1#ifndef __ASM_PREEMPT_H
 2#define __ASM_PREEMPT_H
 3
 4#include <linux/thread_info.h>
 5
 6#define PREEMPT_ENABLED	(0)
 7
 8static __always_inline int preempt_count(void)
 9{
10	return READ_ONCE(current_thread_info()->preempt_count);
11}
12
13static __always_inline volatile int *preempt_count_ptr(void)
14{
15	return &current_thread_info()->preempt_count;
16}
17
18static __always_inline void preempt_count_set(int pc)
19{
20	*preempt_count_ptr() = pc;
21}
22
23/*
24 * must be macros to avoid header recursion hell
25 */
26#define init_task_preempt_count(p) do { \
27	task_thread_info(p)->preempt_count = FORK_PREEMPT_COUNT; \
28} while (0)
29
30#define init_idle_preempt_count(p, cpu) do { \
31	task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \
32} while (0)
33
34static __always_inline void set_preempt_need_resched(void)
35{
36}
37
38static __always_inline void clear_preempt_need_resched(void)
39{
40}
41
42static __always_inline bool test_preempt_need_resched(void)
43{
44	return false;
45}
46
47/*
48 * The various preempt_count add/sub methods
49 */
50
51static __always_inline void __preempt_count_add(int val)
52{
53	*preempt_count_ptr() += val;
54}
55
56static __always_inline void __preempt_count_sub(int val)
57{
58	*preempt_count_ptr() -= val;
59}
60
61static __always_inline bool __preempt_count_dec_and_test(void)
62{
63	/*
64	 * Because of load-store architectures cannot do per-cpu atomic
65	 * operations; we cannot use PREEMPT_NEED_RESCHED because it might get
66	 * lost.
67	 */
68	return !--*preempt_count_ptr() && tif_need_resched();
69}
70
71/*
72 * Returns true when we need to resched and can (barring IRQ state).
73 */
74static __always_inline bool should_resched(int preempt_offset)
75{
76	return unlikely(preempt_count() == preempt_offset &&
77			tif_need_resched());
78}
79
80#ifdef CONFIG_PREEMPT
81extern asmlinkage void preempt_schedule(void);
82#define __preempt_schedule() preempt_schedule()
83extern asmlinkage void preempt_schedule_notrace(void);
84#define __preempt_schedule_notrace() preempt_schedule_notrace()
85#endif /* CONFIG_PREEMPT */
86
87#endif /* __ASM_PREEMPT_H */