1 // SPDX-License-Identifier: GPL-2.0
2 #include <elfutils/libdwfl.h>
3 #include <linux/kernel.h>
4 #include "../../../util/unwind-libdw.h"
5 #include "../../../util/perf_regs.h"
6 #include "../../../util/sample.h"
7 
8 /* See backends/ppc_initreg.c and backends/ppc_regs.c in elfutils.  */
9 static const int special_regs[3][2] = {
10 	{ 65, PERF_REG_POWERPC_LINK },
11 	{ 101, PERF_REG_POWERPC_XER },
12 	{ 109, PERF_REG_POWERPC_CTR },
13 };
14 
15 bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg)
16 {
17 	struct unwind_info *ui = arg;
18 	struct regs_dump *user_regs = &ui->sample->user_regs;
19 	Dwarf_Word dwarf_regs[32], dwarf_nip;
20 	size_t i;
21 
22 #define REG(r) ({						\
23 	Dwarf_Word val = 0;					\
24 	perf_reg_value(&val, user_regs, PERF_REG_POWERPC_##r);	\
25 	val;							\
26 })
27 
28 	dwarf_regs[0]  = REG(R0);
29 	dwarf_regs[1]  = REG(R1);
30 	dwarf_regs[2]  = REG(R2);
31 	dwarf_regs[3]  = REG(R3);
32 	dwarf_regs[4]  = REG(R4);
33 	dwarf_regs[5]  = REG(R5);
34 	dwarf_regs[6]  = REG(R6);
35 	dwarf_regs[7]  = REG(R7);
36 	dwarf_regs[8]  = REG(R8);
37 	dwarf_regs[9]  = REG(R9);
38 	dwarf_regs[10] = REG(R10);
39 	dwarf_regs[11] = REG(R11);
40 	dwarf_regs[12] = REG(R12);
41 	dwarf_regs[13] = REG(R13);
42 	dwarf_regs[14] = REG(R14);
43 	dwarf_regs[15] = REG(R15);
44 	dwarf_regs[16] = REG(R16);
45 	dwarf_regs[17] = REG(R17);
46 	dwarf_regs[18] = REG(R18);
47 	dwarf_regs[19] = REG(R19);
48 	dwarf_regs[20] = REG(R20);
49 	dwarf_regs[21] = REG(R21);
50 	dwarf_regs[22] = REG(R22);
51 	dwarf_regs[23] = REG(R23);
52 	dwarf_regs[24] = REG(R24);
53 	dwarf_regs[25] = REG(R25);
54 	dwarf_regs[26] = REG(R26);
55 	dwarf_regs[27] = REG(R27);
56 	dwarf_regs[28] = REG(R28);
57 	dwarf_regs[29] = REG(R29);
58 	dwarf_regs[30] = REG(R30);
59 	dwarf_regs[31] = REG(R31);
60 	if (!dwfl_thread_state_registers(thread, 0, 32, dwarf_regs))
61 		return false;
62 
63 	dwarf_nip = REG(NIP);
64 	dwfl_thread_state_register_pc(thread, dwarf_nip);
65 	for (i = 0; i < ARRAY_SIZE(special_regs); i++) {
66 		Dwarf_Word val = 0;
67 		perf_reg_value(&val, user_regs, special_regs[i][1]);
68 		if (!dwfl_thread_state_registers(thread,
69 						 special_regs[i][0], 1,
70 						 &val))
71 			return false;
72 	}
73 
74 	return true;
75 }
76