cpufeature.h 8.0 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef _ASM_X86_CPUFEATURE_H
  3. #define _ASM_X86_CPUFEATURE_H
  4. #include <asm/processor.h>
  5. #if defined(__KERNEL__) && !defined(__ASSEMBLY__)
  6. #include <asm/asm.h>
  7. #include <linux/bitops.h>
  8. #include <asm/alternative.h>
  9. enum cpuid_leafs
  10. {
  11. CPUID_1_EDX = 0,
  12. CPUID_8000_0001_EDX,
  13. CPUID_8086_0001_EDX,
  14. CPUID_LNX_1,
  15. CPUID_1_ECX,
  16. CPUID_C000_0001_EDX,
  17. CPUID_8000_0001_ECX,
  18. CPUID_LNX_2,
  19. CPUID_LNX_3,
  20. CPUID_7_0_EBX,
  21. CPUID_D_1_EAX,
  22. CPUID_LNX_4,
  23. CPUID_7_1_EAX,
  24. CPUID_8000_0008_EBX,
  25. CPUID_6_EAX,
  26. CPUID_8000_000A_EDX,
  27. CPUID_7_ECX,
  28. CPUID_8000_0007_EBX,
  29. CPUID_7_EDX,
  30. CPUID_8000_001F_EAX,
  31. CPUID_8000_0021_EAX,
  32. };
  33. #define X86_CAP_FMT_NUM "%d:%d"
  34. #define x86_cap_flag_num(flag) ((flag) >> 5), ((flag) & 31)
  35. #ifdef CONFIG_X86_FEATURE_NAMES
  36. extern const char * const x86_cap_flags[NCAPINTS*32];
  37. extern const char * const x86_power_flags[32];
  38. #define X86_CAP_FMT "%s"
  39. #define x86_cap_flag(flag) x86_cap_flags[flag]
  40. #else
  41. #define X86_CAP_FMT X86_CAP_FMT_NUM
  42. #define x86_cap_flag x86_cap_flag_num
  43. #endif
  44. /*
  45. * In order to save room, we index into this array by doing
  46. * X86_BUG_<name> - NCAPINTS*32.
  47. */
  48. extern const char * const x86_bug_flags[NBUGINTS*32];
  49. #define test_cpu_cap(c, bit) \
  50. arch_test_bit(bit, (unsigned long *)((c)->x86_capability))
  51. /*
  52. * There are 32 bits/features in each mask word. The high bits
  53. * (selected with (bit>>5) give us the word number and the low 5
  54. * bits give us the bit/feature number inside the word.
  55. * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can
  56. * see if it is set in the mask word.
  57. */
  58. #define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \
  59. (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word ))
  60. /*
  61. * {REQUIRED,DISABLED}_MASK_CHECK below may seem duplicated with the
  62. * following BUILD_BUG_ON_ZERO() check but when NCAPINTS gets changed, all
  63. * header macros which use NCAPINTS need to be changed. The duplicated macro
  64. * use causes the compiler to issue errors for all headers so that all usage
  65. * sites can be corrected.
