1/*
  2 * several functions that help interpret ARC instructions
  3 * used for unaligned accesses, kprobes and kgdb
  4 *
  5 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License version 2 as
  9 * published by the Free Software Foundation.
 10 */
 11
 12#ifndef __ARC_DISASM_H__
 13#define __ARC_DISASM_H__
 14
 15enum {
 16	op_Bcc = 0, op_BLcc = 1, op_LD = 2, op_ST = 3, op_MAJOR_4 = 4,
 17	op_MAJOR_5 = 5, op_LD_ADD = 12, op_ADD_SUB_SHIFT = 13,
 18	op_ADD_MOV_CMP = 14, op_S = 15, op_LD_S = 16, op_LDB_S = 17,
 19	op_LDW_S = 18, op_LDWX_S = 19, op_ST_S = 20, op_STB_S = 21,
 20	op_STW_S = 22, op_Su5 = 23, op_SP = 24, op_GP = 25,
 21	op_Pcl = 26, op_MOV_S = 27, op_ADD_CMP = 28, op_BR_S = 29,
 22	op_B_S = 30, op_BL_S = 31
 23};
 24
 25enum flow {
 26	noflow,
 27	direct_jump,
 28	direct_call,
 29	indirect_jump,
 30	indirect_call,
 31	invalid_instr
 32};
 33
 34#define IS_BIT(word, n)		((word) & (1<<n))
 35#define BITS(word, s, e)	(((word) >> (s)) & (~((-2) << ((e) - (s)))))
 36
 37#define MAJOR_OPCODE(word)	(BITS((word), 27, 31))
 38#define MINOR_OPCODE(word)	(BITS((word), 16, 21))
 39#define FIELD_A(word)		(BITS((word), 0, 5))
 40#define FIELD_B(word)		((BITS((word), 12, 14)<<3) | \
 41				(BITS((word), 24, 26)))
 42#define FIELD_C(word)		(BITS((word), 6, 11))
 43#define FIELD_u6(word)		FIELDC(word)
 44#define FIELD_s12(word)		sign_extend(((BITS((word), 0, 5) << 6) | \
 45					BITS((word), 6, 11)), 12)
 46
 47/* note that for BL/BRcc these two macro's need another AND statement to mask
 48 * out bit 1 (make the result a multiple of 4) */
 49#define FIELD_s9(word)		sign_extend(((BITS(word, 15, 15) << 8) | \
 50					BITS(word, 16, 23)), 9)
 51#define FIELD_s21(word)		sign_extend(((BITS(word, 6, 15) << 11) | \
 52					(BITS(word, 17, 26) << 1)), 12)
 53#define FIELD_s25(word)		sign_extend(((BITS(word, 0, 3) << 21) | \
 54					(BITS(word, 6, 15) << 11) | \
 55					(BITS(word, 17, 26) << 1)), 12)
 56
 57/* note: these operate on 16 bits! */
 58#define FIELD_S_A(word)		((BITS((word), 2, 2)<<3) | BITS((word), 0, 2))
 59#define FIELD_S_B(word)		((BITS((word), 10, 10)<<3) | \
 60				BITS((word), 8, 10))
 61#define FIELD_S_C(word)		((BITS((word), 7, 7)<<3) | BITS((word), 5, 7))
 62#define FIELD_S_H(word)		((BITS((word), 0, 2)<<3) | BITS((word), 5, 8))
 63#define FIELD_S_u5(word)	(BITS((word), 0, 4))
 64#define FIELD_S_u6(word)	(BITS((word), 0, 4) << 1)
 65#define FIELD_S_u7(word)	(BITS((word), 0, 4) << 2)
 66#define FIELD_S_u10(word)	(BITS((word), 0, 7) << 2)
 67#define FIELD_S_s7(word)	sign_extend(BITS((word), 0, 5) << 1, 9)
 68#define FIELD_S_s8(word)	sign_extend(BITS((word), 0, 7) << 1, 9)
 69#define FIELD_S_s9(word)	sign_extend(BITS((word), 0, 8), 9)
 70#define FIELD_S_s10(word)	sign_extend(BITS((word), 0, 8) << 1, 10)
 71#define FIELD_S_s11(word)	sign_extend(BITS((word), 0, 8) << 2, 11)
 72#define FIELD_S_s13(word)	sign_extend(BITS((word), 0, 10) << 2, 13)
 73
 74#define STATUS32_L		0x00000100
 75#define REG_LIMM		62
 76
 77struct disasm_state {
 78	/* generic info */
 79	unsigned long words[2];
 80	int instr_len;
 81	int major_opcode;
 82	/* info for branch/jump */
 83	int is_branch;
 84	int target;
 85	int delay_slot;
 86	enum flow flow;
 87	/* info for load/store */
 88	int src1, src2, src3, dest, wb_reg;
 89	int zz, aa, x, pref, di;
 90	int fault, write;
 91};
 92
 93static inline int sign_extend(int value, int bits)
 94{
 95	if (IS_BIT(value, (bits - 1)))
 96		value |= (0xffffffff << bits);
 97
 98	return value;
 99}
100
101static inline int is_short_instr(unsigned long addr)
102{
103	uint16_t word = *((uint16_t *)addr);
104	int opcode = (word >> 11) & 0x1F;
105	return (opcode >= 0x0B);
106}
107
108void disasm_instr(unsigned long addr, struct disasm_state *state,
109	int userspace, struct pt_regs *regs, struct callee_regs *cregs);
110int disasm_next_pc(unsigned long pc, struct pt_regs *regs, struct callee_regs
111	*cregs, unsigned long *fall_thru, unsigned long *target);
112long get_reg(int reg, struct pt_regs *regs, struct callee_regs *cregs);
113void set_reg(int reg, long val, struct pt_regs *regs,
114		struct callee_regs *cregs);
115
116#endif	/* __ARC_DISASM_H__ */