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