1 /*
2 * ring buffer based C-state tracer
3 *
4 * Arjan van de Ven <arjan@linux.intel.com>
5 * Copyright (C) 2008 Intel Corporation
6 *
7 * Much is borrowed from trace_boot.c which is
8 * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
9 *
10 */
11
12 #include <linux/init.h>
13 #include <linux/debugfs.h>
14 #include <linux/ftrace.h>
15 #include <linux/kallsyms.h>
16 #include <linux/module.h>
17
18 #include "trace.h"
19
20 static struct trace_array *power_trace;
21 static int __read_mostly trace_power_enabled;
22
23
start_power_trace(struct trace_array * tr)24 static void start_power_trace(struct trace_array *tr)
25 {
26 trace_power_enabled = 1;
27 }
28
stop_power_trace(struct trace_array * tr)29 static void stop_power_trace(struct trace_array *tr)
30 {
31 trace_power_enabled = 0;
32 }
33
34
power_trace_init(struct trace_array * tr)35 static int power_trace_init(struct trace_array *tr)
36 {
37 int cpu;
38 power_trace = tr;
39
40 trace_power_enabled = 1;
41
42 for_each_cpu(cpu, cpu_possible_mask)
43 tracing_reset(tr, cpu);
44 return 0;
45 }
46
power_print_line(struct trace_iterator * iter)47 static enum print_line_t power_print_line(struct trace_iterator *iter)
48 {
49 int ret = 0;
50 struct trace_entry *entry = iter->ent;
51 struct trace_power *field ;
52 struct power_trace *it;
53 struct trace_seq *s = &iter->seq;
54 struct timespec stamp;
55 struct timespec duration;
56
57 trace_assign_type(field, entry);
58 it = &field->state_data;
59 stamp = ktime_to_timespec(it->stamp);
60 duration = ktime_to_timespec(ktime_sub(it->end, it->stamp));
61
62 if (entry->type == TRACE_POWER) {
63 if (it->type == POWER_CSTATE)
64 ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n",
65 stamp.tv_sec,
66 stamp.tv_nsec,
67 it->state, iter->cpu,
68 duration.tv_sec,
69 duration.tv_nsec);
70 if (it->type == POWER_PSTATE)
71 ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n",
72 stamp.tv_sec,
73 stamp.tv_nsec,
74 it->state, iter->cpu);
75 if (!ret)
76 return TRACE_TYPE_PARTIAL_LINE;
77 return TRACE_TYPE_HANDLED;
78 }
79 return TRACE_TYPE_UNHANDLED;
80 }
81
82 static struct tracer power_tracer __read_mostly =
83 {
84 .name = "power",
85 .init = power_trace_init,
86 .start = start_power_trace,
87 .stop = stop_power_trace,
88 .reset = stop_power_trace,
89 .print_line = power_print_line,
90 };
91
init_power_trace(void)92 static int init_power_trace(void)
93 {
94 return register_tracer(&power_tracer);
95 }
96 device_initcall(init_power_trace);
97
trace_power_start(struct power_trace * it,unsigned int type,unsigned int level)98 void trace_power_start(struct power_trace *it, unsigned int type,
99 unsigned int level)
100 {
101 if (!trace_power_enabled)
102 return;
103
104 memset(it, 0, sizeof(struct power_trace));
105 it->state = level;
106 it->type = type;
107 it->stamp = ktime_get();
108 }
109 EXPORT_SYMBOL_GPL(trace_power_start);
110
111
trace_power_end(struct power_trace * it)112 void trace_power_end(struct power_trace *it)
113 {
114 struct ring_buffer_event *event;
115 struct trace_power *entry;
116 struct trace_array_cpu *data;
117 unsigned long irq_flags;
118 struct trace_array *tr = power_trace;
119
120 if (!trace_power_enabled)
121 return;
122
123 preempt_disable();
124 it->end = ktime_get();
125 data = tr->data[smp_processor_id()];
126
127 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
128 &irq_flags);
129 if (!event)
130 goto out;
131 entry = ring_buffer_event_data(event);
132 tracing_generic_entry_update(&entry->ent, 0, 0);
133 entry->ent.type = TRACE_POWER;
134 entry->state_data = *it;
135 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
136
137 trace_wake_up();
138
139 out:
140 preempt_enable();
141 }
142 EXPORT_SYMBOL_GPL(trace_power_end);
143
trace_power_mark(struct power_trace * it,unsigned int type,unsigned int level)144 void trace_power_mark(struct power_trace *it, unsigned int type,
145 unsigned int level)
146 {
147 struct ring_buffer_event *event;
148 struct trace_power *entry;
149 struct trace_array_cpu *data;
150 unsigned long irq_flags;
151 struct trace_array *tr = power_trace;
152
153 if (!trace_power_enabled)
154 return;
155
156 memset(it, 0, sizeof(struct power_trace));
157 it->state = level;
158 it->type = type;
159 it->stamp = ktime_get();
160 preempt_disable();
161 it->end = it->stamp;
162 data = tr->data[smp_processor_id()];
163
164 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
165 &irq_flags);
166 if (!event)
167 goto out;
168 entry = ring_buffer_event_data(event);
169 tracing_generic_entry_update(&entry->ent, 0, 0);
170 entry->ent.type = TRACE_POWER;
171 entry->state_data = *it;
172 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
173
174 trace_wake_up();
175
176 out:
177 preempt_enable();
178 }
179 EXPORT_SYMBOL_GPL(trace_power_mark);
180