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 const static struct cpuid_dep cpuid_deps[] = {
23 { X86_FEATURE_XSAVEOPT, X86_FEATURE_XSAVE },
24 { X86_FEATURE_XSAVEC, X86_FEATURE_XSAVE },
25 { X86_FEATURE_XSAVES, X86_FEATURE_XSAVE },
26 { X86_FEATURE_AVX, X86_FEATURE_XSAVE },
27 { X86_FEATURE_PKU, X86_FEATURE_XSAVE },
28 { X86_FEATURE_MPX, X86_FEATURE_XSAVE },
29 { X86_FEATURE_XGETBV1, X86_FEATURE_XSAVE },
30 { X86_FEATURE_FXSR_OPT, X86_FEATURE_FXSR },
31 { X86_FEATURE_XMM, X86_FEATURE_FXSR },
32 { X86_FEATURE_XMM2, X86_FEATURE_XMM },
33 { X86_FEATURE_XMM3, X86_FEATURE_XMM2 },
34 { X86_FEATURE_XMM4_1, X86_FEATURE_XMM2 },
35 { X86_FEATURE_XMM4_2, X86_FEATURE_XMM2 },
36 { X86_FEATURE_XMM3, X86_FEATURE_XMM2 },
37 { X86_FEATURE_PCLMULQDQ, X86_FEATURE_XMM2 },
38 { X86_FEATURE_SSSE3, X86_FEATURE_XMM2, },
39 { X86_FEATURE_F16C, X86_FEATURE_XMM2, },
40 { X86_FEATURE_AES, X86_FEATURE_XMM2 },
41 { X86_FEATURE_SHA_NI, X86_FEATURE_XMM2 },
42 { X86_FEATURE_FMA, X86_FEATURE_AVX },
43 { X86_FEATURE_AVX2, X86_FEATURE_AVX, },
44 { X86_FEATURE_AVX512F, X86_FEATURE_AVX, },
45 { X86_FEATURE_AVX512IFMA, X86_FEATURE_AVX512F },
46 { X86_FEATURE_AVX512PF, X86_FEATURE_AVX512F },
47 { X86_FEATURE_AVX512ER, X86_FEATURE_AVX512F },
48 { X86_FEATURE_AVX512CD, X86_FEATURE_AVX512F },
49 { X86_FEATURE_AVX512DQ, X86_FEATURE_AVX512F },
50 { X86_FEATURE_AVX512BW, X86_FEATURE_AVX512F },
51 { X86_FEATURE_AVX512VL, X86_FEATURE_AVX512F },
52 { X86_FEATURE_AVX512VBMI, X86_FEATURE_AVX512F },
53 { X86_FEATURE_AVX512_VBMI2, X86_FEATURE_AVX512VL },
54 { X86_FEATURE_GFNI, X86_FEATURE_AVX512VL },
55 { X86_FEATURE_VAES, X86_FEATURE_AVX512VL },
56 { X86_FEATURE_VPCLMULQDQ, X86_FEATURE_AVX512VL },
57 { X86_FEATURE_AVX512_VNNI, X86_FEATURE_AVX512VL },
58 { X86_FEATURE_AVX512_BITALG, X86_FEATURE_AVX512VL },
59 { X86_FEATURE_AVX512_4VNNIW, X86_FEATURE_AVX512F },
60 { X86_FEATURE_AVX512_4FMAPS, X86_FEATURE_AVX512F },
61 { X86_FEATURE_AVX512_VPOPCNTDQ, X86_FEATURE_AVX512F },
62 { X86_FEATURE_CQM_OCCUP_LLC, X86_FEATURE_CQM_LLC },
63 { X86_FEATURE_CQM_MBM_TOTAL, X86_FEATURE_CQM_LLC },
64 { X86_FEATURE_CQM_MBM_LOCAL, X86_FEATURE_CQM_LLC },
65 {}
66 };
67
clear_feature(struct cpuinfo_x86 * c,unsigned int feature)68 static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature)
69 {
70 /*
71 * Note: This could use the non atomic __*_bit() variants, but the
72 * rest of the cpufeature code uses atomics as well, so keep it for
73 * consistency. Cleanup all of it separately.
74 */
75 if (!c) {
76 clear_cpu_cap(&boot_cpu_data, feature);
77 set_bit(feature, (unsigned long *)cpu_caps_cleared);
78 } else {
79 clear_bit(feature, (unsigned long *)c->x86_capability);
80 }
81 }
82
83 /* Take the capabilities and the BUG bits into account */
84 #define MAX_FEATURE_BITS ((NCAPINTS + NBUGINTS) * sizeof(u32) * 8)
85
do_clear_cpu_cap(struct cpuinfo_x86 * c,unsigned int feature)86 static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
87 {
88 DECLARE_BITMAP(disable, MAX_FEATURE_BITS);
89 const struct cpuid_dep *d;
90 bool changed;
91
92 if (WARN_ON(feature >= MAX_FEATURE_BITS))
93 return;
94
95 clear_feature(c, feature);
96
97 /* Collect all features to disable, handling dependencies */
98 memset(disable, 0, sizeof(disable));
99 __set_bit(feature, disable);
100
101 /* Loop until we get a stable state. */
102 do {
103 changed = false;
104 for (d = cpuid_deps; d->feature; d++) {
105 if (!test_bit(d->depends, disable))
106 continue;
107 if (__test_and_set_bit(d->feature, disable))
108 continue;
109
110 changed = true;
111 clear_feature(c, d->feature);
112 }
113 } while (changed);
114 }
115
clear_cpu_cap(struct cpuinfo_x86 * c,unsigned int feature)116 void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
117 {
118 do_clear_cpu_cap(c, feature);
119 }
120
setup_clear_cpu_cap(unsigned int feature)121 void setup_clear_cpu_cap(unsigned int feature)
122 {
123 do_clear_cpu_cap(NULL, feature);
124 }
125