arch/arm64/include/asm/jump_label.h

   1 /*
   2  * Copyright (C) 2013 Huawei Ltd.
   3  * Author: Jiang Liu <liuj97@gmail.com>
   4  *
   5  * Based on arch/arm/include/asm/jump_label.h
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #ifndef __ASM_JUMP_LABEL_H
  20 #define __ASM_JUMP_LABEL_H
  21
  22 #ifndef __ASSEMBLY__
  23
  24 #include <linux/types.h>
  25 #include <asm/insn.h>
  26
  27 #define JUMP_LABEL_NOP_SIZE             AARCH64_INSN_SIZE
  28
  29 static __always_inline bool arch_static_branch(struct static_key *key,
  30                                                bool branch)
  31 {
  32         asm_volatile_goto(
  33                 "1:     nop                                     \n\t"
  34                  "      .pushsection    __jump_table, \"aw\"    \n\t"
  35                  "      .align          3                       \n\t"
  36                  "      .long           1b - ., %l[l_yes] - .   \n\t"
  37                  "      .quad           %c0 - .                 \n\t"
  38                  "      .popsection                             \n\t"
  39                  :  :  "i"(&((char *)key)[branch]) :  : l_yes);
  40
  41         return false;
  42 l_yes:
  43         return true;
  44 }
  45
  46 static __always_inline bool arch_static_branch_jump(struct static_key *key,
  47                                                     bool branch)
  48 {
  49         asm_volatile_goto(
  50                 "1:     b               %l[l_yes]               \n\t"
  51                  "      .pushsection    __jump_table, \"aw\"    \n\t"
  52                  "      .align          3                       \n\t"
  53                  "      .long           1b - ., %l[l_yes] - .   \n\t"
  54                  "      .quad           %c0 - .                 \n\t"
  55                  "      .popsection                             \n\t"
  56                  :  :  "i"(&((char *)key)[branch]) :  : l_yes);
  57
  58         return false;
  59 l_yes:
  60         return true;
  61 }
  62
  63 #endif  /* __ASSEMBLY__ */
  64 #endif  /* __ASM_JUMP_LABEL_H */