1 /* Declare dependencies between CPUIDs */ 2 #include <linux/kernel.h> 3 #include <linux/init.h> 4 #include <linux/module.h> 5 #include <asm/cpufeature.h> 6 7 struct cpuid_dep { 8 unsigned int feature; 9 unsigned int depends; 10 }; 11 12 /* 13 * Table of CPUID features that depend on others. 14 * 15 * This only includes dependencies that can be usefully disabled, not 16 * features part of the base set (like FPU). 17 * 18 * Note this all is not __init / __initdata because it can be 19 * called from cpu hotplug. It shouldn't do anything in this case, 20 * but it's difficult to tell that to the init reference checker. 21 */ 22 static const struct cpuid_dep cpuid_deps[] = { 23 { X86_FEATURE_FXSR, X86_FEATURE_FPU }, 24 { X86_FEATURE_XSAVEOPT, X86_FEATURE_XSAVE }, 25 { X86_FEATURE_XSAVEC, X86_FEATURE_XSAVE }, 26 { X86_FEATURE_XSAVES, X86_FEATURE_XSAVE }, 27 { X86_FEATURE_AVX, X86_FEATURE_XSAVE }, 28 { X86_FEATURE_PKU, X86_FEATURE_XSAVE }, 29 { X86_FEATURE_MPX, X86_FEATURE_XSAVE }, 30 { X86_FEATURE_XGETBV1, X86_FEATURE_XSAVE }, 31 { X86_FEATURE_CMOV, X86_FEATURE_FXSR }, 32 { X86_FEATURE_MMX, X86_FEATURE_FXSR }, 33 { X86_FEATURE_MMXEXT, X86_FEATURE_MMX }, 34 { X86_FEATURE_FXSR_OPT, X86_FEATURE_FXSR }, 35 { X86_FEATURE_XSAVE, X86_FEATURE_FXSR }, 36 { X86_FEATURE_XMM, X86_FEATURE_FXSR }, 37 { X86_FEATURE_XMM2, X86_FEATURE_XMM }, 38 { X86_FEATURE_XMM3, X86_FEATURE_XMM2 }, 39 { X86_FEATURE_XMM4_1, X86_FEATURE_XMM2 }, 40 { X86_FEATURE_XMM4_2, X86_FEATURE_XMM2 }, 41 { X86_FEATURE_XMM3, X86_FEATURE_XMM2 }, 42 { X86_FEATURE_PCLMULQDQ, X86_FEATURE_XMM2 }, 43 { X86_FEATURE_SSSE3, X86_FEATURE_XMM2, }, 44 { X86_FEATURE_F16C, X86_FEATURE_XMM2, }, 45 { X86_FEATURE_AES, X86_FEATURE_XMM2 }, 46 { X86_FEATURE_SHA_NI, X86_FEATURE_XMM2 }, 47 { X86_FEATURE_FMA, X86_FEATURE_AVX }, 48 { X86_FEATURE_AVX2, X86_FEATURE_AVX, }, 49 { X86_FEATURE_AVX512F, X86_FEATURE_AVX, }, 50 { X86_FEATURE_AVX512IFMA, X86_FEATURE_AVX512F }, 51 { X86_FEATURE_AVX512PF, X86_FEATURE_AVX512F }, 52 { X86_FEATURE_AVX512ER, X86_FEATURE_AVX512F }, 53 { X86_FEATURE_AVX512CD, X86_FEATURE_AVX512F }, 54 { X86_FEATURE_AVX512DQ, X86_FEATURE_AVX512F }, 55 { X86_FEATURE_AVX512BW, X86_FEATURE_AVX512F }, 56 { X86_FEATURE_AVX512VL, X86_FEATURE_AVX512F }, 57 { X86_FEATURE_AVX512VBMI, X86_FEATURE_AVX512F }, 58 { X86_FEATURE_AVX512_VBMI2, X86_FEATURE_AVX512VL }, 59 { X86_FEATURE_GFNI, X86_FEATURE_AVX512VL }, 60 { X86_FEATURE_VAES, X86_FEATURE_AVX512VL }, 61 { X86_FEATURE_VPCLMULQDQ, X86_FEATURE_AVX512VL }, 62 { X86_FEATURE_AVX512_VNNI, X86_FEATURE_AVX512VL }, 63 { X86_FEATURE_AVX512_BITALG, X86_FEATURE_AVX512VL }, 64 { X86_FEATURE_AVX512_4VNNIW, X86_FEATURE_AVX512F }, 65 { X86_FEATURE_AVX512_4FMAPS, X86_FEATURE_AVX512F }, 66 { X86_FEATURE_AVX512_VPOPCNTDQ, X86_FEATURE_AVX512F }, 67 { X86_FEATURE_AVX512_VP2INTERSECT, X86_FEATURE_AVX512VL }, 68 { X86_FEATURE_CQM_OCCUP_LLC, X86_FEATURE_CQM_LLC }, 69 { X86_FEATURE_CQM_MBM_TOTAL, X86_FEATURE_CQM_LLC }, 70 { X86_FEATURE_CQM_MBM_LOCAL, X86_FEATURE_CQM_LLC }, 71 { X86_FEATURE_BMEC, X86_FEATURE_CQM_MBM_TOTAL }, 72 { X86_FEATURE_BMEC, X86_FEATURE_CQM_MBM_LOCAL }, 73 { X86_FEATURE_AVX512_BF16, X86_FEATURE_AVX512VL }, 74 { X86_FEATURE_AVX512_FP16, X86_FEATURE_AVX512BW }, 75 { X86_FEATURE_ENQCMD, X86_FEATURE_XSAVES }, 76 { X86_FEATURE_PER_THREAD_MBA, X86_FEATURE_MBA }, 77 { X86_FEATURE_SGX_LC, X86_FEATURE_SGX }, 78 { X86_FEATURE_SGX1, X86_FEATURE_SGX }, 79 { X86_FEATURE_SGX2, X86_FEATURE_SGX1 }, 80 { X86_FEATURE_SGX_EDECCSSA, X86_FEATURE_SGX1 }, 81 { X86_FEATURE_XFD, X86_FEATURE_XSAVES }, 82 { X86_FEATURE_XFD, X86_FEATURE_XGETBV1 }, 83 { X86_FEATURE_AMX_TILE, X86_FEATURE_XFD }, 84 { X86_FEATURE_SHSTK, X86_FEATURE_XSAVES }, 85 {} 86 }; 87 88 static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature) 89 { 90 /* 91 * Note: This could use the non atomic __*_bit() variants, but the 92 * rest of the cpufeature code uses atomics as well, so keep it for 93 * consistency. Cleanup all of it separately. 94 */ 95 if (!c) { 96 clear_cpu_cap(&boot_cpu_data, feature); 97 set_bit(feature, (unsigned long *)cpu_caps_cleared); 98 } else { 99 clear_bit(feature, (unsigned long *)c->x86_capability); 100 } 101 } 102 103 /* Take the capabilities and the BUG bits into account */ 104 #define MAX_FEATURE_BITS ((NCAPINTS + NBUGINTS) * sizeof(u32) * 8) 105 106 static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature) 107 { 108 DECLARE_BITMAP(disable, MAX_FEATURE_BITS); 109 const struct cpuid_dep *d; 110 bool changed; 111 112 if (WARN_ON(feature >= MAX_FEATURE_BITS)) 113 return; 114 115 clear_feature(c, feature); 116 117 /* Collect all features to disable, handling dependencies */ 118 memset(disable, 0, sizeof(disable)); 119 __set_bit(feature, disable); 120 121 /* Loop until we get a stable state. */ 122 do { 123 changed = false; 124 for (d = cpuid_deps; d->feature; d++) { 125 if (!test_bit(d->depends, disable)) 126 continue; 127 if (__test_and_set_bit(d->feature, disable)) 128 continue; 129 130 changed = true; 131 clear_feature(c, d->feature); 132 } 133 } while (changed); 134 } 135 136 void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature) 137 { 138 do_clear_cpu_cap(c, feature); 139 } 140 141 void setup_clear_cpu_cap(unsigned int feature) 142 { 143 do_clear_cpu_cap(NULL, feature); 144 } 145