1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_JUMP_LABEL_H
3#define _ASM_X86_JUMP_LABEL_H
4
5#define HAVE_JUMP_LABEL_BATCH
6
7#include <asm/asm.h>
8#include <asm/nops.h>
9
10#ifndef __ASSEMBLY__
11
12#include <linux/stringify.h>
13#include <linux/types.h>
14
15#define JUMP_TABLE_ENTRY \
16 ".pushsection __jump_table, \"aw\" \n\t" \
17 _ASM_ALIGN "\n\t" \
18 ".long 1b - . \n\t" \
19 ".long %l[l_yes] - . \n\t" \
20 _ASM_PTR "%c0 + %c1 - .\n\t" \
21 ".popsection \n\t"
22
23#ifdef CONFIG_HAVE_JUMP_LABEL_HACK
24
25static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
26{
27 asm_volatile_goto("1:"
28 "jmp %l[l_yes] # objtool NOPs this \n\t"
29 JUMP_TABLE_ENTRY
30 : : "i" (key), "i" (2 | branch) : : l_yes);
31
32 return false;
33l_yes:
34 return true;
35}
36
37#else /* !CONFIG_HAVE_JUMP_LABEL_HACK */
38
39static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
40{
41 asm_volatile_goto("1:"
42 ".byte " __stringify(BYTES_NOP5) "\n\t"
43 JUMP_TABLE_ENTRY
44 : : "i" (key), "i" (branch) : : l_yes);
45
46 return false;
47l_yes:
48 return true;
49}
50
51#endif /* CONFIG_HAVE_JUMP_LABEL_HACK */
52
53static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)
54{
55 asm_volatile_goto("1:"
56 "jmp %l[l_yes]\n\t"
57 JUMP_TABLE_ENTRY
58 : : "i" (key), "i" (branch) : : l_yes);
59
60 return false;
61l_yes:
62 return true;
63}
64
65extern int arch_jump_entry_size(struct jump_entry *entry);
66
67#endif /* __ASSEMBLY__ */
68
69#endif
70

source code of linux/arch/x86/include/asm/jump_label.h