/*
 * Mapping of DWARF debug register numbers into register names.
 *
 * Copyright (C) 2010 Ian Munsie, IBM Corporation.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <stddef.h>
#include <errno.h>
#include <string.h>
#include <dwarf-regs.h>
#include <linux/ptrace.h>
#include <linux/kernel.h>
#include "util.h"

struct pt_regs_dwarfnum {
	const char *name;
	unsigned int dwarfnum;
	unsigned int ptregs_offset;
};

#define REG_DWARFNUM_NAME(r, num)					\
		{.name = STR(%)STR(r), .dwarfnum = num,			\
		.ptregs_offset = offsetof(struct pt_regs, r)}
#define GPR_DWARFNUM_NAME(num)						\
		{.name = STR(%gpr##num), .dwarfnum = num,		\
		.ptregs_offset = offsetof(struct pt_regs, gpr[num])}
#define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0, .ptregs_offset = 0}

/*
 * Reference:
 * http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi-1.9.html
 */
static const struct pt_regs_dwarfnum regdwarfnum_table[] = {
	GPR_DWARFNUM_NAME(0),
	GPR_DWARFNUM_NAME(1),
	GPR_DWARFNUM_NAME(2),
	GPR_DWARFNUM_NAME(3),
	GPR_DWARFNUM_NAME(4),
	GPR_DWARFNUM_NAME(5),
	GPR_DWARFNUM_NAME(6),
	GPR_DWARFNUM_NAME(7),
	GPR_DWARFNUM_NAME(8),
	GPR_DWARFNUM_NAME(9),
	GPR_DWARFNUM_NAME(10),
	GPR_DWARFNUM_NAME(11),
	GPR_DWARFNUM_NAME(12),
	GPR_DWARFNUM_NAME(13),
	GPR_DWARFNUM_NAME(14),
	GPR_DWARFNUM_NAME(15),
	GPR_DWARFNUM_NAME(16),
	GPR_DWARFNUM_NAME(17),
	GPR_DWARFNUM_NAME(18),
	GPR_DWARFNUM_NAME(19),
	GPR_DWARFNUM_NAME(20),
	GPR_DWARFNUM_NAME(21),
	GPR_DWARFNUM_NAME(22),
	GPR_DWARFNUM_NAME(23),
	GPR_DWARFNUM_NAME(24),
	GPR_DWARFNUM_NAME(25),
	GPR_DWARFNUM_NAME(26),
	GPR_DWARFNUM_NAME(27),
	GPR_DWARFNUM_NAME(28),
	GPR_DWARFNUM_NAME(29),
	GPR_DWARFNUM_NAME(30),
	GPR_DWARFNUM_NAME(31),
	REG_DWARFNUM_NAME(msr,   66),
	REG_DWARFNUM_NAME(ctr,   109),
	REG_DWARFNUM_NAME(link,  108),
	REG_DWARFNUM_NAME(xer,   101),
	REG_DWARFNUM_NAME(dar,   119),
	REG_DWARFNUM_NAME(dsisr, 118),
	REG_DWARFNUM_END,
};

/**
 * get_arch_regstr() - lookup register name from it's DWARF register number
 * @n:	the DWARF register number
 *
 * get_arch_regstr() returns the name of the register in struct
 * regdwarfnum_table from it's DWARF register number. If the register is not
 * found in the table, this returns NULL;
 */
const char *get_arch_regstr(unsigned int n)
{
	const struct pt_regs_dwarfnum *roff;
	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
		if (roff->dwarfnum == n)
			return roff->name;
	return NULL;
}

int regs_query_register_offset(const char *name)
{
	const struct pt_regs_dwarfnum *roff;
	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
		if (!strcmp(roff->name, name))
			return roff->ptregs_offset;
	return -EINVAL;
}