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