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