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 #define JUMP_TABLE_ENTRY(key, label) \
20 ".pushsection __jump_table, \"aw\" \n\t" \
21 ".align " RISCV_LGPTR " \n\t" \
22 ".long 1b - ., " label " - . \n\t" \
23 "" RISCV_PTR " " key " - . \n\t" \
24 ".popsection \n\t"
25
26 /* This macro is also expanded on the Rust side. */
27 #define ARCH_STATIC_BRANCH_ASM(key, label) \
28 " .align 2 \n\t" \
29 " .option push \n\t" \
30 " .option norelax \n\t" \
31 " .option norvc \n\t" \
32 "1: nop \n\t" \
33 " .option pop \n\t" \
34 JUMP_TABLE_ENTRY(key, label)
35
arch_static_branch(struct static_key * const key,const bool branch)36 static __always_inline bool arch_static_branch(struct static_key * const key,
37 const bool branch)
38 {
39 asm goto(
40 ARCH_STATIC_BRANCH_ASM("%0", "%l[label]")
41 : : "i"(&((char *)key)[branch]) : : label);
42
43 return false;
44 label:
45 return true;
46 }
47
48 #define ARCH_STATIC_BRANCH_JUMP_ASM(key, label) \
49 " .align 2 \n\t" \
50 " .option push \n\t" \
51 " .option norelax \n\t" \
52 " .option norvc \n\t" \
53 "1: j " label " \n\t" \
54 " .option pop \n\t" \
55 JUMP_TABLE_ENTRY(key, label)
56
arch_static_branch_jump(struct static_key * const key,const bool branch)57 static __always_inline bool arch_static_branch_jump(struct static_key * const key,
58 const bool branch)
59 {
60 asm goto(
61 ARCH_STATIC_BRANCH_JUMP_ASM("%0", "%l[label]")
62 : : "i"(&((char *)key)[branch]) : : label);
63
64 return false;
65 label:
66 return true;
67 }
68
69 #endif /* __ASSEMBLY__ */
70 #endif /* __ASM_JUMP_LABEL_H */
71