[mirror_ubuntu-artful-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 <linux/atomic.h>

struct workqueue_struct;

struct work_struct;
typedef void (*work_func_t)(struct work_struct *work);
void delayed_work_timer_fn(unsigned long __data);

/*
 * 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_DELAYED_BIT	= 1,	/* work item is delayed */
	WORK_STRUCT_CWQ_BIT	= 2,	/* data points to cwq */
	WORK_STRUCT_LINKED_BIT	= 3,	/* next work is linked to this one */
#ifdef CONFIG_DEBUG_OBJECTS_WORK
	WORK_STRUCT_STATIC_BIT	= 4,	/* static initializer (debugobjects) */
	WORK_STRUCT_COLOR_SHIFT	= 5,	/* color for workqueue flushing */
#else
	WORK_STRUCT_COLOR_SHIFT	= 4,	/* color for workqueue flushing */
#endif

	WORK_STRUCT_COLOR_BITS	= 4,

	WORK_STRUCT_PENDING	= 1 << WORK_STRUCT_PENDING_BIT,
	WORK_STRUCT_DELAYED	= 1 << WORK_STRUCT_DELAYED_BIT,
	WORK_STRUCT_CWQ		= 1 << WORK_STRUCT_CWQ_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_UNBOUND	= NR_CPUS,
	WORK_CPU_NONE		= NR_CPUS + 1,
	WORK_CPU_LAST		= WORK_CPU_NONE,

	/*
	 * Reserve 7 bits off of cwq pointer w/ debugobjects turned
	 * off.  This makes cwqs aligned to 256 bytes and allows 15
	 * workqueue flush colors.
	 */
	WORK_STRUCT_FLAG_BITS	= WORK_STRUCT_COLOR_SHIFT +
				  WORK_STRUCT_COLOR_BITS,

	/* data contains off-queue information when !WORK_STRUCT_CWQ */
	WORK_OFFQ_FLAG_BASE	= WORK_STRUCT_FLAG_BITS,

	WORK_OFFQ_CANCELING	= (1 << WORK_OFFQ_FLAG_BASE),

	/*
	 * When a work item is off queue, its high bits point to the last
	 * cpu it was on.  Cap at 31 bits and use the highest number to
	 * indicate that no cpu is associated.
	 */
	WORK_OFFQ_FLAG_BITS	= 1,
	WORK_OFFQ_CPU_SHIFT	= WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
	WORK_OFFQ_LEFT		= BITS_PER_LONG - WORK_OFFQ_CPU_SHIFT,
	WORK_OFFQ_CPU_BITS	= WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31,
	WORK_OFFQ_CPU_NONE	= (1LU << WORK_OFFQ_CPU_BITS) - 1,

	/* convenience constants */
	WORK_STRUCT_FLAG_MASK	= (1UL << WORK_STRUCT_FLAG_BITS) - 1,
	WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
	WORK_STRUCT_NO_CPU	= (unsigned long)WORK_OFFQ_CPU_NONE << WORK_OFFQ_CPU_SHIFT,

	/* 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;
	int cpu;
};

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, tflags) {			\
	.work = __WORK_INITIALIZER((n).work, (f)),			\
	.timer = __TIMER_INITIALIZER(delayed_work_timer_fn,		\
				     0, (unsigned long)&(n),		\
				     (tflags) | TIMER_IRQSAFE),		\
	}

#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, 0)

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

/*
 * 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_ONSTACK(_work, _func)					\
	do {								\
		__INIT_WORK((_work), (_func), 1);			\
	} while (0)

#define __INIT_DELAYED_WORK(_work, _func, _tflags)			\
	do {								\
		INIT_WORK(&(_work)->work, (_func));			\
		__setup_timer(&(_work)->timer, delayed_work_timer_fn,	\
			      (unsigned long)(_work),			\
			      (_tflags) | TIMER_IRQSAFE);		\
	} while (0)

#define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags)		\
	do {								\
		INIT_WORK_ONSTACK(&(_work)->work, (_func));		\
		__setup_timer_on_stack(&(_work)->timer,			\
				       delayed_work_timer_fn,		\
				       (unsigned long)(_work),		\
				       (_tflags) | TIMER_IRQSAFE);	\
	} while (0)

#define INIT_DELAYED_WORK(_work, _func)					\
	__INIT_DELAYED_WORK(_work, _func, 0)

#define INIT_DELAYED_WORK_ONSTACK(_work, _func)				\
	__INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)

