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 JUMP_LABEL_NOP_SIZE 4
16 
17 static __always_inline bool arch_static_branch(struct static_key * const key,
18 					       const bool branch)
19 {
20 	asm_volatile_goto(
21 		"	.align		2			\n\t"
22 		"	.option push				\n\t"
23 		"	.option norelax				\n\t"
24 		"	.option norvc				\n\t"
25 		"1:	nop					\n\t"
26 		"	.option pop				\n\t"
27 		"	.pushsection	__jump_table, \"aw\"	\n\t"
28 		"	.align		" RISCV_LGPTR "		\n\t"
29 		"	.long		1b - ., %l[label] - .	\n\t"
30 		"	" RISCV_PTR "	%0 - .			\n\t"
31 		"	.popsection				\n\t"
32 		:  :  "i"(&((char *)key)[branch]) :  : label);
33 
34 	return false;
35 label:
36 	return true;
37 }
38 
39 static __always_inline bool arch_static_branch_jump(struct static_key * const key,
40 						    const bool branch)
41 {
42 	asm_volatile_goto(
43 		"	.align		2			\n\t"
44 		"	.option push				\n\t"
45 		"	.option norelax				\n\t"
46 		"	.option norvc				\n\t"
47 		"1:	jal		zero, %l[label]		\n\t"
48 		"	.option pop				\n\t"
49 		"	.pushsection	__jump_table, \"aw\"	\n\t"
50 		"	.align		" RISCV_LGPTR "		\n\t"
51 		"	.long		1b - ., %l[label] - .	\n\t"
52 		"	" RISCV_PTR "	%0 - .			\n\t"
53 		"	.popsection				\n\t"
54 		:  :  "i"(&((char *)key)[branch]) :  : label);
55 
56 	return false;
57 label:
58 	return true;
59 }
60 
61 #endif  /* __ASSEMBLY__ */
62 #endif	/* __ASM_JUMP_LABEL_H */
63