projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| c360192b MS |
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 | ||
| 9 | #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES | |
| 10 | ||
| 08861d33 WD |
11 | /* We use the MSB mostly because its available */ |
| 12 | #define PREEMPT_NEED_RESCHED 0x80000000 | |
| c360192b MS |
13 | #define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED) |
| 14 | ||
| 15 | static inline int preempt_count(void) | |
| 16 | { | |
| 17 | return READ_ONCE(S390_lowcore.preempt_count) & ~PREEMPT_NEED_RESCHED; | |
| 18 | } | |
| 19 | ||
| 20 | static inline void preempt_count_set(int pc) | |
| 21 | { | |
| 22 | int old, new; | |
| 23 | ||
| 24 | do { | |
| 25 | old = READ_ONCE(S390_lowcore.preempt_count); | |
| 26 | new = (old & PREEMPT_NEED_RESCHED) | | |
| 27 | (pc & ~PREEMPT_NEED_RESCHED); | |
| 28 | } while (__atomic_cmpxchg(&S390_lowcore.preempt_count, | |
| 29 | old, new) != old); | |
| 30 | } | |
| 31 | ||
| 32 | #define init_task_preempt_count(p) do { } while (0) | |
| 33 | ||
| 34 | #define init_idle_preempt_count(p, cpu) do { \ | |
| 35 | S390_lowcore.preempt_count = PREEMPT_ENABLED; \ | |
| 36 | } while (0) | |
| 37 | ||
| 38 | static inline void set_preempt_need_resched(void) | |
| 39 | { | |
| 40 | __atomic_and(~PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count); | |
| 41 | } | |
| 42 | ||
| 43 | static inline void clear_preempt_need_resched(void) | |
| 44 | { | |
| 45 | __atomic_or(PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count); | |
| 46 | } | |
| 47 | ||
| 48 | static inline bool test_preempt_need_resched(void) | |
| 49 | { | |
| 50 | return !(READ_ONCE(S390_lowcore.preempt_count) & PREEMPT_NEED_RESCHED); | |
| 51 | } | |
| 52 | ||
| 53 | static inline void __preempt_count_add(int val) | |
| 54 | { | |
| 55 | if (__builtin_constant_p(val) && (val >= -128) && (val <= 127)) | |
| 56 | __atomic_add_const(val, &S390_lowcore.preempt_count); | |
| 57 | else | |
| 58 | __atomic_add(val, &S390_lowcore.preempt_count); | |
| 59 | } | |
| 60 | ||
| 61 | static inline void __preempt_count_sub(int val) | |
| 62 | { | |
| 63 | __preempt_count_add(-val); | |
| 64 | } | |
| 65 | ||
| 66 | static inline bool __preempt_count_dec_and_test(void) | |
| 67 | { | |
| 68 | return __atomic_add(-1, &S390_lowcore.preempt_count) == 1; | |
| 69 | } | |
| 70 | ||
| 71 | static inline bool should_resched(int preempt_offset) | |
| 72 | { | |
| 73 | return unlikely(READ_ONCE(S390_lowcore.preempt_count) == | |
| 74 | preempt_offset); | |
| 75 | } | |
| 76 | ||
| 77 | #else /* CONFIG_HAVE_MARCH_Z196_FEATURES */ | |
| 78 | ||
| 79 | #define PREEMPT_ENABLED (0) | |
| 80 | ||
| 81 | static inline int preempt_count(void) | |
| 82 | { | |
| 83 | return READ_ONCE(S390_lowcore.preempt_count); | |
| 84 | } | |
| 85 | ||
| 86 | static inline void preempt_count_set(int pc) | |
| 87 | { | |
| 88 | S390_lowcore.preempt_count = pc; | |
| 89 | } | |
| 90 | ||
| 91 | #define init_task_preempt_count(p) do { } while (0) | |
| 92 | ||
| 93 | #define init_idle_preempt_count(p, cpu) do { \ | |
| 94 | S390_lowcore.preempt_count = PREEMPT_ENABLED; \ | |
| 95 | } while (0) | |
| 96 | ||
| 97 | static inline void set_preempt_need_resched(void) | |
| 98 | { | |
| 99 | } | |
| 100 | ||
| 101 | static inline void clear_preempt_need_resched(void) | |
| 102 | { | |
| 103 | } | |
| 104 | ||
| 105 | static inline bool test_preempt_need_resched(void) | |
| 106 | { | |
| 107 | return false; | |
| 108 | } | |
| 109 | ||
| 110 | static inline void __preempt_count_add(int val) | |
| 111 | { | |
| 112 | S390_lowcore.preempt_count += val; | |
| 113 | } | |
| 114 | ||
| 115 | static inline void __preempt_count_sub(int val) | |
| 116 | { | |
| 117 | S390_lowcore.preempt_count -= val; | |
| 118 | } | |
| 119 | ||
| 120 | static inline bool __preempt_count_dec_and_test(void) | |
| 121 | { | |
| 122 | return !--S390_lowcore.preempt_count && tif_need_resched(); | |
| 123 | } | |
| 124 | ||
| 125 | static inline bool should_resched(int preempt_offset) | |
| 126 | { | |
| 127 | return unlikely(preempt_count() == preempt_offset && | |
| 128 | tif_need_resched()); | |
| 129 | } | |
| 130 | ||
| 131 | #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */ | |
| 132 | ||
| 133 | #ifdef CONFIG_PREEMPT | |
| 134 | extern asmlinkage void preempt_schedule(void); | |
| 135 | #define __preempt_schedule() preempt_schedule() | |
| 136 | extern asmlinkage void preempt_schedule_notrace(void); | |
| 137 | #define __preempt_schedule_notrace() preempt_schedule_notrace() | |
| 138 | #endif /* CONFIG_PREEMPT */ | |
| 139 | ||
| 140 | #endif /* __ASM_PREEMPT_H */ |