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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_DISABLED; \
} 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_PREEMPTION
extern asmlinkage void preempt_schedule(void);
extern asmlinkage void preempt_schedule_notrace(void);
#if defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
void dynamic_preempt_schedule(void);
void dynamic_preempt_schedule_notrace(void);
#define __preempt_schedule() dynamic_preempt_schedule()
#define __preempt_schedule_notrace() dynamic_preempt_schedule_notrace()
#else /* !CONFIG_PREEMPT_DYNAMIC || !CONFIG_HAVE_PREEMPT_DYNAMIC_KEY*/
#define __preempt_schedule() preempt_schedule()
#define __preempt_schedule_notrace() preempt_schedule_notrace()
#endif /* CONFIG_PREEMPT_DYNAMIC && CONFIG_HAVE_PREEMPT_DYNAMIC_KEY*/
#endif /* CONFIG_PREEMPTION */
#endif /* __ASM_PREEMPT_H */
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