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
15 struct 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 */
24 struct 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; /* L: work being processed */
32 work_func_t current_func; /* L: current_work's fn */
33 struct pool_workqueue *current_pwq; /* L: current_work's pwq */
34 struct list_head scheduled; /* L: scheduled works */
35
36 /* 64 bytes boundary on 64bit, 32 on 32bit */
37
38 struct task_struct *task; /* I: worker task */
39 struct worker_pool *pool; /* A: the associated pool */
40 /* L: for rescuers */
41 struct list_head node; /* A: anchored at pool->workers */
42 /* A: runs through worker->node */
43
44 unsigned long last_active; /* L: last active timestamp */
45 unsigned int flags; /* X: flags */
46 int id; /* I: worker id */
47 int sleeping; /* None */
48
49 /*
50 * Opaque string set with work_set_desc(). Printed out with task
51 * dump for debugging - WARN, BUG, panic or sysrq.
52 */
53 char desc[WORKER_DESC_LEN];
54
55 /* used only by rescuers to point to the target workqueue */
56 struct workqueue_struct *rescue_wq; /* I: the workqueue to rescue */
57
58 /* used by the scheduler to determine a worker's last known identity */
59 work_func_t last_func;
60 };
61
62 /**
63 * current_wq_worker - return struct worker if %current is a workqueue worker
64 */
65 static inline struct worker *current_wq_worker(void)
66 {
67 if (in_task() && (current->flags & PF_WQ_WORKER))
68 return kthread_data(current);
69 return NULL;
70 }
71
72 /*
73 * Scheduler hooks for concurrency managed workqueue. Only to be used from
74 * sched/ and workqueue.c.
75 */
76 void wq_worker_running(struct task_struct *task);
77 void wq_worker_sleeping(struct task_struct *task);
78 work_func_t wq_worker_last_func(struct task_struct *task);
79
80 #endif /* _KERNEL_WORKQUEUE_INTERNAL_H */