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 };
34
35 #ifdef CONFIG_X86_FEATURE_NAMES
36 extern const char * const x86_cap_flags[NCAPINTS*32];
37 extern const char * const x86_power_flags[32];
38 #define X86_CAP_FMT "%s"
39 #define x86_cap_flag(flag) x86_cap_flags[flag]
40 #else
41 #define X86_CAP_FMT "%d:%d"
42 #define x86_cap_flag(flag) ((flag) >> 5), ((flag) & 31)
43 #endif
44
45 /*
46 * In order to save room, we index into this array by doing
47 * X86_BUG_<name> - NCAPINTS*32.
48 */
49 extern const char * const x86_bug_flags[NBUGINTS*32];
50
51 #define test_cpu_cap(c, bit) \
52 test_bit(bit, (unsigned long *)((c)->x86_capability))
53
54 /*
55 * There are 32 bits/features in each mask word. The high bits
56 * (selected with (bit>>5) give us the word number and the low 5
57 * bits give us the bit/feature number inside the word.
58 * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can
59 * see if it is set in the mask word.
60 */
61 #define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \
62 (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word ))
63
64 /*
65 * {REQUIRED,DISABLED}_MASK_CHECK below may seem duplicated with the
66 * following BUILD_BUG_ON_ZERO() check but when NCAPINTS gets changed, all
67 * header macros which use NCAPINTS need to be changed. The duplicated macro
68 * use causes the compiler to issue errors for all headers so that all usage
69 * sites can be corrected.
70 */
71 #define REQUIRED_MASK_BIT_SET(feature_bit) \
72 ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 0, feature_bit) || \
73 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 1, feature_bit) || \
74 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 2, feature_bit) || \
75 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 3, feature_bit) || \
76 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 4, feature_bit) || \
77 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 5, feature_bit) || \
78 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 6, feature_bit) || \
79 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 7, feature_bit) || \
80 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 8, feature_bit) || \
81 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 9, feature_bit) || \
82 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) || \
83 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) || \
84 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) || \
85 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) || \
86 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) || \
87 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \
88 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \
89 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \
90 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \
91 REQUIRED_MASK_CHECK || \
92 BUILD_BUG_ON_ZERO(NCAPINTS != 19))
93
94 #define DISABLED_MASK_BIT_SET(feature_bit) \
95 ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \
96 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 1, feature_bit) || \
97 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 2, feature_bit) || \
98 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 3, feature_bit) || \
99 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 4, feature_bit) || \
100 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 5, feature_bit) || \
101 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 6, feature_bit) || \
102 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 7, feature_bit) || \
103 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 8, feature_bit) || \
104 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 9, feature_bit) || \
105 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) || \
106 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) || \
107 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) || \
108 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) || \
109 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) || \
110 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \
111 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \
112 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \
113 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \
114 DISABLED_MASK_CHECK || \
115 BUILD_BUG_ON_ZERO(NCAPINTS != 19))
116
117 #define cpu_has(c, bit) \
118 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
119 test_cpu_cap(c, bit))
120
121 #define this_cpu_has(bit) \
122 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
123 x86_this_cpu_test_bit(bit, \
124 (unsigned long __percpu *)&cpu_info.x86_capability))
125
126 /*
127 * This macro is for detection of features which need kernel
128 * infrastructure to be used. It may *not* directly test the CPU
129 * itself. Use the cpu_has() family if you want true runtime
130 * testing of CPU features, like in hypervisor code where you are
131 * supporting a possible guest feature where host support for it
132 * is not relevant.
133 */
134 #define cpu_feature_enabled(bit) \
135 (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
136
137 #define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit)
138
139 #define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability))
140
141 extern void setup_clear_cpu_cap(unsigned int bit);
142 extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
143
144 #define setup_force_cpu_cap(bit) do { \
145 set_cpu_cap(&boot_cpu_data, bit); \
146 set_bit(bit, (unsigned long *)cpu_caps_set); \
147 } while (0)
148
149 #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
150
151 #if defined(__clang__) && !defined(CONFIG_CC_HAS_ASM_GOTO)
152
153 /*
154 * Workaround for the sake of BPF compilation which utilizes kernel
155 * headers, but clang does not support ASM GOTO and fails the build.
156 */
157 #ifndef __BPF_TRACING__
158 #warning "Compiler lacks ASM_GOTO support. Add -D __BPF_TRACING__ to your compiler arguments"
159 #endif
160
161 #define static_cpu_has(bit) boot_cpu_has(bit)
162
163 #else
164
165 /*
166 * Static testing of CPU features. Used the same as boot_cpu_has(). It
167 * statically patches the target code for additional performance. Use
168 * static_cpu_has() only in fast paths, where every cycle counts. Which
169 * means that the boot_cpu_has() variant is already fast enough for the
170 * majority of cases and you should stick to using it as it is generally
171 * only two instructions: a RIP-relative MOV and a TEST.
172 */
_static_cpu_has(u16 bit)173 static __always_inline bool _static_cpu_has(u16 bit)
174 {
175 asm_volatile_goto("1: jmp 6f\n"
176 "2:\n"
177 ".skip -(((5f-4f) - (2b-1b)) > 0) * "
178 "((5f-4f) - (2b-1b)),0x90\n"
179 "3:\n"
180 ".section .altinstructions,\"a\"\n"
181 " .long 1b - .\n" /* src offset */
182 " .long 4f - .\n" /* repl offset */
183 " .word %P[always]\n" /* always replace */
184 " .byte 3b - 1b\n" /* src len */
185 " .byte 5f - 4f\n" /* repl len */
186 " .byte 3b - 2b\n" /* pad len */
187 ".previous\n"
188 ".section .altinstr_replacement,\"ax\"\n"
189 "4: jmp %l[t_no]\n"
190 "5:\n"
191 ".previous\n"
192 ".section .altinstructions,\"a\"\n"
193 " .long 1b - .\n" /* src offset */
194 " .long 0\n" /* no replacement */
195 " .word %P[feature]\n" /* feature bit */
196 " .byte 3b - 1b\n" /* src len */
197 " .byte 0\n" /* repl len */
198 " .byte 0\n" /* pad len */
199 ".previous\n"
200 ".section .altinstr_aux,\"ax\"\n"
201 "6:\n"
202 " testb %[bitnum],%[cap_byte]\n"
203 " jnz %l[t_yes]\n"
204 " jmp %l[t_no]\n"
205 ".previous\n"
206 : : [feature] "i" (bit),
207 [always] "i" (X86_FEATURE_ALWAYS),
208 [bitnum] "i" (1 << (bit & 7)),
209 [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
210 : : t_yes, t_no);
211 t_yes:
212 return true;
213 t_no:
214 return false;
215 }
216
217 #define static_cpu_has(bit) \
218 ( \
219 __builtin_constant_p(boot_cpu_has(bit)) ? \
220 boot_cpu_has(bit) : \
221 _static_cpu_has(bit) \
222 )
223 #endif
224
225 #define cpu_has_bug(c, bit) cpu_has(c, (bit))
226 #define set_cpu_bug(c, bit) set_cpu_cap(c, (bit))
227 #define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit))
228
229 #define static_cpu_has_bug(bit) static_cpu_has((bit))
230 #define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit))
231 #define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit))
232
233 #define MAX_CPU_FEATURES (NCAPINTS * 32)
234 #define cpu_have_feature boot_cpu_has
235
236 #define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X"
237 #define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
238 boot_cpu_data.x86_model
239
240 #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */
241 #endif /* _ASM_X86_CPUFEATURE_H */
242
