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Thomas Gleixner906568c2007-02-16 01:28:01 -08001/* linux/include/linux/tick.h
2 *
3 * This file contains the structure definitions for tick related functions
4 *
5 */
6#ifndef _LINUX_TICK_H
7#define _LINUX_TICK_H
8
9#include <linux/clockchips.h>
Frederic Weisbecker2bbb6812011-10-08 16:01:00 +020010#include <linux/irqflags.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080011
12#ifdef CONFIG_GENERIC_CLOCKEVENTS
13
14enum tick_device_mode {
15 TICKDEV_MODE_PERIODIC,
16 TICKDEV_MODE_ONESHOT,
17};
18
19struct tick_device {
20 struct clock_event_device *evtdev;
21 enum tick_device_mode mode;
22};
23
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080024enum tick_nohz_mode {
25 NOHZ_MODE_INACTIVE,
26 NOHZ_MODE_LOWRES,
27 NOHZ_MODE_HIGHRES,
28};
29
30/**
31 * struct tick_sched - sched tick emulation and no idle tick control/stats
32 * @sched_timer: hrtimer to schedule the periodic tick in high
33 * resolution mode
34 * @idle_tick: Store the last idle tick expiry time when the tick
35 * timer is modified for idle sleeps. This is necessary
36 * to resume the tick timer operation in the timeline
37 * when the CPU returns from idle
38 * @tick_stopped: Indicator that the idle tick has been stopped
39 * @idle_jiffies: jiffies at the entry to idle for idle time accounting
40 * @idle_calls: Total number of idle calls
41 * @idle_sleeps: Number of idle calls, where the sched tick was stopped
42 * @idle_entrytime: Time when the idle call was entered
Thomas Gleixner5df7fa12008-02-01 17:45:14 +010043 * @idle_waketime: Time when the idle was interrupted
44 * @idle_exittime: Time when the idle state was left
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080045 * @idle_sleeptime: Sum of the time slept in idle with sched tick stopped
Arjan van de Ven0224cf42010-05-09 08:25:23 -070046 * @iowait_sleeptime: Sum of the time slept in idle with sched tick stopped, with IO outstanding
Len Brown4f86d3a2007-10-03 18:58:00 -040047 * @sleep_length: Duration of the current idle sleep
Thomas Gleixner27185012009-11-12 22:12:06 +010048 * @do_timer_lst: CPU was the last one doing do_timer before going idle
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080049 */
50struct tick_sched {
51 struct hrtimer sched_timer;
52 unsigned long check_clocks;
53 enum tick_nohz_mode nohz_mode;
54 ktime_t idle_tick;
Thomas Gleixnerb8f8c3c2008-07-18 17:27:28 +020055 int inidle;
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080056 int tick_stopped;
57 unsigned long idle_jiffies;
58 unsigned long idle_calls;
59 unsigned long idle_sleeps;
Venki Pallipadi6378ddb2008-01-30 13:30:04 +010060 int idle_active;
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080061 ktime_t idle_entrytime;
Thomas Gleixner5df7fa12008-02-01 17:45:14 +010062 ktime_t idle_waketime;
63 ktime_t idle_exittime;
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080064 ktime_t idle_sleeptime;
Arjan van de Ven0224cf42010-05-09 08:25:23 -070065 ktime_t iowait_sleeptime;
Len Brown4f86d3a2007-10-03 18:58:00 -040066 ktime_t sleep_length;
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080067 unsigned long last_jiffies;
68 unsigned long next_jiffies;
69 ktime_t idle_expires;
Thomas Gleixner27185012009-11-12 22:12:06 +010070 int do_timer_last;
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080071};
72
Thomas Gleixner906568c2007-02-16 01:28:01 -080073extern void __init tick_init(void);
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080074extern int tick_is_oneshot_available(void);
Ingo Molnar289f4802007-02-16 01:28:15 -080075extern struct tick_device *tick_get_device(int cpu);
Thomas Gleixner906568c2007-02-16 01:28:01 -080076
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080077# ifdef CONFIG_HIGH_RES_TIMERS
78extern int tick_init_highres(void);
79extern int tick_program_event(ktime_t expires, int force);
80extern void tick_setup_sched_timer(void);
Miao Xie3c4fbe52008-08-20 16:37:38 -070081# endif
82
83# if defined CONFIG_NO_HZ || defined CONFIG_HIGH_RES_TIMERS
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080084extern void tick_cancel_sched_timer(int cpu);
85# else
86static inline void tick_cancel_sched_timer(int cpu) { }
Miao Xie3c4fbe52008-08-20 16:37:38 -070087# endif
Thomas Gleixner906568c2007-02-16 01:28:01 -080088
Ingo Molnar289f4802007-02-16 01:28:15 -080089# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
90extern struct tick_device *tick_get_broadcast_device(void);
Rusty Russell6b954822009-01-01 10:12:25 +103091extern struct cpumask *tick_get_broadcast_mask(void);
Ingo Molnar289f4802007-02-16 01:28:15 -080092
93# ifdef CONFIG_TICK_ONESHOT
Rusty Russell6b954822009-01-01 10:12:25 +103094extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
Ingo Molnar289f4802007-02-16 01:28:15 -080095# endif
96
97# endif /* BROADCAST */
98
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080099# ifdef CONFIG_TICK_ONESHOT
