4 files changed, 50 insertions, 81 deletions

diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 95ed42951e0a..f06a8a365648 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -6,7 +6,7 @@ config TICK_ONESHOT
 
 config NO_HZ
         bool "Tickless System (Dynamic Ticks)"
-        depends on GENERIC_TIME && GENERIC_CLOCKEVENTS
+        depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS
         select TICK_ONESHOT
         help
           This option enables a tickless system: timer interrupts will
@@ -15,7 +15,7 @@ config NO_HZ
 
 config HIGH_RES_TIMERS
         bool "High Resolution Timer Support"
-        depends on GENERIC_TIME && GENERIC_CLOCKEVENTS
+        depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS
         select TICK_ONESHOT
         help
           This option enables high resolution timer support. If your
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index f08e99c1d561..c18d7efa1b4b 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -531,7 +531,7 @@ static u64 clocksource_max_deferment(struct clocksource *cs)
         return max_nsecs - (max_nsecs >> 5);
 }
 
-#ifdef CONFIG_GENERIC_TIME
+#ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
 
 /**
  * clocksource_select - Select the best clocksource available
@@ -577,7 +577,7 @@ static void clocksource_select(void)
         }
 }
 
-#else /* CONFIG_GENERIC_TIME */
+#else /* !CONFIG_ARCH_USES_GETTIMEOFFSET */
 
 static inline void clocksource_select(void) { }
 
@@ -639,19 +639,18 @@ static void clocksource_enqueue(struct clocksource *cs)
 #define MAX_UPDATE_LENGTH 5 /* Seconds */
 
 /**
- * __clocksource_register_scale - Used to install new clocksources
+ * __clocksource_updatefreq_scale - Used update clocksource with new freq
  * @t:          clocksource to be registered
  * @scale:      Scale factor multiplied against freq to get clocksource hz
  * @freq:       clocksource frequency (cycles per second) divided by scale
  *
- * Returns -EBUSY if registration fails, zero otherwise.
+ * This should only be called from the clocksource->enable() method.
  *
  * This *SHOULD NOT* be called directly! Please use the
- * clocksource_register_hz() or clocksource_register_khz helper functions.
+ * clocksource_updatefreq_hz() or clocksource_updatefreq_khz helper functions.
  */
-int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
+void __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq)
 {
-
         /*
          * Ideally we want to use  some of the limits used in
          * clocksource_max_deferment, to provide a more informed
@@ -662,7 +661,27 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
                                       NSEC_PER_SEC/scale,
                                       MAX_UPDATE_LENGTH*scale);
         cs->max_idle_ns = clocksource_max_deferment(cs);
+}
+EXPORT_SYMBOL_GPL(__clocksource_updatefreq_scale);
+
+/**
+ * __clocksource_register_scale - Used to install new clocksources
+ * @t:          clocksource to be registered
+ * @scale:      Scale factor multiplied against freq to get clocksource hz
+ * @freq:       clocksource frequency (cycles per second) divided by scale
+ *
+ * Returns -EBUSY if registration fails, zero otherwise.
+ *
+ * This *SHOULD NOT* be called directly! Please use the
+ * clocksource_register_hz() or clocksource_register_khz helper functions.
+ */
+int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
+{
+
+        /* Intialize mult/shift and max_idle_ns */
+        __clocksource_updatefreq_scale(cs, scale, freq);
 
+        /* Add clocksource to the clcoksource list */
         mutex_lock(&clocksource_mutex);
         clocksource_enqueue(cs);
         clocksource_select();
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 813993b5fb61..3e216e01bbd1 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -325,7 +325,7 @@ void tick_nohz_stop_sched_tick(int inidle)
         } while (read_seqretry(&xtime_lock, seq));
 
         if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) ||
-            arch_needs_cpu(cpu) || nohz_ratelimit(cpu)) {
+            arch_needs_cpu(cpu)) {
                 next_jiffies = last_jiffies + 1;
                 delta_jiffies = 1;
         } else {
@@ -405,13 +405,7 @@ void tick_nohz_stop_sched_tick(int inidle)
                  * the scheduler tick in nohz_restart_sched_tick.
                  */
                 if (!ts->tick_stopped) {
-                        if (select_nohz_load_balancer(1)) {
-                                /*
-                                 * sched tick not stopped!
-                                 */
-                                cpumask_clear_cpu(cpu, nohz_cpu_mask);
-                                goto out;
-                        }
+                        select_nohz_load_balancer(1);
 
                         ts->idle_tick = hrtimer_get_expires(&ts->sched_timer);
                         ts->tick_stopped = 1;
@@ -780,7 +774,6 @@ void tick_setup_sched_timer(void)
 {
         struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
         ktime_t now = ktime_get();
-        u64 offset;
 
