1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_CPUFEATURE_H
3#define _ASM_X86_CPUFEATURE_H
4
5#include <asm/processor.h>
6
7#if defined(__KERNEL__) && !defined(__ASSEMBLER__)
8
9#include <asm/asm.h>
10#include <linux/bitops.h>
11#include <asm/alternative.h>
12#include <asm/cpufeaturemasks.h>
13
14enum cpuid_leafs
15{
16 CPUID_1_EDX = 0,
17 CPUID_8000_0001_EDX,
18 CPUID_8086_0001_EDX,
19 CPUID_LNX_1,
20 CPUID_1_ECX,
21 CPUID_C000_0001_EDX,
22 CPUID_8000_0001_ECX,
23 CPUID_LNX_2,
24 CPUID_LNX_3,
25 CPUID_7_0_EBX,
26 CPUID_D_1_EAX,
27 CPUID_LNX_4,
28 CPUID_7_1_EAX,
29 CPUID_8000_0008_EBX,
30 CPUID_6_EAX,
31 CPUID_8000_000A_EDX,
32 CPUID_7_ECX,
33 CPUID_8000_0007_EBX,
34 CPUID_7_EDX,
35 CPUID_8000_001F_EAX,
36 CPUID_8000_0021_EAX,
37 CPUID_LNX_5,
38 NR_CPUID_WORDS,
39};
40
41extern const char * const x86_cap_flags[NCAPINTS*32];
42extern const char * const x86_power_flags[32];
43
44/*
45 * In order to save room, we index into this array by doing
46 * X86_BUG_<name> - NCAPINTS*32.
47 */
48extern const char * const x86_bug_flags[NBUGINTS*32];
49#define x86_bug_flag(flag) x86_bug_flags[flag]
50
51#define test_cpu_cap(c, bit) \
52 arch_test_bit(bit, (unsigned long *)((c)->x86_capability))
53
54#define cpu_has(c, bit) \
55 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
56 test_cpu_cap(c, bit))
57
58#define this_cpu_has(bit) \
59 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
60 x86_this_cpu_test_bit(bit, cpu_info.x86_capability))
61
62/*
63 * This is the default CPU features testing macro to use in code.
64 *
65 * It is for detection of features which need kernel infrastructure to be
66 * used. It may *not* directly test the CPU itself. Use the cpu_has() family
67 * if you want true runtime testing of CPU features, like in hypervisor code
68 * where you are supporting a possible guest feature where host support for it
69 * is not relevant.
70 */
71#define cpu_feature_enabled(bit) \
72 (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
73
74#define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit)
75
76#define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability))
77
78extern void setup_clear_cpu_cap(unsigned int bit);
79extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
80void check_cpufeature_deps(struct cpuinfo_x86 *c);
81
82#define setup_force_cpu_cap(bit) do { \
83 \
84 if (!boot_cpu_has(bit)) \
85 WARN_ON(alternatives_patched); \
86 \
87 set_cpu_cap(&boot_cpu_data, bit); \
88 set_bit(bit, (unsigned long *)cpu_caps_set); \
89} while (0)
90
91#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
92
93/*
94 * Do not use an "m" constraint for [cap_byte] here: gcc doesn't know
95 * that this is only used on a fallback path and will sometimes cause
96 * it to manifest the address of boot_cpu_data in a register, fouling
97 * the mainline (post-initialization) code.
98 */
99static __always_inline bool _static_cpu_has(u16 bit)
100{
101 asm goto(ALTERNATIVE_TERNARY("jmp 6f", %c[feature], "", "jmp %l[t_no]")
102 ".pushsection .altinstr_aux,\"ax\"\n"
103 "6:\n"
104 " testb %[bitnum], %a[cap_byte]\n"
105 " jnz %l[t_yes]\n"
106 " jmp %l[t_no]\n"
107 ".popsection\n"
108 : : [feature] "i" (bit),
109 [bitnum] "i" (1 << (bit & 7)),
110 [cap_byte] "i" (&((const char *)boot_cpu_data.x86_capability)[bit >> 3])
111 : : t_yes, t_no);
112t_yes:
113 return true;
114t_no:
115 return false;
116}
117
118#define static_cpu_has(bit) \
119( \
120 __builtin_constant_p(boot_cpu_has(bit)) ? \
121 boot_cpu_has(bit) : \
122 _static_cpu_has(bit) \
123)
124
125#define cpu_has_bug(c, bit) cpu_has(c, (bit))
126#define set_cpu_bug(c, bit) set_cpu_cap(c, (bit))
127#define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit))
128
129#define static_cpu_has_bug(bit) static_cpu_has((bit))
130#define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit))
131#define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit))
132
133#define MAX_CPU_FEATURES (NCAPINTS * 32)
134#define cpu_have_feature boot_cpu_has
135
136#define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X"
137#define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
138 boot_cpu_data.x86_model
139
140#endif /* defined(__KERNEL__) && !defined(__ASSEMBLER__) */
141#endif /* _ASM_X86_CPUFEATURE_H */
142