arch/arm64/include/asm/jump_label.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2013 Huawei Ltd.
   4  * Author: Jiang Liu <liuj97@gmail.com>
   5  *
   6  * Based on arch/arm/include/asm/jump_label.h
   7  */
   8 #ifndef __ASM_JUMP_LABEL_H
   9 #define __ASM_JUMP_LABEL_H
  10
  11 #ifndef __ASSEMBLY__
  12
  13 #include <linux/types.h>
  14 #include <asm/insn.h>
  15
  16 #define JUMP_LABEL_NOP_SIZE             AARCH64_INSN_SIZE
  17
  18 static __always_inline bool arch_static_branch(struct static_key *key,
  19                                                bool branch)
  20 {
  21         asm_volatile_goto(
  22                 "1:     nop                                     \n\t"
  23                  "      .pushsection    __jump_table, \"aw\"    \n\t"
  24                  "      .align          3                       \n\t"
  25                  "      .long           1b - ., %l[l_yes] - .   \n\t"
  26                  "      .quad           %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,
  36                                                     bool branch)
  37 {
  38         asm_volatile_goto(
  39                 "1:     b               %l[l_yes]               \n\t"
  40                  "      .pushsection    __jump_table, \"aw\"    \n\t"
  41                  "      .align          3                       \n\t"
  42                  "      .long           1b - ., %l[l_yes] - .   \n\t"
  43                  "      .quad           %c0 - .                 \n\t"
  44                  "      .popsection                             \n\t"
  45                  :  :  "i"(&((char *)key)[branch]) :  : l_yes);
  46
  47         return false;
  48 l_yes:
  49         return true;
  50 }
  51
  52 #endif  /* __ASSEMBLY__ */
  53 #endif  /* __ASM_JUMP_LABEL_H */