arch/x86/include/asm/cpufeature.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_CPUFEATURE_H
   3 #define _ASM_X86_CPUFEATURE_H
   4
   5 #include <asm/processor.h>
   6
   7 #if defined(__KERNEL__) && !defined(__ASSEMBLY__)
   8
   9 #include <asm/asm.h>
  10 #include <linux/bitops.h>
  11
  12 enum cpuid_leafs
  13 {
  14         CPUID_1_EDX             = 0,
  15         CPUID_8000_0001_EDX,
  16         CPUID_8086_0001_EDX,
  17         CPUID_LNX_1,
  18         CPUID_1_ECX,
  19         CPUID_C000_0001_EDX,
  20         CPUID_8000_0001_ECX,
  21         CPUID_LNX_2,
  22         CPUID_LNX_3,
  23         CPUID_7_0_EBX,
  24         CPUID_D_1_EAX,
  25         CPUID_F_0_EDX,
  26         CPUID_F_1_EDX,
  27         CPUID_8000_0008_EBX,
  28         CPUID_6_EAX,
  29         CPUID_8000_000A_EDX,
  30         CPUID_7_ECX,
  31         CPUID_8000_0007_EBX,
  32 };
  33
  34 #ifdef CONFIG_X86_FEATURE_NAMES
  35 extern const char * const x86_cap_flags[NCAPINTS*32];
  36 extern const char * const x86_power_flags[32];
  37 #define X86_CAP_FMT "%s"
  38 #define x86_cap_flag(flag) x86_cap_flags[flag]
  39 #else
  40 #define X86_CAP_FMT "%d:%d"
  41 #define x86_cap_flag(flag) ((flag) >> 5), ((flag) & 31)
  42 #endif
  43
  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
  50 #define test_cpu_cap(c, bit)                                            \
  51          test_bit(bit, (unsigned long *)((c)->x86_capability))
  52
  53 /*
  54  * There are 32 bits/features in each mask word.  The high bits
  55  * (selected with (bit>>5) give us the word number and the low 5
  56  * bits give us the bit/feature number inside the word.
  57  * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can
  58  * see if it is set in the mask word.
  59  */
  60 #define CHECK_BIT_IN_MASK_WORD(maskname, word, bit)     \
  61         (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word ))
  62
  63 #define REQUIRED_MASK_BIT_SET(feature_bit)              \
  64          ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  0, feature_bit) ||    \
  65            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  1, feature_bit) ||    \
  66            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  2, feature_bit) ||    \
  67            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  3, feature_bit) ||    \
  68            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  4, feature_bit) ||    \
  69            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  5, feature_bit) ||    \
  70            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  6, feature_bit) ||    \
  71            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  7, feature_bit) ||    \
  72            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  8, feature_bit) ||    \
  73            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  9, feature_bit) ||    \
  74            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) ||    \
  75            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) ||    \
  76            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) ||    \
  77            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) ||    \
  78            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) ||    \
  79            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) ||    \
  80            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) ||    \
  81            CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) ||    \
  82            REQUIRED_MASK_CHECK                                    ||    \
  83            BUILD_BUG_ON_ZERO(NCAPINTS != 18))
  84
  85 #define DISABLED_MASK_BIT_SET(feature_bit)                              \
  86          ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  0, feature_bit) ||    \
  87            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  1, feature_bit) ||    \
  88            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  2, feature_bit) ||    \
  89            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  3, feature_bit) ||    \
  90            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  4, feature_bit) ||    \
  91            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  5, feature_bit) ||    \
  92            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  6, feature_bit) ||    \
  93            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  7, feature_bit) ||    \
  94            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  8, feature_bit) ||    \
  95            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  9, feature_bit) ||    \
  96            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) ||    \
  97            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) ||    \
  98            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) ||    \
  99            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) ||    \
 100            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) ||    \
 101            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) ||    \
 102            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) ||    \
 103            CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) ||    \
 104            DISABLED_MASK_CHECK                                    ||    \
 105            BUILD_BUG_ON_ZERO(NCAPINTS != 18))
 106
 107 #define cpu_has(c, bit)                                                 \
 108         (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :  \
 109          test_cpu_cap(c, bit))
 110
 111 #define this_cpu_has(bit)                                               \
 112         (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :  \
 113          x86_this_cpu_test_bit(bit, (unsigned long *)&cpu_info.x86_capability))
 114
 115 /*
 116  * This macro is for detection of features which need kernel
 117  * infrastructure to be used.  It may *not* directly test the CPU
 118  * itself.  Use the cpu_has() family if you want true runtime
 119  * testing of CPU features, like in hypervisor code where you are
 120  * supporting a possible guest feature where host support for it
 121  * is not relevant.
