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/*
* ring buffer based initcalls tracer
*
* Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
*
*/
#include <linux/init.h>
#include <linux/debugfs.h>
#include <linux/ftrace.h>
#include "trace.h"
static struct trace_array *boot_trace;
static int trace_boot_enabled;
/* Should be started after do_pre_smp_initcalls() in init/main.c */
void start_boot_trace(void)
{
trace_boot_enabled = 1;
}
void stop_boot_trace(struct trace_array *tr)
{
trace_boot_enabled = 0;
}
static void boot_trace_init(struct trace_array *tr)
{
int cpu;
boot_trace = tr;
trace_boot_enabled = 0;
for_each_cpu_mask(cpu, cpu_possible_map)
tracing_reset(tr, cpu);
}
static void boot_trace_ctrl_update(struct trace_array *tr)
{
if (tr->ctrl)
start_boot_trace();
else
stop_boot_trace(tr);
}
static int initcall_print_line(struct trace_iterator *iter)
{
int ret = 0;
struct trace_entry *entry = iter->ent;
struct boot_trace *it = &entry->field.initcall;
struct trace_seq *s = &iter->seq;
if (iter->ent->type == TRACE_BOOT)
ret = trace_seq_printf(s, "%pF called from %i "
"returned %d after %lld msecs\n",
it->func, it->caller, it->result,
it->duration);
if (ret)
return 1;
return 0;
}
struct tracer boot_tracer __read_mostly =
{
.name = "initcall",
.init = boot_trace_init,
.reset = stop_boot_trace,
.ctrl_update = boot_trace_ctrl_update,
.print_line = initcall_print_line,
};
void trace_boot(struct boot_trace *it)
{
struct ring_buffer_event *event;
struct trace_entry *entry;
struct trace_array_cpu *data;
unsigned long irq_flags;
struct trace_array *tr = boot_trace;
if (!trace_boot_enabled)
return;
preempt_disable();
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, 0);
entry->type = TRACE_BOOT;
entry->field.initcall = *it;
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
trace_wake_up();
out:
preempt_enable();
}
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