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 	unsigned int		current_color;	/* L: current_work's color */
35 	struct list_head	scheduled;	/* L: scheduled works */
36 
37 	/* 64 bytes boundary on 64bit, 32 on 32bit */
38 
39 	struct task_struct	*task;		/* I: worker task */
40 	struct worker_pool	*pool;		/* A: the associated pool */
41 						/* L: for rescuers */
42 	struct list_head	node;		/* A: anchored at pool->workers */
43 						/* A: runs through worker->node */
44 
45 	unsigned long		last_active;	/* L: last active timestamp */
46 	unsigned int		flags;		/* X: flags */
47 	int			id;		/* I: worker id */
48 	int			sleeping;	/* None */
49 
50 	/*
51 	 * Opaque string set with work_set_desc().  Printed out with task
52 	 * dump for debugging - WARN, BUG, panic or sysrq.
53 	 */
54 	char			desc[WORKER_DESC_LEN];
55 
56 	/* used only by rescuers to point to the target workqueue */
57 	struct workqueue_struct	*rescue_wq;	/* I: the workqueue to rescue */
58 
59 	/* used by the scheduler to determine a worker's last known identity */
60 	work_func_t		last_func;
61 };
62 
63 /**
64  * current_wq_worker - return struct worker if %current is a workqueue worker
65  */
current_wq_worker(void)66 static inline struct worker *current_wq_worker(void)
67 {
68 	if (in_task() && (current->flags & PF_WQ_WORKER))
69 		return kthread_data(current);
70 	return NULL;
71 }
72 
73 /*
74  * Scheduler hooks for concurrency managed workqueue.  Only to be used from
75  * sched/ and workqueue.c.
76  */
77 void wq_worker_running(struct task_struct *task);
78 void wq_worker_sleeping(struct task_struct *task);
79 work_func_t wq_worker_last_func(struct task_struct *task);
80 
81 #endif /* _KERNEL_WORKQUEUE_INTERNAL_H */
82