oprofile: convert oprofile from timer_hook to hrtimer
[linux-2.6.git] / drivers / oprofile / timer_int.c
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
23 static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
24
25 static 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
32 static 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
43 static int oprofile_hrtimer_start(void)
44 {
45         on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
46         return 0;
47 }
48
49 static void __oprofile_hrtimer_stop(int cpu)
50 {
51         struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
52
53         hrtimer_cancel(hrtimer);
54 }
55
56 static void oprofile_hrtimer_stop(void)
57 {
58         int cpu;
59
60         for_each_online_cpu(cpu)
61                 __oprofile_hrtimer_stop(cpu);
62 }
63
64 static 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
83 static struct notifier_block __refdata oprofile_cpu_notifier = {
84         .notifier_call = oprofile_cpu_notify,
85 };
86
87 int __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
103 void __exit oprofile_timer_exit(void)
104 {
105         unregister_hotcpu_notifier(&oprofile_cpu_notifier);
106 }