1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_CPUFEATURE_H
3 #define _ASM_X86_CPUFEATURE_H
5 #include <asm/processor.h>
7 #if defined(__KERNEL__) && !defined(__ASSEMBLY__)
10 #include <linux/bitops.h>
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]
41 #define X86_CAP_FMT "%d:%d"
42 #define x86_cap_flag(flag) ((flag) >> 5), ((flag) & 31)
46 * In order to save room, we index into this array by doing
47 * X86_BUG_<name> - NCAPINTS*32.
49 extern const char * const x86_bug_flags[NBUGINTS*32];
51 #define test_cpu_cap(c, bit) \
52 test_bit(bit, (unsigned long *)((c)->x86_capability))
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.
61 #define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \
62 (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word ))
64 #define REQUIRED_MASK_BIT_SET(feature_bit) \
65 ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 0, feature_bit) || \
66 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 1, feature_bit) || \
67 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 2, feature_bit) || \
68 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 3, feature_bit) || \
69 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 4, feature_bit) || \
70 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 5, feature_bit) || \
71 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 6, feature_bit) || \
72 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 7, feature_bit) || \
73 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 8, feature_bit) || \
74 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 9, feature_bit) || \
75 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) || \
76 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) || \
77 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) || \
78 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) || \
79 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) || \
80 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \
81 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \
82 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \
83 CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \
84 REQUIRED_MASK_CHECK || \
85 BUILD_BUG_ON_ZERO(NCAPINTS != 19))
87 #define DISABLED_MASK_BIT_SET(feature_bit) \
88 ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \
89 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 1, feature_bit) || \
90 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 2, feature_bit) || \
91 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 3, feature_bit) || \
92 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 4, feature_bit) || \
93 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 5, feature_bit) || \
94 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 6, feature_bit) || \
95 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 7, feature_bit) || \
96 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 8, feature_bit) || \
97 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 9, feature_bit) || \
98 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) || \
99 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) || \
100 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) || \
101 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) || \
102 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) || \
103 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \
104 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \
105 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \
106 CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \
107 DISABLED_MASK_CHECK || \
108 BUILD_BUG_ON_ZERO(NCAPINTS != 19))
110 #define cpu_has(c, bit) \
111 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
112 test_cpu_cap(c, bit))
114 #define this_cpu_has(bit) \
115 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \
116 x86_this_cpu_test_bit(bit, (unsigned long *)&cpu_info.x86_capability))
119 * This macro is for detection of features which need kernel
120 * infrastructure to be used. It may *not* directly test the CPU
121 * itself. Use the cpu_has() family if you want true runtime
122 * testing of CPU features, like in hypervisor code where you are
123 * supporting a possible guest feature where host support for it
126 #define cpu_feature_enabled(bit) \
127 (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
129 #define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit)
131 #define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability))
133 extern void setup_clear_cpu_cap(unsigned int bit);
134 extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
136 #define setup_force_cpu_cap(bit) do { \
137 set_cpu_cap(&boot_cpu_data, bit); \
138 set_bit(bit, (unsigned long *)cpu_caps_set); \
141 #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
143 #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_X86_FAST_FEATURE_TESTS)
145 * Static testing of CPU features. Used the same as boot_cpu_has().
146 * These will statically patch the target code for additional
149 static __always_inline __pure bool _static_cpu_has(u16 bit)
151 asm_volatile_goto("1: jmp 6f\n"
153 ".skip -(((5f-4f) - (2b-1b)) > 0) * "
154 "((5f-4f) - (2b-1b)),0x90\n"
156 ".section .altinstructions,\"a\"\n"
157 " .long 1b - .\n" /* src offset */
158 " .long 4f - .\n" /* repl offset */
159 " .word %P1\n" /* always replace */
160 " .byte 3b - 1b\n" /* src len */
161 " .byte 5f - 4f\n" /* repl len */
162 " .byte 3b - 2b\n" /* pad len */
164 ".section .altinstr_replacement,\"ax\"\n"
168 ".section .altinstructions,\"a\"\n"
169 " .long 1b - .\n" /* src offset */
170 " .long 0\n" /* no replacement */
171 " .word %P0\n" /* feature bit */
172 " .byte 3b - 1b\n" /* src len */
173 " .byte 0\n" /* repl len */
174 " .byte 0\n" /* pad len */
176 ".section .altinstr_aux,\"ax\"\n"
178 " testb %[bitnum],%[cap_byte]\n"
182 : : "i" (bit), "i" (X86_FEATURE_ALWAYS),
183 [bitnum] "i" (1 << (bit & 7)),
184 [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
192 #define static_cpu_has(bit) \
194 __builtin_constant_p(boot_cpu_has(bit)) ? \
195 boot_cpu_has(bit) : \
196 _static_cpu_has(bit) \
200 * Fall back to dynamic for gcc versions which don't support asm goto. Should be
201 * a minority now anyway.
203 #define static_cpu_has(bit) boot_cpu_has(bit)
206 #define cpu_has_bug(c, bit) cpu_has(c, (bit))
207 #define set_cpu_bug(c, bit) set_cpu_cap(c, (bit))
208 #define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit))
210 #define static_cpu_has_bug(bit) static_cpu_has((bit))
211 #define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit))
212 #define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit))
214 #define MAX_CPU_FEATURES (NCAPINTS * 32)
215 #define cpu_have_feature boot_cpu_has
217 #define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X"
218 #define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
219 boot_cpu_data.x86_model
221 #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */
222 #endif /* _ASM_X86_CPUFEATURE_H */