2 files changed, 105 insertions, 0 deletions

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index cb2c3fb..b28bf88 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -6,6 +6,7 @@
 #include <linux/sched.h>
 #include <linux/clocksource.h>
 #include <linux/mmiotrace.h>
+#include <linux/ftrace.h>
 
 enum trace_type {
 	__TRACE_FIRST_TYPE = 0,
@@ -19,6 +20,7 @@ enum trace_type {
 	TRACE_SPECIAL,
 	TRACE_MMIO_RW,
 	TRACE_MMIO_MAP,
+	TRACE_BOOT,
 
 	__TRACE_LAST_TYPE
 };
@@ -30,6 +32,7 @@ struct ftrace_entry {
 	unsigned long		ip;
 	unsigned long		parent_ip;
 };
+extern struct tracer boot_tracer;
 
 /*
  * Context switch trace entry - which task (and prio) we switched from/to:
@@ -108,6 +111,7 @@ struct trace_field {
 		struct print_entry		print;
 		struct mmiotrace_rw		mmiorw;
 		struct mmiotrace_map		mmiomap;
+		struct boot_trace		initcall;
 	};
 };
 
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
new file mode 100644
index 0000000..c65ef8f
--- /dev/null
+++ b/kernel/trace/trace_boot.c
@@ -0,0 +1,101 @@
+/*
+ * 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->data[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 = 1;
+	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 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()];
+
+	raw_local_irq_save(irq_flags);
+	__raw_spin_lock(&data->lock);
+
+	entry = tracing_get_trace_entry(tr, data);
+	tracing_generic_entry_update(entry, 0);
+	entry->type = TRACE_BOOT;
+	entry->field.initcall = *it;
+
+	__raw_spin_unlock(&data->lock);
+	raw_local_irq_restore(irq_flags);
+	trace_wake_up();
+
+	preempt_enable();
+}