Merge remote-tracking branches 'asoc/fix/cs4270', 'asoc/fix/da7219', 'asoc/fix/hdmi...
[linux-2.6-microblaze.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 = this_cpu_ptr(&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 oprofile_timer_online(unsigned int cpu)
78 {
79         local_irq_disable();
80         __oprofile_hrtimer_start(NULL);
81         local_irq_enable();
82         return 0;
83 }
84
85 static int oprofile_timer_prep_down(unsigned int cpu)
86 {
87         __oprofile_hrtimer_stop(cpu);
88         return 0;
89 }
90
91 static enum cpuhp_state hp_online;
92
93 static int oprofile_hrtimer_setup(void)
94 {
95         int ret;
96
97         ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
98                                         "oprofile/timer:online",
99                                         oprofile_timer_online,
100                                         oprofile_timer_prep_down);
101         if (ret < 0)
102                 return ret;
103         hp_online = ret;
104         return 0;
105 }
106
107 static void oprofile_hrtimer_shutdown(void)
108 {
109         cpuhp_remove_state_nocalls(hp_online);
110 }
111
112 int oprofile_timer_init(struct oprofile_operations *ops)
113 {
114         ops->create_files       = NULL;
115         ops->setup              = oprofile_hrtimer_setup;
116         ops->shutdown           = oprofile_hrtimer_shutdown;
117         ops->start              = oprofile_hrtimer_start;
118         ops->stop               = oprofile_hrtimer_stop;
119         ops->cpu_type           = "timer";
120         printk(KERN_INFO "oprofile: using timer interrupt.\n");
121         return 0;
122 }