arch/x86/oprofile/init.c

   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/oprofile.h>
  11 #include <linux/init.h>
  12 #include <linux/errno.h>
  13
  14 /*
  15  * We support CPUs that have performance counters like the Pentium Pro
  16  * with the NMI mode driver.
  17  */
  18
  19 extern int op_nmi_init(struct oprofile_operations *ops);
  20 extern int op_nmi_timer_init(struct oprofile_operations *ops);
  21 extern void op_nmi_exit(void);
  22 extern void x86_backtrace(struct pt_regs * const regs, unsigned int depth);
  23
  24 static int nmi_timer;
  25
  26 int __init oprofile_arch_init(struct oprofile_operations *ops)
  27 {
  28         int ret;
  29
  30         ret = -ENODEV;
  31
  32 #ifdef CONFIG_X86_LOCAL_APIC
  33         ret = op_nmi_init(ops);
  34 #endif
  35         nmi_timer = (ret != 0);
  36 #ifdef CONFIG_X86_IO_APIC
  37         if (nmi_timer)
  38                 ret = op_nmi_timer_init(ops);
  39 #endif
  40         ops->backtrace = x86_backtrace;
  41
  42         return ret;
  43 }
  44
  45
  46 void oprofile_arch_exit(void)
  47 {
  48 #ifdef CONFIG_X86_LOCAL_APIC
  49         if (!nmi_timer)
  50                 op_nmi_exit();
  51 #endif
  52 }