1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef __ASM_PREEMPT_H
  3#define __ASM_PREEMPT_H
  4
  5#include <linux/thread_info.h>
  6
  7#define PREEMPT_ENABLED	(0)
  8
  9static __always_inline int preempt_count(void)
 10{
 11	return READ_ONCE(current_thread_info()->preempt_count);
 12}
 13
 14static __always_inline volatile int *preempt_count_ptr(void)
 15{
 16	return &current_thread_info()->preempt_count;
 17}
 18
 19static __always_inline void preempt_count_set(int pc)
 20{
 21	*preempt_count_ptr() = pc;
 22}
 23
 24/*
 25 * must be macros to avoid header recursion hell
 26 */
 
 
 
 27#define init_task_preempt_count(p) do { \
 28	task_thread_info(p)->preempt_count = FORK_PREEMPT_COUNT; \
 29} while (0)
 30
 31#define init_idle_preempt_count(p, cpu) do { \
 32	task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \
 33} while (0)
 34
 35static __always_inline void set_preempt_need_resched(void)
 36{
 37}
 38
 39static __always_inline void clear_preempt_need_resched(void)
 40{
 41}
 42
 43static __always_inline bool test_preempt_need_resched(void)
 44{
 45	return false;
 46}
 47
 48/*
 49 * The various preempt_count add/sub methods
 50 */
 51
 52static __always_inline void __preempt_count_add(int val)
 53{
 54	*preempt_count_ptr() += val;
 55}
 56
 57static __always_inline void __preempt_count_sub(int val)
 58{
 59	*preempt_count_ptr() -= val;
 60}
 61
 62static __always_inline bool __preempt_count_dec_and_test(void)
 63{
 64	/*
 65	 * Because of load-store architectures cannot do per-cpu atomic
 66	 * operations; we cannot use PREEMPT_NEED_RESCHED because it might get
 67	 * lost.
 68	 */
 69	return !--*preempt_count_ptr() && tif_need_resched();
 70}
 71
 72/*
 73 * Returns true when we need to resched and can (barring IRQ state).
 74 */
 75static __always_inline bool should_resched(int preempt_offset)
 76{
 77	return unlikely(preempt_count() == preempt_offset &&
 78			tif_need_resched());
 79}
 80
 81#ifdef CONFIG_PREEMPTION
 82extern asmlinkage void preempt_schedule(void);
 83extern asmlinkage void preempt_schedule_notrace(void);
 84
 85#if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
 86
 87void dynamic_preempt_schedule(void);
 88void dynamic_preempt_schedule_notrace(void);
 89#define __preempt_schedule()		dynamic_preempt_schedule()
 90#define __preempt_schedule_notrace()	dynamic_preempt_schedule_notrace()
 91
 92#else /* !CONFIG_PREEMPT_DYNAMIC || !CONFIG_HAVE_PREEMPT_DYNAMIC_KEY*/
 93
 94#define __preempt_schedule() preempt_schedule()
 95#define __preempt_schedule_notrace() preempt_schedule_notrace()
 96
 97#endif /* CONFIG_PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_KEY*/
 98#endif /* CONFIG_PREEMPTION */
 
 
 
 99
100#endif /* __ASM_PREEMPT_H */

 
 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 current_thread_info()->preempt_count;
11}
12
13static __always_inline 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 task_preempt_count(p) \
27	(task_thread_info(p)->preempt_count & ~PREEMPT_NEED_RESCHED)
28
29#define init_task_preempt_count(p) do { \
30	task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \
31} while (0)
32
33#define init_idle_preempt_count(p, cpu) do { \
34	task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \
35} while (0)
36
37static __always_inline void set_preempt_need_resched(void)
38{
39}
40
41static __always_inline void clear_preempt_need_resched(void)
42{
43}
44
45static __always_inline bool test_preempt_need_resched(void)
46{
47	return false;
48}
49
50/*
51 * The various preempt_count add/sub methods
52 */
53
54static __always_inline void __preempt_count_add(int val)
55{
56	*preempt_count_ptr() += val;
57}
58
59static __always_inline void __preempt_count_sub(int val)
60{
61	*preempt_count_ptr() -= val;
62}
63
64static __always_inline bool __preempt_count_dec_and_test(void)
65{
66	/*
67	 * Because of load-store architectures cannot do per-cpu atomic
68	 * operations; we cannot use PREEMPT_NEED_RESCHED because it might get
69	 * lost.
70	 */
71	return !--*preempt_count_ptr() && tif_need_resched();
72}
73
74/*
75 * Returns true when we need to resched and can (barring IRQ state).
76 */
77static __always_inline bool should_resched(void)
78{
79	return unlikely(!preempt_count() && tif_need_resched());
 
80}
81
82#ifdef CONFIG_PREEMPT
83extern asmlinkage void preempt_schedule(void);
 
 
 
 
 
 
 
 
 
 
 
84#define __preempt_schedule() preempt_schedule()
 
85
86#ifdef CONFIG_CONTEXT_TRACKING
87extern asmlinkage void preempt_schedule_context(void);
88#define __preempt_schedule_context() preempt_schedule_context()
89#endif
90#endif /* CONFIG_PREEMPT */
91
92#endif /* __ASM_PREEMPT_H */