3 files changed, 86 insertions, 3 deletions

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 6f657d7f2d04..7803014f3a11 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -106,6 +106,16 @@ static inline void account_system_vtime(struct task_struct *tsk)
  * always balanced, so the interrupted value of ->hardirq_context
  * will always be restored.
  */
+#define __irq_enter()                                   \
+        do {                                            \
+                account_system_vtime(current);          \
+                add_preempt_count(HARDIRQ_OFFSET);      \
+                trace_hardirq_enter();                  \
+        } while (0)
+
+/*
+ * Enter irq context (on NO_HZ, update jiffies):
+ */
 extern void irq_enter(void);
 
 /*
@@ -123,7 +133,7 @@ extern void irq_enter(void);
  */
 extern void irq_exit(void);
 
-#define nmi_enter()             do { lockdep_off(); irq_enter(); } while (0)
+#define nmi_enter()             do { lockdep_off(); __irq_enter(); } while (0)
 #define nmi_exit()              do { __irq_exit(); lockdep_on(); } while (0)
 
 #endif /* LINUX_HARDIRQ_H */
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index a759636fd09f..e95c96c971c0 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -201,4 +201,10 @@ extern void hrtimer_run_queues(void);
 /* Bootup initialization: */
 extern void __init hrtimers_init(void);
 
+#if BITS_PER_LONG < 64
+extern unsigned long ktime_divns(const ktime_t kt, s64 div);
+#else /* BITS_PER_LONG < 64 */
+# define ktime_divns(kt, div)           (unsigned long)((kt).tv64 / (div))
+#endif
+
 #endif
diff --git a/include/linux/tick.h b/include/linux/tick.h
index e5c0a4e22706..cf435e459598 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -20,12 +20,79 @@ struct tick_device {
         enum tick_device_mode mode;
 };
 
+enum tick_nohz_mode {
+        NOHZ_MODE_INACTIVE,
+        NOHZ_MODE_LOWRES,
+        NOHZ_MODE_HIGHRES,
+};
+
+/**
+ * struct tick_sched - sched tick emulation and no idle tick control/stats
+ * @sched_timer:        hrtimer to schedule the periodic tick in high
+ *                      resolution mode
+ * @idle_tick:          Store the last idle tick expiry time when the tick
+ *                      timer is modified for idle sleeps. This is necessary
+ *                      to resume the tick timer operation in the timeline
+ *                      when the CPU returns from idle
+ * @tick_stopped:       Indicator that the idle tick has been stopped
+ * @idle_jiffies:       jiffies at the entry to idle for idle time accounting
+ * @idle_calls:         Total number of idle calls
+ * @idle_sleeps:        Number of idle calls, where the sched tick was stopped
+ * @idle_entrytime:     Time when the idle call was entered
+ * @idle_sleeptime:     Sum of the time slept in idle with sched tick stopped
+ */
+struct tick_sched {
+        struct hrtimer                  sched_timer;
+        unsigned long                   check_clocks;
+        enum tick_nohz_mode             nohz_mode;
+        ktime_t                         idle_tick;
+        int                             tick_stopped;
+        unsigned long                   idle_jiffies;
+        unsigned long                   idle_calls;
+        unsigned long                   idle_sleeps;
+        ktime_t                         idle_entrytime;
+        ktime_t                         idle_sleeptime;
+        unsigned long                   last_jiffies;
+        unsigned long                   next_jiffies;
+        ktime_t                         idle_expires;
+};
+
 extern void __init tick_init(void);
+extern int tick_is_oneshot_available(void);
+
+# ifdef CONFIG_HIGH_RES_TIMERS
+extern int tick_init_highres(void);
+extern int tick_program_event(ktime_t expires, int force);
+extern void tick_setup_sched_timer(void);
+extern void tick_cancel_sched_timer(int cpu);
+# else
+static inline void tick_cancel_sched_timer(int cpu) { }
+# endif /* HIGHRES */
 
-#else
+# ifdef CONFIG_TICK_ONESHOT
+extern void tick_clock_notify(void);
+extern int tick_check_oneshot_change(int allow_nohz);
+extern struct tick_sched *tick_get_tick_sched(int cpu);
+# else
+static inline void tick_clock_notify(void) { }
+static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
+# endif
 
+#else /* CONFIG_GENERIC_CLOCKEVENTS */
 static inline void tick_init(void) { }
+static inline void tick_cancel_sched_timer(int cpu) { }
+static inline void tick_clock_notify(void) { }
+static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
+#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
 
-#endif
+# ifdef CONFIG_NO_HZ
+extern void tick_nohz_stop_sched_tick(void);
+extern void tick_nohz_restart_sched_tick(void);
+extern void tick_nohz_update_jiffies(void);
+# else
+static inline void tick_nohz_stop_sched_tick(void) { }
+static inline void tick_nohz_restart_sched_tick(void) { }
+static inline void tick_nohz_update_jiffies(void) { }
+# endif /* !NO_HZ */
 
 #endif