1 files changed, 0 insertions, 302 deletions
diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c
deleted file mode 100644
index 2125b09e09d7..000000000000
--- a/kernel/watchdog_hld.c
+++ /dev/null
@@ -1,302 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Detect hard lockups on a system
- *
- * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
- *
- * Note: Most of this code is borrowed heavily from the original softlockup
- * detector, so thanks to Ingo for the initial implementation.
- * Some chunks also taken from the old x86-specific nmi watchdog code, thanks
- * to those contributors as well.
- */
-
-#define pr_fmt(fmt) "NMI watchdog: " fmt
-
-#include <linux/nmi.h>
-#include <linux/atomic.h>
-#include <linux/module.h>
-#include <linux/sched/debug.h>
-
-#include <asm/irq_regs.h>
-#include <linux/perf_event.h>
-
-static DEFINE_PER_CPU(bool, hard_watchdog_warn);
-static DEFINE_PER_CPU(bool, watchdog_nmi_touch);
-static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
-static DEFINE_PER_CPU(struct perf_event *, dead_event);
-static struct cpumask dead_events_mask;
-
-static unsigned long hardlockup_allcpu_dumped;
-static atomic_t watchdog_cpus = ATOMIC_INIT(0);
-
-notrace void arch_touch_nmi_watchdog(void)
-{
-	/*
-	 * Using __raw here because some code paths have
-	 * preemption enabled.  If preemption is enabled
-	 * then interrupts should be enabled too, in which
-	 * case we shouldn't have to worry about the watchdog
-	 * going off.
-	 */
-	raw_cpu_write(watchdog_nmi_touch, true);
-}
-EXPORT_SYMBOL(arch_touch_nmi_watchdog);
-
-#ifdef CONFIG_HARDLOCKUP_CHECK_TIMESTAMP
-static DEFINE_PER_CPU(ktime_t, last_timestamp);
-static DEFINE_PER_CPU(unsigned int, nmi_rearmed);
-static ktime_t watchdog_hrtimer_sample_threshold __read_mostly;
-
-void watchdog_update_hrtimer_threshold(u64 period)
-{
-	/*
-	 * The hrtimer runs with a period of (watchdog_threshold * 2) / 5
-	 *
-	 * So it runs effectively with 2.5 times the rate of the NMI
-	 * watchdog. That means the hrtimer should fire 2-3 times before
-	 * the NMI watchdog expires. The NMI watchdog on x86 is based on
-	 * unhalted CPU cycles, so if Turbo-Mode is enabled the CPU cycles
-	 * might run way faster than expected and the NMI fires in a
-	 * smaller period than the one deduced from the nominal CPU
-	 * frequency. Depending on the Turbo-Mode factor this might be fast
-	 * enough to get the NMI period smaller than the hrtimer watchdog
-	 * period and trigger false positives.
-	 *
-	 * The sample threshold is used to check in the NMI handler whether
-	 * the minimum time between two NMI samples has elapsed. That
-	 * prevents false positives.
-	 *
-	 * Set this to 4/5 of the actual watchdog threshold period so the
-	 * hrtimer is guaranteed to fire at least once within the real
-	 * watchdog threshold.
-	 */
-	watchdog_hrtimer_sample_threshold = period * 2;
-}
-
-static bool watchdog_check_timestamp(void)
-{
-	ktime_t delta, now = ktime_get_mono_fast_ns();
-
-	delta = now - __this_cpu_read(last_timestamp);
-	if (delta < watchdog_hrtimer_sample_threshold) {
-		/*
-		 * If ktime is jiffies based, a stalled timer would prevent
-		 * jiffies from being incremented and the filter would look
-		 * at a stale timestamp and never trigger.
-		 */
-		if (__this_cpu_inc_return(nmi_rearmed) < 10)
-			return false;
-	}
-	__this_cpu_write(nmi_rearmed, 0);
-	__this_cpu_write(last_timestamp, now);
-	return true;
-}
-#else
-static inline bool watchdog_check_timestamp(void)
-{
-	return true;
-}
-#endif
-
-static struct perf_event_attr wd_hw_attr = {
-	.type		= PERF_TYPE_HARDWARE,
-	.config		= PERF_COUNT_HW_CPU_CYCLES,
-	.size		= sizeof(struct perf_event_attr),
-	.pinned		= 1,
-	.disabled	= 1,
-};
-
-/* Callback function for perf event subsystem */
-static void watchdog_overflow_callback(struct perf_event *event,
-				       struct perf_sample_data *data,
-				       struct pt_regs *regs)
-{
-	/* Ensure the watchdog never gets throttled */
-	event->hw.interrupts = 0;
-
-	if (!watchdog_check_timestamp())
-		return;
-
-	if (__this_cpu_read(watchdog_nmi_touch) == true) {
-		__this_cpu_write(watchdog_nmi_touch, false);
-		return;
-	}
-
-	/* check for a hardlockup
-	 * This is done by making sure our timer interrupt
-	 * is incrementing.  The timer interrupt should have
-	 * fired multiple times before we overflow'd.  If it hasn't
-	 * then this is a good indication the cpu is stuck
-	 */
-	if (is_hardlockup()) {
-		int this_cpu = smp_processor_id();
-
-		/* only print hardlockups once */
-		if (__this_cpu_read(hard_watchdog_warn) == true)
-			return;
-
-		pr_emerg("Watchdog detected hard LOCKUP on cpu %d\n",
-			 this_cpu);
-		print_modules();
-		print_irqtrace_events(current);
-		if (regs)
-			show_regs(regs);
-		else
-			dump_stack();
-
-		/*
-		 * Perform all-CPU dump only once to avoid multiple hardlockups
-		 * generating interleaving traces
-		 */
-		if (sysctl_hardlockup_all_cpu_backtrace &&
-				!test_and_set_bit(0, &hardlockup_allcpu_dumped))
-			trigger_allbutself_cpu_backtrace();
-
-		if (hardlockup_panic)
-			nmi_panic(regs, "Hard LOCKUP");
-
-		__this_cpu_write(hard_watchdog_warn, true);
-		return;
-	}
-
-	__this_cpu_write(hard_watchdog_warn, false);
-	return;
-}
-
-static int hardlockup_detector_event_create(void)
-{
-	unsigned int cpu;
-	struct perf_event_attr *wd_attr;
-	struct perf_event *evt;
-
-	/*
-	 * Preemption is not disabled because memory will be allocated.
