xref: /openbmc/linux/arch/x86/include/asm/cpufeature.h (revision bc05aa6e)
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_F_0_EDX,
26 	CPUID_F_1_EDX,
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 #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))
86 
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))
109 
110 #define cpu_has(c, bit)							\
111 	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
112 	 test_cpu_cap(c, bit))
113 
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))
117 
118 /*
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
124  * is not relevant.
125  */
126 #define cpu_feature_enabled(bit)	\
127 	(__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit))
128 
129 #define boot_cpu_has(bit)	cpu_has(&boot_cpu_data, bit)
130 
131 #define set_cpu_cap(c, bit)	set_bit(bit, (unsigned long *)((c)->x86_capability))
132 
133 extern void setup_clear_cpu_cap(unsigned int bit);
134 extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
135 
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);	\
139 } while (0)
140 
141 #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
142 
143 #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_X86_FAST_FEATURE_TESTS)
144 /*
145  * Static testing of CPU features.  Used the same as boot_cpu_has().
146  * These will statically patch the target code for additional
147  * performance.
148  */
149 static __always_inline __pure bool _static_cpu_has(u16 bit)
150 {
151 	asm_volatile_goto("1: jmp 6f\n"
152 		 "2:\n"
153 		 ".skip -(((5f-4f) - (2b-1b)) > 0) * "
154 			 "((5f-4f) - (2b-1b)),0x90\n"
155 		 "3:\n"
156 		 ".section .altinstructions,\"a\"\n"
157 		 " .long 1b - .\n"		/* src offset */
158 		 " .long 4f - .\n"		/* repl offset */
159 		 " .word %P[always]\n"		/* always replace */
160 		 " .byte 3b - 1b\n"		/* src len */
161 		 " .byte 5f - 4f\n"		/* repl len */
162 		 " .byte 3b - 2b\n"		/* pad len */
163 		 ".previous\n"
164 		 ".section .altinstr_replacement,\"ax\"\n"
165 		 "4: jmp %l[t_no]\n"
166 		 "5:\n"
167 		 ".previous\n"
168 		 ".section .altinstructions,\"a\"\n"
169 		 " .long 1b - .\n"		/* src offset */
170 		 " .long 0\n"			/* no replacement */
171 		 " .word %P[feature]\n"		/* feature bit */
172 		 " .byte 3b - 1b\n"		/* src len */
173 		 " .byte 0\n"			/* repl len */
174 		 " .byte 0\n"			/* pad len */
175 		 ".previous\n"
176 		 ".section .altinstr_aux,\"ax\"\n"
177 		 "6:\n"
178 		 " testb %[bitnum],%[cap_byte]\n"
179 		 " jnz %l[t_yes]\n"
180 		 " jmp %l[t_no]\n"
181 		 ".previous\n"
182 		 : : [feature]  "i" (bit),
183 		     [always]   "i" (X86_FEATURE_ALWAYS),
184 		     [bitnum]   "i" (1 << (bit & 7)),
185 		     [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
186 		 : : t_yes, t_no);
187 t_yes:
188 	return true;
189 t_no:
190 	return false;
191 }
192 
193 #define static_cpu_has(bit)					\
194 (								\
195 	__builtin_constant_p(boot_cpu_has(bit)) ?		\
196 		boot_cpu_has(bit) :				\
197 		_static_cpu_has(bit)				\
198 )
199 #else
200 /*
201  * Fall back to dynamic for gcc versions which don't support asm goto. Should be
202  * a minority now anyway.
203  */
204 #define static_cpu_has(bit)		boot_cpu_has(bit)
205 #endif
206 
207 #define cpu_has_bug(c, bit)		cpu_has(c, (bit))
208 #define set_cpu_bug(c, bit)		set_cpu_cap(c, (bit))
209 #define clear_cpu_bug(c, bit)		clear_cpu_cap(c, (bit))
210 
211 #define static_cpu_has_bug(bit)		static_cpu_has((bit))
212 #define boot_cpu_has_bug(bit)		cpu_has_bug(&boot_cpu_data, (bit))
213 #define boot_cpu_set_bug(bit)		set_cpu_cap(&boot_cpu_data, (bit))
214 
215 #define MAX_CPU_FEATURES		(NCAPINTS * 32)
216 #define cpu_have_feature		boot_cpu_has
217 
218 #define CPU_FEATURE_TYPEFMT		"x86,ven%04Xfam%04Xmod%04X"
219 #define CPU_FEATURE_TYPEVAL		boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
220 					boot_cpu_data.x86_model
221 
222 #endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */
223 #endif /* _ASM_X86_CPUFEATURE_H */
224