10 files changed, 315 insertions, 137 deletions

diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 8d53106a0a92..95ed42951e0a 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -3,7 +3,6 @@
 #
 config TICK_ONESHOT
         bool
-        default n
 
 config NO_HZ
         bool "Tickless System (Dynamic Ticks)"
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 3d1e3e1a1971..f8d968063cea 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -72,6 +72,16 @@ void clockevents_set_mode(struct clock_event_device *dev,
 }
 
 /**
+ * clockevents_shutdown - shutdown the device and clear next_event
+ * @dev:        device to shutdown
+ */
+void clockevents_shutdown(struct clock_event_device *dev)
+{
+        clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
+        dev->next_event.tv64 = KTIME_MAX;
+}
+
+/**
  * clockevents_program_event - Reprogram the clock event device.
  * @expires:    absolute expiry time (monotonic clock)
  *
@@ -177,7 +187,7 @@ void clockevents_register_device(struct clock_event_device *dev)
 /*
  * Noop handler when we shut down an event device
  */
-static void clockevents_handle_noop(struct clock_event_device *dev)
+void clockevents_handle_noop(struct clock_event_device *dev)
 {
 }
 
@@ -199,7 +209,6 @@ void clockevents_exchange_device(struct clock_event_device *old,
          * released list and do a notify add later.
          */
         if (old) {
-                old->event_handler = clockevents_handle_noop;
                 clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
                 list_del(&old->list);
                 list_add(&old->list, &clockevents_released);
@@ -207,7 +216,7 @@ void clockevents_exchange_device(struct clock_event_device *old,
 
         if (new) {
                 BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED);
-                clockevents_set_mode(new, CLOCK_EVT_MODE_SHUTDOWN);
+                clockevents_shutdown(new);
         }
         local_irq_restore(flags);
 }
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 5125ddd8196b..1a20715bfd6e 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -10,13 +10,13 @@
 
 #include <linux/mm.h>
 #include <linux/time.h>
-#include <linux/timer.h>
 #include <linux/timex.h>
 #include <linux/jiffies.h>
 #include <linux/hrtimer.h>
 #include <linux/capability.h>
 #include <linux/math64.h>
 #include <linux/clocksource.h>
+#include <linux/workqueue.h>
 #include <asm/timex.h>
 
 /*
@@ -218,11 +218,11 @@ void second_overflow(void)
 /* Disable the cmos update - used by virtualization and embedded */
 int no_sync_cmos_clock  __read_mostly;
 
-static void sync_cmos_clock(unsigned long dummy);
+static void sync_cmos_clock(struct work_struct *work);
 
-static DEFINE_TIMER(sync_cmos_timer, sync_cmos_clock, 0, 0);
+static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock);
 
-static void sync_cmos_clock(unsigned long dummy)
+static void sync_cmos_clock(struct work_struct *work)
 {
         struct timespec now, next;
         int fail = 1;
@@ -245,7 +245,7 @@ static void sync_cmos_clock(unsigned long dummy)
         if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
                 fail = update_persistent_clock(now);
 
-        next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec;
+        next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2);
         if (next.tv_nsec <= 0)
                 next.tv_nsec += NSEC_PER_SEC;
 
@@ -258,13 +258,13 @@ static void sync_cmos_clock(unsigned long dummy)
                 next.tv_sec++;
                 next.tv_nsec -= NSEC_PER_SEC;
         }
-        mod_timer(&sync_cmos_timer, jiffies + timespec_to_jiffies(&next));
+        schedule_delayed_work(&sync_cmos_work, timespec_to_jiffies(&next));
 }
 
 static void notify_cmos_timer(void)
 {
         if (!no_sync_cmos_clock)
-                mod_timer(&sync_cmos_timer, jiffies + 1);
+                schedule_delayed_work(&sync_cmos_work, 0);
 }
 
 #else
@@ -277,38 +277,50 @@ static inline void notify_cmos_timer(void) { }
 int do_adjtimex(struct timex *txc)
 {
         struct timespec ts;
-        long save_adjust, sec;
         int result;
 
