xref: /openbmc/linux/arch/x86/include/asm/jump_label.h (revision fb574682)
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 #define JUMP_LABEL_NOP_SIZE 5
8 
9 #ifdef CONFIG_X86_64
10 # define STATIC_KEY_INIT_NOP P6_NOP5_ATOMIC
11 #else
12 # define STATIC_KEY_INIT_NOP GENERIC_NOP5_ATOMIC
13 #endif
14 
15 #include <asm/asm.h>
16 #include <asm/nops.h>
17 
18 #ifndef __ASSEMBLY__
19 
20 #include <linux/stringify.h>
21 #include <linux/types.h>
22 
23 static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
24 {
25 	asm_volatile_goto("1:"
26 		".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
27 		".pushsection __jump_table,  \"aw\" \n\t"
28 		_ASM_ALIGN "\n\t"
29 		".long 1b - ., %l[l_yes] - . \n\t"
30 		_ASM_PTR "%c0 + %c1 - .\n\t"
31 		".popsection \n\t"
32 		: :  "i" (key), "i" (branch) : : l_yes);
33 
34 	return false;
35 l_yes:
36 	return true;
37 }
38 
39 static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
40 {
41 	asm_volatile_goto("1:"
42 		".byte 0xe9\n\t .long %l[l_yes] - 2f\n\t"
43 		"2:\n\t"
44 		".pushsection __jump_table,  \"aw\" \n\t"
45 		_ASM_ALIGN "\n\t"
46 		".long 1b - ., %l[l_yes] - . \n\t"
47 		_ASM_PTR "%c0 + %c1 - .\n\t"
48 		".popsection \n\t"
49 		: :  "i" (key), "i" (branch) : : l_yes);
50 
51 	return false;
52 l_yes:
53 	return true;
54 }
55 
56 #else	/* __ASSEMBLY__ */
57 
58 .macro STATIC_JUMP_IF_TRUE target, key, def
59 .Lstatic_jump_\@:
60 	.if \def
61 	/* Equivalent to "jmp.d32 \target" */
62 	.byte		0xe9
63 	.long		\target - .Lstatic_jump_after_\@
64 .Lstatic_jump_after_\@:
65 	.else
66 	.byte		STATIC_KEY_INIT_NOP
67 	.endif
68 	.pushsection __jump_table, "aw"
69 	_ASM_ALIGN
70 	.long		.Lstatic_jump_\@ - ., \target - .
71 	_ASM_PTR	\key - .
72 	.popsection
73 .endm
74 
75 .macro STATIC_JUMP_IF_FALSE target, key, def
76 .Lstatic_jump_\@:
77 	.if \def
78 	.byte		STATIC_KEY_INIT_NOP
79 	.else
80 	/* Equivalent to "jmp.d32 \target" */
81 	.byte		0xe9
82 	.long		\target - .Lstatic_jump_after_\@
83 .Lstatic_jump_after_\@:
84 	.endif
85 	.pushsection __jump_table, "aw"
86 	_ASM_ALIGN
87 	.long		.Lstatic_jump_\@ - ., \target - .
88 	_ASM_PTR	\key + 1 - .
89 	.popsection
90 .endm
91 
92 #endif	/* __ASSEMBLY__ */
93 
94 #endif
95