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__ 142extern const unsigned char * const *ideal_nops; 143extern void arch_init_ideal_nops(void); 144#endif 145 146#endif /* _ASM_X86_NOPS_H */ 147