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 22 #ifndef __ASSEMBLY__ 23 24 #include <linux/types.h> 25 #include <asm/insn.h> 26 27 #define JUMP_LABEL_NOP_SIZE AARCH64_INSN_SIZE 28 29 static __always_inline bool arch_static_branch(struct static_key *key) 30 { 31 asm goto("1: nop\n\t" 32 ".pushsection __jump_table, \"aw\"\n\t" 33 ".align 3\n\t" 34 ".quad 1b, %l[l_yes], %c0\n\t" 35 ".popsection\n\t" 36 : : "i"(key) : : l_yes); 37 38 return false; 39 l_yes: 40 return true; 41 } 42 43 typedef u64 jump_label_t; 44 45 struct jump_entry { 46 jump_label_t code; 47 jump_label_t target; 48 jump_label_t key; 49 }; 50 51 #endif /* __ASSEMBLY__ */ 52 #endif /* __ASM_JUMP_LABEL_H */ 53