The interrupt is set using pseudo-NMI if it is available. Arm has a diagnostic interrupt feature called "Arm Generic Diagnostic Dump and Reset device", but the A64FX does not support this feature and instead has its own device definition. I tested on FX700: $ echo 1 > /proc/sys/kernel/sysrq $ echo HARDLOCKUP > /sys/kernel/debug/provoke-crash/DIRECT : : Send the "chassis power diag" command from the management server using ipmitool, the following message is shown: [ 123.272342] Kernel panic - not syncing: a64fx_diag: interrupt received : : Changes in V4: - Call the panic function instead of sysrq. Prepare a handler for each NMI/IRQ and call nmi_panic()/panic() respectively (as in v1). - Fixing other issues raised by Greg. Changes in V3: - Exclude Sumit's patch. - Retest in v5.17. Changes in V2: - Include Sumit's patch. - The handler calls handle_sysrq() to use the sysrq feature to cause a panic. - request_nmi() and request_irq() now use the same handler, and the function name of the handler has also changed. - Use readl()/writel() instead of readl_relaxed()/writel_relaxed(). V3: https://lore.kernel.org/linux-arm-kernel/20220331092235.3000787-1-hasegawa-hitomi@xxxxxxxxxxx/ V2: https://lore.kernel.org/linux-arm-kernel/20220304064324.331217-3-hasegawa-hitomi@xxxxxxxxxxx/ V1: https://lore.kernel.org/linux-arm-kernel/20220218092010.1327309-1-hasegawa-hitomi@xxxxxxxxxxx/ Hitomi Hasegawa (1): soc: fujitsu: Add A64FX diagnostic interrupt driver MAINTAINERS | 5 + drivers/soc/Kconfig | 1 + drivers/soc/Makefile | 1 + drivers/soc/fujitsu/Kconfig | 13 +++ drivers/soc/fujitsu/Makefile | 3 + drivers/soc/fujitsu/a64fx-diag.c | 155 +++++++++++++++++++++++++++++++ 6 files changed, 178 insertions(+) create mode 100644 drivers/soc/fujitsu/Kconfig create mode 100644 drivers/soc/fujitsu/Makefile create mode 100644 drivers/soc/fujitsu/a64fx-diag.c -- 2.27.0
