xref: /linux/arch/arm64/kernel/jump_label.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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 static void __arch_jump_label_transform(struct jump_entry *entry,
26 					enum jump_label_type type,
27 					bool is_static)
28 {
29 	void *addr = (void *)entry->code;
30 	u32 insn;
31 
32 	if (type == JUMP_LABEL_ENABLE) {
33 		insn = aarch64_insn_gen_branch_imm(entry->code,
34 						   entry->target,
35 						   AARCH64_INSN_BRANCH_NOLINK);
36 	} else {
37 		insn = aarch64_insn_gen_nop();
38 	}
39 
40 	if (is_static)
41 		aarch64_insn_patch_text_nosync(addr, insn);
42 	else
43 		aarch64_insn_patch_text(&addr, &insn, 1);
44 }
45 
46 void arch_jump_label_transform(struct jump_entry *entry,
47 			       enum jump_label_type type)
48 {
49 	__arch_jump_label_transform(entry, type, false);
50 }
51 
52 void arch_jump_label_transform_static(struct jump_entry *entry,
53 				      enum jump_label_type type)
54 {
55 	__arch_jump_label_transform(entry, type, true);
56 }
57 
58 #endif	/* HAVE_JUMP_LABEL */
59