/* SPDX-License-Identifier: GPL-2.0 */
/*
 * workqueue.h --- work queue handling for Linux.
 */

#ifndef _LINUX_WORKQUEUE_H
#define _LINUX_WORKQUEUE_H

#include <linux/alloc_tag.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_types.h>
#include <linux/rcupdate.h>
#include <linux/workqueue_types.h>

/*
 * 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_bits {
        WORK_STRUCT_PENDING_BIT = 0,    /* work item is pending execution */
        WORK_STRUCT_INACTIVE_BIT,       /* work item is inactive */
        WORK_STRUCT_PWQ_BIT,            /* data points to pwq */
        WORK_STRUCT_LINKED_BIT,         /* next work is linked to this one */
#ifdef CONFIG_DEBUG_OBJECTS_WORK
        WORK_STRUCT_STATIC_BIT,         /* static initializer (debugobjects) */
#endif
        WORK_STRUCT_FLAG_BITS,

        /* color for workqueue flushing */
        WORK_STRUCT_COLOR_SHIFT = WORK_STRUCT_FLAG_BITS,
        WORK_STRUCT_COLOR_BITS  = 4,

        /*
         * When WORK_STRUCT_PWQ is set, reserve 8 bits off of pwq pointer w/
         * debugobjects turned off. This makes pwqs aligned to 256 bytes (512
         * bytes w/ DEBUG_OBJECTS_WORK) and allows 16 workqueue flush colors.
         *
         * MSB
         * [ pwq pointer ] [ flush color ] [ STRUCT flags ]
         *                     4 bits        4 or 5 bits
         */
        WORK_STRUCT_PWQ_SHIFT   = WORK_STRUCT_COLOR_SHIFT + WORK_STRUCT_COLOR_BITS,

        /*
         * data contains off-queue information when !WORK_STRUCT_PWQ.
         *
         * MSB
         * [ pool ID ] [ disable depth ] [ OFFQ flags ] [ STRUCT flags ]
         *                  16 bits          1 bit        4 or 5 bits
         */
        WORK_OFFQ_FLAG_SHIFT    = WORK_STRUCT_FLAG_BITS,
        WORK_OFFQ_BH_BIT        = WORK_OFFQ_FLAG_SHIFT,
        WORK_OFFQ_FLAG_END,
        WORK_OFFQ_FLAG_BITS     = WORK_OFFQ_FLAG_END - WORK_OFFQ_FLAG_SHIFT,

        WORK_OFFQ_DISABLE_SHIFT = WORK_OFFQ_FLAG_SHIFT + WORK_OFFQ_FLAG_BITS,
        WORK_OFFQ_DISABLE_BITS  = 16,

        /*
         * When a work item is off queue, the high bits encode off-queue flags
         * and the last pool it was on. Cap pool ID to 31 bits and use the
         * highest number to indicate that no pool is associated.
         */
        WORK_OFFQ_POOL_SHIFT    = WORK_OFFQ_DISABLE_SHIFT + WORK_OFFQ_DISABLE_BITS,
        WORK_OFFQ_LEFT          = BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT,
        WORK_OFFQ_POOL_BITS     = WORK_OFFQ_LEFT <= 31 ? WORK_OFFQ_LEFT : 31,
};

enum work_flags {
        WORK_STRUCT_PENDING     = 1 << WORK_STRUCT_PENDING_BIT,
        WORK_STRUCT_INACTIVE    = 1 << WORK_STRUCT_INACTIVE_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
};

enum wq_misc_consts {
        WORK_NR_COLORS          = (1 << WORK_STRUCT_COLOR_BITS),

        /* not bound to any CPU, prefer the local CPU */
        WORK_CPU_UNBOUND        = NR_CPUS,

        /* 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         = 32,
};

/* Convenience constants - of type 'unsigned long', not 'enum'! */
#define WORK_OFFQ_BH            (1ul << WORK_OFFQ_BH_BIT)
#define WORK_OFFQ_FLAG_MASK     (((1ul << WORK_OFFQ_FLAG_BITS) - 1) << WORK_OFFQ_FLAG_SHIFT)
#define WORK_OFFQ_DISABLE_MASK  (((1ul << WORK_OFFQ_DISABLE_BITS) - 1) << WORK_OFFQ_DISABLE_SHIFT)
#define WORK_OFFQ_POOL_NONE     ((1ul << WORK_OFFQ_POOL_BITS) - 1)
#define WORK_STRUCT_NO_POOL     (WORK_OFFQ_POOL_NONE << WORK_OFFQ_POOL_SHIFT)
#define WORK_STRUCT_PWQ_MASK    (~((1ul << WORK_STRUCT_PWQ_SHIFT) - 1))

