arch/powerpc/include/asm/jump_label.h

   1 #ifndef _ASM_POWERPC_JUMP_LABEL_H
   2 #define _ASM_POWERPC_JUMP_LABEL_H
   3
   4 /*
   5  * Copyright 2010 Michael Ellerman, IBM Corp.
   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 #ifndef __ASSEMBLY__
  14 #include <linux/types.h>
  15
  16 #include <asm/feature-fixups.h>
  17 #include <asm/asm-compat.h>
  18
  19 #define JUMP_ENTRY_TYPE         stringify_in_c(FTR_ENTRY_LONG)
  20 #define JUMP_LABEL_NOP_SIZE     4
  21
  22 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
  23 {
  24         asm_volatile_goto("1:\n\t"
  25                  "nop # arch_static_branch\n\t"
  26                  ".pushsection __jump_table,  \"aw\"\n\t"
  27                  JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
  28                  ".popsection \n\t"
  29                  : :  "i" (&((char *)key)[branch]) : : l_yes);
  30
  31         return false;
  32 l_yes:
  33         return true;
  34 }
  35
  36 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
  37 {
  38         asm_volatile_goto("1:\n\t"
  39                  "b %l[l_yes] # arch_static_branch_jump\n\t"
  40                  ".pushsection __jump_table,  \"aw\"\n\t"
  41                  JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
  42                  ".popsection \n\t"
  43                  : :  "i" (&((char *)key)[branch]) : : l_yes);
  44
  45         return false;
  46 l_yes:
  47         return true;
  48 }
  49
  50 #ifdef CONFIG_PPC64
  51 typedef u64 jump_label_t;
  52 #else
  53 typedef u32 jump_label_t;
  54 #endif
  55
  56 struct jump_entry {
  57         jump_label_t code;
  58         jump_label_t target;
  59         jump_label_t key;
  60 };
  61
  62 #else
  63 #define ARCH_STATIC_BRANCH(LABEL, KEY)          \
  64 1098:   nop;                                    \
  65         .pushsection __jump_table, "aw";        \
  66         FTR_ENTRY_LONG 1098b, LABEL, KEY;       \
  67         .popsection
  68 #endif
  69
  70 #endif /* _ASM_POWERPC_JUMP_LABEL_H */