[mirror_ubuntu-hirsute-kernel.git] / include / linux / workqueue.h

/*
 * workqueue.h --- work queue handling for Linux.
 */

#ifndef _LINUX_WORKQUEUE_H
#define _LINUX_WORKQUEUE_H

#include <linux/timer.h>
#include <linux/linkage.h>
#include <linux/bitops.h>
#include <linux/lockdep.h>
#include <linux/threads.h>
#include <asm/atomic.h>

struct workqueue_struct;

struct work_struct;
typedef void (*work_func_t)(struct work_struct *work);

/*
 * The first word is the work queue pointer and the flags rolled into
 * one
 */
#define work_data_bits(work) ((unsigned long *)(&(work)->data))

enum {
	WORK_STRUCT_PENDING_BIT	= 0,	/* work item is pending execution */
	WORK_STRUCT_LINKED_BIT	= 1,	/* next work is linked to this one */
#ifdef CONFIG_DEBUG_OBJECTS_WORK
	WORK_STRUCT_STATIC_BIT	= 2,	/* static initializer (debugobjects) */
	WORK_STRUCT_COLOR_SHIFT	= 3,	/* color for workqueue flushing */
#else
	WORK_STRUCT_COLOR_SHIFT	= 2,	/* color for workqueue flushing */
#endif

	WORK_STRUCT_COLOR_BITS	= 4,

	WORK_STRUCT_PENDING	= 1 << WORK_STRUCT_PENDING_BIT,
	WORK_STRUCT_LINKED	= 1 << WORK_STRUCT_LINKED_BIT,
#ifdef CONFIG_DEBUG_OBJECTS_WORK
	WORK_STRUCT_STATIC	= 1 << WORK_STRUCT_STATIC_BIT,
#else
	WORK_STRUCT_STATIC	= 0,
#endif

	/*
	 * The last color is no color used for works which don't
	 * participate in workqueue flushing.
	 */
	WORK_NR_COLORS		= (1 << WORK_STRUCT_COLOR_BITS) - 1,
	WORK_NO_COLOR		= WORK_NR_COLORS,

	/* special cpu IDs */
	WORK_CPU_NONE		= NR_CPUS,
	WORK_CPU_LAST		= WORK_CPU_NONE,

	/*
	 * Reserve 6 bits off of cwq pointer w/ debugobjects turned
	 * off.  This makes cwqs aligned to 64 bytes which isn't too
	 * excessive while allowing 15 workqueue flush colors.
	 */
	WORK_STRUCT_FLAG_BITS	= WORK_STRUCT_COLOR_SHIFT +
				  WORK_STRUCT_COLOR_BITS,

	WORK_STRUCT_FLAG_MASK	= (1UL << WORK_STRUCT_FLAG_BITS) - 1,
	WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
	WORK_STRUCT_NO_CPU	= WORK_CPU_NONE << WORK_STRUCT_FLAG_BITS,

	/* bit mask for work_busy() return values */
	WORK_BUSY_PENDING	= 1 << 0,
	WORK_BUSY_RUNNING	= 1 << 1,
};

struct work_struct {
	atomic_long_t data;
	struct list_head entry;
	work_func_t func;
#ifdef CONFIG_LOCKDEP
	struct lockdep_map lockdep_map;
#endif
};

#define WORK_DATA_INIT()	ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU)
#define WORK_DATA_STATIC_INIT()	\
	ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU | WORK_STRUCT_STATIC)

struct delayed_work {
	struct work_struct work;
	struct timer_list timer;
};

static inline struct delayed_work *to_delayed_work(struct work_struct *work)
{
	return container_of(work, struct delayed_work, work);
}

struct execute_work {
	struct work_struct work;
};

#ifdef CONFIG_LOCKDEP
/*
 * NB: because we have to copy the lockdep_map, setting _key
 * here is required, otherwise it could get initialised to the
 * copy of the lockdep_map!
 */
#define __WORK_INIT_LOCKDEP_MAP(n, k) \
	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
#else
#define __WORK_INIT_LOCKDEP_MAP(n, k)
#endif