-        /* In order to modify anything, you gotta be super-user! */
-        if (txc->modes && !capable(CAP_SYS_TIME))
-                return -EPERM;
-
-        /* Now we validate the data before disabling interrupts */
-
-        if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT) {
+        /* Validate the data before disabling interrupts */
+        if (txc->modes & ADJ_ADJTIME) {
                 /* singleshot must not be used with any other mode bits */
-                if (txc->modes & ~ADJ_OFFSET_SS_READ)
+                if (!(txc->modes & ADJ_OFFSET_SINGLESHOT))
                         return -EINVAL;
+                if (!(txc->modes & ADJ_OFFSET_READONLY) &&
+                    !capable(CAP_SYS_TIME))
+                        return -EPERM;
+        } else {
+                /* In order to modify anything, you gotta be super-user! */
+                 if (txc->modes && !capable(CAP_SYS_TIME))
+                        return -EPERM;
+
+                /* if the quartz is off by more than 10% something is VERY wrong! */
+                if (txc->modes & ADJ_TICK &&
+                    (txc->tick <  900000/USER_HZ ||
+                     txc->tick > 1100000/USER_HZ))
+                                return -EINVAL;
+
+                if (txc->modes & ADJ_STATUS && time_state != TIME_OK)
+                        hrtimer_cancel(&leap_timer);
         }
 
-        /* if the quartz is off by more than 10% something is VERY wrong ! */
-        if (txc->modes & ADJ_TICK)
-                if (txc->tick <  900000/USER_HZ ||
-                    txc->tick > 1100000/USER_HZ)
-                        return -EINVAL;
-
-        if (time_state != TIME_OK && txc->modes & ADJ_STATUS)
-                hrtimer_cancel(&leap_timer);
         getnstimeofday(&ts);
 
         write_seqlock_irq(&xtime_lock);
 
-        /* Save for later - semantics of adjtime is to return old value */
-        save_adjust = time_adjust;
-
         /* If there are input parameters, then process them */
+        if (txc->modes & ADJ_ADJTIME) {
+                long save_adjust = time_adjust;
+
+                if (!(txc->modes & ADJ_OFFSET_READONLY)) {
+                        /* adjtime() is independent from ntp_adjtime() */
+                        time_adjust = txc->offset;
+                        ntp_update_frequency();
+                }
+                txc->offset = save_adjust;
+                goto adj_done;
+        }
         if (txc->modes) {
+                long sec;
+
                 if (txc->modes & ADJ_STATUS) {
                         if ((time_status & STA_PLL) &&
                             !(txc->status & STA_PLL)) {
@@ -375,13 +387,8 @@ int do_adjtimex(struct timex *txc)
                 if (txc->modes & ADJ_TAI && txc->constant > 0)
                         time_tai = txc->constant;
 
-                if (txc->modes & ADJ_OFFSET) {
-                        if (txc->modes == ADJ_OFFSET_SINGLESHOT)
-                                /* adjtime() is independent from ntp_adjtime() */
-                                time_adjust = txc->offset;
-                        else
-                                ntp_update_offset(txc->offset);
-                }
+                if (txc->modes & ADJ_OFFSET)
+                        ntp_update_offset(txc->offset);
                 if (txc->modes & ADJ_TICK)
                         tick_usec = txc->tick;
 
@@ -389,22 +396,18 @@ int do_adjtimex(struct timex *txc)
                         ntp_update_frequency();
         }
 
+        txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
+                                  NTP_SCALE_SHIFT);
+        if (!(time_status & STA_NANO))
+                txc->offset /= NSEC_PER_USEC;
+
+adj_done:
         result = time_state;    /* mostly `TIME_OK' */
         if (time_status & (STA_UNSYNC|STA_CLOCKERR))
                 result = TIME_ERROR;
 
-        if ((txc->modes == ADJ_OFFSET_SINGLESHOT) ||
-            (txc->modes == ADJ_OFFSET_SS_READ))
-                txc->offset = save_adjust;
-        else {
-                txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
-                                          NTP_SCALE_SHIFT);
-                if (!(time_status & STA_NANO))
-                        txc->offset /= NSEC_PER_USEC;
-        }
-        txc->freq          = shift_right((s32)(time_freq >> PPM_SCALE_INV_SHIFT) *
-                                         (s64)PPM_SCALE_INV,
-                                         NTP_SCALE_SHIFT);
+        txc->freq          = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) *
+                                         (s64)PPM_SCALE_INV, NTP_SCALE_SHIFT);
         txc->maxerror      = time_maxerror;
         txc->esterror      = time_esterror;
         txc->status        = time_status;
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 31463d370b94..f98a1b7b16e9 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -175,6 +175,8 @@ static void tick_do_periodic_broadcast(void)
  */
 static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
 {
+        ktime_t next;
+
         tick_do_periodic_broadcast();
 
         /*
@@ -185,10 +187,13 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev)
 
