1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_IRQ_WORK_H
3 #define _LINUX_IRQ_WORK_H
4 
5 #include <linux/llist.h>
6 
7 /*
8  * An entry can be in one of four states:
9  *
10  * free	     NULL, 0 -> {claimed}       : free to be used
11  * claimed   NULL, 3 -> {pending}       : claimed to be enqueued
12  * pending   next, 3 -> {busy}          : queued, pending callback
13  * busy      NULL, 2 -> {free, claimed} : callback in progress, can be claimed
14  */
15 
16 #define IRQ_WORK_PENDING	BIT(0)
17 #define IRQ_WORK_BUSY		BIT(1)
18 
19 /* Doesn't want IPI, wait for tick: */
20 #define IRQ_WORK_LAZY		BIT(2)
21 
22 #define IRQ_WORK_CLAIMED	(IRQ_WORK_PENDING | IRQ_WORK_BUSY)
23 
24 struct irq_work {
25 	unsigned long flags;
26 	struct llist_node llnode;
27 	void (*func)(struct irq_work *);
28 };
29 
30 static inline
init_irq_work(struct irq_work * work,void (* func)(struct irq_work *))31 void init_irq_work(struct irq_work *work, void (*func)(struct irq_work *))
32 {
33 	work->flags = 0;
34 	work->func = func;
35 }
36 
37 #define DEFINE_IRQ_WORK(name, _f) struct irq_work name = { .func = (_f), }
38 
39 bool irq_work_queue(struct irq_work *work);
40 bool irq_work_queue_on(struct irq_work *work, int cpu);
41 
42 void irq_work_tick(void);
43 void irq_work_sync(struct irq_work *work);
44 
45 #ifdef CONFIG_IRQ_WORK
46 #include <asm/irq_work.h>
47 
48 void irq_work_run(void);
49 bool irq_work_needs_cpu(void);
50 #else
irq_work_needs_cpu(void)51 static inline bool irq_work_needs_cpu(void) { return false; }
irq_work_run(void)52 static inline void irq_work_run(void) { }
53 #endif
54 
55 #endif /* _LINUX_IRQ_WORK_H */
56