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 #include <asm/ppc-opcode.h>
  15
  16 /* Flags for create_branch:
  17  * "b"   == create_branch(addr, target, 0);
  18  * "ba"  == create_branch(addr, target, BRANCH_ABSOLUTE);
  19  * "bl"  == create_branch(addr, target, BRANCH_SET_LINK);
  20  * "bla" == create_branch(addr, target, BRANCH_ABSOLUTE | BRANCH_SET_LINK);
  21  */
  22 #define BRANCH_SET_LINK 0x1
  23 #define BRANCH_ABSOLUTE 0x2
  24
  25 unsigned int create_branch(const unsigned int *addr,
  26                            unsigned long target, int flags);
  27 unsigned int create_cond_branch(const unsigned int *addr,
  28                                 unsigned long target, int flags);
  29 void patch_branch(unsigned int *addr, unsigned long target, int flags);
  30 void patch_instruction(unsigned int *addr, unsigned int instr);
  31
  32 int instr_is_relative_branch(unsigned int instr);
  33 int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr);
  34 unsigned long branch_target(const unsigned int *instr);
  35 unsigned int translate_branch(const unsigned int *dest,
  36                               const unsigned int *src);
  37
  38 static inline unsigned long ppc_function_entry(void *func)
  39 {
  40 #ifdef CONFIG_PPC64
  41         /*
  42          * On PPC64 the function pointer actually points to the function's
  43          * descriptor. The first entry in the descriptor is the address
  44          * of the function text.
  45          */
  46         return ((func_descr_t *)func)->entry;
  47 #else
  48         return (unsigned long)func;
  49 #endif
  50 }
  51
  52 #endif /* _ASM_POWERPC_CODE_PATCHING_H */