xref: /linux/arch/arm64/include/asm/jump_label.h (revision 041b1061d89203e933cb385d70d0e85f90a08417)
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 - ., %l["#label"] - .\n\t"	\
23 	".quad		%c0 - .\n\t"			\
24 	".popsection\n\t"				\
25 	:  :  "i"(key) :  : label
26 
arch_static_branch(struct static_key * const key,const bool branch)27 static __always_inline bool arch_static_branch(struct static_key * const key,
28 					       const bool branch)
29 {
30 	char *k = &((char *)key)[branch];
31 
32 	asm goto(
33 		"1:	nop					\n\t"
34 		JUMP_TABLE_ENTRY(k, l_yes)
35 		);
36 
37 	return false;
38 l_yes:
39 	return true;
40 }
41 
arch_static_branch_jump(struct static_key * const key,const bool branch)42 static __always_inline bool arch_static_branch_jump(struct static_key * const key,
43 						    const bool branch)
44 {
45 	char *k = &((char *)key)[branch];
46 	asm goto(
47 		"1:	b		%l[l_yes]		\n\t"
48 		JUMP_TABLE_ENTRY(k, l_yes)
49 		);
50 	return false;
51 l_yes:
52 	return true;
53 }
54 
55 #endif  /* __ASSEMBLY__ */
56 #endif	/* __ASM_JUMP_LABEL_H */
57