xref: /openbmc/linux/arch/xtensa/kernel/mcount.S (revision 293d5b43)
1/*
2 * arch/xtensa/kernel/mcount.S
3 *
4 * Xtensa specific mcount support
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License.  See the file "COPYING" in the main directory of this archive
8 * for more details.
9 *
10 * Copyright (C) 2013 Tensilica Inc.
11 */
12
13#include <linux/linkage.h>
14#include <asm/ftrace.h>
15
16/*
17 * Entry condition:
18 *
19 *   a2:	a0 of the caller
20 */
21
22ENTRY(_mcount)
23
24	entry	a1, 16
25
26	movi	a4, ftrace_trace_function
27	l32i	a4, a4, 0
28	movi	a3, ftrace_stub
29	bne	a3, a4, 1f
30	retw
31
321: 	xor	a7, a2, a1
33	movi	a3, 0x3fffffff
34	and	a7, a7, a3
35	xor	a7, a7, a1
36
37	xor	a6, a0, a1
38	and	a6, a6, a3
39	xor	a6, a6, a1
40	addi	a6, a6, -MCOUNT_INSN_SIZE
41	callx4	a4
42
43	retw
44
45ENDPROC(_mcount)
46
47ENTRY(ftrace_stub)
48	entry	a1, 16
49	retw
50ENDPROC(ftrace_stub)
51