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_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 {}
63 };
64
clear_feature(struct cpuinfo_x86 * c,unsigned int feature)65 static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature)
66 {
67 /*
68 * Note: This could use the non atomic __*_bit() variants, but the
69 * rest of the cpufeature code uses atomics as well, so keep it for
70 * consistency. Cleanup all of it separately.
71 */
72 if (!c) {
73 clear_cpu_cap(&boot_cpu_data, feature);
74 set_bit(feature, (unsigned long *)cpu_caps_cleared);
75 } else {
76 clear_bit(feature, (unsigned long *)c->x86_capability);
77 }
78 }
79
80 /* Take the capabilities and the BUG bits into account */
81 #define MAX_FEATURE_BITS ((NCAPINTS + NBUGINTS) * sizeof(u32) * 8)
82
do_clear_cpu_cap(struct cpuinfo_x86 * c,unsigned int feature)83 static void do_clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
84 {
85 DECLARE_BITMAP(disable, MAX_FEATURE_BITS);
86 const struct cpuid_dep *d;
87 bool changed;
88
89 if (WARN_ON(feature >= MAX_FEATURE_BITS))
90 return;
91
92 clear_feature(c, feature);
93
94 /* Collect all features to disable, handling dependencies */
95 memset(disable, 0, sizeof(disable));
96 __set_bit(feature, disable);
97
98 /* Loop until we get a stable state. */
99 do {
100 changed = false;
101 for (d = cpuid_deps; d->feature; d++) {
102 if (!test_bit(d->depends, disable))
103 continue;
104 if (__test_and_set_bit(d->feature, disable))
105 continue;
106
107 changed = true;
108 clear_feature(c, d->feature);
109 }
110 } while (changed);
111 }
112
clear_cpu_cap(struct cpuinfo_x86 * c,unsigned int feature)113 void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int feature)
114 {
115 do_clear_cpu_cap(c, feature);
116 }
117
setup_clear_cpu_cap(unsigned int feature)118 void setup_clear_cpu_cap(unsigned int feature)
119 {
120 do_clear_cpu_cap(NULL, feature);
121 }
122