 122  */
 123 #define cpu_feature_enabled(bit)        \
 124         (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
 125
 126 #define boot_cpu_has(bit)       cpu_has(&boot_cpu_data, bit)
 127
 128 #define set_cpu_cap(c, bit)     set_bit(bit, (unsigned long *)((c)->x86_capability))
 129 #define clear_cpu_cap(c, bit)   clear_bit(bit, (unsigned long *)((c)->x86_capability))
 130 #define setup_clear_cpu_cap(bit) do { \
 131         clear_cpu_cap(&boot_cpu_data, bit);     \
 132         set_bit(bit, (unsigned long *)cpu_caps_cleared); \
 133 } while (0)
 134 #define setup_force_cpu_cap(bit) do { \
 135         set_cpu_cap(&boot_cpu_data, bit);       \
 136         set_bit(bit, (unsigned long *)cpu_caps_set);    \
 137 } while (0)
 138
 139 #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_X86_FAST_FEATURE_TESTS)
 140 /*
 141  * Static testing of CPU features.  Used the same as boot_cpu_has().
 142  * These will statically patch the target code for additional
 143  * performance.
 144  */
 145 static __always_inline __pure bool _static_cpu_has(u16 bit)
 146 {
 147                 asm_volatile_goto("1: jmp 6f\n"
 148                          "2:\n"
 149                          ".skip -(((5f-4f) - (2b-1b)) > 0) * "
 150                                  "((5f-4f) - (2b-1b)),0x90\n"
 151                          "3:\n"
 152                          ".section .altinstructions,\"a\"\n"
 153                          " .long 1b - .\n"              /* src offset */
 154                          " .long 4f - .\n"              /* repl offset */
 155                          " .word %P1\n"                 /* always replace */
 156                          " .byte 3b - 1b\n"             /* src len */
 157                          " .byte 5f - 4f\n"             /* repl len */
 158                          " .byte 3b - 2b\n"             /* pad len */
 159                          ".previous\n"
 160                          ".section .altinstr_replacement,\"ax\"\n"
 161                          "4: jmp %l[t_no]\n"
 162                          "5:\n"
 163                          ".previous\n"
 164                          ".section .altinstructions,\"a\"\n"
 165                          " .long 1b - .\n"              /* src offset */
 166                          " .long 0\n"                   /* no replacement */
 167                          " .word %P0\n"                 /* feature bit */
 168                          " .byte 3b - 1b\n"             /* src len */
 169                          " .byte 0\n"                   /* repl len */
 170                          " .byte 0\n"                   /* pad len */
 171                          ".previous\n"
 172                          ".section .altinstr_aux,\"ax\"\n"
 173                          "6:\n"
 174                          " testb %[bitnum],%[cap_byte]\n"
 175                          " jnz %l[t_yes]\n"
 176                          " jmp %l[t_no]\n"
 177                          ".previous\n"
 178                          : : "i" (bit), "i" (X86_FEATURE_ALWAYS),
 179                              [bitnum] "i" (1 << (bit & 7)),
 180                              [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
 181                          : : t_yes, t_no);
 182         t_yes:
 183                 return true;
 184         t_no:
 185                 return false;
 186 }
 187
 188 #define static_cpu_has(bit)                                     \
 189 (                                                               \
 190         __builtin_constant_p(boot_cpu_has(bit)) ?               \
 191                 boot_cpu_has(bit) :                             \
 192                 _static_cpu_has(bit)                            \
 193 )
 194 #else
 195 /*
 196  * Fall back to dynamic for gcc versions which don't support asm goto. Should be
 197  * a minority now anyway.
 198  */
 199 #define static_cpu_has(bit)             boot_cpu_has(bit)
 200 #endif
 201
 202 #define cpu_has_bug(c, bit)             cpu_has(c, (bit))
 203 #define set_cpu_bug(c, bit)             set_cpu_cap(c, (bit))
 204 #define clear_cpu_bug(c, bit)           clear_cpu_cap(c, (bit))
 205
 206 #define static_cpu_has_bug(bit)         static_cpu_has((bit))
 207 #define boot_cpu_has_bug(bit)           cpu_has_bug(&boot_cpu_data, (bit))
 208 #define boot_cpu_set_bug(bit)           set_cpu_cap(&boot_cpu_data, (bit))
 209
 210 #define MAX_CPU_FEATURES                (NCAPINTS * 32)
 211 #define cpu_have_feature                boot_cpu_has
 212
 213 #define CPU_FEATURE_TYPEFMT             "x86,ven%04Xfam%04Xmod%04X"
 214 #define CPU_FEATURE_TYPEVAL             boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
 215                                         boot_cpu_data.x86_model
 216
 217 #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */
 218 #endif /* _ASM_X86_CPUFEATURE_H */