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