Re: [PATCH 0/3] arm64: Fix cpuidle with pseudo-NMI enabled
From: Valentin Schneider <hidden>
Date: 2021-06-09 16:17:42
Hi Marc, On 08/06/21 18:27, Marc Zyngier wrote:
It appears that although cpu_do_idle() is correctly dealing with the
PMR/DAIF duality, the PSCI cpu-suspend code has been left unaware of
it.
On a system that uses PSCI for idle (such as the Ampere Altra I have
access to), the kernel dies as soon as it enters idle (interrupts are
off at the GIC CPU interface level). Boo.
Instead of spreading more magic code around, I've elected to provide a
pair of helpers (arm_cpuidle_{save,restore}_context()) which do the
heavy lifting.
With that in place, I can finally boot the above system with
irqchip.gicv3_pseudo_nmi=1. I'd welcome feedback from people who may
have experienced similar issues in the past (and on different
machines).With pNMIs my Ampere eMAG would always hang at boot, and your patches make it actually survive. I briefly kicked perf to get some PMU IRQs and that also seems to be going just fine. Thanks for digging into this mess! Tested-by: Valentin Schneider <redacted>
Marc Zyngier (3): arm64: Add cpuidle context save/restore helpers arm64: Convert cpu_do_idle() to using cpuidle context helpers PSCI: Use cpuidle context helpers in psci_cpu_suspend_enter() arch/arm/include/asm/cpuidle.h | 5 ++++ arch/arm64/include/asm/cpuidle.h | 35 +++++++++++++++++++++++++++ arch/arm64/kernel/process.c | 41 +++++++------------------------- drivers/firmware/psci/psci.c | 5 ++++ 4 files changed, 54 insertions(+), 32 deletions(-) -- 2.30.2
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