arch/x86/include/asm/nops.h

   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 (arbitary 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 */