arch/loongarch/include/asm/jump_label.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2023 Loongson Technology Corporation Limited
   4  *
   5  * Based on arch/arm64/include/asm/jump_label.h
   6  */
   7 #ifndef __ASM_JUMP_LABEL_H
   8 #define __ASM_JUMP_LABEL_H
   9
  10 #ifndef __ASSEMBLY__
  11
  12 #include <linux/types.h>
  13
  14 #define JUMP_LABEL_NOP_SIZE     4
  15
  16 /* This macro is also expanded on the Rust side. */
  17 #define JUMP_TABLE_ENTRY(key, label)                    \
  18          ".pushsection  __jump_table, \"aw\"    \n\t"   \
  19          ".align        3                       \n\t"   \
  20          ".long         1b - ., " label " - .   \n\t"   \
  21          ".quad         " key " - .             \n\t"   \
  22          ".popsection                           \n\t"
  23
  24 #define ARCH_STATIC_BRANCH_ASM(key, label)              \
  25         "1:     nop                             \n\t"   \
  26         JUMP_TABLE_ENTRY(key, label)
  27
  28 static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
  29 {
  30         asm goto(
  31                 ARCH_STATIC_BRANCH_ASM("%0", "%l[l_yes]")
  32                 :  :  "i"(&((char *)key)[branch]) :  : l_yes);
  33
  34         return false;
  35
  36 l_yes:
  37         return true;
  38 }
  39
  40 static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)
  41 {
  42         asm goto(
  43                 "1:     b       %l[l_yes]       \n\t"
  44                 JUMP_TABLE_ENTRY("%0", "%l[l_yes]")
  45                 :  :  "i"(&((char *)key)[branch]) :  : l_yes);
  46
  47         return false;
  48
  49 l_yes:
  50         return true;
  51 }
  52
  53 #endif  /* __ASSEMBLY__ */
  54 #endif  /* __ASM_JUMP_LABEL_H */