/* SPDX-License-Identifier: GPL-2.0 */
/*
 * kernel/workqueue_internal.h
 *
 * Workqueue internal header file.  Only to be included by workqueue and
 * core kernel subsystems.
 */
#ifndef _KERNEL_WORKQUEUE_INTERNAL_H
#define _KERNEL_WORKQUEUE_INTERNAL_H

#include <linux/workqueue.h>
#include <linux/kthread.h>
#include <linux/preempt.h>

struct worker_pool;

/*
 * The poor guys doing the actual heavy lifting.  All on-duty workers are
 * either serving the manager role, on idle list or on busy hash.  For
 * details on the locking annotation (L, I, X...), refer to workqueue.c.
 *
 * Only to be used in workqueue and async.
 */
struct worker {
        /* on idle list while idle, on busy hash table while busy */
        union {
                struct list_head        entry;  /* L: while idle */
                struct hlist_node       hentry; /* L: while busy */
        };

        struct work_struct      *current_work;  /* K: work being processed and its */
        work_func_t             current_func;   /* K: function */
        struct pool_workqueue   *current_pwq;   /* K: pwq */
        u64                     current_at;     /* K: runtime at start or last wakeup */
        unsigned long           current_start;  /* K: start time of current work item */
        unsigned int            current_color;  /* K: color */

        int                     sleeping;       /* S: is worker sleeping? */

        /* used by the scheduler to determine a worker's last known identity */
        work_func_t             last_func;      /* K: last work's fn */

        struct list_head        scheduled;      /* L: scheduled works */

        struct task_struct      *task;          /* I: worker task */
        struct worker_pool      *pool;          /* A: the associated pool */
                                                /* L: for rescuers */
        struct list_head        node;           /* A: anchored at pool->workers */
                                                /* A: runs through worker->node */

        unsigned long           last_active;    /* K: last active timestamp */
        unsigned int            flags;          /* L: flags */
        int                     id;             /* I: worker id */

        /*
         * Opaque string set with work_set_desc().  Printed out with task
         * dump for debugging - WARN, BUG, panic or sysrq.
         */
        char                    desc[WORKER_DESC_LEN];

        /* used only by rescuers to point to the target workqueue */
        struct workqueue_struct *rescue_wq;     /* I: the workqueue to rescue */
};

/**
 * current_wq_worker - return struct worker if %current is a workqueue worker
 */
static inline struct worker *current_wq_worker(void)
{
        if (in_task() && (current->flags & PF_WQ_WORKER))
                return kthread_data(current);
        return NULL;
}

/*
 * Scheduler hooks for concurrency managed workqueue.  Only to be used from
 * sched/ and workqueue.c.
 */
void wq_worker_running(struct task_struct *task);
void wq_worker_sleeping(struct task_struct *task);
void wq_worker_tick(struct task_struct *task);
work_func_t wq_worker_last_func(struct task_struct *task);

#endif /* _KERNEL_WORKQUEUE_INTERNAL_H */