Root/arch/sparc/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/kernel.h>
11#include <linux/oprofile.h>
12#include <linux/errno.h>
13#include <linux/init.h>
14#include <linux/param.h> /* for HZ */
15 
16#ifdef CONFIG_SPARC64
17#include <linux/notifier.h>
18#include <linux/rcupdate.h>
19#include <linux/kdebug.h>
20#include <asm/nmi.h>
21
22static int profile_timer_exceptions_notify(struct notifier_block *self,
23                       unsigned long val, void *data)
24{
25    struct die_args *args = data;
26    int ret = NOTIFY_DONE;
27
28    switch (val) {
29    case DIE_NMI:
30        oprofile_add_sample(args->regs, 0);
31        ret = NOTIFY_STOP;
32        break;
33    default:
34        break;
35    }
36    return ret;
37}
38
39static struct notifier_block profile_timer_exceptions_nb = {
40    .notifier_call = profile_timer_exceptions_notify,
41};
42
43static int timer_start(void)
44{
45    if (register_die_notifier(&profile_timer_exceptions_nb))
46        return 1;
47    nmi_adjust_hz(HZ);
48    return 0;
49}
50
51
52static void timer_stop(void)
53{
54    nmi_adjust_hz(1);
55    unregister_die_notifier(&profile_timer_exceptions_nb);
56    synchronize_sched(); /* Allow already-started NMIs to complete. */
57}
58
59static int op_nmi_timer_init(struct oprofile_operations *ops)
60{
61    if (atomic_read(&nmi_active) <= 0)
62        return -ENODEV;
63
64    ops->start = timer_start;
65    ops->stop = timer_stop;
66    ops->cpu_type = "timer";
67    printk(KERN_INFO "oprofile: Using perfctr NMI timer interrupt.\n");
68    return 0;
69}
70#endif
71
72int __init oprofile_arch_init(struct oprofile_operations *ops)
73{
74    int ret = -ENODEV;
75
76#ifdef CONFIG_SPARC64
77    ret = op_nmi_timer_init(ops);
78    if (!ret)
79        return ret;
80#endif
81
82    return ret;
83}
84
85void oprofile_arch_exit(void)
86{
87}
88

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