xref: /openbmc/linux/arch/arm64/kernel/jump_label.c (revision 8e774e02)
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/kernel/jump_label.c
7  */
8 #include <linux/kernel.h>
9 #include <linux/jump_label.h>
10 #include <asm/insn.h>
11 
12 void arch_jump_label_transform(struct jump_entry *entry,
13 			       enum jump_label_type type)
14 {
15 	void *addr = (void *)jump_entry_code(entry);
16 	u32 insn;
17 
18 	if (type == JUMP_LABEL_JMP) {
19 		insn = aarch64_insn_gen_branch_imm(jump_entry_code(entry),
20 						   jump_entry_target(entry),
21 						   AARCH64_INSN_BRANCH_NOLINK);
22 	} else {
23 		insn = aarch64_insn_gen_nop();
24 	}
25 
26 	aarch64_insn_patch_text_nosync(addr, insn);
27 }
28 
29 void arch_jump_label_transform_static(struct jump_entry *entry,
30 				      enum jump_label_type type)
31 {
32 	/*
33 	 * We use the architected A64 NOP in arch_static_branch, so there's no
34 	 * need to patch an identical A64 NOP over the top of it here. The core
35 	 * will call arch_jump_label_transform from a module notifier if the
36 	 * NOP needs to be replaced by a branch.
37 	 */
38 }
39