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1#ifndef __ASM_PREEMPT_H
2#define __ASM_PREEMPT_H
3
4#include <linux/thread_info.h>
5
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6#define PREEMPT_ENABLED (0)
7
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8static __always_inline int preempt_count(void)
9{
2e636d5e 10 return READ_ONCE(current_thread_info()->preempt_count);
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11}
12
2e636d5e 13static __always_inline volatile int *preempt_count_ptr(void)
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14{
15 return &current_thread_info()->preempt_count;
16}
17
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18static __always_inline void preempt_count_set(int pc)
19{
20 *preempt_count_ptr() = pc;
21}
22
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23/*
24 * must be macros to avoid header recursion hell
25 */
01028747 26#define init_task_preempt_count(p) do { \
609ca066 27 task_thread_info(p)->preempt_count = FORK_PREEMPT_COUNT; \
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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
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34static __always_inline void set_preempt_need_resched(void)
35{
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36}
37
38static __always_inline void clear_preempt_need_resched(void)
39{
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40}
41
42static __always_inline bool test_preempt_need_resched(void)
43{
ba1f14fb 44 return false;
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45}
46
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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{
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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();
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69}
70
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71/*
72 * Returns true when we need to resched and can (barring IRQ state).
73 */
fe32d3cd 74static __always_inline bool should_resched(int preempt_offset)
bdb43806 75{
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76 return unlikely(preempt_count() == preempt_offset &&
77 tif_need_resched());
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78}
79
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80#ifdef CONFIG_PREEMPT
81extern asmlinkage void preempt_schedule(void);
82#define __preempt_schedule() preempt_schedule()
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83extern asmlinkage void preempt_schedule_notrace(void);
84#define __preempt_schedule_notrace() preempt_schedule_notrace()
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85#endif /* CONFIG_PREEMPT */
86
a7878709 87#endif /* __ASM_PREEMPT_H */