1 /* 2 * Copyright (C) 2013 Huawei Ltd. 3 * Author: Jiang Liu <liuj97@gmail.com> 4 * 5 * Based on arch/arm/kernel/jump_label.c 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 #include <linux/kernel.h> 20 #include <linux/jump_label.h> 21 #include <asm/insn.h> 22 23 #ifdef HAVE_JUMP_LABEL 24 25 void arch_jump_label_transform(struct jump_entry *entry, 26 enum jump_label_type type) 27 { 28 void *addr = (void *)entry->code; 29 u32 insn; 30 31 if (type == JUMP_LABEL_ENABLE) { 32 insn = aarch64_insn_gen_branch_imm(entry->code, 33 entry->target, 34 AARCH64_INSN_BRANCH_NOLINK); 35 } else { 36 insn = aarch64_insn_gen_nop(); 37 } 38 39 aarch64_insn_patch_text(&addr, &insn, 1); 40 } 41 42 void arch_jump_label_transform_static(struct jump_entry *entry, 43 enum jump_label_type type) 44 { 45 /* 46 * We use the architected A64 NOP in arch_static_branch, so there's no 47 * need to patch an identical A64 NOP over the top of it here. The core 48 * will call arch_jump_label_transform from a module notifier if the 49 * NOP needs to be replaced by a branch. 50 */ 51 } 52 53 #endif /* HAVE_JUMP_LABEL */ 54