#define __WORK_INITIALIZER(n, f) {				\
	.data = WORK_DATA_STATIC_INIT(),			\
	.entry	= { &(n).entry, &(n).entry },			\
	.func = (f),						\
	__WORK_INIT_LOCKDEP_MAP(#n, &(n))			\
	}

#define __DELAYED_WORK_INITIALIZER(n, f) {			\
	.work = __WORK_INITIALIZER((n).work, (f)),		\
	.timer = TIMER_INITIALIZER(NULL, 0, 0),			\
	}

#define DECLARE_WORK(n, f)					\
	struct work_struct n = __WORK_INITIALIZER(n, f)

#define DECLARE_DELAYED_WORK(n, f)				\
	struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)

/*
 * initialize a work item's function pointer
 */
#define PREPARE_WORK(_work, _func)				\
	do {							\
		(_work)->func = (_func);			\
	} while (0)

#define PREPARE_DELAYED_WORK(_work, _func)			\
	PREPARE_WORK(&(_work)->work, (_func))

#ifdef CONFIG_DEBUG_OBJECTS_WORK
extern void __init_work(struct work_struct *work, int onstack);
extern void destroy_work_on_stack(struct work_struct *work);
static inline unsigned int work_static(struct work_struct *work)
{
	return *work_data_bits(work) & WORK_STRUCT_STATIC;
}
#else
static inline void __init_work(struct work_struct *work, int onstack) { }
static inline void destroy_work_on_stack(struct work_struct *work) { }
static inline unsigned int work_static(struct work_struct *work) { return 0; }
#endif

/*
 * initialize all of a work item in one go
 *
 * NOTE! No point in using "atomic_long_set()": using a direct
 * assignment of the work data initializer allows the compiler
 * to generate better code.
 */
#ifdef CONFIG_LOCKDEP
#define __INIT_WORK(_work, _func, _onstack)				\
	do {								\
		static struct lock_class_key __key;			\
									\
		__init_work((_work), _onstack);				\
		(_work)->data = (atomic_long_t) WORK_DATA_INIT();	\
		lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0);\
		INIT_LIST_HEAD(&(_work)->entry);			\
		PREPARE_WORK((_work), (_func));				\
	} while (0)
#else
#define __INIT_WORK(_work, _func, _onstack)				\
	do {								\
		__init_work((_work), _onstack);				\
		(_work)->data = (atomic_long_t) WORK_DATA_INIT();	\
		INIT_LIST_HEAD(&(_work)->entry);			\
		PREPARE_WORK((_work), (_func));				\
	} while (0)
#endif

#define INIT_WORK(_work, _func)					\
	do {							\
		__INIT_WORK((_work), (_func), 0);		\
	} while (0)

#define INIT_WORK_ON_STACK(_work, _func)			\
	do {							\
		__INIT_WORK((_work), (_func), 1);		\
	} while (0)

#define INIT_DELAYED_WORK(_work, _func)				\
	do {							\
		INIT_WORK(&(_work)->work, (_func));		\
		init_timer(&(_work)->timer);			\
	} while (0)

#define INIT_DELAYED_WORK_ON_STACK(_work, _func)		\
	do {							\
		INIT_WORK_ON_STACK(&(_work)->work, (_func));	\
		init_timer_on_stack(&(_work)->timer);		\
	} while (0)

#define INIT_DELAYED_WORK_DEFERRABLE(_work, _func)		\
	do {							\
		INIT_WORK(&(_work)->work, (_func));		\
		init_timer_deferrable(&(_work)->timer);		\
	} while (0)

/**
 * work_pending - Find out whether a work item is currently pending
 * @work: The work item in question
 */
#define work_pending(work) \
	test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))

/**
 * delayed_work_pending - Find out whether a delayable work item is currently
 * pending
 * @work: The work item in question
 */
#define delayed_work_pending(w) \
	work_pending(&(w)->work)

