v4.19.13 snapshot.
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
new file mode 100644
index 0000000..60d673e
--- /dev/null
+++ b/include/linux/workqueue.h
@@ -0,0 +1,673 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * 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>
+#include <linux/cpumask.h>
+#include <linux/rcupdate.h>
+
+struct workqueue_struct;
+
+struct work_struct;
+typedef void (*work_func_t)(struct work_struct *work);
+void delayed_work_timer_fn(struct timer_list *t);
+
+/*
+ * 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_PWQ_BIT = 2, /* data points to pwq */
+ 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_PWQ = 1 << WORK_STRUCT_PWQ_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,
+
+ /* not bound to any CPU, prefer the local CPU */
+ WORK_CPU_UNBOUND = NR_CPUS,
+
+ /*
+ * Reserve 7 bits off of pwq pointer w/ debugobjects turned off.
+ * This makes pwqs 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_PWQ */
+ WORK_OFFQ_FLAG_BASE = WORK_STRUCT_COLOR_SHIFT,
+
+ __WORK_OFFQ_CANCELING = WORK_OFFQ_FLAG_BASE,
+ WORK_OFFQ_CANCELING = (1 << __WORK_OFFQ_CANCELING),
+
+ /*
+ * When a work item is off queue, its high bits point to the last
+ * pool it was on. Cap at 31 bits and use the highest number to
+ * indicate that no pool is associated.
+ */
+ WORK_OFFQ_FLAG_BITS = 1,
+ WORK_OFFQ_POOL_SHIFT = WORK_OFFQ_FLAG_BASE + WORK_OFFQ_FLAG_BITS,
+ WORK_OFFQ_LEFT = BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT,
+ WORK_OFFQ_POOL_BITS = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31,
+ WORK_OFFQ_POOL_NONE = (1LU << WORK_OFFQ_POOL_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_POOL = (unsigned long)WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT,
+
+ /* bit mask for work_busy() return values */
+ WORK_BUSY_PENDING = 1 << 0,
+ WORK_BUSY_RUNNING = 1 << 1,
+
+ /* maximum string length for set_worker_desc() */
+ WORKER_DESC_LEN = 24,
+};
+
+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((unsigned long)WORK_STRUCT_NO_POOL)
+#define WORK_DATA_STATIC_INIT() \
+ ATOMIC_LONG_INIT((unsigned long)(WORK_STRUCT_NO_POOL | WORK_STRUCT_STATIC))
+
+struct delayed_work {
+ struct work_struct work;
+ struct timer_list timer;
+
+ /* target workqueue and CPU ->timer uses to queue ->work */
+ struct workqueue_struct *wq;
+ int cpu;
+};
+
+struct rcu_work {
+ struct work_struct work;
+ struct rcu_head rcu;
+
+ /* target workqueue ->rcu uses to queue ->work */
+ struct workqueue_struct *wq;
+};
+
+/**
+ * struct workqueue_attrs - A struct for workqueue attributes.
+ *
+ * This can be used to change attributes of an unbound workqueue.
+ */
+struct workqueue_attrs {
+ /**
+ * @nice: nice level
+ */
+ int nice;
+
+ /**
+ * @cpumask: allowed CPUs
+ */
+ cpumask_var_t cpumask;
+
+ /**
+ * @no_numa: disable NUMA affinity
+ *
+ * Unlike other fields, ``no_numa`` isn't a property of a worker_pool. It
+ * only modifies how :c:func:`apply_workqueue_attrs` select pools and thus
+ * doesn't participate in pool hash calculations or equality comparisons.
