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