[mirror_ubuntu-eoan-kernel.git] / include / linux / timer.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_TIMER_H
#define _LINUX_TIMER_H

#include <linux/list.h>
#include <linux/ktime.h>
#include <linux/stddef.h>
#include <linux/debugobjects.h>
#include <linux/stringify.h>

struct timer_list {
	/*
	 * All fields that change during normal runtime grouped to the
	 * same cacheline
	 */
	struct hlist_node	entry;
	unsigned long		expires;
	void			(*function)(struct timer_list *);
	u32			flags;

#ifdef CONFIG_LOCKDEP
	struct lockdep_map	lockdep_map;
#endif
};

#ifdef CONFIG_LOCKDEP
/*
 * NB: because we have to copy the lockdep_map, setting the lockdep_map key
 * (second argument) here is required, otherwise it could be initialised to
 * the copy of the lockdep_map later! We use the pointer to and the string
 * "<file>:<line>" as the key resp. the name of the lockdep_map.
 */
#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)				\
	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
#else
#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
#endif

/*
 * A deferrable timer will work normally when the system is busy, but
 * will not cause a CPU to come out of idle just to service it; instead,
 * the timer will be serviced when the CPU eventually wakes up with a
 * subsequent non-deferrable timer.
 *
 * An irqsafe timer is executed with IRQ disabled and it's safe to wait for
 * the completion of the running instance from IRQ handlers, for example,
 * by calling del_timer_sync().
 *
 * Note: The irq disabled callback execution is a special case for
 * workqueue locking issues. It's not meant for executing random crap
 * with interrupts disabled. Abuse is monitored!
 */
#define TIMER_CPUMASK		0x0003FFFF
#define TIMER_MIGRATING		0x00040000
#define TIMER_BASEMASK		(TIMER_CPUMASK | TIMER_MIGRATING)
#define TIMER_DEFERRABLE	0x00080000
#define TIMER_PINNED		0x00100000
#define TIMER_IRQSAFE		0x00200000
#define TIMER_ARRAYSHIFT	22
#define TIMER_ARRAYMASK		0xFFC00000

#define TIMER_TRACE_FLAGMASK	(TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE)

#define __TIMER_INITIALIZER(_function, _flags) {		\
		.entry = { .next = TIMER_ENTRY_STATIC },	\
		.function = (_function),			\
		.flags = (_flags),				\
		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
			__FILE__ ":" __stringify(__LINE__))	\
	}

#define DEFINE_TIMER(_name, _function)				\
	struct timer_list _name =				\
		__TIMER_INITIALIZER(_function, 0)

/*
 * LOCKDEP and DEBUG timer interfaces.
 */
void init_timer_key(struct timer_list *timer,
		    void (*func)(struct timer_list *), unsigned int flags,
		    const char *name, struct lock_class_key *key);

#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
extern void init_timer_on_stack_key(struct timer_list *timer,
				    void (*func)(struct timer_list *),
				    unsigned int flags, const char *name,
				    struct lock_class_key *key);
#else
static inline void init_timer_on_stack_key(struct timer_list *timer,
					   void (*func)(struct timer_list *),
					   unsigned int flags,
					   const char *name,
					   struct lock_class_key *key)
{
	init_timer_key(timer, func, flags, name, key);
}
#endif

#ifdef CONFIG_LOCKDEP
#define __init_timer(_timer, _fn, _flags)				\
	do {								\
		static struct lock_class_key __key;			\
		init_timer_key((_timer), (_fn), (_flags), #_timer, &__key);\
	} while (0)

#define __init_timer_on_stack(_timer, _fn, _flags)			\
	do {								\
		static struct lock_class_key __key;			\
		init_timer_on_stack_key((_timer), (_fn), (_flags),	\
					#_timer, &__key);		 \
	} while (0)
#else
#define __init_timer(_timer, _fn, _flags)				\
	init_timer_key((_timer), (_fn), (_flags), NULL, NULL)
#define __init_timer_on_stack(_timer, _fn, _flags)			\
	init_timer_on_stack_key((_timer), (_fn), (_flags), NULL, NULL)
#endif

/**
 * timer_setup - prepare a timer for first use
 * @timer: the timer in question
 * @callback: the function to call when timer expires
 * @flags: any TIMER_* flags
 *
 * Regular timer initialization should use either DEFINE_TIMER() above,
 * or timer_setup(). For timers on the stack, timer_setup_on_stack() must
 * be used and must be balanced with a call to destroy_timer_on_stack().
 */
#define timer_setup(timer, callback, flags)			\
	__init_timer((timer), (callback), (flags))

