1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _ASM_X86_NOPS_H |
3 | #define _ASM_X86_NOPS_H |
4 | |
5 | /* |
6 | * Define nops for use with alternative() and for tracing. |
7 | * |
8 | * *_NOP5_ATOMIC must be a single instruction. |
9 | */ |
10 | |
11 | #define NOP_DS_PREFIX 0x3e |
12 | |
13 | /* generic versions from gas |
14 | 1: nop |
15 | the following instructions are NOT nops in 64-bit mode, |
16 | for 64-bit mode use K8 or P6 nops instead |
17 | 2: movl %esi,%esi |
18 | 3: leal 0x00(%esi),%esi |
19 | 4: leal 0x00(,%esi,1),%esi |
20 | 6: leal 0x00000000(%esi),%esi |
21 | 7: leal 0x00000000(,%esi,1),%esi |
22 | */ |
23 | #define GENERIC_NOP1 0x90 |
24 | #define GENERIC_NOP2 0x89,0xf6 |
25 | #define GENERIC_NOP3 0x8d,0x76,0x00 |
26 | #define GENERIC_NOP4 0x8d,0x74,0x26,0x00 |
27 | #define GENERIC_NOP5 GENERIC_NOP1,GENERIC_NOP4 |
28 | #define GENERIC_NOP6 0x8d,0xb6,0x00,0x00,0x00,0x00 |
29 | #define GENERIC_NOP7 0x8d,0xb4,0x26,0x00,0x00,0x00,0x00 |
30 | #define GENERIC_NOP8 GENERIC_NOP1,GENERIC_NOP7 |
31 | #define GENERIC_NOP5_ATOMIC NOP_DS_PREFIX,GENERIC_NOP4 |
32 | |
33 | /* Opteron 64bit nops |
34 | 1: nop |
35 | 2: osp nop |
36 | 3: osp osp nop |
37 | 4: osp osp osp nop |
38 | */ |
39 | #define K8_NOP1 GENERIC_NOP1 |
40 | #define K8_NOP2 0x66,K8_NOP1 |
41 | #define K8_NOP3 0x66,K8_NOP2 |
42 | #define K8_NOP4 0x66,K8_NOP3 |
43 | #define K8_NOP5 K8_NOP3,K8_NOP2 |
44 | #define K8_NOP6 K8_NOP3,K8_NOP3 |
45 | #define K8_NOP7 K8_NOP4,K8_NOP3 |
46 | #define K8_NOP8 K8_NOP4,K8_NOP4 |
47 | #define K8_NOP5_ATOMIC 0x66,K8_NOP4 |
48 | |
49 | /* K7 nops |
50 | uses eax dependencies (arbitrary choice) |
51 | 1: nop |
52 | 2: movl %eax,%eax |
53 | 3: leal (,%eax,1),%eax |
54 | 4: leal 0x00(,%eax,1),%eax |
55 | 6: leal 0x00000000(%eax),%eax |
56 | 7: leal 0x00000000(,%eax,1),%eax |
57 | */ |
58 | #define K7_NOP1 GENERIC_NOP1 |
59 | #define K7_NOP2 0x8b,0xc0 |
60 | #define K7_NOP3 0x8d,0x04,0x20 |
61 | #define K7_NOP4 0x8d,0x44,0x20,0x00 |
62 | #define K7_NOP5 K7_NOP4,K7_NOP1 |
63 | #define K7_NOP6 0x8d,0x80,0,0,0,0 |
64 | #define K7_NOP7 0x8D,0x04,0x05,0,0,0,0 |
65 | #define K7_NOP8 K7_NOP7,K7_NOP1 |
66 | #define K7_NOP5_ATOMIC NOP_DS_PREFIX,K7_NOP4 |
67 | |
68 | /* P6 nops |
69 | uses eax dependencies (Intel-recommended choice) |
70 | 1: nop |
71 | 2: osp nop |
72 | 3: nopl (%eax) |
73 | 4: nopl 0x00(%eax) |
74 | 5: nopl 0x00(%eax,%eax,1) |
75 | 6: osp nopl 0x00(%eax,%eax,1) |
76 | 7: nopl 0x00000000(%eax) |
77 | 8: nopl 0x00000000(%eax,%eax,1) |
78 | Note: All the above are assumed to be a single instruction. |
79 | There is kernel code that depends on this. |
80 | */ |
81 | #define P6_NOP1 GENERIC_NOP1 |
82 | #define P6_NOP2 0x66,0x90 |
