1 /* 2 * Copyright (C) 2004 Paul Mackerras <paulus@au.ibm.com>, IBM 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 */ 9 10 struct pt_regs; 11 12 /* 13 * We don't allow single-stepping an mtmsrd that would clear 14 * MSR_RI, since that would make the exception unrecoverable. 15 * Since we need to single-step to proceed from a breakpoint, 16 * we don't allow putting a breakpoint on an mtmsrd instruction. 17 * Similarly we don't allow breakpoints on rfid instructions. 18 * These macros tell us if an instruction is a mtmsrd or rfid. 19 * Note that IS_MTMSRD returns true for both an mtmsr (32-bit) 20 * and an mtmsrd (64-bit). 21 */ 22 #define IS_MTMSRD(instr) (((instr) & 0xfc0007be) == 0x7c000124) 23 #define IS_RFID(instr) (((instr) & 0xfc0007fe) == 0x4c000024) 24 #define IS_RFI(instr) (((instr) & 0xfc0007fe) == 0x4c000064) 25 26 enum instruction_type { 27 COMPUTE, /* arith/logical/CR op, etc. */ 28 LOAD, /* load and store types need to be contiguous */ 29 LOAD_MULTI, 30 LOAD_FP, 31 LOAD_VMX, 32 LOAD_VSX, 33 STORE, 34 STORE_MULTI, 35 STORE_FP, 36 STORE_VMX, 37 STORE_VSX, 38 LARX, 39 STCX, 40 BRANCH, 41 MFSPR, 42 MTSPR, 43 CACHEOP, 44 BARRIER, 45 SYSCALL, 46 MFMSR, 47 MTMSR, 48 RFI, 49 INTERRUPT, 50 UNKNOWN 51 }; 52 53 #define INSTR_TYPE_MASK 0x1f 54 55 #define OP_IS_LOAD_STORE(type) (LOAD <= (type) && (type) <= STCX) 56 57 /* Compute flags, ORed in with type */ 58 #define SETREG 0x20 59 #define SETCC 0x40 60 #define SETXER 0x80 61 62 /* Branch flags, ORed in with type */ 63 #define SETLK 0x20 64 #define BRTAKEN 0x40 65 #define DECCTR 0x80 66 67 /* Load/store flags, ORed in with type */ 68 #define SIGNEXT 0x20 69 #define UPDATE 0x40 /* matches bit in opcode 31 instructions */ 70 #define BYTEREV 0x80 71 #define FPCONV 0x100 72 73 /* Barrier type field, ORed in with type */ 74 #define BARRIER_MASK 0xe0 75 #define BARRIER_SYNC 0x00 76 #define BARRIER_ISYNC 0x20 77 #define BARRIER_EIEIO 0x40 78 #define BARRIER_LWSYNC 0x60 79 #define BARRIER_PTESYNC 0x80 80 81 /* Cacheop values, ORed in with type */ 82 #define CACHEOP_MASK 0x700 83 #define DCBST 0 84 #define DCBF 0x100 85 #define DCBTST 0x200 86 #define DCBT 0x300 87 #define ICBI 0x400 88 #define DCBZ 0x500 89 90 /* VSX flags values */ 91 #define VSX_FPCONV 1 /* do floating point SP/DP conversion */ 92 #define VSX_SPLAT 2 /* store loaded value into all elements */ 93 #define VSX_LDLEFT 4 /* load VSX register from left */ 94 #define VSX_CHECK_VEC 8 /* check MSR_VEC not MSR_VSX for reg >= 32 */ 95 96 /* Size field in type word */ 97 #define SIZE(n) ((n) << 12) 98 #define GETSIZE(w) ((w) >> 12) 99 100 #define GETTYPE(t) ((t) & INSTR_TYPE_MASK) 101 102 #define MKOP(t, f, s) ((t) | (f) | SIZE(s)) 103 104 struct instruction_op { 105 int type; 106 int reg; 107 unsigned long val; 108 /* For LOAD/STORE/LARX/STCX */ 109 unsigned long ea; 110 int update_reg; 111 /* For MFSPR */ 112 int spr; 113 u32 ccval; 114 u32 xerval; 115 u8 element_size; /* for VSX/VMX loads/stores */ 116 u8 vsx_flags; 117 }; 118 119 union vsx_reg { 120 u8 b[16]; 121 u16 h[8]; 122 u32 w[4]; 123 unsigned long d[2]; 124 float fp[4]; 125 double dp[2]; 126 __vector128 v; 127 }; 128 129 /* 130 * Decode an instruction, and return information about it in *op 131 * without changing *regs. 132 * 133 * Return value is 1 if the instruction can be emulated just by 134 * updating *regs with the information in *op, -1 if we need the 135 * GPRs but *regs doesn't contain the full register set, or 0 136 * otherwise. 137 */ 138 extern int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, 139 unsigned int instr); 140 141 /* 142 * Emulate an instruction that can be executed just by updating 143 * fields in *regs. 144 */ 145 void emulate_update_regs(struct pt_regs *reg, struct instruction_op *op); 146 147 /* 148 * Emulate instructions that cause a transfer of control, 149 * arithmetic/logical instructions, loads and stores, 150 * cache operations and barriers. 151 * 152 * Returns 1 if the instruction was emulated successfully, 153 * 0 if it could not be emulated, or -1 for an instruction that 154 * should not be emulated (rfid, mtmsrd clearing MSR_RI, etc.). 155 */ 156 extern int emulate_step(struct pt_regs *regs, unsigned int instr); 157 158 /* 159 * Emulate a load or store instruction by reading/writing the 160 * memory of the current process. FP/VMX/VSX registers are assumed 161 * to hold live values if the appropriate enable bit in regs->msr is 162 * set; otherwise this will use the saved values in the thread struct 163 * for user-mode accesses. 164 */ 165 extern int emulate_loadstore(struct pt_regs *regs, struct instruction_op *op); 166 167 extern void emulate_vsx_load(struct instruction_op *op, union vsx_reg *reg, 168 const void *mem, bool cross_endian); 169 extern void emulate_vsx_store(struct instruction_op *op, 170 const union vsx_reg *reg, void *mem, 171 bool cross_endian); 172 extern int emulate_dcbz(unsigned long ea, struct pt_regs *regs); 173