/**
 * work_clear_pending - for internal use only, mark a work item as not pending
 * @work: The work item in question
 */
#define work_clear_pending(work) \
	clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))

enum {
	WQ_NON_REENTRANT	= 1 << 0, /* guarantee non-reentrance */
	WQ_SINGLE_CPU		= 1 << 1, /* only single cpu at a time */
	WQ_FREEZEABLE		= 1 << 2, /* freeze during suspend */
	WQ_RESCUER		= 1 << 3, /* has an rescue worker */
	WQ_HIGHPRI		= 1 << 4, /* high priority */
	WQ_CPU_INTENSIVE	= 1 << 5, /* cpu instensive workqueue */

	WQ_MAX_ACTIVE		= 512,	  /* I like 512, better ideas? */
	WQ_DFL_ACTIVE		= WQ_MAX_ACTIVE / 2,
};

/*
 * System-wide workqueues which are always present.
 *
 * system_wq is the one used by schedule[_delayed]_work[_on]().
 * Multi-CPU multi-threaded.  There are users which expect relatively
 * short queue flush time.  Don't queue works which can run for too
 * long.
 *
 * system_long_wq is similar to system_wq but may host long running
 * works.  Queue flushing might take relatively long.
 *
 * system_nrt_wq is non-reentrant and guarantees that any given work
 * item is never executed in parallel by multiple CPUs.  Queue
 * flushing might take relatively long.
 */
extern struct workqueue_struct *system_wq;
extern struct workqueue_struct *system_long_wq;
extern struct workqueue_struct *system_nrt_wq;

extern struct workqueue_struct *
__alloc_workqueue_key(const char *name, unsigned int flags, int max_active,
		      struct lock_class_key *key, const char *lock_name);

#ifdef CONFIG_LOCKDEP
#define alloc_workqueue(name, flags, max_active)		\
({								\
	static struct lock_class_key __key;			\
	const char *__lock_name;				\
								\
	if (__builtin_constant_p(name))				\
		__lock_name = (name);				\
	else							\
		__lock_name = #name;				\
								\
	__alloc_workqueue_key((name), (flags), (max_active),	\
			      &__key, __lock_name);		\
})
#else
#define alloc_workqueue(name, flags, max_active)		\
	__alloc_workqueue_key((name), (flags), (max_active), NULL, NULL)
#endif

#define create_workqueue(name)					\
	alloc_workqueue((name), WQ_RESCUER, 1)
#define create_freezeable_workqueue(name)			\
	alloc_workqueue((name), WQ_FREEZEABLE | WQ_SINGLE_CPU | WQ_RESCUER, 1)
#define create_singlethread_workqueue(name)			\
	alloc_workqueue((name), WQ_SINGLE_CPU | WQ_RESCUER, 1)

extern void destroy_workqueue(struct workqueue_struct *wq);

extern int queue_work(struct workqueue_struct *wq, struct work_struct *work);
extern int queue_work_on(int cpu, struct workqueue_struct *wq,
			struct work_struct *work);
extern int queue_delayed_work(struct workqueue_struct *wq,
			struct delayed_work *work, unsigned long delay);
extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
			struct delayed_work *work, unsigned long delay);

extern void flush_workqueue(struct workqueue_struct *wq);
extern void flush_scheduled_work(void);
extern void flush_delayed_work(struct delayed_work *work);

extern int schedule_work(struct work_struct *work);
extern int schedule_work_on(int cpu, struct work_struct *work);
extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay);
extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
					unsigned long delay);
extern int schedule_on_each_cpu(work_func_t func);
extern int keventd_up(void);

extern void init_workqueues(void);
int execute_in_process_context(work_func_t fn, struct execute_work *);

extern int flush_work(struct work_struct *work);
extern int cancel_work_sync(struct work_struct *work);

extern void workqueue_set_max_active(struct workqueue_struct *wq,
				     int max_active);
extern bool workqueue_congested(unsigned int cpu, struct workqueue_struct *wq);
extern unsigned int work_cpu(struct work_struct *work);
extern unsigned int work_busy(struct work_struct *work);

