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;	/* 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  */
current_wq_worker(void)67 static 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  */
78 void wq_worker_running(struct task_struct *task);
79 void wq_worker_sleeping(struct task_struct *task);
80 void wq_worker_tick(struct task_struct *task);
81 work_func_t wq_worker_last_func(struct task_struct *task);
82 
83 #endif /* _KERNEL_WORKQUEUE_INTERNAL_H */
84