1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2023 Loongson Technology Corporation Limited
4 *
5 * Based on arch/arm64/include/asm/jump_label.h
6 */
7 #ifndef __ASM_JUMP_LABEL_H
8 #define __ASM_JUMP_LABEL_H
9
10 #ifndef __ASSEMBLY__
11
12 #include <linux/types.h>
13
14 #define JUMP_LABEL_NOP_SIZE 4
15
16 /* This macro is also expanded on the Rust side. */
17 #define JUMP_TABLE_ENTRY(key, label) \
18 ".pushsection __jump_table, \"aw\" \n\t" \
19 ".align 3 \n\t" \
20 ".long 1b - ., " label " - . \n\t" \
21 ".quad " key " - . \n\t" \
22 ".popsection \n\t"
23
24 #define ARCH_STATIC_BRANCH_ASM(key, label) \
25 "1: nop \n\t" \
26 JUMP_TABLE_ENTRY(key, label)
27
arch_static_branch(struct static_key * const key,const bool branch)28 static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
29 {
30 asm goto(
31 ARCH_STATIC_BRANCH_ASM("%0", "%l[l_yes]")
32 : : "i"(&((char *)key)[branch]) : : l_yes);
33
34 return false;
35
36 l_yes:
37 return true;
38 }
39
arch_static_branch_jump(struct static_key * const key,const bool branch)40 static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)
41 {
42 asm goto(
43 "1: b %l[l_yes] \n\t"
44 JUMP_TABLE_ENTRY("%0", "%l[l_yes]")
45 : : "i"(&((char *)key)[branch]) : : l_yes);
46
47 return false;
48
49 l_yes:
50 return true;
51 }
52
53 #endif /* __ASSEMBLY__ */
54 #endif /* __ASM_JUMP_LABEL_H */
55