From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- arch/s390/include/asm/preempt.h | 139 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 arch/s390/include/asm/preempt.h (limited to 'arch/s390/include/asm/preempt.h') diff --git a/arch/s390/include/asm/preempt.h b/arch/s390/include/asm/preempt.h new file mode 100644 index 0000000000..bf15da0fed --- /dev/null +++ b/arch/s390/include/asm/preempt.h @@ -0,0 +1,139 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_PREEMPT_H +#define __ASM_PREEMPT_H + +#include +#include +#include + +#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); +} + +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) +{ + /* + * With some obscure config options and CONFIG_PROFILE_ALL_BRANCHES + * enabled, gcc 12 fails to handle __builtin_constant_p(). + */ + if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES)) { + if (__builtin_constant_p(val) && (val >= -128) && (val <= 127)) { + __atomic_add_const(val, &S390_lowcore.preempt_count); + return; + } + } + __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; +} + +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 */ + +#define init_task_preempt_count(p) do { } while (0) +/* Deferred to CPU bringup time */ +#define init_idle_preempt_count(p, cpu) do { } while (0) + +#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 */ -- cgit v1.2.3