| 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 | #include <asm/alternative.h> |
| 12 | |
| 13 | enum cpuid_leafs |
| 14 | { |
| 15 | CPUID_1_EDX = 0, |
| 16 | CPUID_8000_0001_EDX, |
| 17 | CPUID_8086_0001_EDX, |
| 18 | CPUID_LNX_1, |
| 19 | CPUID_1_ECX, |
| 20 | CPUID_C000_0001_EDX, |
| 21 | CPUID_8000_0001_ECX, |
| 22 | CPUID_LNX_2, |
| 23 | CPUID_LNX_3, |
| 24 | CPUID_7_0_EBX, |
| 25 | CPUID_D_1_EAX, |
| 26 | CPUID_LNX_4, |
| 27 | CPUID_7_1_EAX, |
| 28 | CPUID_8000_0008_EBX, |
| 29 | CPUID_6_EAX, |
| 30 | CPUID_8000_000A_EDX, |
| 31 | CPUID_7_ECX, |
| 32 | CPUID_8000_0007_EBX, |
| 33 | CPUID_7_EDX, |
| 34 | CPUID_8000_001F_EAX, |
| 35 | CPUID_8000_0021_EAX, |
| 36 | CPUID_LNX_5, |
| 37 | NR_CPUID_WORDS, |
| 38 | }; |
| 39 | |
| 40 | #define X86_CAP_FMT_NUM "%d:%d" |
| 41 | #define x86_cap_flag_num(flag) ((flag) >> 5), ((flag) & 31) |
| 42 | |
| 43 | extern const char * const x86_cap_flags[NCAPINTS*32]; |
| 44 | extern const char * const x86_power_flags[32]; |
| 45 | #define X86_CAP_FMT "%s" |
| 46 | #define x86_cap_flag(flag) x86_cap_flags[flag] |
| 47 | |
| 48 | /* |
| 49 | * In order to save room, we index into this array by doing |
| 50 | * X86_BUG_<name> - NCAPINTS*32. |
| 51 | */ |
| 52 | extern const char * const x86_bug_flags[NBUGINTS*32]; |
| 53 | |
| 54 | #define test_cpu_cap(c, bit) \ |
| 55 | arch_test_bit(bit, (unsigned long *)((c)->x86_capability)) |
| 56 | |
| 57 | /* |
| 58 | * There are 32 bits/features in each mask word. The high bits |
| 59 | * (selected with (bit>>5) give us the word number and the low 5 |
| 60 | * bits give us the bit/feature number inside the word. |
| 61 | * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can |
| 62 | * see if it is set in the mask word. |
| 63 | */ |
| 64 | #define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \ |
| 65 | (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word )) |
| 66 | |
| 67 | /* |
| 68 | * {REQUIRED,DISABLED}_MASK_CHECK below may seem duplicated with the |
| 69 | * following BUILD_BUG_ON_ZERO() check but when NCAPINTS gets changed, all |
| 70 | * header macros which use NCAPINTS need to be changed. The duplicated macro |
| 71 | * use causes the compiler to issue errors for all headers so that all usage |
| 72 | * sites can be corrected. |
| 73 | */ |
| 74 | #define REQUIRED_MASK_BIT_SET(feature_bit) \ |
| 75 | ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 0, feature_bit) || \ |
| 76 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 1, feature_bit) || \ |
| 77 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 2, feature_bit) || \ |
| 78 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 3, feature_bit) || \ |
| 79 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 4, feature_bit) || \ |
| 80 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 5, feature_bit) || \ |
| 81 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 6, feature_bit) || \ |
| 82 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 7, feature_bit) || \ |
| 83 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 8, feature_bit) || \ |
| 84 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 9, feature_bit) || \ |
| 85 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) || \ |
| 86 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) || \ |
| 87 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) || \ |
| 88 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) || \ |
| 89 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) || \ |
| 90 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \ |
| 91 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \ |
| 92 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \ |
| 93 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \ |
| 94 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \ |
| 95 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 20, feature_bit) || \ |
| 96 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 21, feature_bit) || \ |
| 97 | REQUIRED_MASK_CHECK || \ |
| 98 | BUILD_BUG_ON_ZERO(NCAPINTS != 22)) |
| 99 | |
| 100 | #define DISABLED_MASK_BIT_SET(feature_bit) \ |
| 101 | ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \ |
| 102 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 1, feature_bit) || \ |
| 103 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 2, feature_bit) || \ |
| 104 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 3, feature_bit) || \ |
| 105 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 4, feature_bit) || \ |
