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