#define INIT_DEFERRABLE_WORK(_work, _func)				\
	__INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)

#define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func)			\
	__INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)

/**
 * 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))

/*
 * Workqueue flags and constants.  For details, please refer to
 * Documentation/workqueue.txt.
 */
enum {
	WQ_NON_REENTRANT	= 1 << 0, /* guarantee non-reentrance */
	WQ_UNBOUND		= 1 << 1, /* not bound to any cpu */
	WQ_FREEZABLE		= 1 << 2, /* freeze during suspend */
	WQ_MEM_RECLAIM		= 1 << 3, /* may be used for memory reclaim */
	WQ_HIGHPRI		= 1 << 4, /* high priority */
	WQ_CPU_INTENSIVE	= 1 << 5, /* cpu instensive workqueue */

	WQ_DRAINING		= 1 << 6, /* internal: workqueue is draining */
	WQ_RESCUER		= 1 << 7, /* internal: workqueue has rescuer */

	WQ_MAX_ACTIVE		= 512,	  /* I like 512, better ideas? */
	WQ_MAX_UNBOUND_PER_CPU	= 4,	  /* 4 * #cpus for unbound wq */
	WQ_DFL_ACTIVE		= WQ_MAX_ACTIVE / 2,
};

/* unbound wq's aren't per-cpu, scale max_active according to #cpus */
#define WQ_UNBOUND_MAX_ACTIVE	\
	max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)

/*
 * 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_unbound_wq is unbound workqueue.  Workers are not bound to
 * any specific CPU, not concurrency managed, and all queued works are
 * executed immediately as long as max_active limit is not reached and
 * resources are available.
 *
 * system_freezable_wq is equivalent to system_wq except that it's
 * freezable.
 */
extern struct workqueue_struct *system_wq;
extern struct workqueue_struct *system_long_wq;
extern struct workqueue_struct *system_unbound_wq;
extern struct workqueue_struct *system_freezable_wq;

static inline struct workqueue_struct * __deprecated __system_nrt_wq(void)
{
	return system_wq;
}

static inline struct workqueue_struct * __deprecated __system_nrt_freezable_wq(void)
{
	return system_freezable_wq;
}

/* equivlalent to system_wq and system_freezable_wq, deprecated */
#define system_nrt_wq			__system_nrt_wq()
#define system_nrt_freezable_wq		__system_nrt_freezable_wq()

extern struct workqueue_struct *
__alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
	struct lock_class_key *key, const char *lock_name, ...) __printf(1, 6);

/**
 * alloc_workqueue - allocate a workqueue
 * @fmt: printf format for the name of the workqueue
 * @flags: WQ_* flags
 * @max_active: max in-flight work items, 0 for default
 * @args: args for @fmt
 *
 * Allocate a workqueue with the specified parameters.  For detailed
 * information on WQ_* flags, please refer to Documentation/workqueue.txt.
 *
 * The __lock_name macro dance is to guarantee that single lock_class_key
 * doesn't end up with different namesm, which isn't allowed by lockdep.
 *
 * RETURNS:
 * Pointer to the allocated workqueue on success, %NULL on failure.
 */
#ifdef CONFIG_LOCKDEP
#define alloc_workqueue(fmt, flags, max_active, args...)		\
({									\
	static struct lock_class_key __key;				\
	const char *__lock_name;					\
									\
	if (__builtin_constant_p(fmt))					\
		__lock_name = (fmt);					\
	else								\
		__lock_name = #fmt;					\
									\
	__alloc_workqueue_key((fmt), (flags), (max_active),		\
			      &__key, __lock_name, ##args);		\
})
#else
#define alloc_workqueue(fmt, flags, max_active, args...)		\
	__alloc_workqueue_key((fmt), (flags), (max_active),		\
			      NULL, NULL, ##args)
#endif

/**
 * alloc_ordered_workqueue - allocate an ordered workqueue
 * @fmt: printf format for the name of the workqueue
 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
 * @args: args for @fmt
 *
 * Allocate an ordered workqueue.  An ordered workqueue executes at
 * most one work item at any given time in the queued order.  They are
 * implemented as unbound workqueues with @max_active of one.
 *
 * RETURNS:
 * Pointer to the allocated workqueue on success, %NULL on failure.
 */
#define alloc_ordered_workqueue(fmt, flags, args...)			\
	alloc_workqueue(fmt, WQ_UNBOUND | (flags), 1, ##args)