         /*
          * Setup the next period for devices, which do not have
-         * periodic mode:
+         * periodic mode. We read dev->next_event first and add to it
+         * when the event alrady expired. clockevents_program_event()
+         * sets dev->next_event only when the event is really
+         * programmed to the device.
          */
-        for (;;) {
-                ktime_t next = ktime_add(dev->next_event, tick_period);
+        for (next = dev->next_event; ;) {
+                next = ktime_add(next, tick_period);
 
                 if (!clockevents_program_event(dev, next, ktime_get()))
                         return;
@@ -205,7 +210,7 @@ static void tick_do_broadcast_on_off(void *why)
         struct clock_event_device *bc, *dev;
         struct tick_device *td;
         unsigned long flags, *reason = why;
-        int cpu;
+        int cpu, bc_stopped;
 
         spin_lock_irqsave(&tick_broadcast_lock, flags);
 
@@ -223,14 +228,16 @@ static void tick_do_broadcast_on_off(void *why)
         if (!tick_device_is_functional(dev))
                 goto out;
 
+        bc_stopped = cpus_empty(tick_broadcast_mask);
+
         switch (*reason) {
         case CLOCK_EVT_NOTIFY_BROADCAST_ON:
         case CLOCK_EVT_NOTIFY_BROADCAST_FORCE:
                 if (!cpu_isset(cpu, tick_broadcast_mask)) {
                         cpu_set(cpu, tick_broadcast_mask);
-                        if (td->mode == TICKDEV_MODE_PERIODIC)
-                                clockevents_set_mode(dev,
-                                                     CLOCK_EVT_MODE_SHUTDOWN);
+                        if (tick_broadcast_device.mode ==
+                            TICKDEV_MODE_PERIODIC)
+                                clockevents_shutdown(dev);
                 }
                 if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_FORCE)
                         tick_broadcast_force = 1;
@@ -239,15 +246,17 @@ static void tick_do_broadcast_on_off(void *why)
                 if (!tick_broadcast_force &&
                     cpu_isset(cpu, tick_broadcast_mask)) {
                         cpu_clear(cpu, tick_broadcast_mask);
-                        if (td->mode == TICKDEV_MODE_PERIODIC)
+                        if (tick_broadcast_device.mode ==
+                            TICKDEV_MODE_PERIODIC)
                                 tick_setup_periodic(dev, 0);
                 }
                 break;
         }
 
-        if (cpus_empty(tick_broadcast_mask))
-                clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
-        else {
+        if (cpus_empty(tick_broadcast_mask)) {
+                if (!bc_stopped)
+                        clockevents_shutdown(bc);
+        } else if (bc_stopped) {
                 if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
                         tick_broadcast_start_periodic(bc);
                 else
@@ -298,7 +307,7 @@ void tick_shutdown_broadcast(unsigned int *cpup)
 
         if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
                 if (bc && cpus_empty(tick_broadcast_mask))
-                        clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+                        clockevents_shutdown(bc);
         }
 
         spin_unlock_irqrestore(&tick_broadcast_lock, flags);
@@ -313,7 +322,7 @@ void tick_suspend_broadcast(void)
 
         bc = tick_broadcast_device.evtdev;
         if (bc)
-                clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+                clockevents_shutdown(bc);
 
         spin_unlock_irqrestore(&tick_broadcast_lock, flags);
 }
@@ -364,16 +373,8 @@ cpumask_t *tick_get_broadcast_oneshot_mask(void)
 static int tick_broadcast_set_event(ktime_t expires, int force)
 {
         struct clock_event_device *bc = tick_broadcast_device.evtdev;
-        ktime_t now = ktime_get();
-        int res;
-
-        for(;;) {
-                res = clockevents_program_event(bc, expires, now);
-                if (!res || !force)
-                        return res;
-                now = ktime_get();
-                expires = ktime_add(now, ktime_set(0, bc->min_delta_ns));
-        }
+
+        return tick_dev_program_event(bc, expires, force);
 }
 
 int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
@@ -383,6 +384,19 @@ int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
 }
 
 /*
+ * Called from irq_enter() when idle was interrupted to reenable the
+ * per cpu device.
+ */
+void tick_check_oneshot_broadcast(int cpu)
+{
+        if (cpu_isset(cpu, tick_broadcast_oneshot_mask)) {
+                struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
+
+                clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_ONESHOT);
+        }
+}
+
+/*
  * Handle oneshot mode broadcasting
  */
 static void tick_handle_oneshot_broadcast(struct clock_event_device *dev)
@@ -491,14 +505,52 @@ static void tick_broadcast_clear_oneshot(int cpu)
         cpu_clear(cpu, tick_broadcast_oneshot_mask);
 }
 
