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
arch_static_branch(struct static_key * key,bool branch)29 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
30 {
31 asm_volatile_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"(&((char *)key)[branch]) : : l_yes);
37
38 return false;
39 l_yes:
40 return true;
41 }
42
arch_static_branch_jump(struct static_key * key,bool branch)43 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
44 {
45 asm_volatile_goto("1: b %l[l_yes]\n\t"
46 ".pushsection __jump_table, \"aw\"\n\t"
47 ".align 3\n\t"
48 ".quad 1b, %l[l_yes], %c0\n\t"
49 ".popsection\n\t"
50 : : "i"(&((char *)key)[branch]) : : l_yes);
51
52 return false;
53 l_yes:
54 return true;
55 }
56
57 typedef u64 jump_label_t;
58
59 struct jump_entry {
60 jump_label_t code;
61 jump_label_t target;
62 jump_label_t key;
63 };
64
65 #endif /* __ASSEMBLY__ */
66 #endif /* __ASM_JUMP_LABEL_H */
67