#define create_workqueue(name)						\
	alloc_workqueue((name), WQ_MEM_RECLAIM, 1)
#define create_freezable_workqueue(name)				\
	alloc_workqueue((name), WQ_FREEZABLE | WQ_UNBOUND | WQ_MEM_RECLAIM, 1)
#define create_singlethread_workqueue(name)				\
	alloc_workqueue((name), WQ_UNBOUND | WQ_MEM_RECLAIM, 1)

extern void destroy_workqueue(struct workqueue_struct *wq);

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

extern void flush_workqueue(struct workqueue_struct *wq);
extern void drain_workqueue(struct workqueue_struct *wq);
extern void flush_scheduled_work(void);

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

int execute_in_process_context(work_func_t fn, struct execute_work *);

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

extern bool flush_delayed_work(struct delayed_work *dwork);
extern bool cancel_delayed_work(struct delayed_work *dwork);
extern bool cancel_delayed_work_sync(struct delayed_work *dwork);

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_busy(struct work_struct *work);

/*
 * 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 bool __deprecated __cancel_delayed_work(struct delayed_work *work)
{
	bool ret;

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

/* used to be different but now identical to flush_work(), deprecated */
static inline bool __deprecated flush_work_sync(struct work_struct *work)
{
	return flush_work(work);
}

/* used to be different but now identical to flush_delayed_work(), deprecated */
static inline bool __deprecated flush_delayed_work_sync(struct delayed_work *dwork)
{
	return flush_delayed_work(dwork);
}

