mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-22 18:44:44 +08:00
7ef858dad9
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Switch the Kconfig dependency, entry code and preemption handling over to use CONFIG_PREEMPTION. Add PREEMPT_RT output in show_stack(). [bigeasy: +traps.c, Kconfig] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20191015191821.11479-3-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
90 lines
2.3 KiB
C
90 lines
2.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __ASM_PREEMPT_H
|
|
#define __ASM_PREEMPT_H
|
|
|
|
#include <linux/thread_info.h>
|
|
|
|
#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_ENABLED; \
|
|
} 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);
|
|
#define __preempt_schedule() preempt_schedule()
|
|
void preempt_schedule_notrace(void);
|
|
#define __preempt_schedule_notrace() preempt_schedule_notrace()
|
|
#endif /* CONFIG_PREEMPTION */
|
|
|
|
#endif /* __ASM_PREEMPT_H */
|