arch/riscv/include/asm/jump_label.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2020 Emil Renner Berthing
   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 #include <asm/asm.h>
  14
  15 #define JUMP_LABEL_NOP_SIZE 4
  16
  17 static __always_inline bool arch_static_branch(struct static_key *key,
  18                                                bool branch)
  19 {
  20         asm_volatile_goto(
  21                 "       .option push                            \n\t"
  22                 "       .option norelax                         \n\t"
  23                 "       .option norvc                           \n\t"
  24                 "1:     nop                                     \n\t"
  25                 "       .option pop                             \n\t"
  26                 "       .pushsection    __jump_table, \"aw\"    \n\t"
  27                 "       .align          " RISCV_LGPTR "         \n\t"
  28                 "       .long           1b - ., %l[label] - .   \n\t"
  29                 "       " RISCV_PTR "   %0 - .                  \n\t"
  30                 "       .popsection                             \n\t"
  31                 :  :  "i"(&((char *)key)[branch]) :  : label);
  32
  33         return false;
  34 label:
  35         return true;
  36 }
  37
  38 static __always_inline bool arch_static_branch_jump(struct static_key *key,
  39                                                     bool branch)
  40 {
  41         asm_volatile_goto(
  42                 "       .option push                            \n\t"
  43                 "       .option norelax                         \n\t"
  44                 "       .option norvc                           \n\t"
  45                 "1:     jal             zero, %l[label]         \n\t"
  46                 "       .option pop                             \n\t"
  47                 "       .pushsection    __jump_table, \"aw\"    \n\t"
  48                 "       .align          " RISCV_LGPTR "         \n\t"
  49                 "       .long           1b - ., %l[label] - .   \n\t"
  50                 "       " RISCV_PTR "   %0 - .                  \n\t"
  51                 "       .popsection                             \n\t"
  52                 :  :  "i"(&((char *)key)[branch]) :  : label);
  53
  54         return false;
  55 label:
  56         return true;
  57 }
  58
  59 #endif  /* __ASSEMBLY__ */
  60 #endif  /* __ASM_JUMP_LABEL_H */