#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>
60063497	13	#include <linux/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);
d8e794df	19	void delayed_work_timer_fn(unsigned long __data);
6bb49e59	20
a08727ba LT	21	/*
	22	* The first word is the work queue pointer and the flags rolled into
	23	* one
	24	*/
	25	#define work_data_bits(work) ((unsigned long *)(&(work)->data))
	26
22df02bb TH	27	enum {
22df02bb TH	28	WORK_STRUCT_PENDING_BIT = 0, /* work item is pending execution */
8a2e8e5d TH	29	WORK_STRUCT_DELAYED_BIT = 1, /* work item is delayed */
	30	WORK_STRUCT_CWQ_BIT = 2, /* data points to cwq */
	31	WORK_STRUCT_LINKED_BIT = 3, /* next work is linked to this one */
22df02bb	32	#ifdef CONFIG_DEBUG_OBJECTS_WORK
8a2e8e5d TH	33	WORK_STRUCT_STATIC_BIT = 4, /* static initializer (debugobjects) */
8a2e8e5d TH	34	WORK_STRUCT_COLOR_SHIFT = 5, /* color for workqueue flushing */
0f900049	35	#else
8a2e8e5d	36	WORK_STRUCT_COLOR_SHIFT = 4, /* color for workqueue flushing */
22df02bb TH	37	#endif
22df02bb TH	38
73f53c4a TH	39	WORK_STRUCT_COLOR_BITS = 4,
73f53c4a TH	40
22df02bb	41	WORK_STRUCT_PENDING = 1 << WORK_STRUCT_PENDING_BIT,
8a2e8e5d	42	WORK_STRUCT_DELAYED = 1 << WORK_STRUCT_DELAYED_BIT,
e120153d	43	WORK_STRUCT_CWQ = 1 << WORK_STRUCT_CWQ_BIT,
affee4b2	44	WORK_STRUCT_LINKED = 1 << WORK_STRUCT_LINKED_BIT,
22df02bb TH	45	#ifdef CONFIG_DEBUG_OBJECTS_WORK
	46	WORK_STRUCT_STATIC = 1 << WORK_STRUCT_STATIC_BIT,
	47	#else
	48	WORK_STRUCT_STATIC = 0,
	49	#endif
	50
73f53c4a TH	51	/*
	52	* The last color is no color used for works which don't
	53	* participate in workqueue flushing.
	54	*/
	55	WORK_NR_COLORS = (1 << WORK_STRUCT_COLOR_BITS) - 1,
	56	WORK_NO_COLOR = WORK_NR_COLORS,
	57
bdbc5dd7	58	/* special cpu IDs */
f3421797 TH	59	WORK_CPU_UNBOUND = NR_CPUS,
f3421797 TH	60	WORK_CPU_NONE = NR_CPUS + 1,
bdbc5dd7 TH	61	WORK_CPU_LAST = WORK_CPU_NONE,
bdbc5dd7 TH	62
73f53c4a	63	/*
e120153d	64	* Reserve 7 bits off of cwq pointer w/ debugobjects turned
8a2e8e5d TH	65	* off. This makes cwqs aligned to 256 bytes and allows 15
8a2e8e5d TH	66	* workqueue flush colors.
73f53c4a TH	67	*/
	68	WORK_STRUCT_FLAG_BITS = WORK_STRUCT_COLOR_SHIFT +
	69	WORK_STRUCT_COLOR_BITS,
	70
b5490077 TH	71	/* data contains off-queue information when !WORK_STRUCT_CWQ */
b5490077 TH	72	WORK_OFFQ_FLAG_BASE = WORK_STRUCT_FLAG_BITS,
bbb68dfa TH	73
	74	WORK_OFFQ_CANCELING = (1 << WORK_OFFQ_FLAG_BASE),
	75
715b06b8 TH	76	/*
	77	* When a work item is off queue, its high bits point to the last
	78	* cpu it was on. Cap at 31 bits and use the highest number to
	79	* indicate that no cpu is associated.
	80	*/
bbb68dfa	81	WORK_OFFQ_FLAG_BITS = 1,
b5490077	82	WORK_OFFQ_CPU_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
715b06b8 TH	83	WORK_OFFQ_LEFT = BITS_PER_LONG - WORK_OFFQ_CPU_SHIFT,
	84	WORK_OFFQ_CPU_BITS = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31,
	85	WORK_OFFQ_CPU_NONE = (1LU << WORK_OFFQ_CPU_BITS) - 1,
b5490077 TH	86
b5490077 TH	87	/* convenience constants */
0f900049	88	WORK_STRUCT_FLAG_MASK = (1UL << WORK_STRUCT_FLAG_BITS) - 1,
22df02bb	89	WORK_STRUCT_WQ_DATA_MASK = ~WORK_STRUCT_FLAG_MASK,
715b06b8	90	WORK_STRUCT_NO_CPU = (unsigned long)WORK_OFFQ_CPU_NONE << WORK_OFFQ_CPU_SHIFT,
dcd989cb TH	91
	92	/* bit mask for work_busy() return values */
	93	WORK_BUSY_PENDING = 1 << 0,
	94	WORK_BUSY_RUNNING = 1 << 1,
22df02bb TH	95	};
22df02bb TH	96
1da177e4	97	struct work_struct {
a08727ba	98	atomic_long_t data;
1da177e4	99	struct list_head entry;
6bb49e59	100	work_func_t func;
4e6045f1 JB	101	#ifdef CONFIG_LOCKDEP
	102	struct lockdep_map lockdep_map;
	103	#endif
52bad64d DH	104	};
52bad64d DH	105
7a22ad75 TH	106	#define WORK_DATA_INIT() ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU)
	107	#define WORK_DATA_STATIC_INIT() \
	108	ATOMIC_LONG_INIT(WORK_STRUCT_NO_CPU \| WORK_STRUCT_STATIC)
