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/arm64/include/asm/preempt.h | 104 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 arch/arm64/include/asm/preempt.h (limited to 'arch/arm64/include/asm/preempt.h') diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h new file mode 100644 index 0000000000..0159b625cc --- /dev/null +++ b/arch/arm64/include/asm/preempt.h @@ -0,0 +1,104 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_PREEMPT_H +#define __ASM_PREEMPT_H + +#include +#include + +#define PREEMPT_NEED_RESCHED BIT(32) +#define PREEMPT_ENABLED (PREEMPT_NEED_RESCHED) + +static inline int preempt_count(void) +{ + return READ_ONCE(current_thread_info()->preempt.count); +} + +static inline void preempt_count_set(u64 pc) +{ + /* Preserve existing value of PREEMPT_NEED_RESCHED */ + WRITE_ONCE(current_thread_info()->preempt.count, pc); +} + +#define init_task_preempt_count(p) do { \ + task_thread_info(p)->preempt_count = FORK_PREEMPT_COUNT; \ +} while (0) + +#define init_idle_preempt_count(p, cpu) do { \ + task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ +} while (0) + +static inline void set_preempt_need_resched(void) +{ + current_thread_info()->preempt.need_resched = 0; +} + +static inline void clear_preempt_need_resched(void) +{ + current_thread_info()->preempt.need_resched = 1; +} + +static inline bool test_preempt_need_resched(void) +{ + return !current_thread_info()->preempt.need_resched; +} + +static inline void __preempt_count_add(int val) +{ + u32 pc = READ_ONCE(current_thread_info()->preempt.count); + pc += val; + WRITE_ONCE(current_thread_info()->preempt.count, pc); +} + +static inline void __preempt_count_sub(int val) +{ + u32 pc = READ_ONCE(current_thread_info()->preempt.count); + pc -= val; + WRITE_ONCE(current_thread_info()->preempt.count, pc); +} + +static inline bool __preempt_count_dec_and_test(void) +{ + struct thread_info *ti = current_thread_info(); + u64 pc = READ_ONCE(ti->preempt_count); + + /* Update only the count field, leaving need_resched unchanged */ + WRITE_ONCE(ti->preempt.count, --pc); + + /* + * If we wrote back all zeroes, then we're preemptible and in + * need of a reschedule. Otherwise, we need to reload the + * preempt_count in case the need_resched flag was cleared by an + * interrupt occurring between the non-atomic READ_ONCE/WRITE_ONCE + * pair. + */ + return !pc || !READ_ONCE(ti->preempt_count); +} + +static inline bool should_resched(int preempt_offset) +{ + u64 pc = READ_ONCE(current_thread_info()->preempt_count); + return pc == preempt_offset; +} + +#ifdef CONFIG_PREEMPTION + +void preempt_schedule(void); +void preempt_schedule_notrace(void); + +#ifdef CONFIG_PREEMPT_DYNAMIC + +DECLARE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched); +void dynamic_preempt_schedule(void); +#define __preempt_schedule() dynamic_preempt_schedule() +void dynamic_preempt_schedule_notrace(void); +#define __preempt_schedule_notrace() dynamic_preempt_schedule_notrace() + +#else /* CONFIG_PREEMPT_DYNAMIC */ + +#define __preempt_schedule() preempt_schedule() +#define __preempt_schedule_notrace() preempt_schedule_notrace() + +#endif /* CONFIG_PREEMPT_DYNAMIC */ +#endif /* CONFIG_PREEMPTION */ + +#endif /* __ASM_PREEMPT_H */ -- cgit v1.2.3