/*
 * Kill off a pending schedule_delayed_work().  Note that the work callback
 * function may still be running on return from cancel_delayed_work(), unless
 * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
 * cancel_work_sync() to wait on it.
 */
static inline int cancel_delayed_work(struct delayed_work *work)
{
	int ret;

	ret = del_timer_sync(&work->timer);
	if (ret)
		work_clear_pending(&work->work);
	return ret;
}

/*
 * Like above, but uses del_timer() instead of del_timer_sync(). This means,
 * if it returns 0 the timer function may be running and the queueing is in
 * progress.
 */
static inline int __cancel_delayed_work(struct delayed_work *work)
{
	int ret;

	ret = del_timer(&work->timer);
	if (ret)
		work_clear_pending(&work->work);
	return ret;
}

extern int cancel_delayed_work_sync(struct delayed_work *work);

/* Obsolete. use cancel_delayed_work_sync() */
static inline
void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
					struct delayed_work *work)
{
	cancel_delayed_work_sync(work);
}

/* Obsolete. use cancel_delayed_work_sync() */
static inline
void cancel_rearming_delayed_work(struct delayed_work *work)
{
	cancel_delayed_work_sync(work);
}

#ifndef CONFIG_SMP
static inline long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
{
	return fn(arg);
}
#else
long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg);
#endif /* CONFIG_SMP */

#ifdef CONFIG_FREEZER
extern void freeze_workqueues_begin(void);
extern bool freeze_workqueues_busy(void);
extern void thaw_workqueues(void);
#endif /* CONFIG_FREEZER */