a08727ba	109
52bad64d DH	110	struct delayed_work {
52bad64d DH	111	struct work_struct work;
1da177e4	112	struct timer_list timer;
1265057f	113	int cpu;
1da177e4 LT	114	};
1da177e4 LT	115
bf6aede7 JD	116	static inline struct delayed_work to_delayed_work(struct work_struct work)
	117	{
	118	return container_of(work, struct delayed_work, work);
	119	}
	120
1fa44eca JB	121	struct execute_work {
	122	struct work_struct work;
	123	};
	124
4e6045f1 JB	125	#ifdef CONFIG_LOCKDEP
	126	/*
	127	* NB: because we have to copy the lockdep_map, setting _key
	128	* here is required, otherwise it could get initialised to the
	129	* copy of the lockdep_map!
	130	*/
	131	#define __WORK_INIT_LOCKDEP_MAP(n, k) \
	132	.lockdep_map = STATIC_LOCKDEP_MAP_INIT(n, k),
	133	#else
	134	#define __WORK_INIT_LOCKDEP_MAP(n, k)
	135	#endif
	136
ee64e7f6 TH	137	#define __WORK_INITIALIZER(n, f) { \
	138	.data = WORK_DATA_STATIC_INIT(), \
	139	.entry = { &(n).entry, &(n).entry }, \
	140	.func = (f), \
	141	__WORK_INIT_LOCKDEP_MAP(#n, &(n)) \
65f27f38 DH	142	}
65f27f38 DH	143
f991b318	144	#define __DELAYED_WORK_INITIALIZER(n, f, tflags) { \
ee64e7f6	145	.work = __WORK_INITIALIZER((n).work, (f)), \
f991b318	146	.timer = __TIMER_INITIALIZER(delayed_work_timer_fn, \
e0aecdd8 TH	147	0, (unsigned long)&(n), \
e0aecdd8 TH	148	(tflags) \| TIMER_IRQSAFE), \
dd6414b5 PC	149	}
dd6414b5 PC	150
ee64e7f6	151	#define DECLARE_WORK(n, f) \
65f27f38 DH	152	struct work_struct n = __WORK_INITIALIZER(n, f)
65f27f38 DH	153
ee64e7f6	154	#define DECLARE_DELAYED_WORK(n, f) \
f991b318	155	struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, 0)
65f27f38	156
203b42f7	157	#define DECLARE_DEFERRABLE_WORK(n, f) \
f991b318	158	struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f, TIMER_DEFERRABLE)
dd6414b5	159
1da177e4	160	/*
65f27f38	161	* initialize a work item's function pointer
1da177e4	162	*/
ee64e7f6 TH	163	#define PREPARE_WORK(_work, _func) \
	164	do { \
	165	(_work)->func = (_func); \
1da177e4 LT	166	} while (0)
1da177e4 LT	167
ee64e7f6	168	#define PREPARE_DELAYED_WORK(_work, _func) \
65f27f38	169	PREPARE_WORK(&(_work)->work, (_func))
52bad64d	170
dc186ad7 TG	171	#ifdef CONFIG_DEBUG_OBJECTS_WORK
	172	extern void __init_work(struct work_struct *work, int onstack);
	173	extern void destroy_work_on_stack(struct work_struct *work);
4690c4ab TH	174	static inline unsigned int work_static(struct work_struct *work)
4690c4ab TH	175	{
22df02bb	176	return *work_data_bits(work) & WORK_STRUCT_STATIC;
4690c4ab	177	}
dc186ad7 TG	178	#else
	179	static inline void __init_work(struct work_struct *work, int onstack) { }
	180	static inline void destroy_work_on_stack(struct work_struct *work) { }
4690c4ab	181	static inline unsigned int work_static(struct work_struct *work) { return 0; }
dc186ad7 TG	182	#endif
dc186ad7 TG	183
1da177e4	184	/*
52bad64d	185	* initialize all of a work item in one go
a08727ba	186	*
b9049df5	187	* NOTE! No point in using "atomic_long_set()": using a direct
a08727ba LT	188	* assignment of the work data initializer allows the compiler
a08727ba LT	189	* to generate better code.
1da177e4	190	*/
4e6045f1	191	#ifdef CONFIG_LOCKDEP
dc186ad7	192	#define __INIT_WORK(_work, _func, _onstack) \
65f27f38	193	do { \
4e6045f1 JB	194	static struct lock_class_key __key; \
4e6045f1 JB	195	\
dc186ad7	196	__init_work((_work), _onstack); \
23b2e599	197	(_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
ee64e7f6	198	lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \
65f27f38 DH	199	INIT_LIST_HEAD(&(_work)->entry); \
	200	PREPARE_WORK((_work), (_func)); \
	201	} while (0)
4e6045f1	202	#else
dc186ad7	203	#define __INIT_WORK(_work, _func, _onstack) \
4e6045f1	204	do { \
dc186ad7	205	__init_work((_work), _onstack); \
4e6045f1 JB	206	(_work)->data = (atomic_long_t) WORK_DATA_INIT(); \
	207	INIT_LIST_HEAD(&(_work)->entry); \
