6 files changed, 52 insertions, 27 deletions

diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h
index dc27a69e5d2a..3d61e204826f 100644
--- a/arch/x86/include/asm/vgtod.h
+++ b/arch/x86/include/asm/vgtod.h
@@ -21,6 +21,7 @@ struct vsyscall_gtod_data {
                 u32     shift;
         } clock;
         struct timespec wall_to_monotonic;
+        struct timespec wall_time_coarse;
 };
 extern struct vsyscall_gtod_data __vsyscall_gtod_data
 __section_vsyscall_gtod_data;
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index 5cf36c053ac4..23c167925a5c 100644
--- a/arch/x86/kernel/i8253.c
+++ b/arch/x86/kernel/i8253.c
@@ -19,12 +19,6 @@
 DEFINE_SPINLOCK(i8253_lock);
 EXPORT_SYMBOL(i8253_lock);
 
-#ifdef CONFIG_X86_32
-static void pit_disable_clocksource(void);
-#else
-static inline void pit_disable_clocksource(void) { }
-#endif
-
 /*
  * HPET replaces the PIT, when enabled. So we need to know, which of
  * the two timers is used
@@ -57,12 +51,10 @@ static void init_pit_timer(enum clock_event_mode mode,
                         outb_pit(0, PIT_CH0);
                         outb_pit(0, PIT_CH0);
                 }
-                pit_disable_clocksource();
                 break;
 
         case CLOCK_EVT_MODE_ONESHOT:
                 /* One shot setup */
-                pit_disable_clocksource();
                 outb_pit(0x38, PIT_MODE);
                 break;
 
@@ -200,17 +192,6 @@ static struct clocksource pit_cs = {
         .shift          = 20,
 };
 
-static void pit_disable_clocksource(void)
-{
-        /*
-         * Use mult to check whether it is registered or not
-         */
-        if (pit_cs.mult) {
-                clocksource_unregister(&pit_cs);
-                pit_cs.mult = 0;
-        }
-}
-
 static int __init init_pit_clocksource(void)
 {
          /*
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index 5d465b207e72..bf67dcb4a44c 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -178,7 +178,7 @@ static int set_rtc_mmss(unsigned long nowtime)
 }
 
 /* not static: needed by APM */
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
         unsigned long retval, flags;
 
@@ -186,7 +186,8 @@ unsigned long read_persistent_clock(void)
         retval = get_wallclock();
         spin_unlock_irqrestore(&rtc_lock, flags);
 
-        return retval;
+        ts->tv_sec = retval;
+        ts->tv_nsec = 0;
 }
 
 int update_persistent_clock(struct timespec now)
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 71f4368b357e..fc3672a303d6 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -744,10 +744,16 @@ static cycle_t __vsyscall_fn vread_tsc(void)
 }
 #endif
 
+static void resume_tsc(void)
+{
+        clocksource_tsc.cycle_last = 0;
+}
+
 static struct clocksource clocksource_tsc = {
         .name                   = "tsc",
         .rating                 = 300,
         .read                   = read_tsc,
+        .resume                 = resume_tsc,
         .mask                   = CLOCKSOURCE_MASK(64),
         .shift                  = 22,
         .flags                  = CLOCK_SOURCE_IS_CONTINUOUS |
@@ -761,12 +767,14 @@ void mark_tsc_unstable(char *reason)
 {
         if (!tsc_unstable) {
                 tsc_unstable = 1;
-                printk("Marking TSC unstable due to %s\n", reason);
+                printk(KERN_INFO "Marking TSC unstable due to %s\n", reason);
                 /* Change only the rating, when not registered */
                 if (clocksource_tsc.mult)
-                        clocksource_change_rating(&clocksource_tsc, 0);
-                else
+                        clocksource_mark_unstable(&clocksource_tsc);
+                else {
+                        clocksource_tsc.flags |= CLOCK_SOURCE_UNSTABLE;
                         clocksource_tsc.rating = 0;
+                }
         }
 }
 
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index 25ee06a80aad..cf53a78e2dcf 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -87,6 +87,7 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock)
         vsyscall_gtod_data.wall_time_sec = wall_time->tv_sec;
         vsyscall_gtod_data.wall_time_nsec = wall_time->tv_nsec;
         vsyscall_gtod_data.wall_to_monotonic = wall_to_monotonic;
+        vsyscall_gtod_data.wall_time_coarse = __current_kernel_time();
         write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
 }
 
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 6a40b78b46aa..ee55754cc3c5 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -86,14 +86,47 @@ notrace static noinline int do_monotonic(struct timespec *ts)
         return 0;
 }
 
+notrace static noinline int do_realtime_coarse(struct timespec *ts)
+{
+        unsigned long seq;
+        do {
+                seq = read_seqbegin(&gtod->lock);
+                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)));
+        return 0;
+}
+
+notrace static noinline int do_monotonic_coarse(struct timespec *ts)
+{
+        unsigned long seq, ns, secs;
+        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)));
+        vset_normalized_timespec(ts, secs, ns);
+        return 0;
+}
+
 notrace int __vdso_clock_gettime(clockid_t clock, struct timespec *ts)
 {
-        if (likely(gtod->sysctl_enabled && gtod->clock.vread))
+        if (likely(gtod->sysctl_enabled))
                 switch (clock) {
                 case CLOCK_REALTIME:
-                        return do_realtime(ts);
+                        if (likely(gtod->clock.vread))
+                                return do_realtime(ts);
+                        break;
                 case CLOCK_MONOTONIC:
-                        return do_monotonic(ts);
+                        if (likely(gtod->clock.vread))
+                                return do_monotonic(ts);
+                        break;
+                case CLOCK_REALTIME_COARSE:
+                        return do_realtime_coarse(ts);
+                case CLOCK_MONOTONIC_COARSE:
+                        return do_monotonic_coarse(ts);
                 }
         return vdso_fallback_gettime(clock, ts);
 }