1/* SPDX-License-Identifier: GPL-2.0-or-later */
2#ifndef _ORC_TYPES_H
3#define _ORC_TYPES_H
4
5#include <linux/types.h>
6
7/*
8 * The ORC_REG_* registers are base registers which are used to find other
9 * registers on the stack.
10 *
11 * ORC_REG_PREV_SP, also known as DWARF Call Frame Address (CFA), is the
12 * address of the previous frame: the caller's SP before it called the current
13 * function.
14 *
15 * ORC_REG_UNDEFINED means the corresponding register's value didn't change in
16 * the current frame.
17 *
18 * The most commonly used base registers are SP and FP -- which the previous SP
19 * is usually based on -- and PREV_SP and UNDEFINED -- which the previous FP is
20 * usually based on.
21 *
22 * The rest of the base registers are needed for special cases like entry code
23 * and GCC realigned stacks.
24 */
25#define ORC_REG_UNDEFINED		0
26#define ORC_REG_PREV_SP			1
27#define ORC_REG_SP			2
28#define ORC_REG_FP			3
29#define ORC_REG_MAX			4
30
31#define ORC_TYPE_UNDEFINED		0
32#define ORC_TYPE_END_OF_STACK		1
33#define ORC_TYPE_CALL			2
34#define ORC_TYPE_REGS			3
35#define ORC_TYPE_REGS_PARTIAL		4
36
37#ifndef __ASSEMBLY__
38/*
39 * This struct is more or less a vastly simplified version of the DWARF Call
40 * Frame Information standard.  It contains only the necessary parts of DWARF
41 * CFI, simplified for ease of access by the in-kernel unwinder.  It tells the
42 * unwinder how to find the previous SP and FP (and sometimes entry regs) on
43 * the stack for a given code address.  Each instance of the struct corresponds
44 * to one or more code locations.
45 */
46struct orc_entry {
47	s16		sp_offset;
48	s16		fp_offset;
49	s16		ra_offset;
50	unsigned int	sp_reg:4;
51	unsigned int	fp_reg:4;
52	unsigned int	ra_reg:4;
53	unsigned int	type:3;
54	unsigned int	signal:1;
55};
56#endif /* __ASSEMBLY__ */
57
58#endif /* _ORC_TYPES_H */
59