1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_UM_CPUFEATURE_H 3 #define _ASM_UM_CPUFEATURE_H 4 5 #include <asm/processor.h> 6 7 #if defined(__KERNEL__) && !defined(__ASSEMBLER__) 8 9 #include <asm/asm.h> 10 #include <linux/bitops.h> 11 12 extern const char * const x86_cap_flags[NCAPINTS*32]; 13 extern const char * const x86_power_flags[32]; 14 #define X86_CAP_FMT "%s" 15 #define x86_cap_flag(flag) x86_cap_flags[flag] 16 17 /* 18 * In order to save room, we index into this array by doing 19 * X86_BUG_<name> - NCAPINTS*32. 20 */ 21 extern const char * const x86_bug_flags[NBUGINTS*32]; 22 23 #define test_cpu_cap(c, bit) \ 24 test_bit(bit, (unsigned long *)((c)->x86_capability)) 25 26 /* 27 * There are 32 bits/features in each mask word. The high bits 28 * (selected with (bit>>5) give us the word number and the low 5 29 * bits give us the bit/feature number inside the word. 30 * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can 31 * see if it is set in the mask word. 32 */ 33 #define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \ 34 (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word )) 35 36 #define cpu_has(c, bit) \ 37 test_cpu_cap(c, bit) 38 39 #define this_cpu_has(bit) \ 40 (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ 41 x86_this_cpu_test_bit(bit, cpu_info.x86_capability)) 42 43 /* 44 * This macro is for detection of features which need kernel 45 * infrastructure to be used. It may *not* directly test the CPU 46 * itself. Use the cpu_has() family if you want true runtime 47 * testing of CPU features, like in hypervisor code where you are 48 * supporting a possible guest feature where host support for it 49 * is not relevant. 50 */ 51 #define cpu_feature_enabled(bit) \ 52 (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : _static_cpu_has(bit)) 53 54 #define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit) 55 56 #define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability)) 57 58 extern void setup_clear_cpu_cap(unsigned int bit); 59 60 #define setup_force_cpu_cap(bit) do { \ 61 set_cpu_cap(&boot_cpu_data, bit); \ 62 set_bit(bit, (unsigned long *)cpu_caps_set); \ 63 } while (0) 64 65 #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit) 66 67 static __always_inline bool __static_cpu_has(u16 bit) 68 { 69 asm goto("1: jmp 6f\n" 70 "2:\n" 71 ".skip -(((5f-4f) - (2b-1b)) > 0) * " 72 "((5f-4f) - (2b-1b)),0x90\n" 73 "3:\n" 74 ".section .altinstructions,\"a\"\n" 75 " .long 1b - .\n" /* src offset */ 76 " .long 4f - .\n" /* repl offset */ 77 " .word %P[always]\n" /* always replace */ 78 " .byte 3b - 1b\n" /* src len */ 79 " .byte 5f - 4f\n" /* repl len */ 80 " .byte 3b - 2b\n" /* pad len */ 81 ".previous\n" 82 ".section .altinstr_replacement,\"ax\"\n" 83 "4: jmp %l[t_no]\n" 84 "5:\n" 85 ".previous\n" 86 ".section .altinstructions,\"a\"\n" 87 " .long 1b - .\n" /* src offset */ 88 " .long 0\n" /* no replacement */ 89 " .word %P[feature]\n" /* feature bit */ 90 " .byte 3b - 1b\n" /* src len */ 91 " .byte 0\n" /* repl len */ 92 " .byte 0\n" /* pad len */ 93 ".previous\n" 94 ".section .altinstr_aux,\"ax\"\n" 95 "6:\n" 96 " testb %[bitnum],%[cap_byte]\n" 97 " jnz %l[t_yes]\n" 98 " jmp %l[t_no]\n" 99 ".previous\n" 100 : : [feature] "i" (bit), 101 [always] "i" (X86_FEATURE_ALWAYS), 102 [bitnum] "i" (1 << (bit & 7)), 103 [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3]) 104 : : t_yes, t_no); 105 t_yes: 106 return true; 107 t_no: 108 return false; 109 } 110 111 #define _static_cpu_has(bit) \ 112 ( \ 113 __builtin_constant_p(boot_cpu_has(bit)) ? \ 114 boot_cpu_has(bit) : \ 115 _static_cpu_has(bit) \ 116 ) 117 118 #define cpu_has_bug(c, bit) cpu_has(c, (bit)) 119 #define set_cpu_bug(c, bit) set_cpu_cap(c, (bit)) 120 121 #define static_cpu_has_bug(bit) _static_cpu_has((bit)) 122 #define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit)) 123 #define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit)) 124 125 #define MAX_CPU_FEATURES (NCAPINTS * 32) 126 #define cpu_have_feature boot_cpu_has 127 128 #define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X" 129 #define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \ 130 boot_cpu_data.x86_model 131 132 #endif /* defined(__KERNEL__) && !defined(__ASSEMBLER__) */ 133 #endif /* _ASM_UM_CPUFEATURE_H */ 134