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(__ASSEMBLER__)
   8
   9 #include <asm/asm.h>
  10 #include <linux/bitops.h>
  11 #include <asm/alternative.h>
  12 #include <asm/cpufeaturemasks.h>
  13
  14 enum cpuid_leafs
  15 {
  16         CPUID_1_EDX             = 0,
  17         CPUID_8000_0001_EDX,
  18         CPUID_8086_0001_EDX,
  19         CPUID_LNX_1,
  20         CPUID_1_ECX,
  21         CPUID_C000_0001_EDX,
  22         CPUID_8000_0001_ECX,
  23         CPUID_LNX_2,
  24         CPUID_LNX_3,
  25         CPUID_7_0_EBX,
  26         CPUID_D_1_EAX,
  27         CPUID_LNX_4,
  28         CPUID_7_1_EAX,
  29         CPUID_8000_0008_EBX,
  30         CPUID_6_EAX,
  31         CPUID_8000_000A_EDX,
  32         CPUID_7_ECX,
  33         CPUID_8000_0007_EBX,
  34         CPUID_7_EDX,
  35         CPUID_8000_001F_EAX,
  36         CPUID_8000_0021_EAX,
  37         CPUID_LNX_5,
  38         NR_CPUID_WORDS,
  39 };
  40
  41 extern const char * const x86_cap_flags[NCAPINTS*32];
  42 extern const char * const x86_power_flags[32];
  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 #define x86_bug_flag(flag) x86_bug_flags[flag]
  50
  51 #define test_cpu_cap(c, bit)                                            \
  52          arch_test_bit(bit, (unsigned long *)((c)->x86_capability))
  53
  54 #define cpu_has(c, bit)                                                 \
  55         (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :  \
  56          test_cpu_cap(c, bit))
  57
  58 #define this_cpu_has(bit)                                               \
  59         (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :  \
  60          x86_this_cpu_test_bit(bit, cpu_info.x86_capability))
  61
  62 /*
  63  * This is the default CPU features testing macro to use in code.
  64  *
  65  * It is for detection of features which need kernel infrastructure to be
  66  * used.  It may *not* directly test the CPU itself.  Use the cpu_has() family
  67  * if you want true runtime testing of CPU features, like in hypervisor code
  68  * where you are supporting a possible guest feature where host support for it
  69  * is not relevant.
  70  */
  71 #define cpu_feature_enabled(bit)        \
  72         (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
  73
  74 #define boot_cpu_has(bit)       cpu_has(&boot_cpu_data, bit)
  75
  76 #define set_cpu_cap(c, bit)     set_bit(bit, (unsigned long *)((c)->x86_capability))
  77
  78 extern void setup_clear_cpu_cap(unsigned int bit);
  79 extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
  80 void check_cpufeature_deps(struct cpuinfo_x86 *c);
  81
  82 #define setup_force_cpu_cap(bit) do {                   \
  83                                                         \
  84         if (!boot_cpu_has(bit))                         \
  85                 WARN_ON(alternatives_patched);          \
  86                                                         \
  87         set_cpu_cap(&boot_cpu_data, bit);               \
  88         set_bit(bit, (unsigned long *)cpu_caps_set);    \
  89 } while (0)
  90
  91 #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
  92
  93 /*
  94  * Do not use an "m" constraint for [cap_byte] here: gcc doesn't know
  95  * that this is only used on a fallback path and will sometimes cause
  96  * it to manifest the address of boot_cpu_data in a register, fouling
  97  * the mainline (post-initialization) code.
  98  */
  99 static __always_inline bool _static_cpu_has(u16 bit)
 100 {
 101         asm goto(ALTERNATIVE_TERNARY("jmp 6f", %c[feature], "", "jmp %l[t_no]")
 102                 ".pushsection .altinstr_aux,\"ax\"\n"
 103                 "6:\n"
 104                 " testb %[bitnum], %a[cap_byte]\n"
 105                 " jnz %l[t_yes]\n"
 106                 " jmp %l[t_no]\n"
 107                 ".popsection\n"
 108                  : : [feature]  "i" (bit),
 109                      [bitnum]   "i" (1 << (bit & 7)),
 110                      [cap_byte] "i" (&((const char *)boot_cpu_data.x86_capability)[bit >> 3])
 111                  : : t_yes, t_no);
 112 t_yes:
 113         return true;
 114 t_no:
 115         return false;
 116 }
 117
 118 #define static_cpu_has(bit)                                     \
 119 (                                                               \
 120         __builtin_constant_p(boot_cpu_has(bit)) ?               \
 121                 boot_cpu_has(bit) :                             \
 122                 _static_cpu_has(bit)                            \
 123 )
 124
 125 #define cpu_has_bug(c, bit)             cpu_has(c, (bit))
 126 #define set_cpu_bug(c, bit)             set_cpu_cap(c, (bit))
 127 #define clear_cpu_bug(c, bit)           clear_cpu_cap(c, (bit))
 128
 129 #define static_cpu_has_bug(bit)         static_cpu_has((bit))
 130 #define boot_cpu_has_bug(bit)           cpu_has_bug(&boot_cpu_data, (bit))
 131 #define boot_cpu_set_bug(bit)           set_cpu_cap(&boot_cpu_data, (bit))
 132
 133 #define MAX_CPU_FEATURES                (NCAPINTS * 32)
 134 #define cpu_have_feature                boot_cpu_has
 135
 136 #define CPU_FEATURE_TYPEFMT             "x86,ven%04Xfam%04Xmod%04X"
 137 #define CPU_FEATURE_TYPEVAL             boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
 138                                         boot_cpu_data.x86_model
 139
 140 #endif /* defined(__KERNEL__) && !defined(__ASSEMBLER__) */
 141 #endif /* _ASM_X86_CPUFEATURE_H */