arch/powerpc/include/asm/jump_label.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 #ifndef _ASM_POWERPC_JUMP_LABEL_H
   3 #define _ASM_POWERPC_JUMP_LABEL_H
   4
   5 /*
   6  * Copyright 2010 Michael Ellerman, IBM Corp.
   7  */
   8
   9 #ifndef __ASSEMBLY__
  10 #include <linux/types.h>
  11
  12 #include <asm/feature-fixups.h>
  13 #include <asm/asm-const.h>
  14
  15 #define JUMP_ENTRY_TYPE         stringify_in_c(FTR_ENTRY_LONG)
  16 #define JUMP_LABEL_NOP_SIZE     4
  17
  18 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
  19 {
  20         asm_volatile_goto("1:\n\t"
  21                  "nop # arch_static_branch\n\t"
  22                  ".pushsection __jump_table,  \"aw\"\n\t"
  23                  ".long 1b - ., %l[l_yes] - .\n\t"
  24                  JUMP_ENTRY_TYPE "%c0 - .\n\t"
  25                  ".popsection \n\t"
  26                  : :  "i" (&((char *)key)[branch]) : : l_yes);
  27
  28         return false;
  29 l_yes:
  30         return true;
  31 }
  32
  33 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
  34 {
  35         asm_volatile_goto("1:\n\t"
  36                  "b %l[l_yes] # arch_static_branch_jump\n\t"
  37                  ".pushsection __jump_table,  \"aw\"\n\t"
  38                  ".long 1b - ., %l[l_yes] - .\n\t"
  39                  JUMP_ENTRY_TYPE "%c0 - .\n\t"
  40                  ".popsection \n\t"
  41                  : :  "i" (&((char *)key)[branch]) : : l_yes);
  42
  43         return false;
  44 l_yes:
  45         return true;
  46 }
  47
  48 #else
  49 #define ARCH_STATIC_BRANCH(LABEL, KEY)          \
  50 1098:   nop;                                    \
  51         .pushsection __jump_table, "aw";        \
  52         .long 1098b - ., LABEL - .;             \
  53         FTR_ENTRY_LONG KEY;                     \
  54         .popsection
  55 #endif
  56
  57 #endif /* _ASM_POWERPC_JUMP_LABEL_H */