#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* workqueue.h --- work queue handling for Linux.
	3	*/
	4
	5	#ifndef _LINUX_WORKQUEUE_H
	6	#define _LINUX_WORKQUEUE_H
	7
	8	#include <linux/timer.h>
	9	#include <linux/linkage.h>
	10	#include <linux/bitops.h>
4e6045f1	11	#include <linux/lockdep.h>
7a22ad75	12	#include <linux/threads.h>
a08727ba	13	#include <asm/atomic.h>
1da177e4 LT	14
	15	struct workqueue_struct;
	16
65f27f38 DH	17	struct work_struct;
65f27f38 DH	18	typedef void (work_func_t)(struct work_struct work);
6bb49e59	19
a08727ba LT	20	/*
	21	* The first word is the work queue pointer and the flags rolled into
	22	* one
	23	*/
	24	#define work_data_bits(work) ((unsigned long *)(&(work)->data))
	25
22df02bb TH	26	enum {
22df02bb TH	27	WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
affee4b2	28	WORK_STRUCT_LINKED_BIT = 1, /* next work is linked to this one */
22df02bb	29	#ifdef CONFIG_DEBUG_OBJECTS_WORK
affee4b2	30	WORK_STRUCT_STATIC_BIT = 2, /* static initializer (debugobjects) */
73f53c4a	31	WORK_STRUCT_COLOR_SHIFT = 3, /* color for workqueue flushing */
0f900049	32	#else
73f53c4a	33	WORK_STRUCT_COLOR_SHIFT = 2, /* color for workqueue flushing */
22df02bb TH	34	#endif
22df02bb TH	35
73f53c4a TH	36	WORK_STRUCT_COLOR_BITS = 4,
73f53c4a TH	37
22df02bb	38	WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
affee4b2	39	WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT,
22df02bb TH	40	#ifdef CONFIG_DEBUG_OBJECTS_WORK
	41	WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
	42	#else
	43	WORK_STRUCT_STATIC = 0,
	44	#endif
	45
73f53c4a TH	46	/*
	47	* The last color is no color used for works which don't
	48	* participate in workqueue flushing.
	49	*/
	50	WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1,
	51	WORK_NO_COLOR = WORK_NR_COLORS,
	52
bdbc5dd7 TH	53	/* special cpu IDs */
	54	WORK_CPU_NONE = NR_CPUS,
	55	WORK_CPU_LAST = WORK_CPU_NONE,
	56
73f53c4a TH	57	/*
	58	* Reserve 6 bits off of cwq pointer w/ debugobjects turned
	59	* off. This makes cwqs aligned to 64 bytes which isn't too
	60	* excessive while allowing 15 workqueue flush colors.
	61	*/
	62	WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
	63	WORK_STRUCT_COLOR_BITS,
	64
0f900049	65	WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1,
22df02bb	66	WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
bdbc5dd7	67	WORK_STRUCT_NO_CPU = WORK_CPU_NONE << WORK_STRUCT_FLAG_BITS,
dcd989cb TH	68
	69	/* bit mask for work_busy() return values */
	70	WORK_BUSY_PENDING = 1 << 0,
	71	WORK_BUSY_RUNNING = 1 << 1,
22df02bb TH	72	};
22df02bb TH	73
1da177e4	74	struct work_struct {
a08727ba	75	atomic_long_t data;
1da177e4	76	struct list_head entry;
6bb49e59	77	work_func_t func;
4e6045f1 JB	78	#ifdef CONFIG_LOCKDEP
	79	struct lockdep_map lockdep_map;
	80	#endif
52bad64d DH	81	};
52bad64d DH	82
7a22ad75 TH	83	#define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU)
	84	#define WORK_DATA_STATIC_INIT() \
	85	ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU \| WORK_STRUCT_STATIC)
a08727ba	86
52bad64d DH	87	struct delayed_work {
52bad64d DH	88	struct work_struct work;
1da177e4 LT	89	struct timer_list timer;
	90	};
	91
bf6aede7 JD	92	static inline struct delayed_work to_delayed_work(struct work_struct work)
	93	{
	94	return container_of(work, struct delayed_work, work);
	95	}
	96
1fa44eca JB	97	struct execute_work {
	98	struct work_struct work;
	99	};
	100
4e6045f1 JB	101	#ifdef CONFIG_LOCKDEP
	102	/*
	103	* NB: because we have to copy the lockdep_map, setting _key
	104	* here is required, otherwise it could get initialised to the
	105	* copy of the lockdep_map!
	106	*/
	107	#define __WORK_INIT_LOCKDEP_MAP(n, k) \
	108	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
