include/asm/jump_label.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * Copyright (C) 2013 Huawei Ltd.
0004  * Author: Jiang Liu <liuj97@gmail.com>
0005  *
0006  * Based on arch/arm/include/asm/jump_label.h
0007  */
0008 #ifndef __ASM_JUMP_LABEL_H
0009 #define __ASM_JUMP_LABEL_H
0010
0011 #ifndef __ASSEMBLY__
0012
0013 #include <linux/types.h>
0014 #include <asm/insn.h>
0015
0016 #define JUMP_LABEL_NOP_SIZE     AARCH64_INSN_SIZE
0017
0018 static __always_inline bool arch_static_branch(struct static_key *key,
0019                            bool branch)
0020 {
0021     asm_volatile_goto(
0022         "1: nop                 \n\t"
0023          "  .pushsection    __jump_table, \"aw\"    \n\t"
0024          "  .align      3           \n\t"
0025          "  .long       1b - ., %l[l_yes] - .   \n\t"
0026          "  .quad       %c0 - .         \n\t"
0027          "  .popsection             \n\t"
0028          :  :  "i"(&((char *)key)[branch]) :  : l_yes);
0029
0030     return false;
0031 l_yes:
0032     return true;
0033 }
0034
0035 static __always_inline bool arch_static_branch_jump(struct static_key *key,
0036                             bool branch)
0037 {
0038     asm_volatile_goto(
0039         "1: b       %l[l_yes]       \n\t"
0040          "  .pushsection    __jump_table, \"aw\"    \n\t"
0041          "  .align      3           \n\t"
0042          "  .long       1b - ., %l[l_yes] - .   \n\t"
0043          "  .quad       %c0 - .         \n\t"
0044          "  .popsection             \n\t"
0045          :  :  "i"(&((char *)key)[branch]) :  : l_yes);
0046
0047     return false;
0048 l_yes:
0049     return true;
0050 }
0051
0052 #endif  /* __ASSEMBLY__ */
0053 #endif  /* __ASM_JUMP_LABEL_H */