1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * Mapping of DWARF debug register numbers into register names.
 4 *
 5 * Copyright (C) 2010 Ian Munsie, IBM Corporation.
 6 */
 7
 8#include <dwarf-regs.h>
 9
10#define PPC_OP(op)	(((op) >> 26) & 0x3F)
11#define PPC_RA(a)	(((a) >> 16) & 0x1f)
12#define PPC_RT(t)	(((t) >> 21) & 0x1f)
13#define PPC_RB(b)	(((b) >> 11) & 0x1f)
14#define PPC_D(D)	((D) & 0xfffe)
15#define PPC_DS(DS)	((DS) & 0xfffc)
16#define OP_LD	58
17#define OP_STD	62
18
19static int get_source_reg(u32 raw_insn)
20{
21	return PPC_RA(raw_insn);
22}
23
24static int get_target_reg(u32 raw_insn)
25{
26	return PPC_RT(raw_insn);
27}
28
29static int get_offset_opcode(u32 raw_insn)
30{
31	int opcode = PPC_OP(raw_insn);
32
33	/* DS- form */
34	if ((opcode == OP_LD) || (opcode == OP_STD))
35		return PPC_DS(raw_insn);
36	else
37		return PPC_D(raw_insn);
38}
39
40/*
41 * Fills the required fields for op_loc depending on if it
42 * is a source or target.
43 * D form: ins RT,D(RA) -> src_reg1 = RA, offset = D, dst_reg1 = RT
44 * DS form: ins RT,DS(RA) -> src_reg1 = RA, offset = DS, dst_reg1 = RT
45 * X form: ins RT,RA,RB -> src_reg1 = RA, src_reg2 = RB, dst_reg1 = RT
46 */
47void get_powerpc_regs(u32 raw_insn, int is_source,
48		struct annotated_op_loc *op_loc)
49{
50	if (is_source)
51		op_loc->reg1 = get_source_reg(raw_insn);
52	else
53		op_loc->reg1 = get_target_reg(raw_insn);
54
55	if (op_loc->multi_regs)
56		op_loc->reg2 = PPC_RB(raw_insn);
57
58	/* TODO: Implement offset handling for X Form */
59	if ((op_loc->mem_ref) && (PPC_OP(raw_insn) != 31))
60		op_loc->offset = get_offset_opcode(raw_insn);
61}