	109	#else
	110	#define __WORK_INIT_LOCKDEP_MAP(n, k)
	111	#endif
	112
65f27f38	113	#define __WORK_INITIALIZER(n, f) { \
dc186ad7	114	.data = WORK_DATA_STATIC_INIT(), \
23b2e599	115	.entry = { &(n).entry, &(n).entry }, \
65f27f38	116	.func = (f), \
4e6045f1	117	__WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
65f27f38 DH	118	}
	119
	120	#define __DELAYED_WORK_INITIALIZER(n, f) { \
	121	.work = __WORK_INITIALIZER((n).work, (f)), \
	122	.timer = TIMER_INITIALIZER(NULL, 0, 0), \
	123	}
	124
65f27f38 DH	125	#define DECLARE_WORK(n, f) \
	126	struct work_struct n = __WORK_INITIALIZER(n, f)
	127
65f27f38 DH	128	#define DECLARE_DELAYED_WORK(n, f) \
	129	struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)
	130
1da177e4	131	/*
65f27f38	132	* initialize a work item's function pointer
1da177e4	133	*/
65f27f38	134	#define PREPARE_WORK(_work, _func) \
1da177e4	135	do { \
52bad64d	136	(_work)->func = (_func); \
1da177e4 LT	137	} while (0)
1da177e4 LT	138
65f27f38 DH	139	#define PREPARE_DELAYED_WORK(_work, _func) \
65f27f38 DH	140	PREPARE_WORK(&(_work)->work, (_func))
52bad64d	141
dc186ad7 TG	142	#ifdef CONFIG_DEBUG_OBJECTS_WORK
	143	extern void __init_work(struct work_struct *work, int onstack);
	144	extern void destroy_work_on_stack(struct work_struct *work);
4690c4ab TH	145	static inline unsigned int work_static(struct work_struct *work)
4690c4ab TH	146	{
22df02bb	147	return *work_data_bits(work) & WORK_STRUCT_STATIC;
4690c4ab	148	}
dc186ad7 TG	149	#else
	150	static inline void __init_work(struct work_struct *work, int onstack) { }
	151	static inline void destroy_work_on_stack(struct work_struct *work) { }
4690c4ab	152	static inline unsigned int work_static(struct work_struct *work) { return 0; }
dc186ad7 TG	153	#endif
dc186ad7 TG	154
1da177e4	155	/*
52bad64d	156	* initialize all of a work item in one go
a08727ba	157	*
b9049df5	158	* NOTE! No point in using "atomic_long_set()": using a direct
a08727ba LT	159	* assignment of the work data initializer allows the compiler
a08727ba LT	160	* to generate better code.
1da177e4	161	*/
4e6045f1	162	#ifdef CONFIG_LOCKDEP
dc186ad7	163	#define __INIT_WORK(_work, _func, _onstack) \
65f27f38	164	do { \
4e6045f1 JB	165	static struct lock_class_key __key; \
4e6045f1 JB	166	\
dc186ad7	167	__init_work((_work), _onstack); \
23b2e599	168	(_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
4e6045f1	169	lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0);\
65f27f38 DH	170	INIT_LIST_HEAD(&(_work)->entry); \
	171	PREPARE_WORK((_work), (_func)); \
	172	} while (0)
4e6045f1	173	#else
dc186ad7	174	#define __INIT_WORK(_work, _func, _onstack) \
4e6045f1	175	do { \
dc186ad7	176	__init_work((_work), _onstack); \
4e6045f1 JB	177	(_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
	178	INIT_LIST_HEAD(&(_work)->entry); \
	179	PREPARE_WORK((_work), (_func)); \
	180	} while (0)
	181	#endif
65f27f38	182
dc186ad7 TG	183	#define INIT_WORK(_work, _func) \
	184	do { \
	185	__INIT_WORK((_work), (_func), 0); \
	186	} while (0)
	187
	188	#define INIT_WORK_ON_STACK(_work, _func) \
	189	do { \
	190	__INIT_WORK((_work), (_func), 1); \
	191	} while (0)
	192
65f27f38 DH	193	#define INIT_DELAYED_WORK(_work, _func) \
	194	do { \
	195	INIT_WORK(&(_work)->work, (_func)); \
	196	init_timer(&(_work)->timer); \
52bad64d DH	197	} while (0)
52bad64d DH	198
6d612b0f PZ	199	#define INIT_DELAYED_WORK_ON_STACK(_work, _func) \
6d612b0f PZ	200	do { \
dc186ad7	201	INIT_WORK_ON_STACK(&(_work)->work, (_func)); \
6d612b0f PZ	202	init_timer_on_stack(&(_work)->timer); \
	203	} while (0)
	204
dc186ad7	205	#define INIT_DELAYED_WORK_DEFERRABLE(_work, _func) \
28287033 VP	206	do { \
	207	INIT_WORK(&(_work)->work, (_func)); \
	208	init_timer_deferrable(&(_work)->timer); \
