[PATCH v2] arm64: use SOFTIRQ_ON_OWN_STACK for enabling softirq stack

[Ryo Takakura <ryotkkr98@gmail.com>]

For those architectures with HAVE_SOFTIRQ_ON_OWN_STACK use
their dedicated softirq stack when !PREEMPT_RT. This condition
is ensured by SOFTIRQ_ON_OWN_STACK.

Let arm64 use SOFTIRQ_ON_OWN_STACK as well to select its
usage of the stack.

Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Will Deacon <will@kernel.org>
---

Changes since v1:
[1] https://lore.kernel.org/linux-rt-devel/20251013013508.74677-1-ryotkkr98@gmail.com/

- Add <Reviewed-by> by Sebastian.
- Add <Acked-by> by Will.

---
 arch/arm64/kernel/irq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
index c0065a1d7..15dedb385 100644
--- a/arch/arm64/kernel/irq.c
+++ b/arch/arm64/kernel/irq.c
@@ -62,7 +62,7 @@ static void __init init_irq_stacks(void)
 	}
 }
 
-#ifndef CONFIG_PREEMPT_RT
+#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
 static void ____do_softirq(struct pt_regs *regs)
 {
 	__do_softirq();
-- 
2.34.1