#define timer_setup_on_stack(timer, callback, flags)		\
	__init_timer_on_stack((timer), (callback), (flags))

#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
extern void destroy_timer_on_stack(struct timer_list *timer);
#else
static inline void destroy_timer_on_stack(struct timer_list *timer) { }
#endif

#define from_timer(var, callback_timer, timer_fieldname) \
	container_of(callback_timer, typeof(*var), timer_fieldname)

/**
 * timer_pending - is a timer pending?
 * @timer: the timer in question
 *
 * timer_pending will tell whether a given timer is currently pending,
 * or not. Callers must ensure serialization wrt. other operations done
 * to this timer, eg. interrupt contexts, or other CPUs on SMP.
 *
 * return value: 1 if the timer is pending, 0 if not.
 */
static inline int timer_pending(const struct timer_list * timer)
{
	return timer->entry.pprev != NULL;
}

extern void add_timer_on(struct timer_list *timer, int cpu);
extern int del_timer(struct timer_list * timer);
extern int mod_timer(struct timer_list *timer, unsigned long expires);
extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
extern int timer_reduce(struct timer_list *timer, unsigned long expires);

/*
 * The jiffies value which is added to now, when there is no timer
 * in the timer wheel:
 */
#define NEXT_TIMER_MAX_DELTA	((1UL << 30) - 1)

extern void add_timer(struct timer_list *timer);

extern int try_to_del_timer_sync(struct timer_list *timer);

#ifdef CONFIG_SMP
  extern int del_timer_sync(struct timer_list *timer);
#else
# define del_timer_sync(t)		del_timer(t)
#endif

#define del_singleshot_timer_sync(t) del_timer_sync(t)

extern void init_timers(void);
extern void run_local_timers(void);
struct hrtimer;
extern enum hrtimer_restart it_real_fn(struct hrtimer *);

#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
struct ctl_table;

extern unsigned int sysctl_timer_migration;
int timer_migration_handler(struct ctl_table *table, int write,
			    void __user *buffer, size_t *lenp,
			    loff_t *ppos);
#endif

unsigned long __round_jiffies(unsigned long j, int cpu);
unsigned long __round_jiffies_relative(unsigned long j, int cpu);
unsigned long round_jiffies(unsigned long j);
unsigned long round_jiffies_relative(unsigned long j);

unsigned long __round_jiffies_up(unsigned long j, int cpu);
unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
unsigned long round_jiffies_up(unsigned long j);
unsigned long round_jiffies_up_relative(unsigned long j);

#ifdef CONFIG_HOTPLUG_CPU
int timers_prepare_cpu(unsigned int cpu);
int timers_dead_cpu(unsigned int cpu);
#else
#define timers_prepare_cpu	NULL
#define timers_dead_cpu		NULL
#endif

