arch/powerpc/include/asm/sstep.h

   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 /* Emulate instructions that cause a transfer of control. */
  27 extern int emulate_step(struct pt_regs *regs, unsigned int instr);