100extern void tick_clock_notify(void);
101extern int tick_check_oneshot_change(int allow_nohz);
102extern struct tick_sched *tick_get_tick_sched(int cpu);
Thomas Gleixner719254f2008-10-17 09:59:47 +0200103extern void tick_check_idle(int cpu);
Thomas Gleixnercd6d95d2009-06-12 11:29:27 +0200104extern int tick_oneshot_mode_active(void);
Martin Schwidefsky3c5d92a2009-09-29 14:25:16 +0200105# ifndef arch_needs_cpu
106# define arch_needs_cpu(cpu) (0)
107# endif
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800108# else
109static inline void tick_clock_notify(void) { }
110static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
Thomas Gleixner719254f2008-10-17 09:59:47 +0200111static inline void tick_check_idle(int cpu) { }
Thomas Gleixnercd6d95d2009-06-12 11:29:27 +0200112static inline int tick_oneshot_mode_active(void) { return 0; }
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800113# endif
114
115#else /* CONFIG_GENERIC_CLOCKEVENTS */
Thomas Gleixner906568c2007-02-16 01:28:01 -0800116static inline void tick_init(void) { }
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800117static inline void tick_cancel_sched_timer(int cpu) { }
118static inline void tick_clock_notify(void) { }
119static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
Thomas Gleixner719254f2008-10-17 09:59:47 +0200120static inline void tick_check_idle(int cpu) { }
Thomas Gleixnercd6d95d2009-06-12 11:29:27 +0200121static inline int tick_oneshot_mode_active(void) { return 0; }
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800122#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
Thomas Gleixner906568c2007-02-16 01:28:01 -0800123
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800124# ifdef CONFIG_NO_HZ
Frederic Weisbecker2bbb6812011-10-08 16:01:00 +0200125extern void __tick_nohz_idle_enter(void);
126static inline void tick_nohz_idle_enter(void)
127{
128 local_irq_disable();
129 __tick_nohz_idle_enter();
130 local_irq_enable();
131}
Frederic Weisbecker280f0672011-10-07 18:22:06 +0200132extern void tick_nohz_idle_exit(void);
Frederic Weisbecker2bbb6812011-10-08 16:01:00 +0200133
134/*
135 * Call this pair of function if the arch doesn't make any use
136 * of RCU in-between. You won't need to call rcu_idle_enter() and
137 * rcu_idle_exit().
138 * Otherwise you need to call tick_nohz_idle_enter() and tick_nohz_idle_exit()
139 * and explicitly tell RCU about the window around the place the CPU enters low
140 * power mode where no RCU use is made. This is done by calling rcu_idle_enter()
141 * after the last use of RCU before the CPU is put to sleep and by calling
142 * rcu_idle_exit() before the first use of RCU after the CPU woke up.
143 */
144static inline void tick_nohz_idle_enter_norcu(void)
145{
146 /*
147 * Also call rcu_idle_enter() in the irq disabled section even
148 * if it disables irq itself.
149 * Just an optimization that prevents from an interrupt happening
150 * between it and __tick_nohz_idle_enter() to lose time to help
151 * completing a grace period while we could be in extended grace
152 * period already.
153 */
154 local_irq_disable();
155 __tick_nohz_idle_enter();
156 rcu_idle_enter();
157 local_irq_enable();
158}
159static inline void tick_nohz_idle_exit_norcu(void)
160{
161 rcu_idle_exit();
162 tick_nohz_idle_exit();
163}
Frederic Weisbecker280f0672011-10-07 18:22:06 +0200164extern void tick_nohz_irq_exit(void);
Len Brown4f86d3a2007-10-03 18:58:00 -0400165extern ktime_t tick_nohz_get_sleep_length(void);
Venki Pallipadi6378ddb2008-01-30 13:30:04 +0100166extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
Arjan van de Ven0224cf42010-05-09 08:25:23 -0700167extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800168# else
Frederic Weisbecker2bbb6812011-10-08 16:01:00 +0200169static inline void tick_nohz_idle_enter(void) { }
170static inline void tick_nohz_idle_exit(void) { }
171static inline void tick_nohz_idle_enter_norcu(void)
Paul E. McKenney9b2e4f12011-09-30 12:10:22 -0700172{
Frederic Weisbecker280f0672011-10-07 18:22:06 +0200173 rcu_idle_enter();
Paul E. McKenney9b2e4f12011-09-30 12:10:22 -0700174}
Frederic Weisbecker2bbb6812011-10-08 16:01:00 +0200175static inline void tick_nohz_idle_exit_norcu(void)
Paul E. McKenney9b2e4f12011-09-30 12:10:22 -0700176{
177 rcu_idle_exit();
178}
Frederic Weisbecker280f0672011-10-07 18:22:06 +0200179
Len Brown4f86d3a2007-10-03 18:58:00 -0400180static inline ktime_t tick_nohz_get_sleep_length(void)
181{
182 ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
183
184 return len;
185}
venkatesh.pallipadi@intel.com8083e4a2008-08-04 11:59:11 -0700186static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
Arjan van de Ven0224cf42010-05-09 08:25:23 -0700187static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800188# endif /* !NO_HZ */
Thomas Gleixner906568c2007-02-16 01:28:01 -0800189
190#endif