1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * HW NMI watchdog support 4 * 5 * started by Don Zickus, Copyright (C) 2010 Red Hat, Inc. 6 * 7 * Arch specific calls to support NMI watchdog 8 * 9 * Bits copied from original nmi.c file 10 * 11 */ 12 #include <linux/thread_info.h> 13 #include <asm/apic.h> 14 #include <asm/nmi.h> 15 16 #include <linux/cpumask.h> 17 #include <linux/kdebug.h> 18 #include <linux/notifier.h> 19 #include <linux/kprobes.h> 20 #include <linux/nmi.h> 21 #include <linux/init.h> 22 #include <linux/delay.h> 23 24 #ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF 25 u64 hw_nmi_get_sample_period(int watchdog_thresh) 26 { 27 return (u64)(cpu_khz) * 1000 * watchdog_thresh; 28 } 29 #endif 30 31 #ifdef arch_trigger_cpumask_backtrace 32 static void nmi_raise_cpu_backtrace(cpumask_t *mask) 33 { 34 apic->send_IPI_mask(mask, NMI_VECTOR); 35 } 36 37 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) 38 { 39 nmi_trigger_cpumask_backtrace(mask, exclude_self, 40 nmi_raise_cpu_backtrace); 41 } 42 43 static int nmi_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs) 44 { 45 if (nmi_cpu_backtrace(regs)) 46 return NMI_HANDLED; 47 48 return NMI_DONE; 49 } 50 NOKPROBE_SYMBOL(nmi_cpu_backtrace_handler); 51 52 static int __init register_nmi_cpu_backtrace_handler(void) 53 { 54 register_nmi_handler(NMI_LOCAL, nmi_cpu_backtrace_handler, 55 0, "arch_bt"); 56 return 0; 57 } 58 early_initcall(register_nmi_cpu_backtrace_handler); 59 #endif 60