| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef __ASM_PREEMPT_H |
| #define __ASM_PREEMPT_H |
| |
| #include <asm/current.h> |
| #include <linux/thread_info.h> |
| #include <asm/atomic_ops.h> |
| |
| #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES |
| |
| /* We use the MSB mostly because its available */ |
| #define PREEMPT_NEED_RESCHED 0x80000000 |
| #define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED) |
| |
| static inline int preempt_count(void) |
| { |
| return READ_ONCE(S390_lowcore.preempt_count) & ~PREEMPT_NEED_RESCHED; |
| } |
| |
| static inline void preempt_count_set(int pc) |
| { |
| int old, new; |
| |
| do { |
| old = READ_ONCE(S390_lowcore.preempt_count); |
| new = (old & PREEMPT_NEED_RESCHED) | |
| (pc & ~PREEMPT_NEED_RESCHED); |
| } while (__atomic_cmpxchg(&S390_lowcore.preempt_count, |
| old, new) != old); |
| } |
| |
| #define init_task_preempt_count(p) do { } while (0) |
| |
| #define init_idle_preempt_count(p, cpu) do { \ |
| S390_lowcore.preempt_count = PREEMPT_DISABLED; \ |
| } while (0) |
| |
| static inline void set_preempt_need_resched(void) |
| { |
| __atomic_and(~PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count); |
| } |
| |
| static inline void clear_preempt_need_resched(void) |
| { |
| __atomic_or(PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count); |
| } |
| |
| static inline bool test_preempt_need_resched(void) |
| { |
| return !(READ_ONCE(S390_lowcore.preempt_count) & PREEMPT_NEED_RESCHED); |
| } |
| |
| static inline void __preempt_count_add(int val) |
| { |
| if (__builtin_constant_p(val) && (val >= -128) && (val <= 127)) |
| __atomic_add_const(val, &S390_lowcore.preempt_count); |
| else |
| __atomic_add(val, &S390_lowcore.preempt_count); |
| } |
| |
| static inline void __preempt_count_sub(int val) |
| { |
| __preempt_count_add(-val); |
| } |
| |
| static inline bool __preempt_count_dec_and_test(void) |
| { |
| return __atomic_add(-1, &S390_lowcore.preempt_count) == 1; |
| } |
| |
| static inline bool should_resched(int preempt_offset) |
| { |
| return unlikely(READ_ONCE(S390_lowcore.preempt_count) == |
| preempt_offset); |
| } |
| |
| #else /* CONFIG_HAVE_MARCH_Z196_FEATURES */ |
| |
| #define PREEMPT_ENABLED (0) |
| |
| static inline int preempt_count(void) |
| { |
| return READ_ONCE(S390_lowcore.preempt_count); |
| } |
| |
| static inline void preempt_count_set(int pc) |
| { |
| S390_lowcore.preempt_count = pc; |
| } |
| |
| #define init_task_preempt_count(p) do { } while (0) |
| |
| #define init_idle_preempt_count(p, cpu) do { \ |
| S390_lowcore.preempt_count = PREEMPT_DISABLED; \ |
| } while (0) |
| |
| static inline void set_preempt_need_resched(void) |
| { |
| } |
| |
| static inline void clear_preempt_need_resched(void) |
| { |
| } |
| |
| static inline bool test_preempt_need_resched(void) |
| { |
| return false; |
| } |
| |
| static inline void __preempt_count_add(int val) |
| { |
| S390_lowcore.preempt_count += val; |
| } |
| |
| static inline void __preempt_count_sub(int val) |
| { |
| S390_lowcore.preempt_count -= val; |
| } |
| |
| static inline bool __preempt_count_dec_and_test(void) |
| { |
| return !--S390_lowcore.preempt_count && tif_need_resched(); |
| } |
| |
| static inline bool should_resched(int preempt_offset) |
| { |
| return unlikely(preempt_count() == preempt_offset && |
| tif_need_resched()); |
| } |
| |
| #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */ |
| |
| #ifdef CONFIG_PREEMPTION |
| extern void preempt_schedule(void); |
| #define __preempt_schedule() preempt_schedule() |
| extern void preempt_schedule_notrace(void); |
| #define __preempt_schedule_notrace() preempt_schedule_notrace() |
| #endif /* CONFIG_PREEMPTION */ |
| |
| #endif /* __ASM_PREEMPT_H */ |