xref: /linux/arch/riscv/include/asm/jump_label.h (revision e04e2b760ddbe3d7b283a05898c3a029085cd8cd)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2020 Emil Renner Berthing
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 #include <asm/asm.h>
14 
15 #define HAVE_JUMP_LABEL_BATCH
16 
17 #define JUMP_LABEL_NOP_SIZE 4
18 
19 static __always_inline bool arch_static_branch(struct static_key * const key,
20 					       const bool branch)
21 {
22 	asm goto(
23 		"	.align		2			\n\t"
24 		"	.option push				\n\t"
25 		"	.option norelax				\n\t"
26 		"	.option norvc				\n\t"
27 		"1:	nop					\n\t"
28 		"	.option pop				\n\t"
29 		"	.pushsection	__jump_table, \"aw\"	\n\t"
30 		"	.align		" RISCV_LGPTR "		\n\t"
31 		"	.long		1b - ., %l[label] - .	\n\t"
32 		"	" RISCV_PTR "	%0 - .			\n\t"
33 		"	.popsection				\n\t"
34 		:  :  "i"(&((char *)key)[branch]) :  : label);
35 
36 	return false;
37 label:
38 	return true;
39 }
40 
41 static __always_inline bool arch_static_branch_jump(struct static_key * const key,
42 						    const bool branch)
43 {
44 	asm goto(
45 		"	.align		2			\n\t"
46 		"	.option push				\n\t"
47 		"	.option norelax				\n\t"
48 		"	.option norvc				\n\t"
49 		"1:	j		%l[label]		\n\t"
50 		"	.option pop				\n\t"
51 		"	.pushsection	__jump_table, \"aw\"	\n\t"
52 		"	.align		" RISCV_LGPTR "		\n\t"
53 		"	.long		1b - ., %l[label] - .	\n\t"
54 		"	" RISCV_PTR "	%0 - .			\n\t"
55 		"	.popsection				\n\t"
56 		:  :  "i"(&((char *)key)[branch]) :  : label);
57 
58 	return false;
59 label:
60 	return true;
61 }
62 
63 #endif  /* __ASSEMBLY__ */
64 #endif	/* __ASM_JUMP_LABEL_H */
65