linux/arch/x86/include/asm/cpufeature.h
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   1#ifndef _ASM_X86_CPUFEATURE_H
   2#define _ASM_X86_CPUFEATURE_H
   3
   4#include <asm/processor.h>
   5
   6#if defined(__KERNEL__) && !defined(__ASSEMBLY__)
   7
   8#include <asm/asm.h>
   9#include <linux/bitops.h>
  10
  11enum cpuid_leafs
  12{
  13        CPUID_1_EDX             = 0,
  14        CPUID_8000_0001_EDX,
  15        CPUID_8086_0001_EDX,
  16        CPUID_LNX_1,
  17        CPUID_1_ECX,
  18        CPUID_C000_0001_EDX,
  19        CPUID_8000_0001_ECX,
  20        CPUID_LNX_2,
  21        CPUID_LNX_3,
  22        CPUID_7_0_EBX,
  23        CPUID_D_1_EAX,
  24        CPUID_F_0_EDX,
  25        CPUID_F_1_EDX,
  26        CPUID_8000_0008_EBX,
  27        CPUID_6_EAX,
  28        CPUID_8000_000A_EDX,
  29        CPUID_7_ECX,
  30        CPUID_8000_0007_EBX,
  31};
  32
  33#ifdef CONFIG_X86_FEATURE_NAMES
  34extern const char * const x86_cap_flags[NCAPINTS*32];
  35extern const char * const x86_power_flags[32];
  36#define X86_CAP_FMT "%s"
  37#define x86_cap_flag(flag) x86_cap_flags[flag]
  38#else
  39#define X86_CAP_FMT "%d:%d"
  40#define x86_cap_flag(flag) ((flag) >> 5), ((flag) & 31)
  41#endif
  42
  43/*
  44 * In order to save room, we index into this array by doing
  45 * X86_BUG_<name> - NCAPINTS*32.
  46 */
  47extern const char * const x86_bug_flags[NBUGINTS*32];
  48
  49#define test_cpu_cap(c, bit)                                            \
  50         test_bit(bit, (unsigned long *)((c)->x86_capability))
  51
  52/*
  53 * There are 32 bits/features in each mask word.  The high bits
  54 * (selected with (bit>>5) give us the word number and the low 5
  55 * bits give us the bit/feature number inside the word.
  56 * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can
  57 * see if it is set in the mask word.
  58 */
  59#define CHECK_BIT_IN_MASK_WORD(maskname, word, bit)     \
  60        (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word ))
  61
  62#define REQUIRED_MASK_BIT_SET(feature_bit)              \
  63         ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  0, feature_bit) ||    \
  64           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  1, feature_bit) ||    \
  65           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  2, feature_bit) ||    \
  66           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  3, feature_bit) ||    \
  67           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  4, feature_bit) ||    \
  68           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  5, feature_bit) ||    \
  69           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  6, feature_bit) ||    \
  70           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  7, feature_bit) ||    \
  71           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  8, feature_bit) ||    \
  72           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK,  9, feature_bit) ||    \
  73           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) ||    \
  74           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) ||    \
  75           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) ||    \
  76           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) ||    \
  77           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) ||    \
  78           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) ||    \
  79           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) ||    \
  80           CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) ||    \
  81           REQUIRED_MASK_CHECK                                    ||    \
  82           BUILD_BUG_ON_ZERO(NCAPINTS != 18))
  83
  84#define DISABLED_MASK_BIT_SET(feature_bit)                              \
  85         ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  0, feature_bit) ||    \
  86           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  1, feature_bit) ||    \
  87           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  2, feature_bit) ||    \
  88           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  3, feature_bit) ||    \
  89           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  4, feature_bit) ||    \
  90           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  5, feature_bit) ||    \
  91           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  6, feature_bit) ||    \
  92           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  7, feature_bit) ||    \
  93           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  8, feature_bit) ||    \
  94           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK,  9, feature_bit) ||    \
  95           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) ||    \
  96           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) ||    \
  97           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) ||    \
  98           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) ||    \
  99           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) ||    \
 100           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) ||    \
 101           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) ||    \
 102           CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) ||    \
 103           DISABLED_MASK_CHECK                                    ||    \
 104           BUILD_BUG_ON_ZERO(NCAPINTS != 18))
 105
 106#define cpu_has(c, bit)                                                 \
 107        (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :  \
 108         test_cpu_cap(c, bit))
 109
 110#define this_cpu_has(bit)                                               \
 111        (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :  \
 112         x86_this_cpu_test_bit(bit, (unsigned long *)&cpu_info.x86_capability))
 113
 114/*
 115 * This macro is for detection of features which need kernel
 116 * infrastructure to be used.  It may *not* directly test the CPU
 117 * itself.  Use the cpu_has() family if you want true runtime
 118 * testing of CPU features, like in hypervisor code where you are
 119 * supporting a possible guest feature where host support for it
 120 * is not relevant.
