blob: e3ecb71b5790228073d5eb089f4a4fc9303ab09a [file] [log] [blame]
/**
* @file nmi_timer_int.c
*
* @remark Copyright 2003 OProfile authors
* @remark Read the file COPYING
*
* @author Zwane Mwaikambo <zwane@linuxpower.ca>
*/
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/oprofile.h>
#include <linux/rcupdate.h>
#include <linux/kdebug.h>
#include <asm/nmi.h>
#include <asm/apic.h>
#include <asm/ptrace.h>
static int profile_timer_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data)
{
struct die_args *args = (struct die_args *)data;
int ret = NOTIFY_DONE;
switch (val) {
case DIE_NMI:
oprofile_add_sample(args->regs, 0);
ret = NOTIFY_STOP;
break;
default:
break;
}
return ret;
}
static struct notifier_block profile_timer_exceptions_nb = {
.notifier_call = profile_timer_exceptions_notify,
.next = NULL,
.priority = 0
};
static int timer_start(void)
{
if (register_die_notifier(&profile_timer_exceptions_nb))
return 1;
return 0;
}
static void timer_stop(void)
{
unregister_die_notifier(&profile_timer_exceptions_nb);
synchronize_sched(); /* Allow already-started NMIs to complete. */
}
int __init op_nmi_timer_init(struct oprofile_operations *ops)
{
if ((nmi_watchdog != NMI_IO_APIC) || (atomic_read(&nmi_active) <= 0))
return -ENODEV;
ops->start = timer_start;
ops->stop = timer_stop;
ops->cpu_type = "timer";
printk(KERN_INFO "oprofile: using NMI timer interrupt.\n");
return 0;
}