Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#ifndef __ASM_PREEMPT_H
2#define __ASM_PREEMPT_H
3
4#include <asm/current.h>
5#include <linux/thread_info.h>
6#include <asm/atomic_ops.h>
7
8#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
9
10#define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED)
11
12static inline int preempt_count(void)
13{
14 return READ_ONCE(S390_lowcore.preempt_count) & ~PREEMPT_NEED_RESCHED;
15}
16
17static inline void preempt_count_set(int pc)
18{
19 int old, new;
20
21 do {
22 old = READ_ONCE(S390_lowcore.preempt_count);
23 new = (old & PREEMPT_NEED_RESCHED) |
24 (pc & ~PREEMPT_NEED_RESCHED);
25 } while (__atomic_cmpxchg(&S390_lowcore.preempt_count,
26 old, new) != old);
27}
28
29#define init_task_preempt_count(p) do { } while (0)
30
31#define init_idle_preempt_count(p, cpu) do { \
32 S390_lowcore.preempt_count = PREEMPT_ENABLED; \
33} while (0)
34
35static inline void set_preempt_need_resched(void)
36{
37 __atomic_and(~PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count);
38}
39
40static inline void clear_preempt_need_resched(void)
41{
42 __atomic_or(PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count);
43}
44
45static inline bool test_preempt_need_resched(void)
46{
47 return !(READ_ONCE(S390_lowcore.preempt_count) & PREEMPT_NEED_RESCHED);
48}
49
50static inline void __preempt_count_add(int val)
51{
52 if (__builtin_constant_p(val) && (val >= -128) && (val <= 127))
53 __atomic_add_const(val, &S390_lowcore.preempt_count);
54 else
55 __atomic_add(val, &S390_lowcore.preempt_count);
56}
57
58static inline void __preempt_count_sub(int val)
59{
60 __preempt_count_add(-val);
61}
62
63static inline bool __preempt_count_dec_and_test(void)
64{
65 return __atomic_add(-1, &S390_lowcore.preempt_count) == 1;
66}
67
68static inline bool should_resched(int preempt_offset)
69{
70 return unlikely(READ_ONCE(S390_lowcore.preempt_count) ==
71 preempt_offset);
72}
73
74#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
75
76#define PREEMPT_ENABLED (0)
77
78static inline int preempt_count(void)
79{
80 return READ_ONCE(S390_lowcore.preempt_count);
81}
82
83static inline void preempt_count_set(int pc)
84{
85 S390_lowcore.preempt_count = pc;
86}
87
88#define init_task_preempt_count(p) do { } while (0)
89
90#define init_idle_preempt_count(p, cpu) do { \
91 S390_lowcore.preempt_count = PREEMPT_ENABLED; \
92} while (0)
93
94static inline void set_preempt_need_resched(void)
95{
96}
97
98static inline void clear_preempt_need_resched(void)
99{
100}
101
102static inline bool test_preempt_need_resched(void)
103{
104 return false;
105}
106
107static inline void __preempt_count_add(int val)
108{
109 S390_lowcore.preempt_count += val;
110}
111
112static inline void __preempt_count_sub(int val)
113{
114 S390_lowcore.preempt_count -= val;
115}
116
117static inline bool __preempt_count_dec_and_test(void)
118{
119 return !--S390_lowcore.preempt_count && tif_need_resched();
120}
121
122static inline bool should_resched(int preempt_offset)
123{
124 return unlikely(preempt_count() == preempt_offset &&
125 tif_need_resched());
126}
127
128#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
129
130#ifdef CONFIG_PREEMPT
131extern asmlinkage void preempt_schedule(void);
132#define __preempt_schedule() preempt_schedule()
133extern asmlinkage void preempt_schedule_notrace(void);
134#define __preempt_schedule_notrace() preempt_schedule_notrace()
135#endif /* CONFIG_PREEMPT */
136
137#endif /* __ASM_PREEMPT_H */