-	 * Ensure CPU-locality by calling this in per-CPU kthread.
-	 */
-	WARN_ON(!is_percpu_thread());
-	cpu = raw_smp_processor_id();
-	wd_attr = &wd_hw_attr;
-	wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
-
-	/* Try to register using hardware perf events */
-	evt = perf_event_create_kernel_counter(wd_attr, cpu, NULL,
-					       watchdog_overflow_callback, NULL);
-	if (IS_ERR(evt)) {
-		pr_debug("Perf event create on CPU %d failed with %ld\n", cpu,
-			 PTR_ERR(evt));
-		return PTR_ERR(evt);
-	}
-	this_cpu_write(watchdog_ev, evt);
-	return 0;
-}
-
-/**
- * hardlockup_detector_perf_enable - Enable the local event
- */
-void hardlockup_detector_perf_enable(void)
-{
-	if (hardlockup_detector_event_create())
-		return;
-
-	/* use original value for check */
-	if (!atomic_fetch_inc(&watchdog_cpus))
-		pr_info("Enabled. Permanently consumes one hw-PMU counter.\n");
-
-	perf_event_enable(this_cpu_read(watchdog_ev));
-}
-
-/**
- * hardlockup_detector_perf_disable - Disable the local event
- */
-void hardlockup_detector_perf_disable(void)
-{
-	struct perf_event *event = this_cpu_read(watchdog_ev);
-
-	if (event) {
-		perf_event_disable(event);
-		this_cpu_write(watchdog_ev, NULL);
-		this_cpu_write(dead_event, event);
-		cpumask_set_cpu(smp_processor_id(), &dead_events_mask);
-		atomic_dec(&watchdog_cpus);
-	}
-}
-
-/**
- * hardlockup_detector_perf_cleanup - Cleanup disabled events and destroy them
- *
- * Called from lockup_detector_cleanup(). Serialized by the caller.
- */
-void hardlockup_detector_perf_cleanup(void)
-{
-	int cpu;
-
-	for_each_cpu(cpu, &dead_events_mask) {
-		struct perf_event *event = per_cpu(dead_event, cpu);
-
-		/*
-		 * Required because for_each_cpu() reports  unconditionally
-		 * CPU0 as set on UP kernels. Sigh.
-		 */
-		if (event)
-			perf_event_release_kernel(event);
-		per_cpu(dead_event, cpu) = NULL;
-	}
-	cpumask_clear(&dead_events_mask);
-}
-
-/**
- * hardlockup_detector_perf_stop - Globally stop watchdog events
- *
- * Special interface for x86 to handle the perf HT bug.
- */
-void __init hardlockup_detector_perf_stop(void)
-{
-	int cpu;
-
-	lockdep_assert_cpus_held();
-
-	for_each_online_cpu(cpu) {
-		struct perf_event *event = per_cpu(watchdog_ev, cpu);
-
-		if (event)
-			perf_event_disable(event);
-	}
-}
-
-/**
- * hardlockup_detector_perf_restart - Globally restart watchdog events
- *
- * Special interface for x86 to handle the perf HT bug.
- */
-void __init hardlockup_detector_perf_restart(void)
-{
-	int cpu;
-
-	lockdep_assert_cpus_held();
-
-	if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
-		return;
-
-	for_each_online_cpu(cpu) {
-		struct perf_event *event = per_cpu(watchdog_ev, cpu);
-
-		if (event)
-			perf_event_enable(event);
-	}
-}
-
-/**
- * hardlockup_detector_perf_init - Probe whether NMI event is available at all
- */
-int __init hardlockup_detector_perf_init(void)
-{
-	int ret = hardlockup_detector_event_create();
-
-	if (ret) {
-		pr_info("Perf NMI watchdog permanently disabled\n");
-	} else {
-		perf_event_release_kernel(this_cpu_read(watchdog_ev));
-		this_cpu_write(watchdog_ev, NULL);
-	}
-	return ret;
-}