+ */
+ bool no_numa;
+};
+
+static inline struct delayed_work *to_delayed_work(struct work_struct *work)
+{
+ return container_of(work, struct delayed_work, work);
+}
+
+static inline struct rcu_work *to_rcu_work(struct work_struct *work)
+{
+ return container_of(work, struct rcu_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,\
+ (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)
+
+#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);
+extern void destroy_delayed_work_on_stack(struct delayed_work *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 void destroy_delayed_work_on_stack(struct delayed_work *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_completion)"#_work, &__key, 0); \
+ INIT_LIST_HEAD(&(_work)->entry); \
+ (_work)->func = (_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); \
+ (_work)->func = (_func); \
+ } while (0)
+#endif
+
+#define INIT_WORK(_work, _func) \
+ __INIT_WORK((_work), (_func), 0)
+
+#define INIT_WORK_ONSTACK(_work, _func) \
+ __INIT_WORK((_work), (_func), 1)
+
+#define __INIT_DELAYED_WORK(_work, _func, _tflags) \
+ do { \
+ INIT_WORK(&(_work)->work, (_func)); \
+ __init_timer(&(_work)->timer, \
+ delayed_work_timer_fn, \
+ (_tflags) | TIMER_IRQSAFE); \
+ } while (0)
+
+#define __INIT_DELAYED_WORK_ONSTACK(_work, _func, _tflags) \
+ do { \
+ INIT_WORK_ONSTACK(&(_work)->work, (_func)); \
+ __init_timer_on_stack(&(_work)->timer, \
+ delayed_work_timer_fn, \
+ (_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)
+
+#define INIT_RCU_WORK(_work, _func) \
+ INIT_WORK(&(_work)->work, (_func))
+
+#define INIT_RCU_WORK_ONSTACK(_work, _func) \
+ INIT_WORK_ONSTACK(&(_work)->work, (_func))
+
+/**
+ * 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
+ * @w: The work item in question
+ */
+#define delayed_work_pending(w) \
+ work_pending(&(w)->work)
+
+/*
+ * Workqueue flags and constants. For details, please refer to
+ * Documentation/core-api/workqueue.rst.
+ */
+enum {
+ 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 intensive workqueue */
+ WQ_SYSFS = 1 << 6, /* visible in sysfs, see wq_sysfs_register() */
+
+ /*
+ * Per-cpu workqueues are generally preferred because they tend to
+ * show better performance thanks to cache locality. Per-cpu
+ * workqueues exclude the scheduler from choosing the CPU to
+ * execute the worker threads, which has an unfortunate side effect
+ * of increasing power consumption.
+ *
+ * The scheduler considers a CPU idle if it doesn't have any task
+ * to execute and tries to keep idle cores idle to conserve power;
+ * however, for example, a per-cpu work item scheduled from an
+ * interrupt handler on an idle CPU will force the scheduler to
+ * excute the work item on that CPU breaking the idleness, which in
+ * turn may lead to more scheduling choices which are sub-optimal
+ * in terms of power consumption.
+ *
+ * Workqueues marked with WQ_POWER_EFFICIENT are per-cpu by default
+ * but become unbound if workqueue.power_efficient kernel param is
+ * specified. Per-cpu workqueues which are identified to
+ * contribute significantly to power-consumption are identified and
+ * marked with this flag and enabling the power_efficient mode
+ * leads to noticeable power saving at the cost of small
+ * performance disadvantage.
+ *
+ * http://thread.gmane.org/gmane.linux.kernel/1480396
+ */
+ WQ_POWER_EFFICIENT = 1 << 7,
+
+ __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */
+ __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */
+ __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */
+ __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: alloc_ordered_workqueue() */
+
+ 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_highpri_wq is similar to system_wq but for work items which
+ * require WQ_HIGHPRI.
+ *
+ * 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.
+ *
+ * *_power_efficient_wq are inclined towards saving power and converted
+ * into WQ_UNBOUND variants if 'wq_power_efficient' is enabled; otherwise,
+ * they are same as their non-power-efficient counterparts - e.g.
+ * system_power_efficient_wq is identical to system_wq if
+ * 'wq_power_efficient' is disabled. See WQ_POWER_EFFICIENT for more info.
