summaryrefslogtreecommitdiff
path: root/arch/xtensa/kernel/mcount.S
diff options
context:
space:
mode:
authorMax Filippov <jcmvbkbc@gmail.com>2013-05-24 07:02:25 +0400
committerChris Zankel <chris@zankel.net>2013-07-08 01:18:57 -0700
commit478ba61afccd3a4d7ca662cadff1d35d183fe67d (patch)
tree9458a98aa39dba5e195241a48a4c31435a4c92e3 /arch/xtensa/kernel/mcount.S
parent220f5354089b27e8eeaa8658806dabc59ce55729 (diff)
xtensa: add static function tracer support
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
Diffstat (limited to 'arch/xtensa/kernel/mcount.S')
-rw-r--r--arch/xtensa/kernel/mcount.S50
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/mcount.S b/arch/xtensa/kernel/mcount.S
new file mode 100644
index 000000000000..0eeda2e4a25e
--- /dev/null
+++ b/arch/xtensa/kernel/mcount.S
@@ -0,0 +1,50 @@
+/*
+ * arch/xtensa/kernel/mcount.S
+ *
+ * Xtensa specific mcount support
+ *
+ * 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
+ * for more details.
+ *
+ * Copyright (C) 2013 Tensilica Inc.
+ */
+
+#include <linux/linkage.h>
+#include <asm/ftrace.h>
+
+/*
+ * Entry condition:
+ *
+ * a2: a0 of the caller
+ */
+
+ENTRY(_mcount)
+
+ entry a1, 16
+
+ movi a4, ftrace_trace_function
+ l32i a4, a4, 0
+ movi a3, ftrace_stub
+ bne a3, a4, 1f
+ retw
+
+1: xor a7, a2, a1
+ movi a3, 0x3fffffff
+ and a7, a7, a3
+ xor a7, a7, a1
+
+ xor a6, a0, a1
+ and a6, a6, a3
+ xor a6, a6, a1
+ addi a6, a6, -MCOUNT_INSN_SIZE
+ callx4 a4
+
+ retw
+
+ENDPROC(_mcount)
+
+ENTRY(ftrace_stub)
+ entry a1, 16
+ retw
+ENDPROC(ftrace_stub)