83 | #define P6_NOP3 0x0f,0x1f,0x00 |
84 | #define P6_NOP4 0x0f,0x1f,0x40,0 |
85 | #define P6_NOP5 0x0f,0x1f,0x44,0x00,0 |
86 | #define P6_NOP6 0x66,0x0f,0x1f,0x44,0x00,0 |
87 | #define P6_NOP7 0x0f,0x1f,0x80,0,0,0,0 |
88 | #define P6_NOP8 0x0f,0x1f,0x84,0x00,0,0,0,0 |
89 | #define P6_NOP5_ATOMIC P6_NOP5 |
90 | |
91 | #ifdef __ASSEMBLY__ |
92 | #define _ASM_MK_NOP(x) .byte x |
93 | #else |
94 | #define _ASM_MK_NOP(x) ".byte " __stringify(x) "\n" |
95 | #endif |
96 | |
97 | #if defined(CONFIG_MK7) |
98 | #define ASM_NOP1 _ASM_MK_NOP(K7_NOP1) |
99 | #define ASM_NOP2 _ASM_MK_NOP(K7_NOP2) |
100 | #define ASM_NOP3 _ASM_MK_NOP(K7_NOP3) |
101 | #define ASM_NOP4 _ASM_MK_NOP(K7_NOP4) |
102 | #define ASM_NOP5 _ASM_MK_NOP(K7_NOP5) |
103 | #define ASM_NOP6 _ASM_MK_NOP(K7_NOP6) |
104 | #define ASM_NOP7 _ASM_MK_NOP(K7_NOP7) |
105 | #define ASM_NOP8 _ASM_MK_NOP(K7_NOP8) |
106 | #define ASM_NOP5_ATOMIC _ASM_MK_NOP(K7_NOP5_ATOMIC) |
107 | #elif defined(CONFIG_X86_P6_NOP) |
108 | #define ASM_NOP1 _ASM_MK_NOP(P6_NOP1) |
109 | #define ASM_NOP2 _ASM_MK_NOP(P6_NOP2) |
110 | #define ASM_NOP3 _ASM_MK_NOP(P6_NOP3) |
111 | #define ASM_NOP4 _ASM_MK_NOP(P6_NOP4) |
112 | #define ASM_NOP5 _ASM_MK_NOP(P6_NOP5) |
113 | #define ASM_NOP6 _ASM_MK_NOP(P6_NOP6) |
114 | #define ASM_NOP7 _ASM_MK_NOP(P6_NOP7) |
115 | #define ASM_NOP8 _ASM_MK_NOP(P6_NOP8) |
116 | #define ASM_NOP5_ATOMIC _ASM_MK_NOP(P6_NOP5_ATOMIC) |
117 | #elif defined(CONFIG_X86_64) |
118 | #define ASM_NOP1 _ASM_MK_NOP(K8_NOP1) |
119 | #define ASM_NOP2 _ASM_MK_NOP(K8_NOP2) |
120 | #define ASM_NOP3 _ASM_MK_NOP(K8_NOP3) |
121 | #define ASM_NOP4 _ASM_MK_NOP(K8_NOP4) |
122 | #define ASM_NOP5 _ASM_MK_NOP(K8_NOP5) |
123 | #define ASM_NOP6 _ASM_MK_NOP(K8_NOP6) |
124 | #define ASM_NOP7 _ASM_MK_NOP(K8_NOP7) |
125 | #define ASM_NOP8 _ASM_MK_NOP(K8_NOP8) |
126 | #define ASM_NOP5_ATOMIC _ASM_MK_NOP(K8_NOP5_ATOMIC) |
127 | #else |
128 | #define ASM_NOP1 _ASM_MK_NOP(GENERIC_NOP1) |
129 | #define ASM_NOP2 _ASM_MK_NOP(GENERIC_NOP2) |
130 | #define ASM_NOP3 _ASM_MK_NOP(GENERIC_NOP3) |
131 | #define ASM_NOP4 _ASM_MK_NOP(GENERIC_NOP4) |
132 | #define ASM_NOP5 _ASM_MK_NOP(GENERIC_NOP5) |
133 | #define ASM_NOP6 _ASM_MK_NOP(GENERIC_NOP6) |
134 | #define ASM_NOP7 _ASM_MK_NOP(GENERIC_NOP7) |
135 | #define ASM_NOP8 _ASM_MK_NOP(GENERIC_NOP8) |
136 | #define ASM_NOP5_ATOMIC _ASM_MK_NOP(GENERIC_NOP5_ATOMIC) |
137 | #endif |
138 | |
139 | #define ASM_NOP_MAX 8 |
140 | #define NOP_ATOMIC5 (ASM_NOP_MAX+1) /* Entry for the 5-byte atomic NOP */ |
141 | |
142 | #ifndef __ASSEMBLY__ |
143 | extern const unsigned char * const *ideal_nops; |
144 | extern void arch_init_ideal_nops(void); |
145 | #endif |
146 | |
147 | #endif /* _ASM_X86_NOPS_H */ |
148 | |