text: /**
   * @file perfmon.c
   *
   * @remark Copyright 2003 OProfile authors
   * @remark Read the file COPYING
   *
   * @author John Levon <levon@movementarian.org>
   */
  
  #include <linux/kernel.h>
  #include <linux/config.h>
  #include <linux/oprofile.h>
  #include <linux/sched.h>
  #include <asm/perfmon.h>
  #include <asm/ptrace.h>
  #include <asm/errno.h>
  
  static int allow_ints;
  
  static int
  perfmon_handler(struct task_struct *task, void *buf, pfm_ovfl_arg_t *arg,
                  struct pt_regs *regs, unsigned long stamp)
  {
  	int event = arg->pmd_eventid;
   
  	arg->ovfl_ctrl.bits.reset_ovfl_pmds = 1;
  
  	/* the owner of the oprofile event buffer may have exited
  	 * without perfmon being shutdown (e.g. SIGSEGV)
  	 */
  	if (allow_ints)
  		oprofile_add_sample(regs, event);
  	return 0;
  }
  
  
  static int perfmon_start(void)
  {
  	allow_ints = 1;
  	return 0;
  }
  
  
  static void perfmon_stop(void)
  {
  	allow_ints = 0;
  }
  
  
  #define OPROFILE_FMT_UUID { \
  	0x77, 0x7a, 0x6e, 0x61, 0x20, 0x65, 0x73, 0x69, 0x74, 0x6e, 0x72, 0x20, 0x61, 0x65, 0x0a, 0x6c }
  
  static pfm_buffer_fmt_t oprofile_fmt = {
   	.fmt_name 	    = "oprofile_format",
   	.fmt_uuid	    = OPROFILE_FMT_UUID,
   	.fmt_handler	    = perfmon_handler,
  };
  
  
  static char * get_cpu_type(void)
  {
  	__u8 family = local_cpu_data->family;
  
  	switch (family) {
  		case 0x07:
  			return "ia64/itanium";
  		case 0x1f:
  			return "ia64/itanium2";
  		default:
  			return "ia64/ia64";
  	}
  }
  
  
  /* all the ops are handled via userspace for IA64 perfmon */
  
  static int using_perfmon;
  
  int perfmon_init(struct oprofile_operations * ops)
  {
  	int ret = pfm_register_buffer_fmt(&oprofile_fmt);
  	if (ret)
  		return -ENODEV;
  
  	ops->cpu_type = get_cpu_type();
  	ops->start = perfmon_start;
  	ops->stop = perfmon_stop;
  	using_perfmon = 1;
  	printk(KERN_INFO "oprofile: using perfmon.\n");
  	return 0;
  }
  
  
  void perfmon_exit(void)
  {
  	if (!using_perfmon)
  		return;
  
  	pfm_unregister_buffer_fmt(oprofile_fmt.fmt_uuid);
  }
  