[2/2] arm64: smp: Don't directly call arch_smp_send_reschedule() for wakeup

Message ID 20231002094526.2.I2e6d22fc42ccbf6b26465a28a10e36e05ccf3075@changeid
State New
Headers
Series [1/2] arm64: smp: Fix pseudo NMI issues w/ broken Mediatek FW |

Commit Message

Doug Anderson Oct. 2, 2023, 4:45 p.m. UTC
  In commit 2b2d0a7a96ab ("arm64: smp: Remove dedicated wakeup IPI") we
started using a scheduler IPI to avoid a dedicated reschedule. When we
did this, we used arch_smp_send_reschedule() directly rather than
calling smp_send_reschedule(). The only difference is that calling
arch_smp_send_reschedule() directly avoids tracing. Presumably we
_don't_ want to avoid tracing here, so switch to
smp_send_reschedule().

Fixes: 2b2d0a7a96ab ("arm64: smp: Remove dedicated wakeup IPI")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
I don't 100% know if this is correct and I don't have any hardware
that uses the "ACPI parking protocol", but I think it's right. My main
incentive for this is that it makes it easier to backport pseudo-NMI
to kernels that don't have arch_smp_send_reschedule(), but I think
it's also more correct.

If for some reason we truly did want to avoid tracing here, please
shout and we can drop this patch.

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

Patch

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 0a6002243a8c..b530d8ef9c1d 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -1063,7 +1063,7 @@  void arch_send_wakeup_ipi(unsigned int cpu)
 	 * We use a scheduler IPI to wake the CPU as this avoids the need for a
 	 * dedicated IPI and we can safely handle spurious scheduler IPIs.
 	 */
-	arch_smp_send_reschedule(cpu);
+	smp_send_reschedule(cpu);
 }
 #endif