xref: /openbmc/linux/include/linux/irq_work.h (revision 82df5b73)
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 /* flags share CSD_FLAG_ space */
17 
18 #define IRQ_WORK_PENDING	BIT(0)
19 #define IRQ_WORK_BUSY		BIT(1)
20 
21 /* Doesn't want IPI, wait for tick: */
22 #define IRQ_WORK_LAZY		BIT(2)
23 /* Run hard IRQ context, even on RT */
24 #define IRQ_WORK_HARD_IRQ	BIT(3)
25 
26 #define IRQ_WORK_CLAIMED	(IRQ_WORK_PENDING | IRQ_WORK_BUSY)
27 
28 /*
29  * structure shares layout with single_call_data_t.
30  */
31 struct irq_work {
32 	struct llist_node llnode;
33 	atomic_t flags;
34 	void (*func)(struct irq_work *);
35 };
36 
37 static inline
38 void init_irq_work(struct irq_work *work, void (*func)(struct irq_work *))
39 {
40 	atomic_set(&work->flags, 0);
41 	work->func = func;
42 }
43 
44 #define DEFINE_IRQ_WORK(name, _f) struct irq_work name = {	\
45 		.flags = ATOMIC_INIT(0),			\
46 		.func  = (_f)					\
47 }
48 
49 
50 bool irq_work_queue(struct irq_work *work);
51 bool irq_work_queue_on(struct irq_work *work, int cpu);
52 
53 void irq_work_tick(void);
54 void irq_work_sync(struct irq_work *work);
55 
56 #ifdef CONFIG_IRQ_WORK
57 #include <asm/irq_work.h>
58 
59 void irq_work_run(void);
60 bool irq_work_needs_cpu(void);
61 void irq_work_single(void *arg);
62 #else
63 static inline bool irq_work_needs_cpu(void) { return false; }
64 static inline void irq_work_run(void) { }
65 static inline void irq_work_single(void *arg) { }
66 #endif
67 
68 #endif /* _LINUX_IRQ_WORK_H */
69