#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	#ifndef _LINUX_TIMER_H
	3	#define _LINUX_TIMER_H
	4
1da177e4	5	#include <linux/list.h>
82f67cd9	6	#include <linux/ktime.h>
1da177e4	7	#include <linux/stddef.h>
c6f3a97f	8	#include <linux/debugobjects.h>
6f2b9b9a	9	#include <linux/stringify.h>
1da177e4	10
1da177e4	11	struct timer_list {
3bbb9ec9 AV	12	/*
	13	* All fields that change during normal runtime grouped to the
	14	* same cacheline
	15	*/
0eeda71b TG	16	struct hlist_node entry;
0eeda71b TG	17	unsigned long expires;
354b46b1	18	void (function)(struct timer_list );
0eeda71b	19	u32 flags;
3bbb9ec9	20
6f2b9b9a	21	#ifdef CONFIG_LOCKDEP
0eeda71b	22	struct lockdep_map lockdep_map;
6f2b9b9a	23	#endif
1da177e4 LT	24	};
1da177e4 LT	25
6f2b9b9a JB	26	#ifdef CONFIG_LOCKDEP
	27	/*
	28	* NB: because we have to copy the lockdep_map, setting the lockdep_map key
	29	* (second argument) here is required, otherwise it could be initialised to
	30	* the copy of the lockdep_map later! We use the pointer to and the string
	31	* "<file>:<line>" as the key resp. the name of the lockdep_map.
	32	*/
	33	#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) \
	34	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn),
	35	#else
	36	#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
	37	#endif
	38
dd6414b5	39	/*
dd6414b5 PC	40	* A deferrable timer will work normally when the system is busy, but
	41	* will not cause a CPU to come out of idle just to service it; instead,
	42	* the timer will be serviced when the CPU eventually wakes up with a
	43	* subsequent non-deferrable timer.
c5f66e99 TH	44	*
	45	* An irqsafe timer is executed with IRQ disabled and it's safe to wait for
	46	* the completion of the running instance from IRQ handlers, for example,
	47	* by calling del_timer_sync().
	48	*
	49	* Note: The irq disabled callback execution is a special case for
	50	* workqueue locking issues. It's not meant for executing random crap
	51	* with interrupts disabled. Abuse is monitored!
dd6414b5	52	*/
b0d6e2dc TG	53	#define TIMER_CPUMASK 0x0003FFFF
b0d6e2dc TG	54	#define TIMER_MIGRATING 0x00040000
0eeda71b	55	#define TIMER_BASEMASK (TIMER_CPUMASK \| TIMER_MIGRATING)
b0d6e2dc TG	56	#define TIMER_DEFERRABLE 0x00080000
	57	#define TIMER_PINNED 0x00100000
	58	#define TIMER_IRQSAFE 0x00200000
500462a9 TG	59	#define TIMER_ARRAYSHIFT 22
500462a9 TG	60	#define TIMER_ARRAYMASK 0xFFC00000
dd6414b5	61
8a58a34b TG	62	#define TIMER_TRACE_FLAGMASK (TIMER_MIGRATING \| TIMER_DEFERRABLE \| TIMER_PINNED \| TIMER_IRQSAFE)
8a58a34b TG	63
1fe66ba5	64	#define __TIMER_INITIALIZER(_function, _flags) { \
1dabbcec	65	.entry = { .next = TIMER_ENTRY_STATIC }, \
1da177e4	66	.function = (_function), \
0eeda71b	67	.flags = (_flags), \
6f2b9b9a JB	68	__TIMER_LOCKDEP_MAP_INITIALIZER( \
6f2b9b9a JB	69	__FILE__ ":" __stringify(__LINE__)) \
1da177e4 LT	70	}
1da177e4 LT	71
1d27e3e2	72	#define DEFINE_TIMER(_name, _function) \
8d06afab	73	struct timer_list _name = \
841b86f3	74	__TIMER_INITIALIZER(_function, 0)
8d06afab	75
919b250f KC	76	/*
	77	* LOCKDEP and DEBUG timer interfaces.
	78	*/
188665b2 KC	79	void init_timer_key(struct timer_list *timer,
188665b2 KC	80	void (func)(struct timer_list ), unsigned int flags,
fc683995	81	const char name, struct lock_class_key key);
6f2b9b9a	82
5a9af38d TH	83	#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
5a9af38d TH	84	extern void init_timer_on_stack_key(struct timer_list *timer,
188665b2	85	void (func)(struct timer_list ),
fc683995	86	unsigned int flags, const char *name,
5a9af38d	87	struct lock_class_key *key);
5a9af38d	88	#else
5a9af38d	89	static inline void init_timer_on_stack_key(struct timer_list *timer,
188665b2 KC	90	void (func)(struct timer_list ),
	91	unsigned int flags,
	92	const char *name,
5a9af38d TH	93	struct lock_class_key *key)
5a9af38d TH	94	{
188665b2	95	init_timer_key(timer, func, flags, name, key);
5a9af38d TH	96	}
	97	#endif
	98
6f2b9b9a	99	#ifdef CONFIG_LOCKDEP
188665b2	100	#define __init_timer(_timer, _fn, _flags) \
6f2b9b9a JB	101	do { \
6f2b9b9a JB	102	static struct lock_class_key __key; \
188665b2	103	init_timer_key((_timer), (_fn), (_flags), #_timer, &__key);\
6f2b9b9a JB	104	} while (0)
6f2b9b9a JB	105
188665b2	106	#define __init_timer_on_stack(_timer, _fn, _flags) \
6f2b9b9a JB	107	do { \
6f2b9b9a JB	108	static struct lock_class_key __key; \
188665b2 KC	109	init_timer_on_stack_key((_timer), (_fn), (_flags), \
188665b2 KC	110	#_timer, &__key); \
