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-rw-r--r--include/linux/workqueue.h450
1 files changed, 450 insertions, 0 deletions
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
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+++ b/include/linux/workqueue.h
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+/*
+ * 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);
+
+/*
+ * 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,
+
+ 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 __DEFERRED_WORK_INITIALIZER(n, f) { \
+ .work = __WORK_INITIALIZER((n).work, (f)), \
+ .timer = TIMER_DEFERRED_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)
+
+#define DECLARE_DEFERRED_WORK(n, f) \
+ struct delayed_work n = __DEFERRED_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_ONSTACK(_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_ONSTACK(_work, _func) \
+ do { \
+ INIT_WORK_ONSTACK(&(_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))
+
+/*
+ * 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_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.
+ *
+ * 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.
+ *
+ * system_nrt_freezable_wq is equivalent to system_nrt_wq except that
+ * it's freezable.
+ */
+extern struct workqueue_struct *system_wq;
+extern struct workqueue_struct *system_long_wq;
+extern struct workqueue_struct *system_nrt_wq;
+extern struct workqueue_struct *system_unbound_wq;
+extern struct workqueue_struct *system_freezable_wq;
+extern struct workqueue_struct *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 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 drain_workqueue(struct workqueue_struct *wq);
+extern void flush_scheduled_work(void);
+
+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);
+
+int execute_in_process_context(work_func_t fn, struct execute_work *);
+
+extern bool flush_work(struct work_struct *work);
+extern bool flush_work_sync(struct work_struct *work);
+extern bool cancel_work_sync(struct work_struct *work);
+
+extern bool flush_delayed_work(struct delayed_work *dwork);
+extern bool flush_delayed_work_sync(struct delayed_work *work);
+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_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 bool cancel_delayed_work(struct delayed_work *work)
+{
+ bool 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 bool __cancel_delayed_work(struct delayed_work *work)
+{
+ bool ret;
+
+ ret = del_timer(&work->timer);
+ if (ret)
+ work_clear_pending(&work->work);
+ return ret;
+}
+
+#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