#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;
};

enum wq_affn_scope {
        WQ_AFFN_DFL,                    /* use system default */
        WQ_AFFN_CPU,                    /* one pod per CPU */
        WQ_AFFN_SMT,                    /* one pod poer SMT */
        WQ_AFFN_CACHE,                  /* one pod per LLC */
        WQ_AFFN_NUMA,                   /* one pod per NUMA node */
        WQ_AFFN_SYSTEM,                 /* one pod across the whole system */

        WQ_AFFN_NR_TYPES,
};

/**
 * 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
         *
         * Work items in this workqueue are affine to these CPUs and not allowed
         * to execute on other CPUs. A pool serving a workqueue must have the
         * same @cpumask.
         */
        cpumask_var_t cpumask;

        /**
         * @__pod_cpumask: internal attribute used to create per-pod pools
         *
         * Internal use only.
         *
         * Per-pod unbound worker pools are used to improve locality. Always a
         * subset of ->cpumask. A workqueue can be associated with multiple
         * worker pools with disjoint @__pod_cpumask's. Whether the enforcement
         * of a pool's @__pod_cpumask is strict depends on @affn_strict.
         */
        cpumask_var_t __pod_cpumask;

        /**
         * @affn_strict: affinity scope is strict
         *
         * If clear, workqueue will make a best-effort attempt at starting the
         * worker inside @__pod_cpumask but the scheduler is free to migrate it
         * outside.
         *
         * If set, workers are only allowed to run inside @__pod_cpumask.
         */
        bool affn_strict;

        /*
         * Below fields aren't properties of a worker_pool. They only modify how
         * :c:func:`apply_workqueue_attrs` select pools and thus don't
         * participate in pool hash calculations or equality comparisons.
         *
         * If @affn_strict is set, @cpumask isn't a property of a worker_pool
         * either.
         */

        /**
         * @affn_scope: unbound CPU affinity scope
         *
         * CPU pods are used to improve execution locality of unbound work
         * items. There are multiple pod types, one for each wq_affn_scope, and
         * every CPU in the system belongs to one pod in every pod type. CPUs
         * that belong to the same pod share the worker pool. For example,
         * selecting %WQ_AFFN_NUMA makes the workqueue use a separate worker
         * pool for each NUMA node.
         */
        enum wq_affn_scope affn_scope;

        /**
         * @ordered: work items must be executed one by one in queueing order
         */
        bool ordered;
};

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_KEY(_work, _func, _onstack, _key)                   \
        do {                                                            \
                __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_KEY(_work, _func, _onstack, _key)                   \
        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, _onstack)                             \
        do {                                                            \
                static __maybe_unused struct lock_class_key __key;      \
                                                                        \
                __INIT_WORK_KEY(_work, _func, _onstack, &__key);        \
        } while (0)

#define INIT_WORK(_work, _func)                                         \
        __INIT_WORK((_work), (_func), 0)

#define INIT_WORK_ONSTACK(_work, _func)                                 \
        __INIT_WORK((_work), (_func), 1)

#define INIT_WORK_ONSTACK_KEY(_work, _func, _key)                       \
        __INIT_WORK_KEY((_work), (_func), 1, _key)

#define __INIT_DELAYED_WORK(_work, _func, _tflags)                      \
        do {                                                            \
                INIT_WORK(&(_work)->work, (_func));                     \
                __timer_init(&(_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));             \
                __timer_init_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_flags {
        WQ_BH                   = 1 << 0, /* execute in bottom half (softirq) context */
        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 workqueue_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
         * execute 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_PERCPU               = 1 << 8, /* bound to a specific cpu */

        __WQ_DESTROYING         = 1 << 15, /* internal: workqueue is destroying */
        __WQ_DRAINING           = 1 << 16, /* internal: workqueue is draining */
        __WQ_ORDERED            = 1 << 17, /* internal: workqueue is ordered */
        __WQ_LEGACY             = 1 << 18, /* internal: create*_workqueue() */

        /* BH wq only allows the following flags */
        __WQ_BH_ALLOWS          = WQ_BH | WQ_HIGHPRI | WQ_PERCPU,
};

enum wq_consts {
        WQ_MAX_ACTIVE           = 2048,   /* I like 2048, better ideas? */
        WQ_UNBOUND_MAX_ACTIVE   = WQ_MAX_ACTIVE,
        WQ_DFL_ACTIVE           = WQ_MAX_ACTIVE / 2,

        /*
         * Per-node default cap on min_active. Unless explicitly set, min_active
         * is set to min(max_active, WQ_DFL_MIN_ACTIVE). For more details, see
         * workqueue_struct->min_active definition.
         */
        WQ_DFL_MIN_ACTIVE       = 8,
};

