media: soc_camera: tegra: fix one building warning
[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 static int ctr_running;
25
26 static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
27 {
28         oprofile_add_sample(get_irq_regs(), 0);
29         hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC));
30         return HRTIMER_RESTART;
31 }
32
33 static void __oprofile_hrtimer_start(void *unused)
34 {
35         struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer);
36
37         if (!ctr_running)
38                 return;
39
40         hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
41         hrtimer->function = oprofile_hrtimer_notify;
42
43         hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC),
44                       HRTIMER_MODE_REL_PINNED);
45 }
46
47 static int oprofile_hrtimer_start(void)
48 {
49         get_online_cpus();
50         ctr_running = 1;
51         on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
52         put_online_cpus();
53         return 0;
54 }
55
56 static void __oprofile_hrtimer_stop(int cpu)
57 {
58         struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
59
60         if (!ctr_running)
61                 return;
62
63         hrtimer_cancel(hrtimer);
64 }
65
66 static void oprofile_hrtimer_stop(void)
67 {
68         int cpu;
69
70         get_online_cpus();
71         for_each_online_cpu(cpu)
72                 __oprofile_hrtimer_stop(cpu);
73         ctr_running = 0;
74         put_online_cpus();
75 }
76
77 static int __cpuinit oprofile_cpu_notify(struct notifier_block *self,
78                                          unsigned long action, void *hcpu)
79 {
80         long cpu = (long) hcpu;
81
82         switch (action) {
83         case CPU_ONLINE:
84         case CPU_ONLINE_FROZEN:
85                 smp_call_function_single(cpu, __oprofile_hrtimer_start,
86                                          NULL, 1);
87                 break;
88         case CPU_DEAD:
89         case CPU_DEAD_FROZEN:
90                 __oprofile_hrtimer_stop(cpu);
91                 break;
92         }
93         return NOTIFY_OK;
94 }
95
96 static struct notifier_block __refdata oprofile_cpu_notifier = {
97         .notifier_call = oprofile_cpu_notify,
98 };
99
100 int oprofile_timer_init(struct oprofile_operations *ops)
101 {
102         int rc;
103
104         rc = register_hotcpu_notifier(&oprofile_cpu_notifier);
105         if (rc)
106                 return rc;
107         ops->create_files = NULL;
108         ops->setup = NULL;
109         ops->shutdown = NULL;
110         ops->start = oprofile_hrtimer_start;
111         ops->stop = oprofile_hrtimer_stop;
112         ops->cpu_type = "timer";
113         printk(KERN_INFO "oprofile: using timer interrupt.\n");
114         return 0;
115 }
116
117 void oprofile_timer_exit(void)
118 {
119         unregister_hotcpu_notifier(&oprofile_cpu_notifier);
120 }