	208	PREPARE_WORK((_work), (_func)); \
	209	} while (0)
	210	#endif
65f27f38	211
ee64e7f6 TH	212	#define INIT_WORK(_work, _func) \
	213	do { \
	214	__INIT_WORK((_work), (_func), 0); \
dc186ad7 TG	215	} while (0)
dc186ad7 TG	216
ee64e7f6 TH	217	#define INIT_WORK_ONSTACK(_work, _func) \
	218	do { \
	219	__INIT_WORK((_work), (_func), 1); \
dc186ad7 TG	220	} while (0)
dc186ad7 TG	221
f991b318	222	#define __INIT_DELAYED_WORK(_work, _func, _tflags) \
ee64e7f6 TH	223	do { \
ee64e7f6 TH	224	INIT_WORK(&(_work)->work, (_func)); \
f991b318	225	__setup_timer(&(_work)->timer, delayed_work_timer_fn, \
e0aecdd8 TH	226	(unsigned long)(_work), \
e0aecdd8 TH	227	(_tflags) \| TIMER_IRQSAFE); \
52bad64d DH	228	} while (0)
52bad64d DH	229
f991b318	230	#define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
ee64e7f6 TH	231	do { \
ee64e7f6 TH	232	INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
f991b318 TH	233	__setup_timer_on_stack(&(_work)->timer, \
	234	delayed_work_timer_fn, \
	235	(unsigned long)(_work), \
e0aecdd8	236	(_tflags) \| TIMER_IRQSAFE); \
6d612b0f PZ	237	} while (0)
6d612b0f PZ	238
f991b318 TH	239	#define INIT_DELAYED_WORK(_work, _func) \
	240	__INIT_DELAYED_WORK(_work, _func, 0)
	241
	242	#define INIT_DELAYED_WORK_ONSTACK(_work, _func) \
	243	__INIT_DELAYED_WORK_ONSTACK(_work, _func, 0)
	244
203b42f7	245	#define INIT_DEFERRABLE_WORK(_work, _func) \
f991b318 TH	246	__INIT_DELAYED_WORK(_work, _func, TIMER_DEFERRABLE)
	247
	248	#define INIT_DEFERRABLE_WORK_ONSTACK(_work, _func) \
	249	__INIT_DELAYED_WORK_ONSTACK(_work, _func, TIMER_DEFERRABLE)
28287033	250
365970a1 DH	251	/**
	252	* work_pending - Find out whether a work item is currently pending
	253	* @work: The work item in question
	254	*/
	255	#define work_pending(work) \
22df02bb	256	test_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
365970a1 DH	257
	258	/**
	259	* delayed_work_pending - Find out whether a delayable work item is currently
	260	* pending
	261	* @work: The work item in question
	262	*/
0221872a LT	263	#define delayed_work_pending(w) \
0221872a LT	264	work_pending(&(w)->work)
365970a1	265
65f27f38	266	/**
23b2e599 ON	267	* work_clear_pending - for internal use only, mark a work item as not pending
23b2e599 ON	268	* @work: The work item in question
65f27f38	269	*/
23b2e599	270	#define work_clear_pending(work) \
22df02bb	271	clear_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))
65f27f38	272
c54fce6e TH	273	/*
	274	* Workqueue flags and constants. For details, please refer to
	275	* Documentation/workqueue.txt.
	276	*/
97e37d7b	277	enum {
bdbc5dd7	278	WQ_NON_REENTRANT = 1 << 0, /* guarantee non-reentrance */
c7fc77f7	279	WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
58a69cb4	280	WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
6370a6ad	281	WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */
649027d7	282	WQ_HIGHPRI = 1 << 4, /* high priority */
fb0e7beb	283	WQ_CPU_INTENSIVE = 1 << 5, /* cpu instensive workqueue */
b71ab8c2	284
9c5a2ba7	285	WQ_DRAINING = 1 << 6, /* internal: workqueue is draining */
6370a6ad	286	WQ_RESCUER = 1 << 7, /* internal: workqueue has rescuer */
e41e704b	287
b71ab8c2	288	WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
f3421797	289	WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
b71ab8c2	290	WQ_DFL_ACTIVE = WQ_MAX_ACTIVE / 2,
97e37d7b	291	};
52bad64d	292
f3421797 TH	293	/* unbound wq's aren't per-cpu, scale max_active according to #cpus */
	294	#define WQ_UNBOUND_MAX_ACTIVE \
	295	max_t(int, WQ_MAX_ACTIVE, num_possible_cpus() * WQ_MAX_UNBOUND_PER_CPU)
65f27f38	296
d320c038 TH	297	/*
	298	* System-wide workqueues which are always present.
	299	*
	300	* system_wq is the one used by schedule[_delayed]_work[_on]().
	301	* Multi-CPU multi-threaded. There are users which expect relatively
	302	* short queue flush time. Don't queue works which can run for too
