nops.h 4.2 KB

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