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 */ 142