	303	* long.
	304	*
	305	* system_long_wq is similar to system_wq but may host long running
	306	* works. Queue flushing might take relatively long.
	307	*
f3421797 TH	308	* system_unbound_wq is unbound workqueue. Workers are not bound to
	309	* any specific CPU, not concurrency managed, and all queued works are
	310	* executed immediately as long as max_active limit is not reached and
	311	* resources are available.
4149efb2	312	*
24d51add TH	313	* system_freezable_wq is equivalent to system_wq except that it's
24d51add TH	314	* freezable.
d320c038 TH	315	*/
	316	extern struct workqueue_struct *system_wq;
	317	extern struct workqueue_struct *system_long_wq;
f3421797	318	extern struct workqueue_struct *system_unbound_wq;
24d51add	319	extern struct workqueue_struct *system_freezable_wq;
ae930e0f	320
3b07e9ca	321	static inline struct workqueue_struct * __deprecated __system_nrt_wq(void)
ae930e0f TH	322	{
	323	return system_wq;
	324	}
	325
3b07e9ca	326	static inline struct workqueue_struct * __deprecated __system_nrt_freezable_wq(void)
ae930e0f TH	327	{
	328	return system_freezable_wq;
	329	}
	330
	331	/* equivlalent to system_wq and system_freezable_wq, deprecated */
	332	#define system_nrt_wq __system_nrt_wq()
	333	#define system_nrt_freezable_wq __system_nrt_freezable_wq()
52bad64d	334
4e6045f1	335	extern struct workqueue_struct *
b196be89 TH	336	__alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
b196be89 TH	337	struct lock_class_key key, const char lock_name, ...) __printf(1, 6);
4e6045f1	338
b196be89 TH	339	/**
	340	* alloc_workqueue - allocate a workqueue
	341	* @fmt: printf format for the name of the workqueue
	342	* @flags: WQ_* flags
	343	* @max_active: max in-flight work items, 0 for default
	344	* @args: args for @fmt
	345	*
	346	* Allocate a workqueue with the specified parameters. For detailed
	347	* information on WQ_* flags, please refer to Documentation/workqueue.txt.
	348	*
	349	* The __lock_name macro dance is to guarantee that single lock_class_key
	350	* doesn't end up with different namesm, which isn't allowed by lockdep.
	351	*
	352	* RETURNS:
	353	* Pointer to the allocated workqueue on success, %NULL on failure.
	354	*/
4e6045f1	355	#ifdef CONFIG_LOCKDEP
ee64e7f6 TH	356	#define alloc_workqueue(fmt, flags, max_active, args...) \
	357	({ \
	358	static struct lock_class_key __key; \
	359	const char *__lock_name; \
	360	\
	361	if (__builtin_constant_p(fmt)) \
	362	__lock_name = (fmt); \
	363	else \
	364	__lock_name = #fmt; \
	365	\
	366	__alloc_workqueue_key((fmt), (flags), (max_active), \
	367	&__key, __lock_name, ##args); \
4e6045f1 JB	368	})
4e6045f1 JB	369	#else
ee64e7f6 TH	370	#define alloc_workqueue(fmt, flags, max_active, args...) \
ee64e7f6 TH	371	__alloc_workqueue_key((fmt), (flags), (max_active), \
b196be89	372	NULL, NULL, ##args)
4e6045f1 JB	373	#endif
4e6045f1 JB	374
81dcaf65 TH	375	/**
81dcaf65 TH	376	* alloc_ordered_workqueue - allocate an ordered workqueue
b196be89	377	* @fmt: printf format for the name of the workqueue
58a69cb4	378	* @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
b196be89	379	* @args: args for @fmt
81dcaf65 TH	380	*
	381	* Allocate an ordered workqueue. An ordered workqueue executes at
	382	* most one work item at any given time in the queued order. They are
	383	* implemented as unbound workqueues with @max_active of one.
	384	*
	385	* RETURNS:
	386	* Pointer to the allocated workqueue on success, %NULL on failure.
	387	*/
ee64e7f6	388	#define alloc_ordered_workqueue(fmt, flags, args...) \
b196be89	389	alloc_workqueue(fmt, WQ_UNBOUND \| (flags), 1, ##args)
81dcaf65	390
ee64e7f6	391	#define create_workqueue(name) \
6370a6ad	392	alloc_workqueue((name), WQ_MEM_RECLAIM, 1)
ee64e7f6	393	#define create_freezable_workqueue(name) \
58a69cb4	394	alloc_workqueue((name), WQ_FREEZABLE \| WQ_UNBOUND \| WQ_MEM_RECLAIM, 1)
