1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2013 Huawei Ltd. 4 * Author: Jiang Liu <liuj97@gmail.com> 5 * 6 * Based on arch/arm/include/asm/jump_label.h 7 */ 8 #ifndef __ASM_JUMP_LABEL_H 9 #define __ASM_JUMP_LABEL_H 10 11 #ifndef __ASSEMBLY__ 12 13 #include <linux/types.h> 14 #include <asm/insn.h> 15 16 #define HAVE_JUMP_LABEL_BATCH 17 #define JUMP_LABEL_NOP_SIZE AARCH64_INSN_SIZE 18 19 #define JUMP_TABLE_ENTRY(key, label) \ 20 ".pushsection __jump_table, \"aw\"\n\t" \ 21 ".align 3\n\t" \ 22 ".long 1b - ., " label " - .\n\t" \ 23 ".quad " key " - .\n\t" \ 24 ".popsection\n\t" 25 26 /* This macro is also expanded on the Rust side. */ 27 #define ARCH_STATIC_BRANCH_ASM(key, label) \ 28 "1: nop\n\t" \ 29 JUMP_TABLE_ENTRY(key, label) 30 31 static __always_inline bool arch_static_branch(struct static_key * const key, 32 const bool branch) 33 { 34 char *k = &((char *)key)[branch]; 35 36 asm goto( 37 ARCH_STATIC_BRANCH_ASM("%c0", "%l[l_yes]") 38 : : "i"(k) : : l_yes 39 ); 40 41 return false; 42 l_yes: 43 return true; 44 } 45 46 static __always_inline bool arch_static_branch_jump(struct static_key * const key, 47 const bool branch) 48 { 49 char *k = &((char *)key)[branch]; 50 51 asm goto( 52 "1: b %l[l_yes] \n\t" 53 JUMP_TABLE_ENTRY("%c0", "%l[l_yes]") 54 : : "i"(k) : : l_yes 55 ); 56 return false; 57 l_yes: 58 return true; 59 } 60 61 #endif /* __ASSEMBLY__ */ 62 #endif /* __ASM_JUMP_LABEL_H */ 63