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Diffstat (limited to 'arch/x86/include/asm/cpufeature.h')
| -rw-r--r-- | arch/x86/include/asm/cpufeature.h | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h new file mode 100644 index 000000000..68889ace9 --- /dev/null +++ b/arch/x86/include/asm/cpufeature.h @@ -0,0 +1,230 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_CPUFEATURE_H +#define _ASM_X86_CPUFEATURE_H + +#include <asm/processor.h> + +#if defined(__KERNEL__) && !defined(__ASSEMBLY__) + +#include <asm/asm.h> +#include <linux/bitops.h> + +enum cpuid_leafs +{ + CPUID_1_EDX = 0, + CPUID_8000_0001_EDX, + CPUID_8086_0001_EDX, + CPUID_LNX_1, + CPUID_1_ECX, + CPUID_C000_0001_EDX, + CPUID_8000_0001_ECX, + CPUID_LNX_2, + CPUID_LNX_3, + CPUID_7_0_EBX, + CPUID_D_1_EAX, + CPUID_LNX_4, + CPUID_DUMMY, + CPUID_8000_0008_EBX, + CPUID_6_EAX, + CPUID_8000_000A_EDX, + CPUID_7_ECX, + CPUID_8000_0007_EBX, + CPUID_7_EDX, +}; + +#ifdef CONFIG_X86_FEATURE_NAMES +extern const char * const x86_cap_flags[NCAPINTS*32]; +extern const char * const x86_power_flags[32]; +#define X86_CAP_FMT "%s" +#define x86_cap_flag(flag) x86_cap_flags[flag] +#else +#define X86_CAP_FMT "%d:%d" +#define x86_cap_flag(flag) ((flag) >> 5), ((flag) & 31) +#endif + +/* + * In order to save room, we index into this array by doing + * X86_BUG_<name> - NCAPINTS*32. + */ +extern const char * const x86_bug_flags[NBUGINTS*32]; + +#define test_cpu_cap(c, bit) \ + test_bit(bit, (unsigned long *)((c)->x86_capability)) + +/* + * There are 32 bits/features in each mask word. The high bits + * (selected with (bit>>5) give us the word number and the low 5 + * bits give us the bit/feature number inside the word. + * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can + * see if it is set in the mask word. + */ +#define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \ + (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word )) + +#define REQUIRED_MASK_BIT_SET(feature_bit) \ + ( CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 0, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 1, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 2, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 3, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 4, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 5, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 6, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 7, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 8, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 9, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 10, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 11, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 12, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 13, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 14, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 15, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 16, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \ + REQUIRED_MASK_CHECK || \ + BUILD_BUG_ON_ZERO(NCAPINTS != 19)) + +#define DISABLED_MASK_BIT_SET(feature_bit) \ + ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 1, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 2, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 3, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 4, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 5, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 6, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 7, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 8, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 9, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 10, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 11, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 12, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 13, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 14, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 15, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 16, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \ + DISABLED_MASK_CHECK || \ + BUILD_BUG_ON_ZERO(NCAPINTS != 19)) + +#define cpu_has(c, bit) \ + (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ + test_cpu_cap(c, bit)) + +#define this_cpu_has(bit) \ + (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ + x86_this_cpu_test_bit(bit, (unsigned long *)&cpu_info.x86_capability)) + +/* + * This macro is for detection of features which need kernel + * infrastructure to be used. It may *not* directly test the CPU + * itself. Use the cpu_has() family if you want true runtime + * testing of CPU features, like in hypervisor code where you are + * supporting a possible guest feature where host support for it + * is not relevant. + */ +#define cpu_feature_enabled(bit) \ + (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit)) + +#define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit) + +#define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability)) + +extern void setup_clear_cpu_cap(unsigned int bit); +extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); + +#define setup_force_cpu_cap(bit) do { \ + set_cpu_cap(&boot_cpu_data, bit); \ + set_bit(bit, (unsigned long *)cpu_caps_set); \ +} while (0) + +#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit) + +#if defined(__clang__) && !defined(CONFIG_CC_HAS_ASM_GOTO) + +/* + * Workaround for the sake of BPF compilation which utilizes kernel + * headers, but clang does not support ASM GOTO and fails the build. + */ +#ifndef __BPF_TRACING__ +#warning "Compiler lacks ASM_GOTO support. Add -D __BPF_TRACING__ to your compiler arguments" +#endif + +#define static_cpu_has(bit) boot_cpu_has(bit) + +#else + +/* + * Static testing of CPU features. Used the same as boot_cpu_has(). + * These will statically patch the target code for additional + * performance. + */ +static __always_inline __pure bool _static_cpu_has(u16 bit) +{ + asm_volatile_goto("1: jmp 6f\n" + "2:\n" + ".skip -(((5f-4f) - (2b-1b)) > 0) * " + "((5f-4f) - (2b-1b)),0x90\n" + "3:\n" + ".section .altinstructions,\"a\"\n" + " .long 1b - .\n" /* src offset */ + " .long 4f - .\n" /* repl offset */ + " .word %P[always]\n" /* always replace */ + " .byte 3b - 1b\n" /* src len */ + " .byte 5f - 4f\n" /* repl len */ + " .byte 3b - 2b\n" /* pad len */ + ".previous\n" + ".section .altinstr_replacement,\"ax\"\n" + "4: jmp %l[t_no]\n" + "5:\n" + ".previous\n" + ".section .altinstructions,\"a\"\n" + " .long 1b - .\n" /* src offset */ + " .long 0\n" /* no replacement */ + " .word %P[feature]\n" /* feature bit */ + " .byte 3b - 1b\n" /* src len */ + " .byte 0\n" /* repl len */ + " .byte 0\n" /* pad len */ + ".previous\n" + ".section .altinstr_aux,\"ax\"\n" + "6:\n" + " testb %[bitnum],%[cap_byte]\n" + " jnz %l[t_yes]\n" + " jmp %l[t_no]\n" + ".previous\n" + : : [feature] "i" (bit), + [always] "i" (X86_FEATURE_ALWAYS), + [bitnum] "i" (1 << (bit & 7)), + [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3]) + : : t_yes, t_no); +t_yes: + return true; +t_no: + return false; +} + +#define static_cpu_has(bit) \ +( \ + __builtin_constant_p(boot_cpu_has(bit)) ? \ + boot_cpu_has(bit) : \ + _static_cpu_has(bit) \ +) +#endif + +#define cpu_has_bug(c, bit) cpu_has(c, (bit)) +#define set_cpu_bug(c, bit) set_cpu_cap(c, (bit)) +#define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit)) + +#define static_cpu_has_bug(bit) static_cpu_has((bit)) +#define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit)) +#define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit)) + +#define MAX_CPU_FEATURES (NCAPINTS * 32) +#define cpu_have_feature boot_cpu_has + +#define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X" +#define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \ + boot_cpu_data.x86_model + +#endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */ +#endif /* _ASM_X86_CPUFEATURE_H */ |