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/* 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 /** * @TIMER_DEFERRABLE: 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. * * @TIMER_IRQSAFE: 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! * * @TIMER_PINNED: A pinned timer will not be affected by any timer * placement heuristics (like, NOHZ) and will always expire on the CPU * on which the timer was enqueued. * * Note: Because enqueuing of timers can migrate the timer from one * CPU to another, pinned timers are not guaranteed to stay on the * initialy selected CPU. They move to the CPU on which the enqueue * function is invoked via mod_timer() or add_timer(). If the timer * should be placed on a particular CPU, then add_timer_on() has to be * used. */ #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_INIT_FLAGS (TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE) #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 !hlist_unhashed_lockless(&timer->entry); } 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); #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT) 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); 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 *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