/*
 * System-wide workqueues which are always present.
 *
 * system_percpu_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_percpu_wq but for work items which
 * require WQ_HIGHPRI.
 *
 * system_long_wq is similar to system_percpu_wq but may host long running
 * works.  Queue flushing might take relatively long.
 *
 * system_dfl_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_percpu_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_percpu_wq if
 * 'wq_power_efficient' is disabled.  See WQ_POWER_EFFICIENT for more info.
 *
 * system_bh[_highpri]_wq are convenience interface to softirq. BH work items
 * are executed in the queueing CPU's BH context in the queueing order.
 */
extern struct workqueue_struct *system_wq; /* use system_percpu_wq, this will be removed */
extern struct workqueue_struct *system_percpu_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_dfl_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 *system_bh_wq;
extern struct workqueue_struct *system_bh_highpri_wq;

void workqueue_softirq_action(bool highpri);
void workqueue_softirq_dead(unsigned int cpu);

/**
 * 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 for @fmt
 *
 * For a per-cpu workqueue, @max_active limits the number of in-flight work
 * items for each CPU. e.g. @max_active of 1 indicates that each CPU can be
 * executing at most one work item for the workqueue.
 *
 * For unbound workqueues, @max_active limits the number of in-flight work items
 * for the whole system. e.g. @max_active of 16 indicates that there can be
 * at most 16 work items executing for the workqueue in the whole system.
 *
 * As sharing the same active counter for an unbound workqueue across multiple
 * NUMA nodes can be expensive, @max_active is distributed to each NUMA node
 * according to the proportion of the number of online CPUs and enforced
 * independently.
 *
 * Depending on online CPU distribution, a node may end up with per-node
 * max_active which is significantly lower than @max_active, which can lead to
 * deadlocks if the per-node concurrency limit is lower than the maximum number
 * of interdependent work items for the workqueue.
 *
 * To guarantee forward progress regardless of online CPU distribution, the
 * concurrency limit on every node is guaranteed to be equal to or greater than
 * min_active which is set to min(@max_active, %WQ_DFL_MIN_ACTIVE). This means
 * that the sum of per-node max_active's may be larger than @max_active.
 *
 * For detailed information on %WQ_\* flags, please refer to
 * Documentation/core-api/workqueue.rst.
 *
 * RETURNS:
 * Pointer to the allocated workqueue on success, %NULL on failure.
 */
__printf(1, 4) struct workqueue_struct *
alloc_workqueue_noprof(const char *fmt, unsigned int flags, int max_active, ...);
#define alloc_workqueue(...)    alloc_hooks(alloc_workqueue_noprof(__VA_ARGS__))

#ifdef CONFIG_LOCKDEP
/**
 * alloc_workqueue_lockdep_map - allocate a workqueue with user-defined lockdep_map
 * @fmt: printf format for the name of the workqueue
 * @flags: WQ_* flags
 * @max_active: max in-flight work items, 0 for default
 * @lockdep_map: user-defined lockdep_map
 * @...: args for @fmt
 *
 * Same as alloc_workqueue but with the a user-define lockdep_map. Useful for
 * workqueues created with the same purpose and to avoid leaking a lockdep_map
 * on each workqueue creation.
 *
 * RETURNS:
 * Pointer to the allocated workqueue on success, %NULL on failure.
 */
__printf(1, 5) struct workqueue_struct *
alloc_workqueue_lockdep_map(const char *fmt, unsigned int flags, int max_active,
                            struct lockdep_map *lockdep_map, ...);

/**
 * alloc_ordered_workqueue_lockdep_map - allocate an ordered workqueue with
 * user-defined lockdep_map
 *
 * @fmt: printf format for the name of the workqueue
 * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
 * @lockdep_map: user-defined lockdep_map
 * @args: args for @fmt
 *
 * Same as alloc_ordered_workqueue but with the a user-define lockdep_map.
 * Useful for workqueues created with the same purpose and to avoid leaking a
 * lockdep_map on each workqueue creation.
 *
 * RETURNS:
 * Pointer to the allocated workqueue on success, %NULL on failure.
 */
#define alloc_ordered_workqueue_lockdep_map(fmt, flags, lockdep_map, args...)   \
        alloc_hooks(alloc_workqueue_lockdep_map(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags),\
                                                1, lockdep_map, ##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 | (flags), 1, ##args)

#define create_workqueue(name)                                          \
        alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_PERCPU, 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)