         /*
          * Emulate tick processing via per-CPU hrtimers:
@@ -790,10 +783,6 @@ void tick_setup_sched_timer(void)
 
         /* Get the next period (per cpu) */
         hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update());
-        offset = ktime_to_ns(tick_period) >> 1;
-        do_div(offset, num_possible_cpus());
-        offset *= smp_processor_id();
-        hrtimer_add_expires_ns(&ts->sched_timer, offset);
 
         for (;;) {
                 hrtimer_forward(&ts->sched_timer, now, tick_period);
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index caf8d4d4f5c8..e14c839e9faa 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -153,8 +153,8 @@ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
  * - wall_to_monotonic is no longer the boot time, getboottime must be
  * used instead.
  */
-struct timespec xtime __attribute__ ((aligned (16)));
-struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
+static struct timespec xtime __attribute__ ((aligned (16)));
+static struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
 static struct timespec total_sleep_time;
 
 /*
@@ -170,11 +170,10 @@ void timekeeping_leap_insert(int leapsecond)
 {
         xtime.tv_sec += leapsecond;
         wall_to_monotonic.tv_sec -= leapsecond;
-        update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
+        update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
+                        timekeeper.mult);
 }
 
-#ifdef CONFIG_GENERIC_TIME
-
 /**
  * timekeeping_forward_now - update clock to the current time
  *
@@ -328,7 +327,8 @@ int do_settimeofday(struct timespec *tv)
         timekeeper.ntp_error = 0;
         ntp_clear();
 
-        update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
+        update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
+                                timekeeper.mult);
 
         write_sequnlock_irqrestore(&xtime_lock, flags);
 
@@ -376,52 +376,6 @@ void timekeeping_notify(struct clocksource *clock)
         tick_clock_notify();
 }
 
-#else /* GENERIC_TIME */
-
-static inline void timekeeping_forward_now(void) { }
-
-/**
- * ktime_get - get the monotonic time in ktime_t format
- *
- * returns the time in ktime_t format
- */
-ktime_t ktime_get(void)
-{
-        struct timespec now;
-
-        ktime_get_ts(&now);
-
-        return timespec_to_ktime(now);
-}
-EXPORT_SYMBOL_GPL(ktime_get);
-
-/**
- * ktime_get_ts - get the monotonic clock in timespec format
- * @ts:         pointer to timespec variable
- *
- * The function calculates the monotonic clock from the realtime
- * clock and the wall_to_monotonic offset and stores the result
- * in normalized timespec format in the variable pointed to by @ts.
- */
-void ktime_get_ts(struct timespec *ts)
-{
-        struct timespec tomono;
-        unsigned long seq;
-
-        do {
-                seq = read_seqbegin(&xtime_lock);
-                getnstimeofday(ts);
-                tomono = wall_to_monotonic;
-
-        } while (read_seqretry(&xtime_lock, seq));
-
-        set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
-                                ts->tv_nsec + tomono.tv_nsec);
-}
-EXPORT_SYMBOL_GPL(ktime_get_ts);
-
-#endif /* !GENERIC_TIME */
-
 /**
  * ktime_get_real - get the real (wall-) time in ktime_t format
  *
@@ -579,9 +533,9 @@ static int timekeeping_resume(struct sys_device *dev)
 
         if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
                 ts = timespec_sub(ts, timekeeping_suspend_time);
-                xtime = timespec_add_safe(xtime, ts);
+                xtime = timespec_add(xtime, ts);
                 wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
-                total_sleep_time = timespec_add_safe(total_sleep_time, ts);
+                total_sleep_time = timespec_add(total_sleep_time, ts);
         }
         /* re-base the last cycle value */
         timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
@@ -784,10 +738,11 @@ void update_wall_time(void)
                 return;
 
         clock = timekeeper.clock;
-#ifdef CONFIG_GENERIC_TIME
-        offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
-#else
+
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
         offset = timekeeper.cycle_interval;
+#else
+        offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
 #endif
         timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift;
 
@@ -856,7 +811,8 @@ void update_wall_time(void)
         }
 
         /* check to see if there is a new clocksource to use */
-        update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
+        update_vsyscall(&xtime, &wall_to_monotonic, timekeeper.clock,
+                                timekeeper.mult);
 }
 
 /**
@@ -887,7 +843,7 @@ EXPORT_SYMBOL_GPL(getboottime);
  */
 void monotonic_to_bootbased(struct timespec *ts)
 {
-        *ts = timespec_add_safe(*ts, total_sleep_time);
+        *ts = timespec_add(*ts, total_sleep_time);
 }
 EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
 
@@ -902,6 +858,11 @@ struct timespec __current_kernel_time(void)
         return xtime;
 }
 
+struct timespec __get_wall_to_monotonic(void)
+{
+        return wall_to_monotonic;
+}
+
 struct timespec current_kernel_time(void)
 {
         struct timespec now;