  66. */
  67. #define REQUIRED_MASK_BIT_SET(feature_bit) \
  68. ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 0, feature_bit) || \
  69. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 1, feature_bit) || \
  70. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 2, feature_bit) || \
  71. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 3, feature_bit) || \
  72. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 4, feature_bit) || \
  73. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 5, feature_bit) || \
  74. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 6, feature_bit) || \
  75. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 7, feature_bit) || \
  76. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 8, feature_bit) || \
  77. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 9, feature_bit) || \
  78. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) || \
  79. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) || \
  80. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) || \
  81. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) || \
  82. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) || \
  83. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \
  84. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \
  85. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \
  86. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \
  87. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \
  88. CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 20, feature_bit) || \
  89. REQUIRED_MASK_CHECK || \
  90. BUILD_BUG_ON_ZERO(NCAPINTS != 21))
  91. #define DISABLED_MASK_BIT_SET(feature_bit) \
  92. ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \
  93. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 1, feature_bit) || \
  94. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 2, feature_bit) || \
  95. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 3, feature_bit) || \
  96. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 4, feature_bit) || \
  97. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 5, feature_bit) || \
  98. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 6, feature_bit) || \
  99. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 7, feature_bit) || \
  100. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 8, feature_bit) || \
  101. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 9, feature_bit) || \
  102. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) || \
  103. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) || \
  104. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) || \
  105. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) || \
  106. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) || \
  107. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \
  108. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \
  109. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \
  110. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \
  111. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \
  112. CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 20, feature_bit) || \
  113. DISABLED_MASK_CHECK || \
  114. BUILD_BUG_ON_ZERO(NCAPINTS != 21))
  115. #define cpu_has(c, bit) \
  116. (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
  117. test_cpu_cap(c, bit))
  118. #define this_cpu_has(bit) \
  119. (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
  120. x86_this_cpu_test_bit(bit, \
  121. (unsigned long __percpu *)&cpu_info.x86_capability))
  122. /*
  123. * This macro is for detection of features which need kernel
  124. * infrastructure to be used. It may *not* directly test the CPU
  125. * itself. Use the cpu_has() family if you want true runtime
  126. * testing of CPU features, like in hypervisor code where you are
  127. * supporting a possible guest feature where host support for it
  128. * is not relevant.
  129. */
  130. #define cpu_feature_enabled(bit) \
  131. (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
  132. #define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit)
  133. #define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability))
  134. extern void setup_clear_cpu_cap(unsigned int bit);
  135. extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
  136. #define setup_force_cpu_cap(bit) do { \
  137. set_cpu_cap(&boot_cpu_data, bit); \
  138. set_bit(bit, (unsigned long *)cpu_caps_set); \
  139. } while (0)
  140. #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
  141. /*
  142. * Static testing of CPU features. Used the same as boot_cpu_has(). It
  143. * statically patches the target code for additional performance. Use
  144. * static_cpu_has() only in fast paths, where every cycle counts. Which
  145. * means that the boot_cpu_has() variant is already fast enough for the
  146. * majority of cases and you should stick to using it as it is generally
  147. * only two instructions: a RIP-relative MOV and a TEST.
  148. *
  149. * Do not use an "m" constraint for [cap_byte] here: gcc doesn't know
  150. * that this is only used on a fallback path and will sometimes cause
  151. * it to manifest the address of boot_cpu_data in a register, fouling
  152. * the mainline (post-initialization) code.
  153. */
  154. static __always_inline bool _static_cpu_has(u16 bit)
  155. {
  156. asm_volatile_goto(
  157. ALTERNATIVE_TERNARY("jmp 6f", %P[feature], "", "jmp %l[t_no]")
  158. ".pushsection .altinstr_aux,\"ax\"\n"
  159. "6:\n"
  160. " testb %[bitnum]," _ASM_RIP(%P[cap_byte]) "\n"
  161. " jnz %l[t_yes]\n"
  162. " jmp %l[t_no]\n"
  163. ".popsection\n"
  164. : : [feature] "i" (bit),
  165. [bitnum] "i" (1 << (bit & 7)),
  166. [cap_byte] "i" (&((const char *)boot_cpu_data.x86_capability)[bit >> 3])
  167. : : t_yes, t_no);
  168. t_yes:
  169. return true;
  170. t_no:
  171. return false;
  172. }
  173. #define static_cpu_has(bit) \
  174. ( \
  175. __builtin_constant_p(boot_cpu_has(bit)) ? \
  176. boot_cpu_has(bit) : \
  177. _static_cpu_has(bit) \
  178. )
  179. #define cpu_has_bug(c, bit) cpu_has(c, (bit))
  180. #define set_cpu_bug(c, bit) set_cpu_cap(c, (bit))
  181. #define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit))
  182. #define static_cpu_has_bug(bit) static_cpu_has((bit))
  183. #define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit))
  184. #define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit))
  185. #define MAX_CPU_FEATURES (NCAPINTS * 32)
  186. #define cpu_have_feature boot_cpu_has
  187. #define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X"
  188. #define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
  189. boot_cpu_data.x86_model
  190. #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */
  191. #endif /* _ASM_X86_CPUFEATURE_H */