arch/powerpc/include/asm/code-patching.h

   1 #ifndef _ASM_POWERPC_CODE_PATCHING_H
   2 #define _ASM_POWERPC_CODE_PATCHING_H
   3
   4 /*
   5  * Copyright 2008, Michael Ellerman, IBM Corporation.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <asm/types.h>
  14
  15 #define PPC_NOP_INSTR           0x60000000
  16 #define PPC_LWSYNC_INSTR        0x7c2004ac
  17
  18 /* Flags for create_branch:
  19  * "b"   == create_branch(addr, target, 0);
  20  * "ba"  == create_branch(addr, target, BRANCH_ABSOLUTE);
  21  * "bl"  == create_branch(addr, target, BRANCH_SET_LINK);
  22  * "bla" == create_branch(addr, target, BRANCH_ABSOLUTE | BRANCH_SET_LINK);
  23  */
  24 #define BRANCH_SET_LINK 0x1
  25 #define BRANCH_ABSOLUTE 0x2
  26
  27 unsigned int create_branch(const unsigned int *addr,
  28                            unsigned long target, int flags);
  29 unsigned int create_cond_branch(const unsigned int *addr,
  30                                 unsigned long target, int flags);
  31 void patch_branch(unsigned int *addr, unsigned long target, int flags);
  32 void patch_instruction(unsigned int *addr, unsigned int instr);
  33
  34 int instr_is_relative_branch(unsigned int instr);
  35 int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr);
  36 unsigned long branch_target(const unsigned int *instr);
  37 unsigned int translate_branch(const unsigned int *dest,
  38                               const unsigned int *src);
  39
  40 static inline unsigned long ppc_function_entry(void *func)
  41 {
  42 #ifdef CONFIG_PPC64
  43         /*
  44          * On PPC64 the function pointer actually points to the function's
  45          * descriptor. The first entry in the descriptor is the address
  46          * of the function text.
  47          */
  48         return ((func_descr_t *)func)->entry;
  49 #else
  50         return (unsigned long)func;
  51 #endif
  52 }
  53
  54 #endif /* _ASM_POWERPC_CODE_PATCHING_H */