+static void tick_broadcast_init_next_event(cpumask_t *mask, ktime_t expires)
+{
+        struct tick_device *td;
+        int cpu;
+
+        for_each_cpu_mask_nr(cpu, *mask) {
+                td = &per_cpu(tick_cpu_device, cpu);
+                if (td->evtdev)
+                        td->evtdev->next_event = expires;
+        }
+}
+
 /**
  * tick_broadcast_setup_oneshot - setup the broadcast device
  */
 void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
 {
-        bc->event_handler = tick_handle_oneshot_broadcast;
-        clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
-        bc->next_event.tv64 = KTIME_MAX;
+        /* Set it up only once ! */
+        if (bc->event_handler != tick_handle_oneshot_broadcast) {
+                int was_periodic = bc->mode == CLOCK_EVT_MODE_PERIODIC;
+                int cpu = smp_processor_id();
+                cpumask_t mask;
+
+                bc->event_handler = tick_handle_oneshot_broadcast;
+                clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
+
+                /* Take the do_timer update */
+                tick_do_timer_cpu = cpu;
+
+                /*
+                 * We must be careful here. There might be other CPUs
+                 * waiting for periodic broadcast. We need to set the
+                 * oneshot_mask bits for those and program the
+                 * broadcast device to fire.
+                 */
+                mask = tick_broadcast_mask;
+                cpu_clear(cpu, mask);
+                cpus_or(tick_broadcast_oneshot_mask,
+                        tick_broadcast_oneshot_mask, mask);
+
+                if (was_periodic && !cpus_empty(mask)) {
+                        tick_broadcast_init_next_event(&mask, tick_next_period);
+                        tick_broadcast_set_event(tick_next_period, 1);
+                } else
+                        bc->next_event.tv64 = KTIME_MAX;
+        }
 }
 
 /*
@@ -538,4 +590,12 @@ void tick_shutdown_broadcast_oneshot(unsigned int *cpup)
         spin_unlock_irqrestore(&tick_broadcast_lock, flags);
 }
 
+/*
+ * Check, whether the broadcast device is in one shot mode
+ */
+int tick_broadcast_oneshot_active(void)
+{
+        return tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT;
+}
+
 #endif
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 80c4336f4188..df12434b43ca 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -33,7 +33,7 @@ DEFINE_PER_CPU(struct tick_device, tick_cpu_device);
  */
 ktime_t tick_next_period;
 ktime_t tick_period;
-int tick_do_timer_cpu __read_mostly = -1;
+int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT;
 DEFINE_SPINLOCK(tick_device_lock);
 
 /*
@@ -109,7 +109,8 @@ void tick_setup_periodic(struct clock_event_device *dev, int broadcast)
         if (!tick_device_is_functional(dev))
                 return;
 
-        if (dev->features & CLOCK_EVT_FEAT_PERIODIC) {
+        if ((dev->features & CLOCK_EVT_FEAT_PERIODIC) &&
+            !tick_broadcast_oneshot_active()) {
                 clockevents_set_mode(dev, CLOCK_EVT_MODE_PERIODIC);
         } else {
                 unsigned long seq;
@@ -148,7 +149,7 @@ static void tick_setup_device(struct tick_device *td,
                  * If no cpu took the do_timer update, assign it to
                  * this cpu:
                  */
-                if (tick_do_timer_cpu == -1) {
+                if (tick_do_timer_cpu == TICK_DO_TIMER_BOOT) {
                         tick_do_timer_cpu = cpu;
                         tick_next_period = ktime_get();
                         tick_period = ktime_set(0, NSEC_PER_SEC / HZ);
@@ -161,6 +162,7 @@ static void tick_setup_device(struct tick_device *td,
         } else {
                 handler = td->evtdev->event_handler;
                 next_event = td->evtdev->next_event;
+                td->evtdev->event_handler = clockevents_handle_noop;
         }
 
         td->evtdev = newdev;
@@ -248,7 +250,7 @@ static int tick_check_new_device(struct clock_event_device *newdev)
          * not give it back to the clockevents layer !
          */
         if (tick_is_broadcast_device(curdev)) {
-                clockevents_set_mode(curdev, CLOCK_EVT_MODE_SHUTDOWN);
+                clockevents_shutdown(curdev);
                 curdev = NULL;
         }
         clockevents_exchange_device(curdev, newdev);
@@ -299,7 +301,8 @@ static void tick_shutdown(unsigned int *cpup)
         if (*cpup == tick_do_timer_cpu) {
                 int cpu = first_cpu(cpu_online_map);
 
