aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/arch/x86/include/asm/cpuid.h
blob: 6b122a31da065a22ed660b04f41160d66c705c18 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * CPUID-related helpers/definitions
 */

#ifndef _ASM_X86_CPUID_H
#define _ASM_X86_CPUID_H

#include <asm/string.h>

struct cpuid_regs {
	u32 eax, ebx, ecx, edx;
};

enum cpuid_regs_idx {
	CPUID_EAX = 0,
	CPUID_EBX,
	CPUID_ECX,
	CPUID_EDX,
};

#ifdef CONFIG_X86_32
extern int have_cpuid_p(void);
#else
static inline int have_cpuid_p(void)
{
	return 1;
}
#endif
static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
				unsigned int *ecx, unsigned int *edx)
{
	/* ecx is often an input as well as an output. */
	asm volatile("cpuid"
	    : "=a" (*eax),
	      "=b" (*ebx),
	      "=c" (*ecx),
	      "=d" (*edx)
	    : "0" (*eax), "2" (*ecx)
	    : "memory");
}

#define native_cpuid_reg(reg)					\
static inline unsigned int native_cpuid_##reg(unsigned int op)	\
{								\
	unsigned int eax = op, ebx, ecx = 0, edx;		\
								\
	native_cpuid(&eax, &ebx, &ecx, &edx);			\
								\
	return reg;						\
}

/*
 * Native CPUID functions returning a single datum.
 */
native_cpuid_reg(eax)
native_cpuid_reg(ebx)
native_cpuid_reg(ecx)
native_cpuid_reg(edx)

#ifdef CONFIG_PARAVIRT_XXL
#include <asm/paravirt.h>
#else
#define __cpuid			native_cpuid
#endif

/*
 * Generic CPUID function
 * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
 * resulting in stale register contents being returned.
 */
static inline void cpuid(unsigned int op,
			 unsigned int *eax, unsigned int *ebx,
			 unsigned int *ecx, unsigned int *edx)
{
	*eax = op;
	*ecx = 0;
	__cpuid(eax, ebx, ecx, edx);
}

/* Some CPUID calls want 'count' to be placed in ecx */
static inline void cpuid_count(unsigned int op, int count,
			       unsigned int *eax, unsigned int *ebx,
			       unsigned int *ecx, unsigned int *edx)
{
	*eax = op;
	*ecx = count;
	__cpuid(eax, ebx, ecx, edx);
}

/*
 * CPUID functions returning a single datum
 */
static inline unsigned int cpuid_eax(unsigned int op)
{
	unsigned int eax, ebx, ecx, edx;

	cpuid(op, &eax, &ebx, &ecx, &edx);

	return eax;
}

static inline unsigned int cpuid_ebx(unsigned int op)
{
	unsigned int eax, ebx, ecx, edx;

	cpuid(op, &eax, &ebx, &ecx, &edx);

	return ebx;
}

static inline unsigned int cpuid_ecx(unsigned int op)
{
	unsigned int eax, ebx, ecx, edx;

	cpuid(op, &eax, &ebx, &ecx, &edx);

	return ecx;
}

static inline unsigned int cpuid_edx(unsigned int op)
{
	unsigned int eax, ebx, ecx, edx;

	cpuid(op, &eax, &ebx, &ecx, &edx);

	return edx;
}

static inline void __cpuid_read(unsigned int leaf, unsigned int subleaf, u32 *regs)
{
	regs[CPUID_EAX] = leaf;
	regs[CPUID_ECX] = subleaf;
	__cpuid(regs + CPUID_EAX, regs + CPUID_EBX, regs + CPUID_ECX, regs + CPUID_EDX);
}

#define cpuid_subleaf(leaf, subleaf, regs) {		\
	static_assert(sizeof(*(regs)) == 16);		\
	__cpuid_read(leaf, subleaf, (u32 *)(regs));	\
}

#define cpuid_leaf(leaf, regs) {			\
	static_assert(sizeof(*(regs)) == 16);		\
	__cpuid_read(leaf, 0, (u32 *)(regs));		\
}

static inline void __cpuid_read_reg(unsigned int leaf, unsigned int subleaf,
				    enum cpuid_regs_idx regidx, u32 *reg)
{
	u32 regs[4];

	__cpuid_read(leaf, subleaf, regs);
	*reg = regs[regidx];
}

#define cpuid_subleaf_reg(leaf, subleaf, regidx, reg) {		\
	static_assert(sizeof(*(reg)) == 4);			\
	__cpuid_read_reg(leaf, subleaf, regidx, (u32 *)(reg));	\
}

#define cpuid_leaf_reg(leaf, regidx, reg) {			\
	static_assert(sizeof(*(reg)) == 4);			\
	__cpuid_read_reg(leaf, 0, regidx, (u32 *)(reg));	\
}

static __always_inline bool cpuid_function_is_indexed(u32 function)
{
	switch (function) {
	case 4:
	case 7:
	case 0xb:
	case 0xd:
	case 0xf:
	case 0x10:
	case 0x12:
	case 0x14:
	case 0x17:
	case 0x18:
	case 0x1d:
	case 0x1e:
	case 0x1f:
	case 0x8000001d:
		return true;
	}

	return false;
}

#define for_each_possible_hypervisor_cpuid_base(function) \
	for (function = 0x40000000; function < 0x40010000; function += 0x100)

static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
{
	uint32_t base, eax, signature[3];

	for_each_possible_hypervisor_cpuid_base(base) {
		cpuid(base, &eax, &signature[0], &signature[1], &signature[2]);

		if (!memcmp(sig, signature, 12) &&
		    (leaves == 0 || ((eax - base) >= leaves)))
			return base;
	}

	return 0;
}

#endif /* _ASM_X86_CPUID_H */