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- /* SPDX-License-Identifier: GPL-2.0 */
- #ifndef __ASM_PREEMPT_H
- #define __ASM_PREEMPT_H
- #include <linux/thread_info.h>
- #define PREEMPT_ENABLED (0)
- static __always_inline int preempt_count(void)
- {
- return READ_ONCE(current_thread_info()->preempt_count);
- }
- static __always_inline volatile int *preempt_count_ptr(void)
- {
- return ¤t_thread_info()->preempt_count;
- }
- static __always_inline void preempt_count_set(int pc)
- {
- *preempt_count_ptr() = pc;
- }
- /*
- * must be macros to avoid header recursion hell
- */
- #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_ENABLED; \
- } while (0)
- static __always_inline void set_preempt_need_resched(void)
- {
- }
- static __always_inline void clear_preempt_need_resched(void)
- {
- }
- static __always_inline bool test_preempt_need_resched(void)
- {
- return false;
- }
- /*
- * The various preempt_count add/sub methods
- */
- static __always_inline void __preempt_count_add(int val)
- {
- *preempt_count_ptr() += val;
- }
- static __always_inline void __preempt_count_sub(int val)
- {
- *preempt_count_ptr() -= val;
- }
- static __always_inline bool __preempt_count_dec_and_test(void)
- {
- /*
- * Because of load-store architectures cannot do per-cpu atomic
- * operations; we cannot use PREEMPT_NEED_RESCHED because it might get
- * lost.
- */
- return !--*preempt_count_ptr() && tif_need_resched();
- }
- /*
- * Returns true when we need to resched and can (barring IRQ state).
- */
- static __always_inline bool should_resched(int preempt_offset)
- {
- return unlikely(preempt_count() == preempt_offset &&
- tif_need_resched());
- }
- #ifdef CONFIG_PREEMPT
- extern asmlinkage void preempt_schedule(void);
- #define __preempt_schedule() preempt_schedule()
- extern asmlinkage void preempt_schedule_notrace(void);
- #define __preempt_schedule_notrace() preempt_schedule_notrace()
- #endif /* CONFIG_PREEMPT */
- #endif /* __ASM_PREEMPT_H */
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