-                tick_do_timer_cpu = (cpu != NR_CPUS) ? cpu : -1;
+                tick_do_timer_cpu = (cpu != NR_CPUS) ? cpu :
+                        TICK_DO_TIMER_NONE;
         }
         spin_unlock_irqrestore(&tick_device_lock, flags);
 }
@@ -310,7 +313,7 @@ static void tick_suspend(void)
         unsigned long flags;
 
         spin_lock_irqsave(&tick_device_lock, flags);
-        clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN);
+        clockevents_shutdown(td->evtdev);
         spin_unlock_irqrestore(&tick_device_lock, flags);
 }
 
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index f13f2b7f4fd4..b1c05bf75ee0 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -1,6 +1,10 @@
 /*
  * tick internal variable and functions used by low/high res code
  */
+
+#define TICK_DO_TIMER_NONE      -1
+#define TICK_DO_TIMER_BOOT      -2
+
 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
 extern spinlock_t tick_device_lock;
 extern ktime_t tick_next_period;
@@ -10,6 +14,8 @@ extern int tick_do_timer_cpu __read_mostly;
 extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
 extern void tick_handle_periodic(struct clock_event_device *dev);
 
+extern void clockevents_shutdown(struct clock_event_device *dev);
+
 /*
  * NO_HZ / high resolution timer shared code
  */
@@ -17,6 +23,8 @@ extern void tick_handle_periodic(struct clock_event_device *dev);
 extern void tick_setup_oneshot(struct clock_event_device *newdev,
                                void (*handler)(struct clock_event_device *),
                                ktime_t nextevt);
+extern int tick_dev_program_event(struct clock_event_device *dev,
+                                  ktime_t expires, int force);
 extern int tick_program_event(ktime_t expires, int force);
 extern void tick_oneshot_notify(void);
 extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
@@ -27,6 +35,8 @@ extern void tick_broadcast_oneshot_control(unsigned long reason);
 extern void tick_broadcast_switch_to_oneshot(void);
 extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
 extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
+extern int tick_broadcast_oneshot_active(void);
+extern void tick_check_oneshot_broadcast(int cpu);
 # else /* BROADCAST */
 static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
 {
@@ -35,6 +45,8 @@ static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
 static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
 static inline void tick_broadcast_switch_to_oneshot(void) { }
 static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
+static inline int tick_broadcast_oneshot_active(void) { return 0; }
+static inline void tick_check_oneshot_broadcast(int cpu) { }
 # endif /* !BROADCAST */
 
 #else /* !ONESHOT */
@@ -64,6 +76,7 @@ static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
 {
         return 0;
 }
+static inline int tick_broadcast_oneshot_active(void) { return 0; }
 #endif /* !TICK_ONESHOT */
 
 /*
diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
index 450c04935b66..2e8de678e767 100644
--- a/kernel/time/tick-oneshot.c
+++ b/kernel/time/tick-oneshot.c
@@ -23,24 +23,56 @@
 #include "tick-internal.h"
 
 /**
- * tick_program_event
+ * tick_program_event internal worker function
  */
-int tick_program_event(ktime_t expires, int force)
+int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires,
+                           int force)
 {
-        struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
         ktime_t now = ktime_get();
+        int i;
 
-        while (1) {
+        for (i = 0;;) {
                 int ret = clockevents_program_event(dev, expires, now);
 
                 if (!ret || !force)
                         return ret;
+
+                /*
+                 * We tried 2 times to program the device with the given
+                 * min_delta_ns. If that's not working then we double it
+                 * and emit a warning.
+                 */
+                if (++i > 2) {
+                        /* Increase the min. delta and try again */
+                        if (!dev->min_delta_ns)
+                                dev->min_delta_ns = 5000;
+                        else
+                                dev->min_delta_ns += dev->min_delta_ns >> 1;
+
+                        printk(KERN_WARNING
+                               "CE: %s increasing min_delta_ns to %lu nsec\n",
+                               dev->name ? dev->name : "?",
+                               dev->min_delta_ns << 1);
+
+                        i = 0;
+                }
+
                 now = ktime_get();
-                expires = ktime_add(now, ktime_set(0, dev->min_delta_ns));
+                expires = ktime_add_ns(now, dev->min_delta_ns);
         }
 }
 
 /**
+ * tick_program_event
+ */
+int tick_program_event(ktime_t expires, int force)
+{
+        struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
+
+        return tick_dev_program_event(dev, expires, force);
+}
+
+/**
  * tick_resume_onshot - resume oneshot mode
  */
 void tick_resume_oneshot(void)
@@ -61,7 +93,7 @@ void tick_setup_oneshot(struct clock_event_device *newdev,
 {
         newdev->event_handler = handler;
         clockevents_set_mode(newdev, CLOCK_EVT_MODE_ONESHOT);
-        clockevents_program_event(newdev, next_event, ktime_get());
+        tick_dev_program_event(newdev, next_event, 1);
 }
 
