misc: nct1008: change overheat enable message
[linux-3.10.git] / drivers / oprofile / nmi_timer_int.c
1 /**
2  * @file nmi_timer_int.c
3  *
4  * @remark Copyright 2011 Advanced Micro Devices, Inc.
5  *
6  * @author Robert Richter <robert.richter@amd.com>
7  */
8
9 #include <linux/init.h>
10 #include <linux/smp.h>
11 #include <linux/errno.h>
12 #include <linux/oprofile.h>
13 #include <linux/perf_event.h>
14
15 #ifdef CONFIG_OPROFILE_NMI_TIMER
16
17 static DEFINE_PER_CPU(struct perf_event *, nmi_timer_events);
18 static int ctr_running;
19
20 static struct perf_event_attr nmi_timer_attr = {
21         .type           = PERF_TYPE_HARDWARE,
22         .config         = PERF_COUNT_HW_CPU_CYCLES,
23         .size           = sizeof(struct perf_event_attr),
24         .pinned         = 1,
25         .disabled       = 1,
26 };
27
28 static void nmi_timer_callback(struct perf_event *event,
29                                struct perf_sample_data *data,
30                                struct pt_regs *regs)
31 {
32         event->hw.interrupts = 0;       /* don't throttle interrupts */
33         oprofile_add_sample(regs, 0);
34 }
35
36 static int nmi_timer_start_cpu(int cpu)
37 {
38         struct perf_event *event = per_cpu(nmi_timer_events, cpu);
39
40         if (!event) {
41                 event = perf_event_create_kernel_counter(&nmi_timer_attr, cpu, NULL,
42                                                          nmi_timer_callback, NULL);
43                 if (IS_ERR(event))
44                         return PTR_ERR(event);
45                 per_cpu(nmi_timer_events, cpu) = event;
46         }
47
48         if (event && ctr_running)
49                 perf_event_enable(event);
50
51         return 0;
52 }
53
54 static void nmi_timer_stop_cpu(int cpu)
55 {
56         struct perf_event *event = per_cpu(nmi_timer_events, cpu);
57
58         if (event && ctr_running)
59                 perf_event_disable(event);
60 }
61
62 static int nmi_timer_cpu_notifier(struct notifier_block *b, unsigned long action,
63                                   void *data)
64 {
65         int cpu = (unsigned long)data;
66         switch (action) {
67         case CPU_DOWN_FAILED:
68         case CPU_ONLINE:
69                 nmi_timer_start_cpu(cpu);
70                 break;
71         case CPU_DOWN_PREPARE:
72                 nmi_timer_stop_cpu(cpu);
73                 break;
74         }
75         return NOTIFY_DONE;
76 }
77
78 static struct notifier_block nmi_timer_cpu_nb = {
79         .notifier_call = nmi_timer_cpu_notifier
80 };
81
82 static int nmi_timer_start(void)
83 {
84         int cpu;
85
86         get_online_cpus();
87         ctr_running = 1;
88         for_each_online_cpu(cpu)
89                 nmi_timer_start_cpu(cpu);
90         put_online_cpus();
91
92         return 0;
93 }
94
95 static void nmi_timer_stop(void)
96 {
97         int cpu;
98
99         get_online_cpus();
100         for_each_online_cpu(cpu)
101                 nmi_timer_stop_cpu(cpu);
102         ctr_running = 0;
103         put_online_cpus();
104 }
105
106 static void nmi_timer_shutdown(void)
107 {
108         struct perf_event *event;
109         int cpu;
110
111         get_online_cpus();
112         unregister_cpu_notifier(&nmi_timer_cpu_nb);
113         for_each_possible_cpu(cpu) {
114                 event = per_cpu(nmi_timer_events, cpu);
115                 if (!event)
116                         continue;
117                 perf_event_disable(event);
118                 per_cpu(nmi_timer_events, cpu) = NULL;
119                 perf_event_release_kernel(event);
120         }
121
122         put_online_cpus();
123 }
124
125 static int nmi_timer_setup(void)
126 {
127         int cpu, err;
128         u64 period;
129
130         /* clock cycles per tick: */
131         period = (u64)cpu_khz * 1000;
132         do_div(period, HZ);
133         nmi_timer_attr.sample_period = period;
134
135         get_online_cpus();
136         err = register_cpu_notifier(&nmi_timer_cpu_nb);
137         if (err)
138                 goto out;
139         /* can't attach events to offline cpus: */
140         for_each_online_cpu(cpu) {
141                 err = nmi_timer_start_cpu(cpu);
142                 if (err)
143                         break;
144         }
145         if (err)
146                 nmi_timer_shutdown();
147 out:
148         put_online_cpus();
149         return err;
150 }
151
152 int __init op_nmi_timer_init(struct oprofile_operations *ops)
153 {
154         int err = 0;
155
156         err = nmi_timer_setup();
157         if (err)
158                 return err;
159         nmi_timer_shutdown();           /* only check, don't alloc */
160
161         ops->create_files       = NULL;
162         ops->setup              = nmi_timer_setup;
163         ops->shutdown           = nmi_timer_shutdown;
164         ops->start              = nmi_timer_start;
165         ops->stop               = nmi_timer_stop;
166         ops->cpu_type           = "timer";
167
168         printk(KERN_INFO "oprofile: using NMI timer interrupt.\n");
169
170         return 0;
171 }
172
173 #endif