1*4882a593Smuzhiyun /**
2*4882a593Smuzhiyun * @file timer_int.c
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * @remark Copyright 2002 OProfile authors
5*4882a593Smuzhiyun * @remark Read the file COPYING
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * @author John Levon <levon@movementarian.org>
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/kernel.h>
11*4882a593Smuzhiyun #include <linux/notifier.h>
12*4882a593Smuzhiyun #include <linux/smp.h>
13*4882a593Smuzhiyun #include <linux/oprofile.h>
14*4882a593Smuzhiyun #include <linux/profile.h>
15*4882a593Smuzhiyun #include <linux/init.h>
16*4882a593Smuzhiyun #include <linux/cpu.h>
17*4882a593Smuzhiyun #include <linux/hrtimer.h>
18*4882a593Smuzhiyun #include <asm/irq_regs.h>
19*4882a593Smuzhiyun #include <asm/ptrace.h>
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun #include "oprof.h"
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
24*4882a593Smuzhiyun static int ctr_running;
25*4882a593Smuzhiyun
oprofile_hrtimer_notify(struct hrtimer * hrtimer)26*4882a593Smuzhiyun static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
27*4882a593Smuzhiyun {
28*4882a593Smuzhiyun oprofile_add_sample(get_irq_regs(), 0);
29*4882a593Smuzhiyun hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC));
30*4882a593Smuzhiyun return HRTIMER_RESTART;
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyun
__oprofile_hrtimer_start(void * unused)33*4882a593Smuzhiyun static void __oprofile_hrtimer_start(void *unused)
34*4882a593Smuzhiyun {
35*4882a593Smuzhiyun struct hrtimer *hrtimer = this_cpu_ptr(&oprofile_hrtimer);
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun if (!ctr_running)
38*4882a593Smuzhiyun return;
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
41*4882a593Smuzhiyun hrtimer->function = oprofile_hrtimer_notify;
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC),
44*4882a593Smuzhiyun HRTIMER_MODE_REL_PINNED);
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun
oprofile_hrtimer_start(void)47*4882a593Smuzhiyun static int oprofile_hrtimer_start(void)
48*4882a593Smuzhiyun {
49*4882a593Smuzhiyun get_online_cpus();
50*4882a593Smuzhiyun ctr_running = 1;
51*4882a593Smuzhiyun on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
52*4882a593Smuzhiyun put_online_cpus();
53*4882a593Smuzhiyun return 0;
54*4882a593Smuzhiyun }
55*4882a593Smuzhiyun
__oprofile_hrtimer_stop(int cpu)56*4882a593Smuzhiyun static void __oprofile_hrtimer_stop(int cpu)
57*4882a593Smuzhiyun {
58*4882a593Smuzhiyun struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun if (!ctr_running)
61*4882a593Smuzhiyun return;
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun hrtimer_cancel(hrtimer);
64*4882a593Smuzhiyun }
65*4882a593Smuzhiyun
oprofile_hrtimer_stop(void)66*4882a593Smuzhiyun static void oprofile_hrtimer_stop(void)
67*4882a593Smuzhiyun {
68*4882a593Smuzhiyun int cpu;
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun get_online_cpus();
71*4882a593Smuzhiyun for_each_online_cpu(cpu)
72*4882a593Smuzhiyun __oprofile_hrtimer_stop(cpu);
73*4882a593Smuzhiyun ctr_running = 0;
74*4882a593Smuzhiyun put_online_cpus();
75*4882a593Smuzhiyun }
76*4882a593Smuzhiyun
oprofile_timer_online(unsigned int cpu)77*4882a593Smuzhiyun static int oprofile_timer_online(unsigned int cpu)
78*4882a593Smuzhiyun {
79*4882a593Smuzhiyun local_irq_disable();
80*4882a593Smuzhiyun __oprofile_hrtimer_start(NULL);
81*4882a593Smuzhiyun local_irq_enable();
82*4882a593Smuzhiyun return 0;
83*4882a593Smuzhiyun }
84*4882a593Smuzhiyun
oprofile_timer_prep_down(unsigned int cpu)85*4882a593Smuzhiyun static int oprofile_timer_prep_down(unsigned int cpu)
86*4882a593Smuzhiyun {
87*4882a593Smuzhiyun __oprofile_hrtimer_stop(cpu);
88*4882a593Smuzhiyun return 0;
89*4882a593Smuzhiyun }
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun static enum cpuhp_state hp_online;
92*4882a593Smuzhiyun
oprofile_hrtimer_setup(void)93*4882a593Smuzhiyun static int oprofile_hrtimer_setup(void)
94*4882a593Smuzhiyun {
95*4882a593Smuzhiyun int ret;
96*4882a593Smuzhiyun
97*4882a593Smuzhiyun ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
98*4882a593Smuzhiyun "oprofile/timer:online",
99*4882a593Smuzhiyun oprofile_timer_online,
100*4882a593Smuzhiyun oprofile_timer_prep_down);
101*4882a593Smuzhiyun if (ret < 0)
102*4882a593Smuzhiyun return ret;
103*4882a593Smuzhiyun hp_online = ret;
104*4882a593Smuzhiyun return 0;
105*4882a593Smuzhiyun }
106*4882a593Smuzhiyun
oprofile_hrtimer_shutdown(void)107*4882a593Smuzhiyun static void oprofile_hrtimer_shutdown(void)
108*4882a593Smuzhiyun {
109*4882a593Smuzhiyun cpuhp_remove_state_nocalls(hp_online);
110*4882a593Smuzhiyun }
111*4882a593Smuzhiyun
oprofile_timer_init(struct oprofile_operations * ops)112*4882a593Smuzhiyun int oprofile_timer_init(struct oprofile_operations *ops)
113*4882a593Smuzhiyun {
114*4882a593Smuzhiyun ops->create_files = NULL;
115*4882a593Smuzhiyun ops->setup = oprofile_hrtimer_setup;
116*4882a593Smuzhiyun ops->shutdown = oprofile_hrtimer_shutdown;
117*4882a593Smuzhiyun ops->start = oprofile_hrtimer_start;
118*4882a593Smuzhiyun ops->stop = oprofile_hrtimer_stop;
119*4882a593Smuzhiyun ops->cpu_type = "timer";
120*4882a593Smuzhiyun printk(KERN_INFO "oprofile: using timer interrupt.\n");
121*4882a593Smuzhiyun return 0;
122*4882a593Smuzhiyun }
123