 /**
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index f5da526424a9..0581c11fe6c6 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -20,6 +20,7 @@
 #include <linux/profile.h>
 #include <linux/sched.h>
 #include <linux/tick.h>
+#include <linux/module.h>
 
 #include <asm/irq_regs.h>
 
@@ -75,6 +76,9 @@ static void tick_do_update_jiffies64(ktime_t now)
                                                            incr * ticks);
                 }
                 do_timer(++ticks);
+
+                /* Keep the tick_next_period variable up to date */
+                tick_next_period = ktime_add(last_jiffies_update, tick_period);
         }
         write_sequnlock(&xtime_lock);
 }
@@ -151,7 +155,7 @@ void tick_nohz_update_jiffies(void)
         touch_softlockup_watchdog();
 }
 
-void tick_nohz_stop_idle(int cpu)
+static void tick_nohz_stop_idle(int cpu)
 {
         struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
 
@@ -162,6 +166,8 @@ void tick_nohz_stop_idle(int cpu)
                 ts->idle_lastupdate = now;
                 ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
                 ts->idle_active = 0;
+
+                sched_clock_idle_wakeup_event(0);
         }
 }
 
@@ -177,6 +183,7 @@ static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
         }
         ts->idle_entrytime = now;
         ts->idle_active = 1;
+        sched_clock_idle_sleep_event();
         return now;
 }
 
@@ -184,9 +191,17 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
 {
         struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
 
-        *last_update_time = ktime_to_us(ts->idle_lastupdate);
+        if (!tick_nohz_enabled)
+                return -1;
+
+        if (ts->idle_active)
+                *last_update_time = ktime_to_us(ts->idle_lastupdate);
+        else
+                *last_update_time = ktime_to_us(ktime_get());
+
         return ktime_to_us(ts->idle_sleeptime);
 }
+EXPORT_SYMBOL_GPL(get_cpu_idle_time_us);
 
 /**
  * tick_nohz_stop_sched_tick - stop the idle tick from the idle task
@@ -218,7 +233,7 @@ void tick_nohz_stop_sched_tick(int inidle)
          */
         if (unlikely(!cpu_online(cpu))) {
                 if (cpu == tick_do_timer_cpu)
-                        tick_do_timer_cpu = -1;
+                        tick_do_timer_cpu = TICK_DO_TIMER_NONE;
         }
 
         if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
@@ -255,7 +270,7 @@ void tick_nohz_stop_sched_tick(int inidle)
         next_jiffies = get_next_timer_interrupt(last_jiffies);
         delta_jiffies = next_jiffies - last_jiffies;
 
-        if (rcu_needs_cpu(cpu))
+        if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu))
                 delta_jiffies = 1;
         /*
          * Do not stop the tick, if we are only one off
@@ -300,7 +315,7 @@ void tick_nohz_stop_sched_tick(int inidle)
                  * invoked.
                  */
                 if (cpu == tick_do_timer_cpu)
-                        tick_do_timer_cpu = -1;
+                        tick_do_timer_cpu = TICK_DO_TIMER_NONE;
 
                 ts->idle_sleeps++;
 
@@ -362,6 +377,32 @@ ktime_t tick_nohz_get_sleep_length(void)
         return ts->sleep_length;
 }
 
+static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
+{
+        hrtimer_cancel(&ts->sched_timer);
+        ts->sched_timer.expires = ts->idle_tick;
+
+        while (1) {
+                /* Forward the time to expire in the future */
+                hrtimer_forward(&ts->sched_timer, now, tick_period);
+
+                if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
+                        hrtimer_start(&ts->sched_timer,
+                                      ts->sched_timer.expires,
+                                      HRTIMER_MODE_ABS);
+                        /* Check, if the timer was already in the past */
+                        if (hrtimer_active(&ts->sched_timer))
+                                break;
+                } else {
+                        if (!tick_program_event(ts->sched_timer.expires, 0))
+                                break;
+                }
+                /* Update jiffies and reread time */
+                tick_do_update_jiffies64(now);
+                now = ktime_get();
+        }
+}
+
 /**
  * tick_nohz_restart_sched_tick - restart the idle tick from the idle task
  *
@@ -415,28 +456,7 @@ void tick_nohz_restart_sched_tick(void)
          */
         ts->tick_stopped  = 0;
         ts->idle_exittime = now;
-        hrtimer_cancel(&ts->sched_timer);
-        ts->sched_timer.expires = ts->idle_tick;
-
-        while (1) {
-                /* Forward the time to expire in the future */
-                hrtimer_forward(&ts->sched_timer, now, tick_period);
-
-                if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
-                        hrtimer_start(&ts->sched_timer,
-                                      ts->sched_timer.expires,
-                                      HRTIMER_MODE_ABS);
-                        /* Check, if the timer was already in the past */
-                        if (hrtimer_active(&ts->sched_timer))
-                                break;
-                } else {
-                        if (!tick_program_event(ts->sched_timer.expires, 0))
-                                break;
-                }
-                /* Update jiffies and reread time */
-                tick_do_update_jiffies64(now);
-                now = ktime_get();
-        }
+        tick_nohz_restart(ts, now);
         local_irq_enable();
 }
 
