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 pt_regs *regs)
  19 {
  20         int cpu = smp_processor_id();
  21         unsigned long eip = profile_pc(regs);
  22
  23         oprofile_add_sample(eip, !user_mode(regs), 0, cpu);
  24         return 0;
  25 }
  26
  27 static int timer_start(void)
  28 {
  29         return register_timer_hook(timer_notify);
  30 }
  31
  32
  33 static void timer_stop(void)
  34 {
  35         unregister_timer_hook(timer_notify);
  36 }
  37
  38
  39 static struct oprofile_operations timer_ops = {
  40         .start  = timer_start,
  41         .stop   = timer_stop,
  42         .cpu_type = "timer"
  43 };
  44
  45
  46 void __init timer_init(struct oprofile_operations ** ops)
  47 {
  48         *ops = &timer_ops;
  49         printk(KERN_INFO "oprofile: using timer interrupt.\n");
  50 }