drivers/oprofile/timer_int.c

   1 /**
   2  * @file timer_int.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/notifier.h>
  12 #include <linux/smp.h>
  13 #include <linux/oprofile.h>
  14 #include <linux/profile.h>
  15 #include <linux/init.h>
  16 #include <asm/ptrace.h>
  17
  18 static int timer_notify(struct notifier_block * self, unsigned long val, void * data)
  19 {
  20         struct pt_regs * regs = (struct pt_regs *)data;
  21         int cpu = smp_processor_id();
  22         unsigned long eip = profile_pc(regs);
  23
  24         oprofile_add_sample(eip, !user_mode(regs), 0, cpu);
  25         return 0;
  26 }
  27
  28
  29 static struct notifier_block timer_notifier = {
  30         .notifier_call  = timer_notify,
  31 };
  32
  33
  34 static int timer_start(void)
  35 {
  36         return register_profile_notifier(&timer_notifier);
  37 }
  38
  39
  40 static void timer_stop(void)
  41 {
  42         unregister_profile_notifier(&timer_notifier);
  43 }
  44
  45
  46 static struct oprofile_operations timer_ops = {
  47         .start  = timer_start,
  48         .stop   = timer_stop,
  49         .cpu_type = "timer"
  50 };
  51
  52
  53 void __init timer_init(struct oprofile_operations ** ops)
  54 {
  55         *ops = &timer_ops;
  56         printk(KERN_INFO "oprofile: using timer interrupt.\n");
  57 }