Merge branch 'for-linus' from kernel.org:/.../shaggy/jfs-2.6 manually
[linux-2.6] / arch / i386 / oprofile / nmi_timer_int.c
1 /**
2  * @file nmi_timer_int.c
3  *
4  * @remark Copyright 2003 OProfile authors
5  * @remark Read the file COPYING
6  *
7  * @author Zwane Mwaikambo <zwane@linuxpower.ca>
8  */
9
10 #include <linux/init.h>
11 #include <linux/smp.h>
12 #include <linux/irq.h>
13 #include <linux/oprofile.h>
14 #include <linux/rcupdate.h>
15
16
17 #include <asm/nmi.h>
18 #include <asm/apic.h>
19 #include <asm/ptrace.h>
20  
21 static int nmi_timer_callback(struct pt_regs * regs, int cpu)
22 {
23         oprofile_add_sample(regs, 0);
24         return 1;
25 }
26
27 static int timer_start(void)
28 {
29         disable_timer_nmi_watchdog();
30         set_nmi_callback(nmi_timer_callback);
31         return 0;
32 }
33
34
35 static void timer_stop(void)
36 {
37         enable_timer_nmi_watchdog();
38         unset_nmi_callback();
39         synchronize_sched();  /* Allow already-started NMIs to complete. */
40 }
41
42
43 int __init op_nmi_timer_init(struct oprofile_operations * ops)
44 {
45         extern int nmi_active;
46
47         if (nmi_active <= 0)
48                 return -ENODEV;
49
50         ops->start = timer_start;
51         ops->stop = timer_stop;
52         ops->cpu_type = "timer";
53         printk(KERN_INFO "oprofile: using NMI timer interrupt.\n");
54         return 0;
55 }