1 /* SPDX-License-Identifier: GPL-2.0 */ 1
2 #ifndef __ASM_PREEMPT_H
3 #define __ASM_PREEMPT_H
4
5 #include <asm/current.h>
6 #include <linux/thread_info.h>
7 #include <asm/atomic_ops.h>
8 #include <asm/march.h>
9
10 #ifdef MARCH_HAS_Z196_FEATURES
11
12 /* We use the MSB mostly because its available
13 #define PREEMPT_NEED_RESCHED 0x80000000
14 #define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESC
15
16 static __always_inline int preempt_count(void)
17 {
18 return READ_ONCE(get_lowcore()->preemp
19 }
20
21 static __always_inline void preempt_count_set(
22 {
23 int old, new;
24
25 do {
26 old = READ_ONCE(get_lowcore()-
27 new = (old & PREEMPT_NEED_RESC
28 (pc & ~PREEMPT_NEED_RE
29 } while (__atomic_cmpxchg(&get_lowcore
30 old, new) !=
31 }
32
33 static __always_inline void set_preempt_need_r
34 {
35 __atomic_and(~PREEMPT_NEED_RESCHED, &g
36 }
37
38 static __always_inline void clear_preempt_need
39 {
40 __atomic_or(PREEMPT_NEED_RESCHED, &get
41 }
42
43 static __always_inline bool test_preempt_need_
44 {
45 return !(READ_ONCE(get_lowcore()->pree
46 }
47
48 static __always_inline void __preempt_count_ad
49 {
50 /*
51 * With some obscure config options an
52 * enabled, gcc 12 fails to handle __b
53 */
54 if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRA
55 if (__builtin_constant_p(val)
56 __atomic_add_const(val
57 return;
58 }
59 }
60 __atomic_add(val, &get_lowcore()->pree
61 }
62
63 static __always_inline void __preempt_count_su
64 {
65 __preempt_count_add(-val);
66 }
67
68 static __always_inline bool __preempt_count_de
69 {
70 return __atomic_add(-1, &get_lowcore()
71 }
72
73 static __always_inline bool should_resched(int
74 {
75 return unlikely(READ_ONCE(get_lowcore(
76 preempt_offset);
77 }
78
79 #else /* MARCH_HAS_Z196_FEATURES */
80
81 #define PREEMPT_ENABLED (0)
82
83 static __always_inline int preempt_count(void)
84 {
85 return READ_ONCE(get_lowcore()->preemp
86 }
87
88 static __always_inline void preempt_count_set(
89 {
90 get_lowcore()->preempt_count = pc;
91 }
92
93 static __always_inline void set_preempt_need_r
94 {
95 }
96
97 static __always_inline void clear_preempt_need
98 {
99 }
100
101 static __always_inline bool test_preempt_need_
102 {
103 return false;
104 }
105
106 static __always_inline void __preempt_count_ad
107 {
108 get_lowcore()->preempt_count += val;
109 }
110
111 static __always_inline void __preempt_count_su
112 {
113 get_lowcore()->preempt_count -= val;
114 }
115
116 static __always_inline bool __preempt_count_de
117 {
118 return !--get_lowcore()->preempt_count
119 }
120
121 static __always_inline bool should_resched(int
122 {
123 return unlikely(preempt_count() == pre
124 tif_need_resched());
125 }
126
127 #endif /* MARCH_HAS_Z196_FEATURES */
128
129 #define init_task_preempt_count(p) do { }
130 /* Deferred to CPU bringup time */
131 #define init_idle_preempt_count(p, cpu) do { }
132
133 #ifdef CONFIG_PREEMPTION
134 extern void preempt_schedule(void);
135 #define __preempt_schedule() preempt_schedule(
136 extern void preempt_schedule_notrace(void);
137 #define __preempt_schedule_notrace() preempt_s
138 #endif /* CONFIG_PREEMPTION */
139
140 #endif /* __ASM_PREEMPT_H */
141
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