aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace_power.c
blob: faa6ab7a1f5c589b92a9b4ea7e23f20168ea6263 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/*
 * ring buffer based C-state tracer
 *
 * Arjan van de Ven <arjan@linux.intel.com>
 * Copyright (C) 2008 Intel Corporation
 *
 * Much is borrowed from trace_boot.c which is
 * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
 *
 */

#include <linux/init.h>
#include <linux/debugfs.h>
#include <linux/ftrace.h>
#include <linux/kallsyms.h>
#include <linux/module.h>

#include "trace.h"
#include "trace_output.h"

static struct trace_array *power_trace;
static int __read_mostly trace_power_enabled;


static void start_power_trace(struct trace_array *tr)
{
	trace_power_enabled = 1;
}

static void stop_power_trace(struct trace_array *tr)
{
	trace_power_enabled = 0;
}


static int power_trace_init(struct trace_array *tr)
{
	int cpu;
	power_trace = tr;

	trace_power_enabled = 1;

	for_each_cpu(cpu, cpu_possible_mask)
		tracing_reset(tr, cpu);
	return 0;
}

static enum print_line_t power_print_line(struct trace_iterator *iter)
{
	int ret = 0;
	struct trace_entry *entry = iter->ent;
	struct trace_power *field ;
	struct power_trace *it;
	struct trace_seq *s = &iter->seq;
	struct timespec stamp;
	struct timespec duration;

	trace_assign_type(field, entry);
	it = &field->state_data;
	stamp = ktime_to_timespec(it->stamp);
	duration = ktime_to_timespec(ktime_sub(it->end, it->stamp));

	if (entry->type == TRACE_POWER) {
		if (it->type == POWER_CSTATE)
			ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n",
					  stamp.tv_sec,
					  stamp.tv_nsec,
					  it->state, iter->cpu,
					  duration.tv_sec,
					  duration.tv_nsec);
		if (it->type == POWER_PSTATE)
			ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n",
					  stamp.tv_sec,
					  stamp.tv_nsec,
					  it->state, iter->cpu);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
		return TRACE_TYPE_HANDLED;
	}
	return TRACE_TYPE_UNHANDLED;
}

static struct tracer power_tracer __read_mostly =
{
	.name		= "power",
	.init		= power_trace_init,
	.start		= start_power_trace,
	.stop		= stop_power_trace,
	.reset		= stop_power_trace,
	.print_line	= power_print_line,
};

static int init_power_trace(void)
{
	return register_tracer(&power_tracer);
}
device_initcall(init_power_trace);

void trace_power_start(struct power_trace *it, unsigned int type,
			 unsigned int level)
{
	if (!trace_power_enabled)
		return;

	memset(it, 0, sizeof(struct power_trace));
	it->state = level;
	it->type = type;
	it->stamp = ktime_get();
}
EXPORT_SYMBOL_GPL(trace_power_start);


void trace_power_end(struct power_trace *it)
{
	struct ring_buffer_event *event;
	struct trace_power *entry;
	struct trace_array_cpu *data;
	unsigned long irq_flags;
	struct trace_array *tr = power_trace;

	if (!trace_power_enabled)
		return;

	preempt_disable();
	it->end = ktime_get();
	data = tr->data[smp_processor_id()];

	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
					 &irq_flags);
	if (!event)
		goto out;
	entry	= ring_buffer_event_data(event);
	tracing_generic_entry_update(&entry->ent, 0, 0);
	entry->ent.type = TRACE_POWER;
	entry->state_data = *it;
	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);

	trace_wake_up();

 out:
	preempt_enable();
}
EXPORT_SYMBOL_GPL(trace_power_end);

void trace_power_mark(struct power_trace *it, unsigned int type,
			 unsigned int level)
{
	struct ring_buffer_event *event;
	struct trace_power *entry;
	struct trace_array_cpu *data;
	unsigned long irq_flags;
	struct trace_array *tr = power_trace;

	if (!trace_power_enabled)
		return;

	memset(it, 0, sizeof(struct power_trace));
	it->state = level;
	it->type = type;
	it->stamp = ktime_get();
	preempt_disable();
	it->end = it->stamp;
	data = tr->data[smp_processor_id()];

	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
					 &irq_flags);
	if (!event)
		goto out;
	entry	= ring_buffer_event_data(event);
	tracing_generic_entry_update(&entry->ent, 0, 0);
	entry->ent.type = TRACE_POWER;
	entry->state_data = *it;
	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);

	trace_wake_up();

 out:
	preempt_enable();
}
EXPORT_SYMBOL_GPL(trace_power_mark);