6f2b9b9a	111	} while (0)
fc683995	112	#else
188665b2 KC	113	#define __init_timer(_timer, _fn, _flags) \
	114	init_timer_key((_timer), (_fn), (_flags), NULL, NULL)
	115	#define __init_timer_on_stack(_timer, _fn, _flags) \
	116	init_timer_on_stack_key((_timer), (_fn), (_flags), NULL, NULL)
fc683995	117	#endif
6f2b9b9a	118
919b250f KC	119	/**
	120	* timer_setup - prepare a timer for first use
	121	* @timer: the timer in question
	122	* @callback: the function to call when timer expires
	123	* @flags: any TIMER_* flags
	124	*
	125	* Regular timer initialization should use either DEFINE_TIMER() above,
	126	* or timer_setup(). For timers on the stack, timer_setup_on_stack() must
	127	* be used and must be balanced with a call to destroy_timer_on_stack().
	128	*/
	129	#define timer_setup(timer, callback, flags) \
	130	__init_timer((timer), (callback), (flags))
6f2b9b9a	131
919b250f KC	132	#define timer_setup_on_stack(timer, callback, flags) \
919b250f KC	133	__init_timer_on_stack((timer), (callback), (flags))
686fef92	134
919b250f KC	135	#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
919b250f KC	136	extern void destroy_timer_on_stack(struct timer_list *timer);
52f737c2	137	#else
919b250f	138	static inline void destroy_timer_on_stack(struct timer_list *timer) { }
52f737c2	139	#endif
58e1177b	140
686fef92 KC	141	#define from_timer(var, callback_timer, timer_fieldname) \
	142	container_of(callback_timer, typeof(*var), timer_fieldname)
	143
45f8bde0	144	/**
1da177e4 LT	145	* timer_pending - is a timer pending?
	146	* @timer: the timer in question
	147	*
	148	* timer_pending will tell whether a given timer is currently pending,
	149	* or not. Callers must ensure serialization wrt. other operations done
	150	* to this timer, eg. interrupt contexts, or other CPUs on SMP.
	151	*
	152	* return value: 1 if the timer is pending, 0 if not.
	153	*/
	154	static inline int timer_pending(const struct timer_list * timer)
	155	{
1dabbcec	156	return timer->entry.pprev != NULL;
1da177e4 LT	157	}
	158
	159	extern void add_timer_on(struct timer_list *timer, int cpu);
	160	extern int del_timer(struct timer_list * timer);
1da177e4	161	extern int mod_timer(struct timer_list *timer, unsigned long expires);
74019224	162	extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
b24591e2	163	extern int timer_reduce(struct timer_list *timer, unsigned long expires);
1da177e4	164
eaad084b TG	165	/*
	166	* The jiffies value which is added to now, when there is no timer
	167	* in the timer wheel:
	168	*/
	169	#define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1)
	170
74019224	171	extern void add_timer(struct timer_list *timer);
1da177e4	172
6f1bc451 YZ	173	extern int try_to_del_timer_sync(struct timer_list *timer);
6f1bc451 YZ	174
1da177e4 LT	175	#ifdef CONFIG_SMP
1da177e4 LT	176	extern int del_timer_sync(struct timer_list *timer);
1da177e4	177	#else
fd450b73	178	# define del_timer_sync(t) del_timer(t)
1da177e4 LT	179	#endif
1da177e4 LT	180
55c888d6 ON	181	#define del_singleshot_timer_sync(t) del_timer_sync(t)
55c888d6 ON	182
1da177e4 LT	183	extern void init_timers(void);
1da177e4 LT	184	extern void run_local_timers(void);
05cfb614	185	struct hrtimer;
c9cb2e3d	186	extern enum hrtimer_restart it_real_fn(struct hrtimer *);
1da177e4	187
bc7a34b8	188	#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
b2d5bfea	189	struct ctl_table;
bc7a34b8 TG	190
	191	extern unsigned int sysctl_timer_migration;
	192	int timer_migration_handler(struct ctl_table *table, int write,
	193	void __user buffer, size_t lenp,
	194	loff_t *ppos);
	195	#endif
	196
4c36a5de AV	197	unsigned long __round_jiffies(unsigned long j, int cpu);
	198	unsigned long __round_jiffies_relative(unsigned long j, int cpu);
	199	unsigned long round_jiffies(unsigned long j);
	200	unsigned long round_jiffies_relative(unsigned long j);
	201
9c133c46 AS	202	unsigned long __round_jiffies_up(unsigned long j, int cpu);
	203	unsigned long __round_jiffies_up_relative(unsigned long j, int cpu);
	204	unsigned long round_jiffies_up(unsigned long j);
	205	unsigned long round_jiffies_up_relative(unsigned long j);
	206
24f73b99	207	#ifdef CONFIG_HOTPLUG_CPU
26456f87	208	int timers_prepare_cpu(unsigned int cpu);
24f73b99 RC	209	int timers_dead_cpu(unsigned int cpu);
24f73b99 RC	210	#else
26456f87 TG	211	#define timers_prepare_cpu NULL
26456f87 TG	212	#define timers_dead_cpu NULL
24f73b99 RC	213	#endif
24f73b99 RC	214
1da177e4	215	#endif