gtod->sys_tz.tz_minuteswest;
+                tz->tz_dsttime = gtod->sys_tz.tz_dsttime;
+        }
+
+        if (ret == VCLOCK_NONE)
+                return vdso_fallback_gtod(tv, tz);
+        return 0;
 }
 int gettimeofday(struct timeval *, struct timezone *)
         __attribute__((weak, alias("__vdso_gettimeofday")));