blob: 010725117dbb0c81d042c7257a94724554425491 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/**
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>
Martin Schwidefskybc078e42010-03-02 16:01:10 +010016#include <linux/cpu.h>
17#include <linux/hrtimer.h>
18#include <asm/irq_regs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <asm/ptrace.h>
20
21#include "oprof.h"
22
Martin Schwidefskybc078e42010-03-02 16:01:10 +010023static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
Santosh Shilimkar4ac3dbe2010-10-27 11:17:15 -040024static int ctr_running;
Martin Schwidefskybc078e42010-03-02 16:01:10 +010025
26static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
Linus Torvalds1da177e2005-04-16 15:20:36 -070027{
Martin Schwidefskybc078e42010-03-02 16:01:10 +010028 oprofile_add_sample(get_irq_regs(), 0);
29 hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC));
30 return HRTIMER_RESTART;
31}
32
33static void __oprofile_hrtimer_start(void *unused)
34{
35 struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer);
36
Santosh Shilimkar4ac3dbe2010-10-27 11:17:15 -040037 if (!ctr_running)
38 return;
39
Martin Schwidefskybc078e42010-03-02 16:01:10 +010040 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
47static int oprofile_hrtimer_start(void)
48{
Santosh Shilimkar4ac3dbe2010-10-27 11:17:15 -040049 get_online_cpus();
50 ctr_running = 1;
Martin Schwidefskybc078e42010-03-02 16:01:10 +010051 on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
Santosh Shilimkar4ac3dbe2010-10-27 11:17:15 -040052 put_online_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 return 0;
54}
55
Martin Schwidefskybc078e42010-03-02 16:01:10 +010056static void __oprofile_hrtimer_stop(int cpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -070057{
Martin Schwidefskybc078e42010-03-02 16:01:10 +010058 struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
59
Santosh Shilimkar4ac3dbe2010-10-27 11:17:15 -040060 if (!ctr_running)
61 return;
62
Martin Schwidefskybc078e42010-03-02 16:01:10 +010063 hrtimer_cancel(hrtimer);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064}
65
Martin Schwidefskybc078e42010-03-02 16:01:10 +010066static void oprofile_hrtimer_stop(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{
Martin Schwidefskybc078e42010-03-02 16:01:10 +010068 int cpu;
69
Santosh Shilimkar4ac3dbe2010-10-27 11:17:15 -040070 get_online_cpus();
Martin Schwidefskybc078e42010-03-02 16:01:10 +010071 for_each_online_cpu(cpu)
72 __oprofile_hrtimer_stop(cpu);
Santosh Shilimkar4ac3dbe2010-10-27 11:17:15 -040073 ctr_running = 0;
74 put_online_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -070075}
76
Martin Schwidefskybc078e42010-03-02 16:01:10 +010077static int __cpuinit oprofile_cpu_notify(struct notifier_block *self,
78 unsigned long action, void *hcpu)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079{
Martin Schwidefskybc078e42010-03-02 16:01:10 +010080 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
96static struct notifier_block __refdata oprofile_cpu_notifier = {
97 .notifier_call = oprofile_cpu_notify,
98};
99
100int __init 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 ops->create_files = NULL;
108 ops->setup = NULL;
109 ops->shutdown = NULL;
Martin Schwidefskybc078e42010-03-02 16:01:10 +0100110 ops->start = oprofile_hrtimer_start;
111 ops->stop = oprofile_hrtimer_stop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 ops->cpu_type = "timer";
Martin Schwidefskybc078e42010-03-02 16:01:10 +0100113 return 0;
114}
115
116void __exit oprofile_timer_exit(void)
117{
118 unregister_hotcpu_notifier(&oprofile_cpu_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119}