Blackfin: implement ftrace mcount test

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

2 files changed, 11 insertions, 1 deletions

diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index f46db59eac8a..3123aa49ff79 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -25,6 +25,7 @@ config BLACKFIN
         def_bool y
         select HAVE_FUNCTION_GRAPH_TRACER
         select HAVE_FUNCTION_TRACER
+        select HAVE_FUNCTION_TRACE_MCOUNT_TEST
         select HAVE_IDE
         select HAVE_KERNEL_GZIP if RAMKERNEL
         select HAVE_KERNEL_BZIP2 if RAMKERNEL
diff --git a/arch/blackfin/kernel/ftrace-entry.S b/arch/blackfin/kernel/ftrace-entry.S
index 76dd4fbcd17a..db3a51b0af21 100644
--- a/arch/blackfin/kernel/ftrace-entry.S
+++ b/arch/blackfin/kernel/ftrace-entry.S
@@ -1,7 +1,7 @@
 /*
  * mcount and friends -- ftrace stuff
  *
- * Copyright (C) 2009 Analog Devices Inc.
+ * Copyright (C) 2009-2010 Analog Devices Inc.
  * Licensed under the GPL-2 or later.
  */
 
@@ -21,6 +21,15 @@
  * function will be waiting there.  mmmm pie.
  */
 ENTRY(__mcount)
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+        /* optional micro optimization: return if stopped */
+        p1.l = _function_trace_stop;
+        p1.h = _function_trace_stop;
+        r3 = [p1];
+        cc = r3 == 0;
+        if ! cc jump _ftrace_stub (bp);
+#endif
+
         /* save third function arg early so we can do testing below */
         [--sp] = r2;