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-rw-r--r--arch/x86/kernel/apic/hw_nmi.c90
1 files changed, 90 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
new file mode 100644
index 00000000000..31cb9ae992b
--- /dev/null
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -0,0 +1,90 @@
+/*
+ * HW NMI watchdog support
+ *
+ * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
+ *
+ * Arch specific calls to support NMI watchdog
+ *
+ * Bits copied from original nmi.c file
+ *
+ */
+#include <asm/apic.h>
+
+#include <linux/cpumask.h>
+#include <linux/kdebug.h>
+#include <linux/notifier.h>
+#include <linux/kprobes.h>
+#include <linux/nmi.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+
+#ifdef CONFIG_HARDLOCKUP_DETECTOR
+u64 hw_nmi_get_sample_period(int watchdog_thresh)
+{
+ return (u64)(cpu_khz) * 1000 * watchdog_thresh;
+}
+#endif
+
+#ifdef arch_trigger_all_cpu_backtrace
+/* For reliability, we're prepared to waste bits here. */
+static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;
+
+/* "in progress" flag of arch_trigger_all_cpu_backtrace */
+static unsigned long backtrace_flag;
+
+void arch_trigger_all_cpu_backtrace(void)
+{
+ int i;
+
+ if (test_and_set_bit(0, &backtrace_flag))
+ /*
+ * If there is already a trigger_all_cpu_backtrace() in progress
+ * (backtrace_flag == 1), don't output double cpu dump infos.
+ */
+ return;
+
+ cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask);
+
+ printk(KERN_INFO "sending NMI to all CPUs:\n");
+ apic->send_IPI_all(NMI_VECTOR);
+
+ /* Wait for up to 10 seconds for all CPUs to do the backtrace */
+ for (i = 0; i < 10 * 1000; i++) {
+ if (cpumask_empty(to_cpumask(backtrace_mask)))
+ break;
+ mdelay(1);
+ }
+
+ clear_bit(0, &backtrace_flag);
+ smp_mb__after_clear_bit();
+}
+
+static int __kprobes
+arch_trigger_all_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs)
+{
+ int cpu;
+
+ cpu = smp_processor_id();
+
+ if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
+ static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;
+
+ arch_spin_lock(&lock);
+ printk(KERN_WARNING "NMI backtrace for cpu %d\n", cpu);
+ show_regs(regs);
+ arch_spin_unlock(&lock);
+ cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
+ return NMI_HANDLED;
+ }
+
+ return NMI_DONE;
+}
+
+static int __init register_trigger_all_cpu_backtrace(void)
+{
+ register_nmi_handler(NMI_LOCAL, arch_trigger_all_cpu_backtrace_handler,
+ 0, "arch_bt");
+ return 0;
+}
+early_initcall(register_trigger_all_cpu_backtrace);
+#endif