Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1/**
2 * @file timer_int.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/notifier.h>
12#include <linux/smp.h>
13#include <linux/oprofile.h>
14#include <linux/profile.h>
15#include <linux/init.h>
16#include <linux/cpu.h>
17#include <linux/hrtimer.h>
18#include <asm/irq_regs.h>
19#include <asm/ptrace.h>
20
21#include "oprof.h"
22
23static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
24
25static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
26{
27 oprofile_add_sample(get_irq_regs(), 0);
28 hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC));
29 return HRTIMER_RESTART;
30}
31
32static void __oprofile_hrtimer_start(void *unused)
33{
34 struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer);
35
36 hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
37 hrtimer->function = oprofile_hrtimer_notify;
38
39 hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC),
40 HRTIMER_MODE_REL_PINNED);
41}
42
43static int oprofile_hrtimer_start(void)
44{
45 on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
46 return 0;
47}
48
49static void __oprofile_hrtimer_stop(int cpu)
50{
51 struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
52
53 hrtimer_cancel(hrtimer);
54}
55
56static void oprofile_hrtimer_stop(void)
57{
58 int cpu;
59
60 for_each_online_cpu(cpu)
61 __oprofile_hrtimer_stop(cpu);
62}
63
64static int __cpuinit oprofile_cpu_notify(struct notifier_block *self,
65 unsigned long action, void *hcpu)
66{
67 long cpu = (long) hcpu;
68
69 switch (action) {
70 case CPU_ONLINE:
71 case CPU_ONLINE_FROZEN:
72 smp_call_function_single(cpu, __oprofile_hrtimer_start,
73 NULL, 1);
74 break;
75 case CPU_DEAD:
76 case CPU_DEAD_FROZEN:
77 __oprofile_hrtimer_stop(cpu);
78 break;
79 }
80 return NOTIFY_OK;
81}
82
83static struct notifier_block __refdata oprofile_cpu_notifier = {
84 .notifier_call = oprofile_cpu_notify,
85};
86
87int __init oprofile_timer_init(struct oprofile_operations *ops)
88{
89 int rc;
90
91 rc = register_hotcpu_notifier(&oprofile_cpu_notifier);
92 if (rc)
93 return rc;
94 ops->create_files = NULL;
95 ops->setup = NULL;
96 ops->shutdown = NULL;
97 ops->start = oprofile_hrtimer_start;
98 ops->stop = oprofile_hrtimer_stop;
99 ops->cpu_type = "timer";
100 return 0;
101}
102
103void __exit oprofile_timer_exit(void)
104{
105 unregister_hotcpu_notifier(&oprofile_cpu_notifier);
106}