#define from_work(var, callback_work, work_fieldname)   \
        container_of(callback_work, typeof(*var), work_fieldname)

extern void destroy_workqueue(struct workqueue_struct *wq);

struct workqueue_attrs *alloc_workqueue_attrs_noprof(void);
#define alloc_workqueue_attrs(...)      alloc_hooks(alloc_workqueue_attrs_noprof(__VA_ARGS__))

void free_workqueue_attrs(struct workqueue_attrs *attrs);
int apply_workqueue_attrs(struct workqueue_struct *wq,
                          const struct workqueue_attrs *attrs);
extern int workqueue_unbound_housekeeping_update(const struct cpumask *hk);

extern bool queue_work_on(int cpu, struct workqueue_struct *wq,
                        struct work_struct *work);
extern bool queue_work_node(int node, 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(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 disable_work(struct work_struct *work);
extern bool disable_work_sync(struct work_struct *work);
extern bool enable_work(struct work_struct *work);

extern bool disable_delayed_work(struct delayed_work *dwork);
extern bool disable_delayed_work_sync(struct delayed_work *dwork);
extern bool enable_delayed_work(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 void workqueue_set_min_active(struct workqueue_struct *wq,
                                     int min_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_all_workqueues(void);
extern void show_freezable_workqueues(void);
extern void show_one_workqueue(struct workqueue_struct *wq);
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.
 *
 * Memory-ordering properties:  If it returns %true, guarantees that all stores
 * preceding the call to queue_work() in the program order will be visible from
 * the CPU which will execute @work by the time such work executes, e.g.,
 *
 * { x is initially 0 }
 *
 *   CPU0                               CPU1
 *
 *   WRITE_ONCE(x, 1);                  [ @work is being executed ]
 *   r0 = queue_work(wq, work);           r1 = READ_ONCE(x);
 *
 * Forbids: r0 == true && r1 == 0
 */
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_percpu_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.
 *
 * Shares the same memory-ordering properties of queue_work(), cf. the
 * DocBook header of queue_work().
 */
static inline bool schedule_work(struct work_struct *work)
{
        return queue_work(system_percpu_wq, work);
}

/**
 * enable_and_queue_work - Enable and queue a work item on a specific workqueue
 * @wq: The target workqueue
 * @work: The work item to be enabled and queued
 *
 * This function combines the operations of enable_work() and queue_work(),
 * providing a convenient way to enable and queue a work item in a single call.
 * It invokes enable_work() on @work and then queues it if the disable depth
 * reached 0. Returns %true if the disable depth reached 0 and @work is queued,
 * and %false otherwise.
 *
 * Note that @work is always queued when disable depth reaches zero. If the
 * desired behavior is queueing only if certain events took place while @work is
 * disabled, the user should implement the necessary state tracking and perform
 * explicit conditional queueing after enable_work().
 */
static inline bool enable_and_queue_work(struct workqueue_struct *wq,
                                         struct work_struct *work)
{
        if (enable_work(work)) {
                queue_work(wq, work);
                return true;
        }
        return false;
}

/*
 * Detect attempt to flush system-wide workqueues at compile time when possible.
 * Warn attempt to flush system-wide workqueues at runtime.
 *
 * See https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp
 * for reasons and steps for converting system-wide workqueues into local workqueues.
 */
extern void __warn_flushing_systemwide_wq(void)
        __compiletime_warning("Please avoid flushing system-wide workqueues.");

/* Please stop using this function, for this function will be removed in near future. */
#define flush_scheduled_work()                                          \
({                                                                      \
        __warn_flushing_systemwide_wq();                                \
        __flush_workqueue(system_percpu_wq);                                    \
})

#define flush_workqueue(wq)                                             \
({                                                                      \
        struct workqueue_struct *_wq = (wq);                            \
                                                                        \
        if ((__builtin_constant_p(_wq == system_percpu_wq) &&                   \
             _wq == system_percpu_wq) ||                                        \
            (__builtin_constant_p(_wq == system_highpri_wq) &&          \
             _wq == system_highpri_wq) ||                               \
            (__builtin_constant_p(_wq == system_long_wq) &&             \
             _wq == system_long_wq) ||                                  \
            (__builtin_constant_p(_wq == system_dfl_wq) &&              \
             _wq == system_dfl_wq) ||                           \
            (__builtin_constant_p(_wq == system_freezable_wq) &&        \
             _wq == system_freezable_wq) ||                             \
            (__builtin_constant_p(_wq == system_power_efficient_wq) &&  \
             _wq == system_power_efficient_wq) ||                       \
            (__builtin_constant_p(_wq == system_freezable_power_efficient_wq) && \
             _wq == system_freezable_power_efficient_wq))               \
                __warn_flushing_systemwide_wq();                        \
        __flush_workqueue(_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_percpu_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_percpu_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_key(int cpu, long (*fn)(void *),
                     void *arg, struct lock_class_key *key);
/*
 * A new key is defined for each caller to make sure the work
 * associated with the function doesn't share its locking class.
 */
#define work_on_cpu(_cpu, _fn, _arg)                    \
({                                                      \
        static struct lock_class_key __key;             \
                                                        \
        work_on_cpu_key(_cpu, _fn, _arg, &__key);       \
})

#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

void __init workqueue_init_early(void);
void __init workqueue_init(void);
void __init workqueue_init_topology(void);

#endif