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