xref: /linux/arch/loongarch/include/asm/jump_label.h (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 
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 
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