[PATCH 2/2] arm64: Mark the recheduling IPI as naked interrupt

From: Marc Zyngier
Date: Sun Nov 01 2020 - 08:14:44 EST


Flag the rescheduling IPI as 'naked', making sure such interrupt
doesn't trigger a rescheduling event by itself.

Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/kernel/smp.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 82e75fc2c903..6c11be3e74d3 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -993,6 +993,10 @@ void __init set_smp_ipi_range(int ipi_base, int n)

ipi_desc[i] = irq_to_desc(ipi_base + i);
irq_set_status_flags(ipi_base + i, IRQ_HIDDEN);
+
+ /* The recheduling IPI is special... */
+ if (i == IPI_RESCHEDULE)
+ irq_set_status_flags(ipi_base + i, IRQ_NAKED);
}

ipi_irq_base = ipi_base;
--
2.28.0