1/** 2 * @file init.c 3 * 4 * @remark Copyright 2002 OProfile authors 5 * @remark Read the file COPYING 6 * 7 * @author John Levon <levon@movementarian.org> 8 */ 9 10#include <linux/kernel.h> 11#include <linux/oprofile.h> 12#include <linux/errno.h> 13#include <linux/init.h> 14#include <linux/param.h> /* for HZ */ 15 16#ifdef CONFIG_SPARC64 17#include <linux/notifier.h> 18#include <linux/rcupdate.h> 19#include <linux/kdebug.h> 20#include <asm/nmi.h> 21 22static int profile_timer_exceptions_notify(struct notifier_block *self, 23 unsigned long val, void *data) 24{ 25 struct die_args *args = data; 26 int ret = NOTIFY_DONE; 27 28 switch (val) { 29 case DIE_NMI: 30 oprofile_add_sample(args->regs, 0); 31 ret = NOTIFY_STOP; 32 break; 33 default: 34 break; 35 } 36 return ret; 37} 38 39static struct notifier_block profile_timer_exceptions_nb = { 40 .notifier_call = profile_timer_exceptions_notify, 41}; 42 43static int timer_start(void) 44{ 45 if (register_die_notifier(&profile_timer_exceptions_nb)) 46 return 1; 47 nmi_adjust_hz(HZ); 48 return 0; 49} 50 51 52static void timer_stop(void) 53{ 54 nmi_adjust_hz(1); 55 unregister_die_notifier(&profile_timer_exceptions_nb); 56 synchronize_sched(); /* Allow already-started NMIs to complete. */ 57} 58 59static int op_nmi_timer_init(struct oprofile_operations *ops) 60{ 61 if (atomic_read(&nmi_active) <= 0) 62 return -ENODEV; 63 64 ops->start = timer_start; 65 ops->stop = timer_stop; 66 ops->cpu_type = "timer"; 67 printk(KERN_INFO "oprofile: Using perfctr NMI timer interrupt.\n"); 68 return 0; 69} 70#endif 71 72int __init oprofile_arch_init(struct oprofile_operations *ops) 73{ 74 int ret = -ENODEV; 75 76#ifdef CONFIG_SPARC64 77 ret = op_nmi_timer_init(ops); 78 if (!ret) 79 return ret; 80#endif 81 82 return ret; 83} 84 85void oprofile_arch_exit(void) 86{ 87} 88