sh: Define HAVE_FUNCTION_TRACE_MCOUNT_TEST

Enable HAVE_FUNCTION_TRACE_MCOUNT_TEST and test the value of
function_trace_stop from our assembly code as opposed to using the
generic C function. This should optimise our mcount/ftrace code path.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 17 insertions, 1 deletions

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index e2bdd7b94fd9..801a4a79ffe3 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -31,6 +31,7 @@ config SUPERH32
         select HAVE_FUNCTION_TRACER
         select HAVE_FTRACE_MCOUNT_RECORD
         select HAVE_DYNAMIC_FTRACE
+        select HAVE_FUNCTION_TRACE_MCOUNT_TEST
         select HAVE_ARCH_KGDB
         select ARCH_HIBERNATION_POSSIBLE if MMU
 
diff --git a/arch/sh/lib/mcount.S b/arch/sh/lib/mcount.S
index 110fbfe1831f..cb87ef580b31 100644
--- a/arch/sh/lib/mcount.S
+++ b/arch/sh/lib/mcount.S
@@ -2,7 +2,7 @@
  * arch/sh/lib/mcount.S
  *
  *  Copyright (C) 2008  Paul Mundt
- *  Copyright (C) 2008  Matt Fleming
+ *  Copyright (C) 2008, 2009  Matt Fleming
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
@@ -35,6 +35,12 @@
         .type   mcount,@function
 _mcount:
 mcount:
+#ifndef CONFIG_DYNAMIC_FTRACE
+        mov.l   .Lfunction_trace_stop, r0
+        mov.l   @r0, r0
+        tst     r0, r0
+        bf      ftrace_stub
+#endif
         MCOUNT_ENTER()
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -62,6 +68,11 @@ skip_trace:
 #ifdef CONFIG_DYNAMIC_FTRACE
         .globl ftrace_caller
 ftrace_caller:
+        mov.l   .Lfunction_trace_stop, r0
+        mov.l   @r0, r0
+        tst     r0, r0
+        bf      ftrace_stub
+        
         MCOUNT_ENTER()
 
         .globl ftrace_call
@@ -88,3 +99,7 @@ ftrace_call:
 ftrace_stub:
         rts
          nop
+
+        .align 2
+.Lfunction_trace_stop:
+        .long   function_trace_stop