	209	} while (0)
	210
365970a1 DH	211	/**
	212	* work_pending - Find out whether a work item is currently pending
	213	* @work: The work item in question
	214	*/
	215	#define work_pending(work) \
22df02bb	216	test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
365970a1 DH	217
	218	/**
	219	* delayed_work_pending - Find out whether a delayable work item is currently
	220	* pending
	221	* @work: The work item in question
	222	*/
0221872a LT	223	#define delayed_work_pending(w) \
0221872a LT	224	work_pending(&(w)->work)
365970a1	225
65f27f38	226	/**
23b2e599 ON	227	* work_clear_pending - for internal use only, mark a work item as not pending
23b2e599 ON	228	* @work: The work item in question
65f27f38	229	*/
23b2e599	230	#define work_clear_pending(work) \
22df02bb	231	clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
65f27f38	232
97e37d7b	233	enum {
bdbc5dd7	234	WQ_NON_REENTRANT = 1 << 0, /* guarantee non-reentrance */
502ca9d8	235	WQ_SINGLE_CPU = 1 << 1, /* only single cpu at a time */
bdbc5dd7	236	WQ_FREEZEABLE = 1 << 2, /* freeze during suspend */
e22bee78	237	WQ_RESCUER = 1 << 3, /* has an rescue worker */
649027d7	238	WQ_HIGHPRI = 1 << 4, /* high priority */
fb0e7beb	239	WQ_CPU_INTENSIVE = 1 << 5, /* cpu instensive workqueue */
b71ab8c2 TH	240
	241	WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
	242	WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
97e37d7b	243	};
52bad64d	244
d320c038 TH	245	/*
	246	* System-wide workqueues which are always present.
	247	*
	248	* system_wq is the one used by schedule[_delayed]_work[_on]().
	249	* Multi-CPU multi-threaded. There are users which expect relatively
	250	* short queue flush time. Don't queue works which can run for too
	251	* long.
	252	*
	253	* system_long_wq is similar to system_wq but may host long running
	254	* works. Queue flushing might take relatively long.
	255	*
	256	* system_nrt_wq is non-reentrant and guarantees that any given work
	257	* item is never executed in parallel by multiple CPUs. Queue
	258	* flushing might take relatively long.
	259	*/
	260	extern struct workqueue_struct *system_wq;
	261	extern struct workqueue_struct *system_long_wq;
	262	extern struct workqueue_struct *system_nrt_wq;
	263
4e6045f1	264	extern struct workqueue_struct *
d320c038 TH	265	__alloc_workqueue_key(const char *name, unsigned int flags, int max_active,
d320c038 TH	266	struct lock_class_key key, const char lock_name);
4e6045f1 JB	267
4e6045f1 JB	268	#ifdef CONFIG_LOCKDEP
d320c038	269	#define alloc_workqueue(name, flags, max_active) \
4e6045f1 JB	270	({ \
4e6045f1 JB	271	static struct lock_class_key __key; \
eb13ba87 JB	272	const char *__lock_name; \
	273	\
	274	if (__builtin_constant_p(name)) \
	275	__lock_name = (name); \
	276	else \
	277	__lock_name = #name; \
4e6045f1	278	\
d320c038 TH	279	__alloc_workqueue_key((name), (flags), (max_active), \
d320c038 TH	280	&__key, __lock_name); \
4e6045f1 JB	281	})
4e6045f1 JB	282	#else
d320c038 TH	283	#define alloc_workqueue(name, flags, max_active) \
d320c038 TH	284	__alloc_workqueue_key((name), (flags), (max_active), NULL, NULL)
4e6045f1 JB	285	#endif
4e6045f1 JB	286
97e37d7b	287	#define create_workqueue(name) \
d320c038	288	alloc_workqueue((name), WQ_RESCUER, 1)
97e37d7b	289	#define create_freezeable_workqueue(name) \
d320c038	290	alloc_workqueue((name), WQ_FREEZEABLE \| WQ_SINGLE_CPU \| WQ_RESCUER, 1)
97e37d7b	291	#define create_singlethread_workqueue(name) \
d320c038	292	alloc_workqueue((name), WQ_SINGLE_CPU \| WQ_RESCUER, 1)
1da177e4 LT	293
	294	extern void destroy_workqueue(struct workqueue_struct *wq);
	295
b3c97528	296	extern int queue_work(struct workqueue_struct wq, struct work_struct work);
