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/include/asm/jump_label.h
7 */
8 #ifndef __ASM_JUMP_LABEL_H
9 #define __ASM_JUMP_LABEL_H
10
11 #ifndef __ASSEMBLY__
12
13 #include <linux/types.h>
14 #include <asm/insn.h>
15
16 #define HAVE_JUMP_LABEL_BATCH
17 #define JUMP_LABEL_NOP_SIZE AARCH64_INSN_SIZE
18
19 #define JUMP_TABLE_ENTRY(key, label) \
20 ".pushsection __jump_table, \"aw\"\n\t" \
21 ".align 3\n\t" \
22 ".long 1b - ., " label " - .\n\t" \
23 ".quad " key " - .\n\t" \
24 ".popsection\n\t"
25
26 /* This macro is also expanded on the Rust side. */
27 #define ARCH_STATIC_BRANCH_ASM(key, label) \
28 "1: nop\n\t" \
29 JUMP_TABLE_ENTRY(key, label)
30
arch_static_branch(struct static_key * const key,const bool branch)31 static __always_inline bool arch_static_branch(struct static_key * const key,
32 const bool branch)
33 {
34 char *k = &((char *)key)[branch];
35
36 asm goto(
37 ARCH_STATIC_BRANCH_ASM("%c0", "%l[l_yes]")
38 : : "i"(k) : : l_yes
39 );
40
41 return false;
42 l_yes:
43 return true;
44 }
45
arch_static_branch_jump(struct static_key * const key,const bool branch)46 static __always_inline bool arch_static_branch_jump(struct static_key * const key,
47 const bool branch)
48 {
49 char *k = &((char *)key)[branch];
50
51 asm goto(
52 "1: b %l[l_yes] \n\t"
53 JUMP_TABLE_ENTRY("%c0", "%l[l_yes]")
54 : : "i"(k) : : l_yes
55 );
56 return false;
57 l_yes:
58 return true;
59 }
60
61 #endif /* __ASSEMBLY__ */
62 #endif /* __ASM_JUMP_LABEL_H */
63