 121 */
 122#define cpu_feature_enabled(bit)        \
 123        (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
 124
 125#define boot_cpu_has(bit)       cpu_has(&boot_cpu_data, bit)
 126
 127#define set_cpu_cap(c, bit)     set_bit(bit, (unsigned long *)((c)->x86_capability))
 128#define clear_cpu_cap(c, bit)   clear_bit(bit, (unsigned long *)((c)->x86_capability))
 129#define setup_clear_cpu_cap(bit) do { \
 130        clear_cpu_cap(&boot_cpu_data, bit);     \
 131        set_bit(bit, (unsigned long *)cpu_caps_cleared); \
 132} while (0)
 133#define setup_force_cpu_cap(bit) do { \
 134        set_cpu_cap(&boot_cpu_data, bit);       \
 135        set_bit(bit, (unsigned long *)cpu_caps_set);    \
 136} while (0)
 137
 138#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_X86_FAST_FEATURE_TESTS)
 139/*
 140 * Static testing of CPU features.  Used the same as boot_cpu_has().
 141 * These will statically patch the target code for additional
 142 * performance.
 143 */
 144static __always_inline __pure bool _static_cpu_has(u16 bit)
 145{
 146                asm_volatile_goto("1: jmp 6f\n"
 147                         "2:\n"
 148                         ".skip -(((5f-4f) - (2b-1b)) > 0) * "
 149                                 "((5f-4f) - (2b-1b)),0x90\n"
 150                         "3:\n"
 151                         ".section .altinstructions,\"a\"\n"
 152                         " .long 1b - .\n"              /* src offset */
 153                         " .long 4f - .\n"              /* repl offset */
 154                         " .word %P1\n"                 /* always replace */
 155                         " .byte 3b - 1b\n"             /* src len */
 156                         " .byte 5f - 4f\n"             /* repl len */
 157                         " .byte 3b - 2b\n"             /* pad len */
 158                         ".previous\n"
 159                         ".section .altinstr_replacement,\"ax\"\n"
 160                         "4: jmp %l[t_no]\n"
 161                         "5:\n"
 162                         ".previous\n"
 163                         ".section .altinstructions,\"a\"\n"
 164                         " .long 1b - .\n"              /* src offset */
 165                         " .long 0\n"                   /* no replacement */
 166                         " .word %P0\n"                 /* feature bit */
 167                         " .byte 3b - 1b\n"             /* src len */
 168                         " .byte 0\n"                   /* repl len */
 169                         " .byte 0\n"                   /* pad len */
 170                         ".previous\n"
 171                         ".section .altinstr_aux,\"ax\"\n"
 172                         "6:\n"
 173                         " testb %[bitnum],%[cap_byte]\n"
 174                         " jnz %l[t_yes]\n"
 175                         " jmp %l[t_no]\n"
 176                         ".previous\n"
 177                         : : "i" (bit), "i" (X86_FEATURE_ALWAYS),
 178                             [bitnum] "i" (1 << (bit & 7)),
 179                             [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
 180                         : : t_yes, t_no);
 181        t_yes:
 182                return true;
 183        t_no:
 184                return false;
 185}
 186
 187#define static_cpu_has(bit)                                     \
 188(                                                               \
 189        __builtin_constant_p(boot_cpu_has(bit)) ?               \
 190                boot_cpu_has(bit) :                             \
 191                _static_cpu_has(bit)                            \
 192)
 193#else
 194/*
 195 * Fall back to dynamic for gcc versions which don't support asm goto. Should be
 196 * a minority now anyway.
 197 */
 198#define static_cpu_has(bit)             boot_cpu_has(bit)
 199#endif
 200
 201#define cpu_has_bug(c, bit)             cpu_has(c, (bit))
 202#define set_cpu_bug(c, bit)             set_cpu_cap(c, (bit))
 203#define clear_cpu_bug(c, bit)           clear_cpu_cap(c, (bit))
 204
 205#define static_cpu_has_bug(bit)         static_cpu_has((bit))
 206#define boot_cpu_has_bug(bit)           cpu_has_bug(&boot_cpu_data, (bit))
 207#define boot_cpu_set_bug(bit)           set_cpu_cap(&boot_cpu_data, (bit))
 208
 209#define MAX_CPU_FEATURES                (NCAPINTS * 32)
 210#define cpu_have_feature                boot_cpu_has
 211
 212#define CPU_FEATURE_TYPEFMT             "x86,ven%04Xfam%04Xmod%04X"
 213#define CPU_FEATURE_TYPEVAL             boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
 214                                        boot_cpu_data.x86_model
 215
 216#endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */
 217#endif /* _ASM_X86_CPUFEATURE_H */
 218
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