1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * kernel/workqueue_internal.h
4 *
5 * Workqueue internal header file.  Only to be included by workqueue and
6 * core kernel subsystems.
7 */
8#ifndef _KERNEL_WORKQUEUE_INTERNAL_H
9#define _KERNEL_WORKQUEUE_INTERNAL_H
10
11#include <linux/workqueue.h>
12#include <linux/kthread.h>
13#include <linux/preempt.h>
14
15struct worker_pool;
16
17/*
18 * The poor guys doing the actual heavy lifting.  All on-duty workers are
19 * either serving the manager role, on idle list or on busy hash.  For
20 * details on the locking annotation (L, I, X...), refer to workqueue.c.
21 *
22 * Only to be used in workqueue and async.
23 */
24struct worker {
25	/* on idle list while idle, on busy hash table while busy */
26	union {
27		struct list_head	entry;	/* L: while idle */
28		struct hlist_node	hentry;	/* L: while busy */
29	};
30
31	struct work_struct	*current_work;	/* K: work being processed and its */
32	work_func_t		current_func;	/* K: function */
33	struct pool_workqueue	*current_pwq;	/* K: pwq */
34	u64			current_at;	/* K: runtime at start or last wakeup */
35	unsigned int		current_color;	/* K: color */
36
37	int			sleeping;	/* S: is worker sleeping? */
38
39	/* used by the scheduler to determine a worker's last known identity */
40	work_func_t		last_func;	/* K: last work's fn */
41
42	struct list_head	scheduled;	/* L: scheduled works */
43
44	struct task_struct	*task;		/* I: worker task */
45	struct worker_pool	*pool;		/* A: the associated pool */
46						/* L: for rescuers */
47	struct list_head	node;		/* A: anchored at pool->workers */
48						/* A: runs through worker->node */
49
50	unsigned long		last_active;	/* K: last active timestamp */
51	unsigned int		flags;		/* L: flags */
52	int			id;		/* I: worker id */
53
54	/*
55	 * Opaque string set with work_set_desc().  Printed out with task
56	 * dump for debugging - WARN, BUG, panic or sysrq.
57	 */
58	char			desc[WORKER_DESC_LEN];
59
60	/* used only by rescuers to point to the target workqueue */
61	struct workqueue_struct	*rescue_wq;	/* I: the workqueue to rescue */
62};
63
64/**
65 * current_wq_worker - return struct worker if %current is a workqueue worker
66 */
67static inline struct worker *current_wq_worker(void)
68{
69	if (in_task() && (current->flags & PF_WQ_WORKER))
70		return kthread_data(current);
71	return NULL;
72}
73
74/*
75 * Scheduler hooks for concurrency managed workqueue.  Only to be used from
76 * sched/ and workqueue.c.
77 */
78void wq_worker_running(struct task_struct *task);
79void wq_worker_sleeping(struct task_struct *task);
80void wq_worker_tick(struct task_struct *task);
81work_func_t wq_worker_last_func(struct task_struct *task);
82
83#endif /* _KERNEL_WORKQUEUE_INTERNAL_H */
84