Line data Source code
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 :
12 : enum cpuid_leafs
13 : {
14 : CPUID_1_EDX = 0,
15 : CPUID_8000_0001_EDX,
16 : CPUID_8086_0001_EDX,
17 : CPUID_LNX_1,
18 : CPUID_1_ECX,
19 : CPUID_C000_0001_EDX,
20 : CPUID_8000_0001_ECX,
21 : CPUID_LNX_2,
22 : CPUID_LNX_3,
23 : CPUID_7_0_EBX,
24 : CPUID_D_1_EAX,
25 : CPUID_LNX_4,
26 : CPUID_7_1_EAX,
27 : CPUID_8000_0008_EBX,
28 : CPUID_6_EAX,
29 : CPUID_8000_000A_EDX,
30 : CPUID_7_ECX,
31 : CPUID_8000_0007_EBX,
32 : CPUID_7_EDX,
33 : CPUID_8000_001F_EAX,
34 : };
35 :
36 : #ifdef CONFIG_X86_FEATURE_NAMES
37 : extern const char * const x86_cap_flags[NCAPINTS*32];
38 : extern const char * const x86_power_flags[32];
39 : #define X86_CAP_FMT "%s"
40 : #define x86_cap_flag(flag) x86_cap_flags[flag]
41 : #else
42 : #define X86_CAP_FMT "%d:%d"
43 : #define x86_cap_flag(flag) ((flag) >> 5), ((flag) & 31)
44 : #endif
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 : 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 : REQUIRED_MASK_CHECK || \
94 : BUILD_BUG_ON_ZERO(NCAPINTS != 20))
95 :
96 : #define DISABLED_MASK_BIT_SET(feature_bit) \
97 : ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \
98 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 1, feature_bit) || \
99 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 2, feature_bit) || \
100 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 3, feature_bit) || \
101 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 4, feature_bit) || \
102 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 5, feature_bit) || \
103 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 6, feature_bit) || \
104 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 7, feature_bit) || \
105 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 8, feature_bit) || \
106 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 9, feature_bit) || \
107 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) || \
108 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) || \
109 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) || \
110 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) || \
111 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) || \
112 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \
113 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \
114 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \
115 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \
116 : CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \
117 : DISABLED_MASK_CHECK || \
118 : BUILD_BUG_ON_ZERO(NCAPINTS != 20))
119 :
120 : #define cpu_has(c, bit) \
121 : (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
122 : test_cpu_cap(c, bit))
123 :
124 : #define this_cpu_has(bit) \
125 : (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
126 : x86_this_cpu_test_bit(bit, \
127 : (unsigned long __percpu *)&cpu_info.x86_capability))
128 :
129 : /*
130 : * This macro is for detection of features which need kernel
131 : * infrastructure to be used. It may *not* directly test the CPU
132 : * itself. Use the cpu_has() family if you want true runtime
133 : * testing of CPU features, like in hypervisor code where you are
134 : * supporting a possible guest feature where host support for it
135 : * is not relevant.
136 : */
137 : #define cpu_feature_enabled(bit) \
138 : (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
139 :
140 : #define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit)
141 :
142 : #define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability))
143 :
144 : extern void setup_clear_cpu_cap(unsigned int bit);
145 : extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
146 :
147 : #define setup_force_cpu_cap(bit) do { \
148 : set_cpu_cap(&boot_cpu_data, bit); \
149 : set_bit(bit, (unsigned long *)cpu_caps_set); \
150 : } while (0)
151 :
152 : #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
153 :
154 : #if defined(__clang__) && !defined(CONFIG_CC_HAS_ASM_GOTO)
155 :
156 : /*
157 : * Workaround for the sake of BPF compilation which utilizes kernel
158 : * headers, but clang does not support ASM GOTO and fails the build.
159 : */
160 : #ifndef __BPF_TRACING__
161 : #warning "Compiler lacks ASM_GOTO support. Add -D __BPF_TRACING__ to your compiler arguments"
162 : #endif
163 :
164 : #define static_cpu_has(bit) boot_cpu_has(bit)
165 :
166 : #else
167 :
168 : /*
169 : * Static testing of CPU features. Used the same as boot_cpu_has(). It
170 : * statically patches the target code for additional performance. Use
171 : * static_cpu_has() only in fast paths, where every cycle counts. Which
172 : * means that the boot_cpu_has() variant is already fast enough for the
173 : * majority of cases and you should stick to using it as it is generally
174 : * only two instructions: a RIP-relative MOV and a TEST.
175 : */
176 520898 : static __always_inline bool _static_cpu_has(u16 bit)
177 : {
178 520898 : asm_volatile_goto("1: jmp 6f\n"
179 : "2:\n"
180 : ".skip -(((5f-4f) - (2b-1b)) > 0) * "
181 : "((5f-4f) - (2b-1b)),0x90\n"
182 : "3:\n"
183 : ".section .altinstructions,\"a\"\n"
184 : " .long 1b - .\n" /* src offset */
185 : " .long 4f - .\n" /* repl offset */
186 : " .word %P[always]\n" /* always replace */
187 : " .byte 3b - 1b\n" /* src len */
188 : " .byte 5f - 4f\n" /* repl len */
189 : " .byte 3b - 2b\n" /* pad len */
190 : ".previous\n"
191 : ".section .altinstr_replacement,\"ax\"\n"
192 : "4: jmp %l[t_no]\n"
193 : "5:\n"
194 : ".previous\n"
195 : ".section .altinstructions,\"a\"\n"
196 : " .long 1b - .\n" /* src offset */
197 : " .long 0\n" /* no replacement */
198 : " .word %P[feature]\n" /* feature bit */
199 : " .byte 3b - 1b\n" /* src len */
200 : " .byte 0\n" /* repl len */
201 : " .byte 0\n" /* pad len */
202 : ".previous\n"
203 : ".section .altinstr_aux,\"ax\"\n"
204 : "6:\n"
205 : " testb %[bitnum],%[cap_byte]\n"
206 : " jnz %l[t_yes]\n"
207 : " jmp %l[t_no]\n"
208 : ".previous\n"
209 : : : [feature] "i" (bit),
210 : [always] "i" (X86_FEATURE_ALWAYS),
211 : [bitnum] "i" (1 << (bit & 7)),
212 : [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
213 : : : t_yes, t_no);
214 24447 : t_yes:
215 : return true;
216 113808 : t_no:
217 117923 : return false;
218 : }
219 :
220 : #define static_cpu_has(bit) \
221 : ( \
222 : __builtin_constant_p(boot_cpu_has(bit)) ? \
223 : boot_cpu_has(bit) : \
224 : _static_cpu_has(bit) \
225 : )
226 : #endif
227 :
228 : #define cpu_has_bug(c, bit) cpu_has(c, (bit))
229 : #define set_cpu_bug(c, bit) set_cpu_cap(c, (bit))
230 : #define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit))
231 :
232 : #define static_cpu_has_bug(bit) static_cpu_has((bit))
233 : #define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit))
234 : #define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit))
235 :
236 : #define MAX_CPU_FEATURES (NCAPINTS * 32)
237 : #define cpu_have_feature boot_cpu_has
238 :
239 : #define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X"
240 : #define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
241 : boot_cpu_data.x86_model
242 :
243 : #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */
244 : #endif /* _ASM_X86_CPUFEATURE_H */
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