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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2025 Chen Miao
4 *
5 * Based on arch/arm/include/asm/jump_label.h
6 */
7#ifndef __ASM_OPENRISC_JUMP_LABEL_H
8#define __ASM_OPENRISC_JUMP_LABEL_H
9
10#ifndef __ASSEMBLER__
11
12#include <linux/types.h>
13#include <asm/insn-def.h>
14
15#define HAVE_JUMP_LABEL_BATCH
16
17#define JUMP_LABEL_NOP_SIZE OPENRISC_INSN_SIZE
18
19/**
20 * JUMP_TABLE_ENTRY - Create a jump table entry
21 * @key: Jump key identifier (typically a symbol address)
22 * @label: Target label address
23 *
24 * This macro creates a jump table entry in the dedicated kernel section (__jump_table).
25 * Each entry contains the following information:
26 * Offset from current instruction to jump instruction (1b - .)
27 * Offset from current instruction to target label (label - .)
28 * Offset from current instruction to key identifier (key - .)
29 */
30#define JUMP_TABLE_ENTRY(key, label) \
31 ".pushsection __jump_table, \"aw\" \n\t" \
32 ".align 4 \n\t" \
33 ".long 1b - ., " label " - . \n\t" \
34 ".long " key " - . \n\t" \
35 ".popsection \n\t"
36
37#define ARCH_STATIC_BRANCH_ASM(key, label) \
38 ".align 4 \n\t" \
39 "1: l.nop \n\t" \
40 " l.nop \n\t" \
41 JUMP_TABLE_ENTRY(key, label)
42
43static __always_inline bool arch_static_branch(struct static_key *const key,
44 const bool branch)
45{
46 asm goto (ARCH_STATIC_BRANCH_ASM("%0", "%l[l_yes]")
47 ::"i"(&((char *)key)[branch])::l_yes);
48
49 return false;
50l_yes:
51 return true;
52}
53
54#define ARCH_STATIC_BRANCH_JUMP_ASM(key, label) \
55 ".align 4 \n\t" \
56 "1: l.j " label " \n\t" \
57 " l.nop \n\t" \
58 JUMP_TABLE_ENTRY(key, label)
59
60static __always_inline bool
61arch_static_branch_jump(struct static_key *const key, const bool branch)
62{
63 asm goto (ARCH_STATIC_BRANCH_JUMP_ASM("%0", "%l[l_yes]")
64 ::"i"(&((char *)key)[branch])::l_yes);
65
66 return false;
67l_yes:
68 return true;
69}
70
71#endif /* __ASSEMBLER__ */
72#endif /* __ASM_OPENRISC_JUMP_LABEL_H */