watchdog: add nmi_watchdog support for arm64 based on SDEI (cc19c0b3) · Commits · EulixOS / Software / Kernel

arch/arm64/kernel/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -60,6 +60,7 @@ arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o
		obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
		obj-$(CONFIG_CRASH_CORE) += crash_core.o
		obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o
		obj-$(CONFIG_SDEI_WATCHDOG) += watchdog_sdei.o
		obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o
		obj-$(CONFIG_SHADOW_CALL_STACK) += scs.o
		obj-$(CONFIG_ARM64_MTE) += mte.o

arch/arm64/kernel/watchdog_sdei.c

0 → 100644

+112 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* Detect hard lockups on a system
		*
		* Note: Most of this code is borrowed heavily from the perf hardlockup
		* detector, so thanks to Don for the initial implementation.
		*/

		#define pr_fmt(fmt) "SDEI NMI watchdog: " fmt

		#include <asm/irq_regs.h>
		#include <asm/kvm_hyp.h>
		#include <asm/smp_plat.h>
		#include <asm/sdei.h>
		#include <asm/virt.h>
		#include <linux/arm_sdei.h>
		#include <linux/nmi.h>

		/* We use the secure physical timer as SDEI NMI watchdog timer */
		#define SDEI_NMI_WATCHDOG_HWIRQ 29

		static int sdei_watchdog_event_num;
		static bool disable_sdei_nmi_watchdog;
		static bool sdei_watchdog_registered;

		int watchdog_nmi_enable(unsigned int cpu)
		{
		int ret;

		if (!sdei_watchdog_registered)
		return -EINVAL;

		ret = sdei_api_event_enable(sdei_watchdog_event_num);
		if (ret) {
		pr_err("Enable NMI Watchdog failed on cpu%d\n",
		smp_processor_id());
		return ret;
		}

		return 0;
		}

		void watchdog_nmi_disable(unsigned int cpu)
		{
		int ret;

		if (!sdei_watchdog_registered)
		return;

		ret = sdei_api_event_disable(sdei_watchdog_event_num);
		if (ret)
		pr_err("Disable NMI Watchdog failed on cpu%d\n",
		smp_processor_id());
		}

		static int sdei_watchdog_callback(u32 event,
		struct pt_regs regs, void arg)
		{
		watchdog_hardlockup_check(regs);

		return 0;
		}

		static void sdei_nmi_watchdog_bind(void *data)
		{
		int ret;

		ret = sdei_api_event_interrupt_bind(SDEI_NMI_WATCHDOG_HWIRQ);
		if (ret < 0)
		pr_err("SDEI bind failed on cpu%d, return %d\n",
		smp_processor_id(), ret);
		}

		static int __init disable_sdei_nmi_watchdog_setup(char *str)
		{
		disable_sdei_nmi_watchdog = true;
		return 1;
		}
		__setup("disable_sdei_nmi_watchdog", disable_sdei_nmi_watchdog_setup);

		int __init watchdog_nmi_probe(void)
		{
		int ret;

		if (disable_sdei_nmi_watchdog)
		return -EINVAL;

		if (!is_hyp_mode_available()) {
		pr_err("Disable SDEI NMI Watchdog in VM\n");
		return -EINVAL;
		}

		sdei_watchdog_event_num = sdei_api_event_interrupt_bind(SDEI_NMI_WATCHDOG_HWIRQ);
		if (sdei_watchdog_event_num < 0) {
		pr_err("Bind interrupt failed. Firmware may not support SDEI !\n");
		return sdei_watchdog_event_num;
		}

		on_each_cpu(sdei_nmi_watchdog_bind, NULL, true);

		ret = sdei_event_register(sdei_watchdog_event_num,
		sdei_watchdog_callback, NULL);
		if (ret) {
		pr_err("SDEI Watchdog register callback failed\n");
		return ret;
		}

		sdei_watchdog_registered = true;
		pr_info("SDEI Watchdog registered successfully\n");

		return 0;
		}

lib/Kconfig.debug

+7 −0

Original line number	Diff line number	Diff line
		@@ -964,6 +964,13 @@ config HARDLOCKUP_DETECTOR_PERF
		bool
		select SOFTLOCKUP_DETECTOR

		config SDEI_WATCHDOG
		bool "SDEI NMI Watchdog support"
		depends on ARM_SDE_INTERFACE
		select HAVE_HARDLOCKUP_DETECTOR_ARCH
		select HARDLOCKUP_CHECK_TIMESTAMP
		select HARDLOCKUP_DETECTOR

		#
		# Enables a timestamp based low pass filter to compensate for perf based
		# hard lockup detection which runs too fast due to turbo modes.