From bb3c3c95f330f7bf16e33b002e48882616089db1 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Thu, 15 Jan 2009 20:40:23 -0500
Subject: ftrace: move function tracer functions out of trace.c

Impact: clean up of trace.c

The function tracer functions were put in trace.c because it needed
to share static variables that were in trace.c.  Since then, those
variables have become global for various reasons. This patch moves
the function tracer functions into trace_function.c where they belong.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace_functions.c | 84 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 83 insertions(+), 1 deletion(-)

(limited to 'kernel/trace/trace_functions.c')

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 3a5fa08cedb0..2dce3c7370d1 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -20,6 +20,7 @@ static struct trace_array	*func_trace;
 
 static void start_function_trace(struct trace_array *tr)
 {
+	func_trace = tr;
 	tr->cpu = get_cpu();
 	tracing_reset_online_cpus(tr);
 	put_cpu();
@@ -36,7 +37,6 @@ static void stop_function_trace(struct trace_array *tr)
 
 static int function_trace_init(struct trace_array *tr)
 {
-	func_trace = tr;
 	start_function_trace(tr);
 	return 0;
 }
@@ -51,6 +51,64 @@ static void function_trace_start(struct trace_array *tr)
 	tracing_reset_online_cpus(tr);
 }
 
+static void
+function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
+{
+	struct trace_array *tr = func_trace;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int cpu, resched;
+	int pc;
+
+	if (unlikely(!ftrace_function_enabled))
+		return;
+
+	pc = preempt_count();
+	resched = ftrace_preempt_disable();
+	local_save_flags(flags);
+	cpu = raw_smp_processor_id();
+	data = tr->data[cpu];
+	disabled = atomic_inc_return(&data->disabled);
+
+	if (likely(disabled == 1))
+		trace_function(tr, data, ip, parent_ip, flags, pc);
+
+	atomic_dec(&data->disabled);
+	ftrace_preempt_enable(resched);
+}
+
+static void
+function_trace_call(unsigned long ip, unsigned long parent_ip)
+{
+	struct trace_array *tr = func_trace;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int cpu;
+	int pc;
+
+	if (unlikely(!ftrace_function_enabled))
+		return;
+
+	/*
+	 * Need to use raw, since this must be called before the
+	 * recursive protection is performed.
+	 */
+	local_irq_save(flags);
+	cpu = raw_smp_processor_id();
+	data = tr->data[cpu];
+	disabled = atomic_inc_return(&data->disabled);
+
+	if (likely(disabled == 1)) {
+		pc = preempt_count();
+		trace_function(tr, data, ip, parent_ip, flags, pc);
+	}
+
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
+}
+
 static void
 function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
 {
@@ -90,6 +148,30 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
 	local_irq_restore(flags);
 }
 
+
+static struct ftrace_ops trace_ops __read_mostly =
+{
+	.func = function_trace_call,
+};
+
+void tracing_start_function_trace(void)
+{
+	ftrace_function_enabled = 0;
+
+	if (trace_flags & TRACE_ITER_PREEMPTONLY)
+		trace_ops.func = function_trace_call_preempt_only;
+	else
+		trace_ops.func = function_trace_call;
+
+	register_ftrace_function(&trace_ops);
+	ftrace_function_enabled = 1;
+}
+
+void tracing_stop_function_trace(void)
+{
+	ftrace_function_enabled = 0;
+	unregister_ftrace_function(&trace_ops);
+}
 static struct ftrace_ops trace_stack_ops __read_mostly =
 {
 	.func = function_stack_trace_call,
-- 
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