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 __ASSEMBLER__
11
12 #include <linux/stringify.h>
13 #include <linux/types.h>
14
15 #define JUMP_TABLE_ENTRY(key, label) \
16 ".pushsection __jump_table, \"aw\" \n\t" \
17 _ASM_ALIGN "\n\t" \
18 ANNOTATE_DATA_SPECIAL "\n" \
19 ".long 1b - . \n\t" \
20 ".long " label " - . \n\t" \
21 _ASM_PTR " " key " - . \n\t" \
22 ".popsection \n\t"
23
24 /* This macro is also expanded on the Rust side. */
25 #ifdef CONFIG_HAVE_JUMP_LABEL_HACK
26 #define ARCH_STATIC_BRANCH_ASM(key, label) \
27 "1: jmp " label " # objtool NOPs this \n\t" \
28 JUMP_TABLE_ENTRY(key " + 2", label)
29 #else /* !CONFIG_HAVE_JUMP_LABEL_HACK */
30 #define ARCH_STATIC_BRANCH_ASM(key, label) \
31 "1: .byte " __stringify(BYTES_NOP5) "\n\t" \
32 JUMP_TABLE_ENTRY(key, label)
33 #endif /* CONFIG_HAVE_JUMP_LABEL_HACK */
34
arch_static_branch(struct static_key * const key,const bool branch)35 static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
36 {
37 asm goto(ARCH_STATIC_BRANCH_ASM("%c0 + %c1", "%l[l_yes]")
38 : : "i" (key), "i" (branch) : : l_yes);
39
40 return false;
41 l_yes:
42 return true;
43 }
44
arch_static_branch_jump(struct static_key * const key,const bool branch)45 static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)
46 {
47 asm goto("1:"
48 "jmp %l[l_yes]\n\t"
49 JUMP_TABLE_ENTRY("%c0 + %c1", "%l[l_yes]")
50 : : "i" (key), "i" (branch) : : l_yes);
51
52 return false;
53 l_yes:
54 return true;
55 }
56
57 extern int arch_jump_entry_size(struct jump_entry *entry);
58
59 #endif /* __ASSEMBLER__ */
60
61 #endif
62