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(__ASSEMBLY__) |
8 | |
9 | #include <asm/asm.h> |
10 | #include <linux/bitops.h> |
11 | #include <asm/alternative.h> |
12 | |
13 | enum cpuid_leafs |
14 | { |
15 | CPUID_1_EDX = 0, |
16 | CPUID_8000_0001_EDX, |
17 | CPUID_8086_0001_EDX, |
18 | CPUID_LNX_1, |
19 | CPUID_1_ECX, |
20 | CPUID_C000_0001_EDX, |
21 | CPUID_8000_0001_ECX, |
22 | CPUID_LNX_2, |
23 | CPUID_LNX_3, |
24 | CPUID_7_0_EBX, |
25 | CPUID_D_1_EAX, |
26 | CPUID_LNX_4, |
27 | CPUID_7_1_EAX, |
28 | CPUID_8000_0008_EBX, |
29 | CPUID_6_EAX, |
30 | CPUID_8000_000A_EDX, |
31 | CPUID_7_ECX, |
32 | CPUID_8000_0007_EBX, |
33 | CPUID_7_EDX, |
34 | CPUID_8000_001F_EAX, |
35 | CPUID_8000_0021_EAX, |
36 | }; |
37 | |
38 | #define X86_CAP_FMT_NUM "%d:%d" |
39 | #define x86_cap_flag_num(flag) ((flag) >> 5), ((flag) & 31) |
40 | |
41 | extern const char * const x86_cap_flags[NCAPINTS*32]; |
42 | extern const char * const x86_power_flags[32]; |
43 | #define X86_CAP_FMT "%s" |
44 | #define x86_cap_flag(flag) x86_cap_flags[flag] |
45 | |
46 | /* |
47 | * In order to save room, we index into this array by doing |
48 | * X86_BUG_<name> - NCAPINTS*32. |
49 | */ |
50 | extern const char * const x86_bug_flags[NBUGINTS*32]; |
51 | |
52 | #define test_cpu_cap(c, bit) \ |
53 | arch_test_bit(bit, (unsigned long *)((c)->x86_capability)) |
54 | |
55 | /* |
56 | * There are 32 bits/features in each mask word. The high bits |
57 | * (selected with (bit>>5) give us the word number and the low 5 |
58 | * bits give us the bit/feature number inside the word. |
59 | * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can |
60 | * see if it is set in the mask word. |
61 | */ |
62 | #define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \ |
63 | (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word )) |
64 | |
65 | /* |
66 | * {REQUIRED,DISABLED}_MASK_CHECK below may seem duplicated with the |
67 | * following BUILD_BUG_ON_ZERO() check but when NCAPINTS gets changed, all |
68 | * header macros which use NCAPINTS need to be changed. The duplicated macro |
69 | * use causes the compiler to issue errors for all headers so that all usage |
70 | * sites can be corrected. |
71 | */ |
72 | #define REQUIRED_MASK_BIT_SET(feature_bit) \ |
73 | ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 0, feature_bit) || \ |
74 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 1, feature_bit) || \ |
75 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 2, feature_bit) || \ |
76 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 3, feature_bit) || \ |
77 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 4, feature_bit) || \ |
78 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 5, feature_bit) || \ |
79 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 6, feature_bit) || \ |
80 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 7, feature_bit) || \ |
81 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 8, feature_bit) || \ |
82 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 9, feature_bit) || \ |
83 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) || \ |
84 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) || \ |
85 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) || \ |
86 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) || \ |
87 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) || \ |
88 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \ |
89 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \ |
90 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \ |
91 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \ |
92 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \ |
93 | CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 20, feature_bit) || \ |
94 | REQUIRED_MASK_CHECK || \ |
95 | BUILD_BUG_ON_ZERO(NCAPINTS != 21)) |
96 | |
97 | #define DISABLED_MASK_BIT_SET(feature_bit) \ |
98 | ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \ |
99 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 1, feature_bit) || \ |
100 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 2, feature_bit) || \ |
101 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 3, feature_bit) || \ |
102 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 4, feature_bit) || \ |
103 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 5, feature_bit) || \ |
104 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 6, feature_bit) || \ |
105 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 7, feature_bit) || \ |
106 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 8, feature_bit) || \ |