+ */
+extern struct workqueue_struct *system_wq;
+extern struct workqueue_struct *system_highpri_wq;
+extern struct workqueue_struct *system_long_wq;
+extern struct workqueue_struct *system_unbound_wq;
+extern struct workqueue_struct *system_freezable_wq;
+extern struct workqueue_struct *system_power_efficient_wq;
+extern struct workqueue_struct *system_freezable_power_efficient_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/core-api/workqueue.rst.
+ *
+ * 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; \
+ \
+ __lock_name = "(wq_completion)"#fmt#args; \
+ \
+ __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 | __WQ_ORDERED | \
+ __WQ_ORDERED_EXPLICIT | (flags), 1, ##args)
+
+#define create_workqueue(name) \
+ alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, 1, (name))
+#define create_freezable_workqueue(name) \
+ alloc_workqueue("%s", __WQ_LEGACY | WQ_FREEZABLE | WQ_UNBOUND | \
+ WQ_MEM_RECLAIM, 1, (name))
+#define create_singlethread_workqueue(name) \
+ alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)
+
+extern void destroy_workqueue(struct workqueue_struct *wq);
+
+struct workqueue_attrs *alloc_workqueue_attrs(gfp_t gfp_mask);
+void free_workqueue_attrs(struct workqueue_attrs *attrs);
+int apply_workqueue_attrs(struct workqueue_struct *wq,
+ const struct workqueue_attrs *attrs);
+int workqueue_set_unbound_cpumask(cpumask_var_t cpumask);
+
+extern bool queue_work_on(int cpu, 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 mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
+ struct delayed_work *dwork, unsigned long delay);
+extern bool queue_rcu_work(struct workqueue_struct *wq, struct rcu_work *rwork);
+
+extern void flush_workqueue(struct workqueue_struct *wq);
+extern void drain_workqueue(struct workqueue_struct *wq);
+
+extern int schedule_on_each_cpu(work_func_t func);
+
+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 bool flush_rcu_work(struct rcu_work *rwork);
+
+extern void workqueue_set_max_active(struct workqueue_struct *wq,
+ int max_active);
+extern struct work_struct *current_work(void);
+extern bool current_is_workqueue_rescuer(void);
+extern bool workqueue_congested(int cpu, struct workqueue_struct *wq);
+extern unsigned int work_busy(struct work_struct *work);
+extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
+extern void print_worker_info(const char *log_lvl, struct task_struct *task);
+extern void show_workqueue_state(void);
+extern void wq_worker_comm(char *buf, size_t size, struct task_struct *task);
+
+/**
+ * queue_work - queue work on a workqueue
+ * @wq: workqueue to use
+ * @work: work to queue
+ *
+ * Returns %false if @work was already on a queue, %true otherwise.
+ *
+ * We queue the work to the CPU on which it was submitted, but if the CPU dies
+ * it can be processed by another CPU.
+ */
+static inline bool queue_work(struct workqueue_struct *wq,
+ struct work_struct *work)
+{
+ return queue_work_on(WORK_CPU_UNBOUND, wq, work);
+}
+
+/**
+ * queue_delayed_work - queue work on a workqueue after delay
+ * @wq: workqueue to use
+ * @dwork: delayable work to queue
+ * @delay: number of jiffies to wait before queueing
+ *
+ * Equivalent to queue_delayed_work_on() but tries to use the local CPU.
+ */
+static inline bool queue_delayed_work(struct workqueue_struct *wq,
+ struct delayed_work *dwork,
+ unsigned long delay)
+{
+ return queue_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
+}
+
+/**
+ * mod_delayed_work - modify delay of or queue a delayed work
+ * @wq: workqueue to use
+ * @dwork: work to queue
+ * @delay: number of jiffies to wait before queueing
+ *
+ * mod_delayed_work_on() on local CPU.
