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 #define X86_CAP_FMT_NUM "%d:%d" 38 #define x86_cap_flag_num(flag) ((flag) >> 5), ((flag) & 31) 39 40 #ifdef CONFIG_X86_FEATURE_NAMES 41 extern const char * const x86_cap_flags[NCAPINTS*32]; 42 extern const char * const x86_power_flags[32]; 43 #define X86_CAP_FMT "%s" 44 #define x86_cap_flag(flag) x86_cap_flags[flag] 45 #else 46 #define X86_CAP_FMT X86_CAP_FMT_NUM 47 #define x86_cap_flag x86_cap_flag_num 48 #endif 49 50 /* 51 * In order to save room, we index into this array by doing 52 * X86_BUG_<name> - NCAPINTS*32. 53 */ 54 extern const char * const x86_bug_flags[NBUGINTS*32]; 55 56 #define test_cpu_cap(c, bit) \ 57 arch_test_bit(bit, (unsigned long *)((c)->x86_capability)) 58 59 /* 60 * There are 32 bits/features in each mask word. The high bits 61 * (selected with (bit>>5) give us the word number and the low 5 62 * bits give us the bit/feature number inside the word. 63 * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can 64 * see if it is set in the mask word. 65 */ 66 #define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \ 67 (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word )) 68 69 /* 70 * {REQUIRED,DISABLED}_MASK_CHECK below may seem duplicated with the 71 * following BUILD_BUG_ON_ZERO() check but when NCAPINTS gets changed, all 72 * header macros which use NCAPINTS need to be changed. The duplicated macro 73 * use causes the compiler to issue errors for all headers so that all usage 74 * sites can be corrected. 75 */ 76 #define REQUIRED_MASK_BIT_SET(feature_bit) \ 77 ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 0, feature_bit) || \ 78 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 1, feature_bit) || \ 79 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 2, feature_bit) || \ 80 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 3, feature_bit) || \ 81 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 4, feature_bit) || \ 82 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 5, feature_bit) || \ 83 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 6, feature_bit) || \ 84 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 7, feature_bit) || \ 85 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 8, feature_bit) || \ 86 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 9, feature_bit) || \ 87 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) || \ 88 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) || \ 89 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) || \ 90 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) || \ 91 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) || \ 92 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \ 93 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \ 94 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \ 95 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \ 96 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \ 97 REQUIRED_MASK_CHECK || \ 98 BUILD_BUG_ON_ZERO(NCAPINTS != 20)) 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 DISABLED_MASK_CHECK || \ 122 BUILD_BUG_ON_ZERO(NCAPINTS != 20)) 123 124 #define cpu_has(c, bit) \ 125 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ 126 test_cpu_cap(c, bit)) 127 128 #define this_cpu_has(bit) \ 129 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ 130 x86_this_cpu_test_bit(bit, \ 131 (unsigned long __percpu *)&cpu_info.x86_capability)) 132 133 /* 134 * This macro is for detection of features which need kernel 135 * infrastructure to be used. It may *not* directly test the CPU 136 * itself. Use the cpu_has() family if you want true runtime 137 * testing of CPU features, like in hypervisor code where you are 138 * supporting a possible guest feature where host support for it 139 * is not relevant. 140 */ 141 #define cpu_feature_enabled(bit) \ 142 (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit)) 143 144 #define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit) 145 146 #define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability)) 147 148 extern void setup_clear_cpu_cap(unsigned int bit); 149 extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); 150 151 #define setup_force_cpu_cap(bit) do { \ 152 set_cpu_cap(&boot_cpu_data, bit); \ 153 set_bit(bit, (unsigned long *)cpu_caps_set); \ 154 } while (0) 155 156 #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit) 157 158 /* 159 * Static testing of CPU features. Used the same as boot_cpu_has(). It 160 * statically patches the target code for additional performance. Use 161 * static_cpu_has() only in fast paths, where every cycle counts. Which 162 * means that the boot_cpu_has() variant is already fast enough for the 163 * majority of cases and you should stick to using it as it is generally 164 * only two instructions: a RIP-relative MOV and a TEST. 165 * 166 * Do not use an "m" constraint for [cap_byte] here: gcc doesn't know 167 * that this is only used on a fallback path and will sometimes cause 168 * it to manifest the address of boot_cpu_data in a register, fouling 169 * the mainline (post-initialization) code. 170 */ 171 static __always_inline bool _static_cpu_has(u16 bit) 172 { 173 asm_volatile_goto( 174 ALTERNATIVE_TERNARY("jmp 6f", %P[feature], "", "jmp %l[t_no]") 175 ".pushsection .altinstr_aux,\"ax\"\n" 176 "6:\n" 177 " testb %[bitnum]," _ASM_RIP(%P[cap_byte]) "\n" 178 " jnz %l[t_yes]\n" 179 " jmp %l[t_no]\n" 180 ".popsection\n" 181 : : [feature] "i" (bit), 182 [bitnum] "i" (1 << (bit & 7)), 183 [cap_byte] "i" (&((const char *)boot_cpu_data.x86_capability)[bit >> 3]) 184 : : t_yes, t_no); 185 t_yes: 186 return true; 187 t_no: 188 return false; 189 } 190 191 #define static_cpu_has(bit) \ 192 ( \ 193 __builtin_constant_p(boot_cpu_has(bit)) ? \ 194 boot_cpu_has(bit) : \ 195 _static_cpu_has(bit) \ 196 ) 197 198 #define cpu_has_bug(c, bit) cpu_has(c, (bit)) 199 #define set_cpu_bug(c, bit) set_cpu_cap(c, (bit)) 200 #define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit)) 201 202 #define static_cpu_has_bug(bit) static_cpu_has((bit)) 203 #define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit)) 204 #define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit)) 205 206 #define MAX_CPU_FEATURES (NCAPINTS * 32) 207 #define cpu_have_feature boot_cpu_has 208 209 #define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X" 210 #define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \ 211 boot_cpu_data.x86_model 212 213 #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */ 214 #endif /* _ASM_X86_CPUFEATURE_H */ 215