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 }; 36 37 #ifdef CONFIG_X86_FEATURE_NAMES 38 extern const char * const x86_cap_flags[NCAPINTS*32]; 39 extern const char * const x86_power_flags[32]; 40 #define X86_CAP_FMT "%s" 41 #define x86_cap_flag(flag) x86_cap_flags[flag] 42 #else 43 #define X86_CAP_FMT "%d:%d" 44 #define x86_cap_flag(flag) ((flag) >> 5), ((flag) & 31) 45 #endif 46 47 /* 48 * In order to save room, we index into this array by doing 49 * X86_BUG_<name> - NCAPINTS*32. 50 */ 51 extern const char * const x86_bug_flags[NBUGINTS*32]; 52 53 #define test_cpu_cap(c, bit) \ 54 test_bit(bit, (unsigned long *)((c)->x86_capability)) 55 56 /* 57 * There are 32 bits/features in each mask word. The high bits 58 * (selected with (bit>>5) give us the word number and the low 5 59 * bits give us the bit/feature number inside the word. 60 * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can 61 * see if it is set in the mask word. 62 */ 63 #define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \ 64 (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word )) 65 66 /* 67 * {REQUIRED,DISABLED}_MASK_CHECK below may seem duplicated with the 68 * following BUILD_BUG_ON_ZERO() check but when NCAPINTS gets changed, all 69 * header macros which use NCAPINTS need to be changed. The duplicated macro 70 * use causes the compiler to issue errors for all headers so that all usage 71 * sites can be corrected. 72 */ 73 #define REQUIRED_MASK_BIT_SET(feature_bit) \ 74 ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 0, feature_bit) || \ 75 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 1, feature_bit) || \ 76 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 2, feature_bit) || \ 77 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 3, feature_bit) || \ 78 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 4, feature_bit) || \ 79 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 5, feature_bit) || \ 80 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 6, feature_bit) || \ 81 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 7, feature_bit) || \ 82 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 8, feature_bit) || \ 83 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 9, feature_bit) || \ 84 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) || \ 85 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) || \ 86 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) || \ 87 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) || \ 88 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) || \ 89 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \ 90 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \ 91 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \ 92 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \ 93 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \ 94 REQUIRED_MASK_CHECK || \ 95 BUILD_BUG_ON_ZERO(NCAPINTS != 20)) 96 97 #define DISABLED_MASK_BIT_SET(feature_bit) \ 98 ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \ 99 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 1, feature_bit) || \ 100 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 2, feature_bit) || \ 101 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 3, feature_bit) || \ 102 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 4, feature_bit) || \ 103 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 5, feature_bit) || \ 104 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 6, feature_bit) || \ 105 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 7, feature_bit) || \ 106 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 8, feature_bit) || \ 107 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 9, feature_bit) || \ 108 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) || \ 109 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) || \ 110 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) || \ 111 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) || \ 112 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) || \ 113 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \ 114 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \ 115 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \ 116 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \ 117 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \ 118 DISABLED_MASK_CHECK || \ 119 BUILD_BUG_ON_ZERO(NCAPINTS != 20)) 120 121 #define cpu_has(c, bit) \ 122 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ 123 test_cpu_cap(c, bit)) 124 125 #define this_cpu_has(bit) \ 126 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ 127 x86_this_cpu_test_bit(bit, \ 128 (unsigned long __percpu *)&cpu_info.x86_capability)) 129 130 /* 131 * This macro is for detection of features which need kernel 132 * infrastructure to be used. It may *not* directly test the CPU 133 * itself. Use the cpu_has() family if you want true runtime 134 * testing of CPU features, like in hypervisor code where you are 135 * supporting a possible guest feature where host support for it 136 * is not relevant. 137 */ 138 #define cpu_feature_enabled(bit) \ 139 (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit)) 140 141 #define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit) 142 143 #define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability)) 144 145 extern void setup_clear_cpu_cap(unsigned int bit); 146 extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); 147 148 #define setup_force_cpu_cap(bit) do { \ 149 set_cpu_cap(&boot_cpu_data, bit); \ 150 set_bit(bit, (unsigned long *)cpu_caps_set); \ 151 } while (0) 152 153 #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit) 154 155 #if defined(__clang__) && !defined(CONFIG_CC_HAS_ASM_GOTO) 156 157 /* 158 * Workaround for the sake of BPF compilation which utilizes kernel 159 * headers, but clang does not support ASM GOTO and fails the build. 160 */ 161 #ifndef __BPF_TRACING__ 162 #warning "Compiler lacks ASM_GOTO support. Add -D __BPF_TRACING__ to your compiler arguments" 163 #endif 164 165 #define static_cpu_has(bit) boot_cpu_has(bit) 166 167 #else 168 169 /* 170 * Static testing of CPU features. Used the same as boot_cpu_has(). It 171 * statically patches the target code for additional performance. Use 172 * static_cpu_has() only in fast paths, where every cycle counts. Which 173 * means that the boot_cpu_has() variant is already fast enough for the 174 * majority of cases and you should stick to using it as it is generally 175 * only two instructions: a RIP-relative MOV and a TEST. 176 * 177 * Do not use an "m" constraint for [cap_byte] here: gcc doesn't know 178 * that this is only used on a fallback path and will sometimes cause 179 * it to manifest the address of boot_cpu_data in a register, fouling 180 * the mainline (post-initialization) code. 181 */ 182 static __always_inline bool _static_cpu_has(u16 bit) 183 { 184 asm_volatile_goto( 185 ALTERNATIVE_TERNARY("jmp 6f", %P[feature], "", "jmp %l[t_no]") 186 ".pushsection .altinstr_aux,\"ax\"\n" 187 "6:\n" 188 " testb %[bitnum]," _ASM_RIP(%P[cap_byte]) "\n" 189 " jnz %l[t_yes]\n" 190 " jmp %l[t_no]\n" 191 ".popsection\n" 192 : : [feature] "i" (bit), 193 [bitnum] "i" (1 << (bit & 7)), 194 [cap_byte] "i" (&((const char *)boot_cpu_data.x86_capability)[bit >> 3]) 195 : : t_yes, t_no); 196 t_yes: 197 return true; 198 t_no: 199 return false; 200 } 201 202 #define static_cpu_has(bit) \ 203 ( \ 204 __builtin_constant_p(boot_cpu_has(bit)) ? \ 205 boot_cpu_has(bit) : \ 206 _static_cpu_has(bit) \ 207 ) 208 #endif 209 210 #define cpu_has_bug(c, bit) cpu_has(c, (bit)) 211 #define set_cpu_bug(c, bit) set_cpu_cap(c, (bit)) 212 #define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit)) 213 214 #define static_cpu_has_bug(bit) static_cpu_has((bit)) 215 #define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit)) 216 #define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit)) 217 218 #define MAX_CPU_FEATURES (NCAPINTS * 32) 219 #define cpu_have_feature boot_cpu_has 220 221 #define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X" 222 #define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \ 223 boot_cpu_data.x86_model 224 225 #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */ 226 #endif /* _ASM_X86_CPUFEATURE_H */ 227