ee64e7f6	395	#define create_singlethread_workqueue(name) \
6370a6ad	396	alloc_workqueue((name), WQ_UNBOUND \| WQ_MEM_RECLAIM, 1)
1da177e4 LT	397
	398	extern void destroy_workqueue(struct workqueue_struct *wq);
	399
d4283e93	400	extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
c1a220e7	401	struct work_struct *work);
d4283e93 TH	402	extern bool queue_work(struct workqueue_struct wq, struct work_struct work);
d4283e93 TH	403	extern bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
28e53bdd	404	struct delayed_work *work, unsigned long delay);
d4283e93	405	extern bool queue_delayed_work(struct workqueue_struct *wq,
0a13c00e	406	struct delayed_work *work, unsigned long delay);
8376fe22 TH	407	extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
	408	struct delayed_work *dwork, unsigned long delay);
	409	extern bool mod_delayed_work(struct workqueue_struct *wq,
	410	struct delayed_work *dwork, unsigned long delay);
28e53bdd	411
b3c97528	412	extern void flush_workqueue(struct workqueue_struct *wq);
9c5a2ba7	413	extern void drain_workqueue(struct workqueue_struct *wq);
28e53bdd	414	extern void flush_scheduled_work(void);
1da177e4	415
d4283e93 TH	416	extern bool schedule_work_on(int cpu, struct work_struct *work);
	417	extern bool schedule_work(struct work_struct *work);
	418	extern bool schedule_delayed_work_on(int cpu, struct delayed_work *work,
	419	unsigned long delay);
	420	extern bool schedule_delayed_work(struct delayed_work *work,
	421	unsigned long delay);
65f27f38	422	extern int schedule_on_each_cpu(work_func_t func);
1da177e4 LT	423	extern int keventd_up(void);
1da177e4 LT	424
65f27f38	425	int execute_in_process_context(work_func_t fn, struct execute_work *);
1da177e4	426
401a8d04 TH	427	extern bool flush_work(struct work_struct *work);
	428	extern bool cancel_work_sync(struct work_struct *work);
	429
	430	extern bool flush_delayed_work(struct delayed_work *dwork);
57b30ae7	431	extern bool cancel_delayed_work(struct delayed_work *dwork);
401a8d04	432	extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
28e53bdd	433
dcd989cb TH	434	extern void workqueue_set_max_active(struct workqueue_struct *wq,
	435	int max_active);
	436	extern bool workqueue_congested(unsigned int cpu, struct workqueue_struct *wq);
dcd989cb TH	437	extern unsigned int work_busy(struct work_struct *work);
dcd989cb TH	438
4e49627b ON	439	/*
	440	* Like above, but uses del_timer() instead of del_timer_sync(). This means,
	441	* if it returns 0 the timer function may be running and the queueing is in
	442	* progress.
	443	*/
136b5721	444	static inline bool __deprecated __cancel_delayed_work(struct delayed_work *work)
4e49627b	445	{
401a8d04	446	bool ret;
4e49627b ON	447
	448	ret = del_timer(&work->timer);
	449	if (ret)
	450	work_clear_pending(&work->work);
	451	return ret;
	452	}
	453
606a5020	454	/* used to be different but now identical to flush_work(), deprecated */
43829731	455	static inline bool __deprecated flush_work_sync(struct work_struct *work)
606a5020 TH	456	{
	457	return flush_work(work);
	458	}
	459
	460	/* used to be different but now identical to flush_delayed_work(), deprecated */
43829731	461	static inline bool __deprecated flush_delayed_work_sync(struct delayed_work *dwork)
606a5020 TH	462	{
	463	return flush_delayed_work(dwork);
	464	}
	465
2d3854a3 RR	466	#ifndef CONFIG_SMP
	467	static inline long work_on_cpu(unsigned int cpu, long (fn)(void ), void *arg)
	468	{
	469	return fn(arg);
	470	}
	471	#else
	472	long work_on_cpu(unsigned int cpu, long (fn)(void ), void *arg);
	473	#endif /* CONFIG_SMP */
a25909a4	474
a0a1a5fd TH	475	#ifdef CONFIG_FREEZER
	476	extern void freeze_workqueues_begin(void);
	477	extern bool freeze_workqueues_busy(void);
	478	extern void thaw_workqueues(void);
	479	#endif /* CONFIG_FREEZER */
	480
1da177e4	481	#endif