+ */
+static inline bool mod_delayed_work(struct workqueue_struct *wq,
+ struct delayed_work *dwork,
+ unsigned long delay)
+{
+ return mod_delayed_work_on(WORK_CPU_UNBOUND, wq, dwork, delay);
+}
+
+/**
+ * schedule_work_on - put work task on a specific cpu
+ * @cpu: cpu to put the work task on
+ * @work: job to be done
+ *
+ * This puts a job on a specific cpu
+ */
+static inline bool schedule_work_on(int cpu, struct work_struct *work)
+{
+ return queue_work_on(cpu, system_wq, work);
+}
+
+/**
+ * schedule_work - put work task in global workqueue
+ * @work: job to be done
+ *
+ * Returns %false if @work was already on the kernel-global workqueue and
+ * %true otherwise.
+ *
+ * This puts a job in the kernel-global workqueue if it was not already
+ * queued and leaves it in the same position on the kernel-global
+ * workqueue otherwise.
+ */
+static inline bool schedule_work(struct work_struct *work)
+{
+ return queue_work(system_wq, work);
+}
+
+/**
+ * flush_scheduled_work - ensure that any scheduled work has run to completion.
+ *
+ * Forces execution of the kernel-global workqueue and blocks until its
+ * completion.
+ *
+ * Think twice before calling this function! It's very easy to get into
+ * trouble if you don't take great care. Either of the following situations
+ * will lead to deadlock:
+ *
+ * One of the work items currently on the workqueue needs to acquire
+ * a lock held by your code or its caller.
+ *
+ * Your code is running in the context of a work routine.
+ *
+ * They will be detected by lockdep when they occur, but the first might not
+ * occur very often. It depends on what work items are on the workqueue and
+ * what locks they need, which you have no control over.
+ *
+ * In most situations flushing the entire workqueue is overkill; you merely
+ * need to know that a particular work item isn't queued and isn't running.
+ * In such cases you should use cancel_delayed_work_sync() or
+ * cancel_work_sync() instead.
+ */
+static inline void flush_scheduled_work(void)
+{
+ flush_workqueue(system_wq);
+}
+
+/**
+ * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
+ * @cpu: cpu to use
+ * @dwork: job to be done
+ * @delay: number of jiffies to wait
+ *
+ * After waiting for a given time this puts a job in the kernel-global
+ * workqueue on the specified CPU.
+ */
+static inline bool schedule_delayed_work_on(int cpu, struct delayed_work *dwork,
+ unsigned long delay)
+{
+ return queue_delayed_work_on(cpu, system_wq, dwork, delay);
+}
+
+/**
+ * schedule_delayed_work - put work task in global workqueue after delay
+ * @dwork: job to be done
+ * @delay: number of jiffies to wait or 0 for immediate execution
+ *
+ * After waiting for a given time this puts a job in the kernel-global
+ * workqueue.
+ */
+static inline bool schedule_delayed_work(struct delayed_work *dwork,
+ unsigned long delay)
+{
+ return queue_delayed_work(system_wq, dwork, delay);
+}
+
+#ifndef CONFIG_SMP
+static inline long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
+{
+ return fn(arg);
+}
+static inline long work_on_cpu_safe(int cpu, long (*fn)(void *), void *arg)
+{
+ return fn(arg);
+}
+#else
+long work_on_cpu(int cpu, long (*fn)(void *), void *arg);
+long work_on_cpu_safe(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 */
+
+#ifdef CONFIG_SYSFS
+int workqueue_sysfs_register(struct workqueue_struct *wq);
+#else /* CONFIG_SYSFS */
+static inline int workqueue_sysfs_register(struct workqueue_struct *wq)
+{ return 0; }
+#endif /* CONFIG_SYSFS */
+
+#ifdef CONFIG_WQ_WATCHDOG
+void wq_watchdog_touch(int cpu);
+#else /* CONFIG_WQ_WATCHDOG */
+static inline void wq_watchdog_touch(int cpu) { }
+#endif /* CONFIG_WQ_WATCHDOG */
+
+#ifdef CONFIG_SMP
+int workqueue_prepare_cpu(unsigned int cpu);
+int workqueue_online_cpu(unsigned int cpu);
+int workqueue_offline_cpu(unsigned int cpu);
+#endif
+
+int __init workqueue_init_early(void);
+int __init workqueue_init(void);
+
+#endif