107 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 9, feature_bit) || \ |
108 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) || \ |
109 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) || \ |
110 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) || \ |
111 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) || \ |
112 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) || \ |
113 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \ |
114 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \ |
115 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \ |
116 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \ |
117 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \ |
118 | CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 20, feature_bit) || \ |
119 | DISABLED_MASK_CHECK || \ |
120 | BUILD_BUG_ON_ZERO(NCAPINTS != 21)) |
121 | |
122 | #define cpu_has(c, bit) \ |
123 | (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ |
124 | test_cpu_cap(c, bit)) |
125 | |
126 | #define this_cpu_has(bit) \ |
127 | (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ |
128 | x86_this_cpu_test_bit(bit, \ |
129 | (unsigned long __percpu *)&cpu_info.x86_capability)) |
130 | |
131 | /* |
132 | * This macro is for detection of features which need kernel |
133 | * infrastructure to be used. It may *not* directly test the CPU |
134 | * itself. Use the cpu_has() family if you want true runtime |
135 | * testing of CPU features, like in hypervisor code where you are |
136 | * supporting a possible guest feature where host support for it |
137 | * is not relevant. |
138 | */ |
139 | #define cpu_feature_enabled(bit) \ |
140 | (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit)) |
141 | |
142 | #define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit) |
143 | |
144 | #define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability)) |
145 | |
146 | extern void setup_clear_cpu_cap(unsigned int bit); |
147 | extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); |
148 | |
149 | #define setup_force_cpu_cap(bit) do { \ |
150 | set_cpu_cap(&boot_cpu_data, bit); \ |
151 | set_bit(bit, (unsigned long *)cpu_caps_set); \ |
152 | } while (0) |
153 | |
154 | #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit) |
155 | |
156 | /* |
157 | * Static testing of CPU features. Used the same as boot_cpu_has(). It |
158 | * statically patches the target code for additional performance. Use |
159 | * static_cpu_has() only in fast paths, where every cycle counts. Which |
160 | * means that the boot_cpu_has() variant is already fast enough for the |
161 | * majority of cases and you should stick to using it as it is generally |
162 | * only two instructions: a RIP-relative MOV and a TEST. |
163 | * |
164 | * Do not use an "m" constraint for [cap_byte] here: gcc doesn't know |
165 | * that this is only used on a fallback path and will sometimes cause |
166 | * it to manifest the address of boot_cpu_data in a register, fouling |
167 | * the mainline (post-initialization) code. |
168 | */ |
169 | static __always_inline bool _static_cpu_has(u16 bit) |
170 | { |
171 | asm_volatile_goto( |
172 | ALTERNATIVE_TERNARY("jmp 6f" , %P[feature], "" , "jmp %l[t_no]" ) |
173 | ".pushsection .altinstr_aux,\"ax\"\n" |
174 | "6:\n" |
175 | " testb %[bitnum]," _ASM_RIP(%P[cap_byte]) "\n" |
176 | " jnz %l[t_yes]\n" |
177 | " jmp %l[t_no]\n" |
178 | ".popsection\n" |
179 | : : [feature] "i" (bit), |
180 | [bitnum] "i" (1 << (bit & 7)), |
181 | [cap_byte] "i" (&((const char *)boot_cpu_data.x86_capability)[bit >> 3]) |
182 | : : t_yes, t_no); |
183 | t_yes: |
184 | return true; |
185 | t_no: |
186 | return false; |
187 | } |
188 | |
189 | #define static_cpu_has(bit) \ |
190 | ( \ |
191 | __builtin_constant_p(boot_cpu_has(bit)) ? \ |
192 | boot_cpu_has(bit) : \ |
193 | _static_cpu_has(bit) \ |
194 | ) |
195 | |
196 | #define cpu_has_bug(c, bit) cpu_has(c, (bit)) |
197 | #define set_cpu_bug(c, bit) set_cpu_cap(c, (bit)) |
198 | #define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit)) |
199 | |
200 | #define static_cpu_has_bug(bit) static_cpu_has((bit)) |
201 | #define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit)) |
202 | #define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit)) |
203 | |
204 | #define MAX_CPU_FEATURES (NCAPINTS * 32) |
205 | #define cpu_have_feature boot_cpu_has |
206 | |
207 | #define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X" |
208 | #define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \ |
209 | boot_cpu_data.x86_model |
210 | |
211 | #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */ |
212 | #endif /* _ASM_X86_CPUFEATURE_H */ |
213 | |