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