Line data Source code
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_AVX512_BF16, X86_FEATURE_AVX512VL },
72 : { X86_FEATURE_AVX512_FP16, X86_FEATURE_AVX512BW },
73 : { X86_FEATURE_ENQCMD, X86_FEATURE_XSAVES },
74 : { X86_FEATURE_PER_THREAD_MBA, X86_FEATURE_MBA },
75 : {}
76 : };
77 :
78 27 : static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature)
79 : {
80 : /*
81 : * Note: This could use the non atomic __*_bit() variants, but the
82 : * rest of the cpufeature code uses atomics as well, so keep it for
83 : * consistency. Cleanup all of it separately.
84 : */
85 27 : if (!c) {
86 18 : clear_cpu_cap(&boot_cpu_data, feature);
87 9 : set_bit(feature, (unsigned long *)cpu_caps_cleared);
88 : } else {
89 18 : clear_bit(feature, (unsigned long *)c->x86_capability);
90 : }
91 27 : }
92 :
93 : /* Take the capabilities and the BUG bits into account */
94 : #define MAX_FEATURE_BITS ((NCAPINTS + NBUGINTS) * sizeof(u32) * 8)
95 :
96 27 : static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
97 : {
98 27 : DECLARE_BITMAP(disable, MAX_FEATURE_BITS);
99 27 : const struct cpuid_dep *d;
100 27 : bool changed;
101 :
102 27 : if (WARN_ON(feature >= MAX_FEATURE_BITS))
103 0 : return;
104 :
105 27 : clear_feature(c, feature);
106 :
107 : /* Collect all features to disable, handling dependencies */
108 27 : memset(disable, 0, sizeof(disable));
109 27 : __set_bit(feature, disable);
110 :
111 : /* Loop until we get a stable state. */
112 27 : do {
113 27 : changed = false;
114 1431 : for (d = cpuid_deps; d->feature; d++) {
115 1404 : if (!test_bit(d->depends, disable))
116 1404 : continue;
117 0 : if (__test_and_set_bit(d->feature, disable))
118 0 : continue;
119 :
120 0 : changed = true;
121 0 : clear_feature(c, d->feature);
122 : }
123 27 : } while (changed);
124 : }
125 :
126 18 : void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
127 : {
128 18 : do_clear_cpu_cap(c, feature);
129 9 : }
130 :
131 9 : void setup_clear_cpu_cap(unsigned int feature)
132 : {
133 9 : do_clear_cpu_cap(NULL, feature);
134 9 : }
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