@@ -465,7 +485,7 @@ static void tick_nohz_handler(struct clock_event_device *dev)
          * this duty, then the jiffies update is still serialized by
          * xtime_lock.
          */
-        if (unlikely(tick_do_timer_cpu == -1))
+        if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE))
                 tick_do_timer_cpu = cpu;
 
         /* Check, if the jiffies need an update */
@@ -488,10 +508,6 @@ static void tick_nohz_handler(struct clock_event_device *dev)
         update_process_times(user_mode(regs));
         profile_tick(CPU_PROFILING);
 
-        /* Do not restart, when we are in the idle loop */
-        if (ts->tick_stopped)
-                return;
-
         while (tick_nohz_reprogram(ts, now)) {
                 now = ktime_get();
                 tick_do_update_jiffies64(now);
@@ -537,6 +553,27 @@ static void tick_nohz_switch_to_nohz(void)
                smp_processor_id());
 }
 
+/*
+ * When NOHZ is enabled and the tick is stopped, we need to kick the
+ * tick timer from irq_enter() so that the jiffies update is kept
+ * alive during long running softirqs. That's ugly as hell, but
+ * correctness is key even if we need to fix the offending softirq in
+ * the first place.
+ *
+ * Note, this is different to tick_nohz_restart. We just kick the
+ * timer and do not touch the other magic bits which need to be done
+ * when idle is left.
+ */
+static void tick_nohz_kick_tick(int cpu)
+{
+        struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+
+        if (!ts->tick_stopped)
+                return;
+
+        tick_nohz_restart(ts, ktime_get());
+}
+
 #else
 
 static inline void tick_nohz_switch_to_nohz(void) { }
@@ -544,6 +581,19 @@ static inline void tick_nohz_switch_to_nohz(void) { }
 #endif /* NO_HZ */
 
 /*
+ * Called from irq_enter to notify about the possible interruption of idle()
+ */
+void tick_check_idle(int cpu)
+{
+        tick_check_oneshot_broadcast(cpu);
+#ifdef CONFIG_NO_HZ
+        tick_nohz_stop_idle(cpu);
+        tick_nohz_update_jiffies();
+        tick_nohz_kick_tick(cpu);
+#endif
+}
+
+/*
  * High resolution timer specific code
  */
 #ifdef CONFIG_HIGH_RES_TIMERS
@@ -567,7 +617,7 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
          * this duty, then the jiffies update is still serialized by
          * xtime_lock.
          */
-        if (unlikely(tick_do_timer_cpu == -1))
+        if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE))
                 tick_do_timer_cpu = cpu;
 #endif
 
@@ -596,10 +646,6 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
                 profile_tick(CPU_PROFILING);
         }
 
-        /* Do not restart, when we are in the idle loop */
-        if (ts->tick_stopped)
-                return HRTIMER_NORESTART;
-
         hrtimer_forward(timer, now, tick_period);
 
         return HRTIMER_RESTART;
@@ -619,7 +665,7 @@ void tick_setup_sched_timer(void)
          */
         hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
         ts->sched_timer.function = tick_sched_timer;
-        ts->sched_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
+        ts->sched_timer.cb_mode = HRTIMER_CB_IRQSAFE_PERCPU;
 
         /* Get the next period (per cpu) */
         ts->sched_timer.expires = tick_init_jiffy_update();
@@ -643,17 +689,21 @@ void tick_setup_sched_timer(void)
                 ts->nohz_mode = NOHZ_MODE_HIGHRES;
 #endif
 }
+#endif /* HIGH_RES_TIMERS */
 
+#if defined CONFIG_NO_HZ || defined CONFIG_HIGH_RES_TIMERS
 void tick_cancel_sched_timer(int cpu)
 {
         struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
 
