^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /* SPDX-License-Identifier: GPL-2.0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) #ifndef __ASM_PREEMPT_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #define __ASM_PREEMPT_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #include <asm/current.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/thread_info.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <asm/atomic_ops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) /* We use the MSB mostly because its available */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #define PREEMPT_NEED_RESCHED 0x80000000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) static inline int preempt_count(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) return READ_ONCE(S390_lowcore.preempt_count) & ~PREEMPT_NEED_RESCHED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) static inline void preempt_count_set(int pc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) int old, new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) old = READ_ONCE(S390_lowcore.preempt_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) new = (old & PREEMPT_NEED_RESCHED) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) (pc & ~PREEMPT_NEED_RESCHED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) } while (__atomic_cmpxchg(&S390_lowcore.preempt_count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) old, new) != old);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) static inline void set_preempt_need_resched(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) __atomic_and(~PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static inline void clear_preempt_need_resched(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) __atomic_or(PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) static inline bool test_preempt_need_resched(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) return !(READ_ONCE(S390_lowcore.preempt_count) & PREEMPT_NEED_RESCHED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) static inline void __preempt_count_add(int val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) if (__builtin_constant_p(val) && (val >= -128) && (val <= 127))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) __atomic_add_const(val, &S390_lowcore.preempt_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) __atomic_add(val, &S390_lowcore.preempt_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) static inline void __preempt_count_sub(int val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) __preempt_count_add(-val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) static inline bool __preempt_count_dec_and_test(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) return __atomic_add(-1, &S390_lowcore.preempt_count) == 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) static inline bool should_resched(int preempt_offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) return unlikely(READ_ONCE(S390_lowcore.preempt_count) ==
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) preempt_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) #else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) #define PREEMPT_ENABLED (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) static inline int preempt_count(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) return READ_ONCE(S390_lowcore.preempt_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) static inline void preempt_count_set(int pc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) S390_lowcore.preempt_count = pc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) static inline void set_preempt_need_resched(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) static inline void clear_preempt_need_resched(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) static inline bool test_preempt_need_resched(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) static inline void __preempt_count_add(int val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) S390_lowcore.preempt_count += val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) static inline void __preempt_count_sub(int val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) S390_lowcore.preempt_count -= val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) static inline bool __preempt_count_dec_and_test(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) return !--S390_lowcore.preempt_count && tif_need_resched();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) static inline bool should_resched(int preempt_offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return unlikely(preempt_count() == preempt_offset &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) tif_need_resched());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) #define init_task_preempt_count(p) do { } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) /* Deferred to CPU bringup time */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) #define init_idle_preempt_count(p, cpu) do { } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) #ifdef CONFIG_PREEMPTION
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) extern asmlinkage void preempt_schedule(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) #define __preempt_schedule() preempt_schedule()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) extern asmlinkage void preempt_schedule_notrace(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) #define __preempt_schedule_notrace() preempt_schedule_notrace()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) #endif /* CONFIG_PREEMPTION */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) #endif /* __ASM_PREEMPT_H */