1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_IRQ_WORK_H
3 #define _LINUX_IRQ_WORK_H
4 
5 #include <linux/smp_types.h>
6 #include <linux/rcuwait.h>
7 
8 /*
9  * An entry can be in one of four states:
10  *
11  * free	     NULL, 0 -> {claimed}       : free to be used
12  * claimed   NULL, 3 -> {pending}       : claimed to be enqueued
13  * pending   next, 3 -> {busy}          : queued, pending callback
14  * busy      NULL, 2 -> {free, claimed} : callback in progress, can be claimed
15  */
16 
17 struct irq_work {
18 	struct __call_single_node node;
19 	void (*func)(struct irq_work *);
20 	struct rcuwait irqwait;
21 };
22 
23 #define __IRQ_WORK_INIT(_func, _flags) (struct irq_work){	\
24 	.node = { .u_flags = (_flags), },			\
25 	.func = (_func),					\
26 	.irqwait = __RCUWAIT_INITIALIZER(irqwait),		\
27 }
28 
29 #define IRQ_WORK_INIT(_func) __IRQ_WORK_INIT(_func, 0)
30 #define IRQ_WORK_INIT_LAZY(_func) __IRQ_WORK_INIT(_func, IRQ_WORK_LAZY)
31 #define IRQ_WORK_INIT_HARD(_func) __IRQ_WORK_INIT(_func, IRQ_WORK_HARD_IRQ)
32 
33 #define DEFINE_IRQ_WORK(name, _f)				\
34 	struct irq_work name = IRQ_WORK_INIT(_f)
35 
36 static inline
init_irq_work(struct irq_work * work,void (* func)(struct irq_work *))37 void init_irq_work(struct irq_work *work, void (*func)(struct irq_work *))
38 {
39 	*work = IRQ_WORK_INIT(func);
40 }
41 
irq_work_is_pending(struct irq_work * work)42 static inline bool irq_work_is_pending(struct irq_work *work)
43 {
44 	return atomic_read(&work->node.a_flags) & IRQ_WORK_PENDING;
45 }
46 
irq_work_is_busy(struct irq_work * work)47 static inline bool irq_work_is_busy(struct irq_work *work)
48 {
49 	return atomic_read(&work->node.a_flags) & IRQ_WORK_BUSY;
50 }
51 
irq_work_is_hard(struct irq_work * work)52 static inline bool irq_work_is_hard(struct irq_work *work)
53 {
54 	return atomic_read(&work->node.a_flags) & IRQ_WORK_HARD_IRQ;
55 }
56 
57 bool irq_work_queue(struct irq_work *work);
58 bool irq_work_queue_on(struct irq_work *work, int cpu);
59 
60 void irq_work_tick(void);
61 void irq_work_sync(struct irq_work *work);
62 
63 #ifdef CONFIG_IRQ_WORK
64 #include <asm/irq_work.h>
65 
66 void irq_work_run(void);
67 bool irq_work_needs_cpu(void);
68 void irq_work_single(void *arg);
69 #else
irq_work_needs_cpu(void)70 static inline bool irq_work_needs_cpu(void) { return false; }
irq_work_run(void)71 static inline void irq_work_run(void) { }
irq_work_single(void * arg)72 static inline void irq_work_single(void *arg) { }
73 #endif
74 
75 #endif /* _LINUX_IRQ_WORK_H */
76