[RFC PATCH 08/86] Revert "arm64: Support PREEMPT_DYNAMIC"

From: Ankur Arora
Date: Tue Nov 07 2023 - 17:01:21 EST


This reverts commit 1b2d3451ee50a0968cb9933f726e50b368ba5073.

Signed-off-by: Ankur Arora <ankur.a.arora@xxxxxxxxxx>
---
arch/arm64/Kconfig | 1 -
arch/arm64/include/asm/preempt.h | 19 ++-----------------
arch/arm64/kernel/entry-common.c | 10 +---------
3 files changed, 3 insertions(+), 27 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 78f20e632712..856d7be2ee45 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -221,7 +221,6 @@ config ARM64
select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
- select HAVE_PREEMPT_DYNAMIC_KEY
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_POSIX_CPU_TIMERS_TASK_WORK
select HAVE_FUNCTION_ARG_ACCESS_API
diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h
index 0159b625cc7f..e83f0982b99c 100644
--- a/arch/arm64/include/asm/preempt.h
+++ b/arch/arm64/include/asm/preempt.h
@@ -2,7 +2,6 @@
#ifndef __ASM_PREEMPT_H
#define __ASM_PREEMPT_H

-#include <linux/jump_label.h>
#include <linux/thread_info.h>

#define PREEMPT_NEED_RESCHED BIT(32)
@@ -81,24 +80,10 @@ static inline bool should_resched(int preempt_offset)
}

#ifdef CONFIG_PREEMPTION
-
void preempt_schedule(void);
+#define __preempt_schedule() preempt_schedule()
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 */
+#define __preempt_schedule_notrace() preempt_schedule_notrace()
#endif /* CONFIG_PREEMPTION */

#endif /* __ASM_PREEMPT_H */
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 0fc94207e69a..5d9c9951562b 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -225,17 +225,9 @@ static void noinstr arm64_exit_el1_dbg(struct pt_regs *regs)
lockdep_hardirqs_on(CALLER_ADDR0);
}

-#ifdef CONFIG_PREEMPT_DYNAMIC
-DEFINE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
-#define need_irq_preemption() \
- (static_branch_unlikely(&sk_dynamic_irqentry_exit_cond_resched))
-#else
-#define need_irq_preemption() (IS_ENABLED(CONFIG_PREEMPTION))
-#endif
-
static void __sched arm64_preempt_schedule_irq(void)
{
- if (!need_irq_preemption())
+ if (!IS_ENABLED(CONFIG_PREEMPTION))
return;

/*
--
2.31.1