arch/arc/include/asm/disasm.h

   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
  15 enum {
  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
  25 enum 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
  77 struct 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
  93 static 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
 101 static 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
 108 void disasm_instr(unsigned long addr, struct disasm_state *state,
 109         int userspace, struct pt_regs *regs, struct callee_regs *cregs);
 110 int disasm_next_pc(unsigned long pc, struct pt_regs *regs, struct callee_regs
 111         *cregs, unsigned long *fall_thru, unsigned long *target);
 112 long get_reg(int reg, struct pt_regs *regs, struct callee_regs *cregs);
 113 void set_reg(int reg, long val, struct pt_regs *regs,
 114                 struct callee_regs *cregs);
 115
 116 #endif  /* __ARC_DISASM_H__ */