| 106 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 5, feature_bit) || \ |
| 107 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 6, feature_bit) || \ |
| 108 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 7, feature_bit) || \ |
| 109 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 8, feature_bit) || \ |
| 110 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 9, feature_bit) || \ |
| 111 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) || \ |
| 112 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) || \ |
| 113 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) || \ |
| 114 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) || \ |
| 115 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) || \ |
| 116 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \ |
| 117 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \ |
| 118 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \ |
| 119 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \ |
| 120 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \ |
| 121 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 20, feature_bit) || \ |
| 122 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 21, feature_bit) || \ |
| 123 | DISABLED_MASK_CHECK || \ |
| 124 | BUILD_BUG_ON_ZERO(NCAPINTS != 22)) |
| 125 | |
| 126 | #define cpu_has(c, bit) \ |
| 127 | (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ |
| 128 | test_cpu_cap(c, bit)) |
| 129 | |
| 130 | #define this_cpu_has(bit) \ |
| 131 | (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ |
| 132 | x86_this_cpu_test_bit(bit, cpu_info.x86_capability)) |
| 133 | |
| 134 | /* |
| 135 | * This macro is for detection of features which need kernel |
| 136 | * infrastructure to be used. It may *not* directly test the CPU |
| 137 | * itself. Use the cpu_has() family if you want true runtime |
| 138 | * testing of CPU features, like in hypervisor code where you are |
| 139 | * supporting a possible guest feature where host support for it |
| 140 | * is not relevant. |
| 141 | */ |
| 142 | #define cpu_feature_enabled(bit) \ |
| 143 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit)) |
| 144 | |
| 145 | #define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit) |
| 146 | |
| 147 | #define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability)) |
| 148 | |
| 149 | extern void setup_clear_cpu_cap(unsigned int bit); |
| 150 | extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); |
| 151 | |
| 152 | #define setup_force_cpu_cap(bit) do { \ |
| 153 | \ |
| 154 | if (!boot_cpu_has(bit)) \ |
| 155 | WARN_ON(alternatives_patched); \ |
| 156 | \ |
| 157 | set_cpu_cap(&boot_cpu_data, bit); \ |
| 158 | set_bit(bit, (unsigned long *)cpu_caps_set); \ |
| 159 | } while (0) |
| 160 | |
| 161 | #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit) |
| 162 | |
| 163 | /* |
| 164 | * Static testing of CPU features. Used the same as boot_cpu_has(). It |
| 165 | * statically patches the target code for additional performance. Use |
| 166 | * static_cpu_has() only in fast paths, where every cycle counts. Which |
| 167 | * means that the boot_cpu_has() variant is already fast enough for the |
| 168 | * majority of cases and you should stick to using it as it is generally |
| 169 | * only two instructions: a RIP-relative MOV and a TEST. |
| 170 | * |
| 171 | * Do not use an "m" constraint for [cap_byte] here: gcc doesn't know |
| 172 | * that this is only used on a fallback path and will sometimes cause |
| 173 | * it to manifest the address of boot_cpu_data in a register, fouling |
| 174 | * the mainline (post-initialization) code. |
| 175 | */ |
| 176 | static __always_inline bool _static_cpu_has(u16 bit) |
| 177 | { |
| 178 | asm goto(ALTERNATIVE_TERNARY("jmp 6f", %c[feature], "", "jmp %l[t_no]") |
| 179 | ".pushsection .altinstr_aux,\"ax\"\n" |
| 180 | "6:\n" |
| 181 | " testb %[bitnum], %a[cap_byte]\n" |
| 182 | " jnz %l[t_yes]\n" |
| 183 | " jmp %l[t_no]\n" |
| 184 | ".popsection\n" |
| 185 | : : [feature] "i" (bit), |
| 186 | [bitnum] "i" (1 << (bit & 7)), |
| 187 | [cap_byte] "i" (&((const char *)boot_cpu_data.x86_capability)[bit >> 3]) |
| 188 | : : t_yes, t_no); |
| 189 | t_yes: |
| 190 | return true; |
| 191 | t_no: |
| 192 | return false; |
| 193 | } |
| 194 | |
| 195 | #define static_cpu_has(bit) \ |
| 196 | ( \ |
| 197 | __builtin_constant_p(boot_cpu_has(bit)) ? \ |
| 198 | boot_cpu_has(bit) : \ |
| 199 | _static_cpu_has(bit) \ |
| 200 | ) |
| 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 */ |