c1a220e7 ZR	297	extern int queue_work_on(int cpu, struct workqueue_struct *wq,
c1a220e7 ZR	298	struct work_struct *work);
b3c97528 HH	299	extern int queue_delayed_work(struct workqueue_struct *wq,
b3c97528 HH	300	struct delayed_work *work, unsigned long delay);
7a6bc1cd	301	extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
28e53bdd ON	302	struct delayed_work *work, unsigned long delay);
28e53bdd ON	303
b3c97528	304	extern void flush_workqueue(struct workqueue_struct *wq);
28e53bdd	305	extern void flush_scheduled_work(void);
43046b60	306	extern void flush_delayed_work(struct delayed_work *work);
1da177e4	307
b3c97528	308	extern int schedule_work(struct work_struct *work);
c1a220e7	309	extern int schedule_work_on(int cpu, struct work_struct *work);
b3c97528	310	extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay);
28e53bdd ON	311	extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
28e53bdd ON	312	unsigned long delay);
65f27f38	313	extern int schedule_on_each_cpu(work_func_t func);
1da177e4 LT	314	extern int keventd_up(void);
	315
	316	extern void init_workqueues(void);
65f27f38	317	int execute_in_process_context(work_func_t fn, struct execute_work *);
1da177e4	318
db700897	319	extern int flush_work(struct work_struct *work);
1f1f642e	320	extern int cancel_work_sync(struct work_struct *work);
28e53bdd	321
dcd989cb TH	322	extern void workqueue_set_max_active(struct workqueue_struct *wq,
	323	int max_active);
	324	extern bool workqueue_congested(unsigned int cpu, struct workqueue_struct *wq);
	325	extern unsigned int work_cpu(struct work_struct *work);
	326	extern unsigned int work_busy(struct work_struct *work);
	327
1da177e4 LT	328	/*
1da177e4 LT	329	* Kill off a pending schedule_delayed_work(). Note that the work callback
071b6386 ON	330	* function may still be running on return from cancel_delayed_work(), unless
071b6386 ON	331	* it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
28e53bdd	332	* cancel_work_sync() to wait on it.
1da177e4	333	*/
52bad64d	334	static inline int cancel_delayed_work(struct delayed_work *work)
1da177e4 LT	335	{
	336	int ret;
	337
223a10a9	338	ret = del_timer_sync(&work->timer);
1da177e4	339	if (ret)
23b2e599	340	work_clear_pending(&work->work);
1da177e4 LT	341	return ret;
	342	}
	343
4e49627b ON	344	/*
	345	* Like above, but uses del_timer() instead of del_timer_sync(). This means,
	346	* if it returns 0 the timer function may be running and the queueing is in
	347	* progress.
	348	*/
	349	static inline int __cancel_delayed_work(struct delayed_work *work)
	350	{
	351	int ret;
	352
	353	ret = del_timer(&work->timer);
	354	if (ret)
	355	work_clear_pending(&work->work);
	356	return ret;
	357	}
	358
1f1f642e	359	extern int cancel_delayed_work_sync(struct delayed_work *work);
1634c48f	360
f5a421a4	361	/* Obsolete. use cancel_delayed_work_sync() */
1634c48f ON	362	static inline
	363	void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq,
	364	struct delayed_work *work)
	365	{
f5a421a4 ON	366	cancel_delayed_work_sync(work);
	367	}
	368
	369	/* Obsolete. use cancel_delayed_work_sync() */
	370	static inline
	371	void cancel_rearming_delayed_work(struct delayed_work *work)
	372	{
	373	cancel_delayed_work_sync(work);
1634c48f ON	374	}
1634c48f ON	375
2d3854a3 RR	376	#ifndef CONFIG_SMP
	377	static inline long work_on_cpu(unsigned int cpu, long (fn)(void ), void *arg)
	378	{
	379	return fn(arg);
	380	}
	381	#else
	382	long work_on_cpu(unsigned int cpu, long (fn)(void ), void *arg);
	383	#endif /* CONFIG_SMP */
a0a1a5fd TH	384
	385	#ifdef CONFIG_FREEZER
	386	extern void freeze_workqueues_begin(void);
	387	extern bool freeze_workqueues_busy(void);
	388	extern void thaw_workqueues(void);
	389	#endif /* CONFIG_FREEZER */
	390
1da177e4	391	#endif