[PATCH v2 3/6] arm64: Mark the recheduling IPI as raw interrupt

Marc Zyngier
2020-11-24T14:15:41Z

Flag the rescheduling IPI as 'raw', making sure such interrupt
skips both tick management and irqtime accounting.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/Kconfig | 1 +
arch/arm64/kernel/smp.c | 4 ++++
2 files changed, 5 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1515f6f153a0..d18c2c15848d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -108,6 +108,7 @@ config ARM64
select GENERIC_EARLY_IOREMAP
select GENERIC_IDLE_POLL_SETUP
select GENERIC_IRQ_IPI
+ select ARCH_WANTS_IRQ_RAW
select GENERIC_IRQ_MULTI_HANDLER
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 18e9727d3f64..bad51f7f7ffe 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -995,6 +995,10 @@ 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_modify_status(ipi_base + i, 0, IRQ_RAW, ~0);
}

ipi_irq_base = ipi_base;
--
2.28.0