+# ifdef CONFIG_HIGH_RES_TIMERS
         if (ts->sched_timer.base)
                 hrtimer_cancel(&ts->sched_timer);
+# endif
 
         ts->nohz_mode = NOHZ_MODE_INACTIVE;
 }
-#endif /* HIGH_RES_TIMERS */
+#endif
 
 /**
  * Async notification about clocksource changes
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 5099c95b8aa2..e7acfb482a68 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -487,7 +487,7 @@ void update_wall_time(void)
 #else
         offset = clock->cycle_interval;
 #endif
-        clock->xtime_nsec += (s64)xtime.tv_nsec << clock->shift;
+        clock->xtime_nsec = (s64)xtime.tv_nsec << clock->shift;
 
         /* normally this loop will run just once, however in the
          * case of lost or late ticks, it will accumulate correctly.
@@ -518,9 +518,12 @@ void update_wall_time(void)
         /* correct the clock when NTP error is too big */
         clocksource_adjust(offset);
 
-        /* store full nanoseconds into xtime */
-        xtime.tv_nsec = (s64)clock->xtime_nsec >> clock->shift;
+        /* store full nanoseconds into xtime after rounding it up and
+         * add the remainder to the error difference.
+         */
+        xtime.tv_nsec = ((s64)clock->xtime_nsec >> clock->shift) + 1;
         clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift;
+        clock->error += clock->xtime_nsec << (NTP_SCALE_SHIFT - clock->shift);
 
         update_xtime_cache(cyc2ns(clock, offset));
 
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index a40e20fd0001..f6426911e35a 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -47,13 +47,14 @@ static void print_name_offset(struct seq_file *m, void *sym)
 }
 
 static void
-print_timer(struct seq_file *m, struct hrtimer *timer, int idx, u64 now)
+print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
+            int idx, u64 now)
 {
 #ifdef CONFIG_TIMER_STATS
         char tmp[TASK_COMM_LEN + 1];
 #endif
         SEQ_printf(m, " #%d: ", idx);
-        print_name_offset(m, timer);
+        print_name_offset(m, taddr);
         SEQ_printf(m, ", ");
         print_name_offset(m, timer->function);
         SEQ_printf(m, ", S:%02lx", timer->state);
@@ -99,7 +100,7 @@ next_one:
                 tmp = *timer;
                 spin_unlock_irqrestore(&base->cpu_base->lock, flags);
 
-                print_timer(m, &tmp, i, now);
+                print_timer(m, timer, &tmp, i, now);
                 next++;
                 goto next_one;
         }
@@ -109,6 +110,7 @@ next_one:
 static void
 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
 {
+        SEQ_printf(m, "  .base:       %p\n", base);
         SEQ_printf(m, "  .index:      %d\n",
                         base->index);
         SEQ_printf(m, "  .resolution: %Lu nsecs\n",
@@ -183,12 +185,16 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now)
 
 #ifdef CONFIG_GENERIC_CLOCKEVENTS
 static void
-print_tickdevice(struct seq_file *m, struct tick_device *td)
+print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
 {
         struct clock_event_device *dev = td->evtdev;
 
         SEQ_printf(m, "\n");
         SEQ_printf(m, "Tick Device: mode:     %d\n", td->mode);
+        if (cpu < 0)
+                SEQ_printf(m, "Broadcast device\n");
+        else
+                SEQ_printf(m, "Per CPU device: %d\n", cpu);
 
         SEQ_printf(m, "Clock Event Device: ");
         if (!dev) {
@@ -222,7 +228,7 @@ static void timer_list_show_tickdevices(struct seq_file *m)
         int cpu;
 
 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
-        print_tickdevice(m, tick_get_broadcast_device());
+        print_tickdevice(m, tick_get_broadcast_device(), -1);
         SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
                    tick_get_broadcast_mask()->bits[0]);
 #ifdef CONFIG_TICK_ONESHOT
@@ -232,7 +238,7 @@ static void timer_list_show_tickdevices(struct seq_file *m)
         SEQ_printf(m, "\n");
 #endif
         for_each_online_cpu(cpu)
-                   print_tickdevice(m, tick_get_device(cpu));
+                print_tickdevice(m, tick_get_device(cpu), cpu);
         SEQ_printf(m, "\n");
 }
 #else
@@ -244,7 +250,7 @@ static int timer_list_show(struct seq_file *m, void *v)
         u64 now = ktime_to_ns(ktime_get());
         int cpu;
 
-        SEQ_printf(m, "Timer List Version: v0.3\n");
+        SEQ_printf(m, "Timer List Version: v0.4\n");
         SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
         SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);