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 #define JUMP_TABLE_ENTRY				\
17 	 ".pushsection	__jump_table, \"aw\"	\n\t"	\
18 	 ".align	3			\n\t"	\
19 	 ".long		1b - ., %l[l_yes] - .	\n\t"	\
20 	 ".quad		%0 - .			\n\t"	\
21 	 ".popsection				\n\t"
22 
23 static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
24 {
25 	asm goto(
26 		"1:	nop			\n\t"
27 		JUMP_TABLE_ENTRY
28 		:  :  "i"(&((char *)key)[branch]) :  : l_yes);
29 
30 	return false;
31 
32 l_yes:
33 	return true;
34 }
35 
36 static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)
37 {
38 	asm goto(
39 		"1:	b	%l[l_yes]	\n\t"
40 		JUMP_TABLE_ENTRY
41 		:  :  "i"(&((char *)key)[branch]) :  : l_yes);
42 
43 	return false;
44 
45 l_yes:
46 	return true;
47 }
48 
49 #endif  /* __ASSEMBLY__ */
50 #endif	/* __ASM_JUMP_LABEL_H */
51