| 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 | |
| 24 | static void start_power_trace(struct trace_array *tr) |
| 25 | { |
| 26 | trace_power_enabled = 1; |
| 27 | } |
| 28 | |
| 29 | static void stop_power_trace(struct trace_array *tr) |
| 30 | { |
| 31 | trace_power_enabled = 0; |
| 32 | } |
| 33 | |
| 34 | |
| 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_mask(cpu, cpu_possible_map) |
| 43 | tracing_reset(tr, cpu); |
| 44 | return 0; |
| 45 | } |
| 46 | |
| 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 | |
| 92 | static int init_power_trace(void) |
| 93 | { |
| 94 | return register_tracer(&power_tracer); |
| 95 | } |
| 96 | device_initcall(init_power_trace); |
| 97 | |
| 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 | |
| 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 | |
| 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); |