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 #include <linux/types.h>
  22 #include <asm/insn.h>
  23
  24 #ifdef __KERNEL__
  25
  26 #define JUMP_LABEL_NOP_SIZE             AARCH64_INSN_SIZE
  27
  28 static __always_inline bool arch_static_branch(struct static_key *key)
  29 {
  30         asm goto("1: nop\n\t"
  31                  ".pushsection __jump_table,  \"aw\"\n\t"
  32                  ".align 3\n\t"
  33                  ".quad 1b, %l[l_yes], %c0\n\t"
  34                  ".popsection\n\t"
  35                  :  :  "i"(key) :  : l_yes);
  36
  37         return false;
  38 l_yes:
  39         return true;
  40 }
  41
  42 #endif /* __KERNEL__ */
  43
  44 typedef u64 jump_label_t;
  45
  46 struct jump_entry {
  47         jump_label_t code;
  48         jump_label_t target;
  49         jump_label_t key;
  50 };
  51
  52 #endif  /* __ASM_JUMP_LABEL_H */