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Diffstat (limited to 'arch/x86/include/asm/cpufeature.h')
| -rw-r--r-- | arch/x86/include/asm/cpufeature.h | 217 |
1 files changed, 217 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..ce0c8f7d3 --- /dev/null +++ b/arch/x86/include/asm/cpufeature.h @@ -0,0 +1,217 @@ +/* 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> +#include <asm/alternative.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_7_1_EAX, + CPUID_8000_0008_EBX, + CPUID_6_EAX, + CPUID_8000_000A_EDX, + CPUID_7_ECX, + CPUID_8000_0007_EBX, + CPUID_7_EDX, + CPUID_8000_001F_EAX, + CPUID_8000_0021_EAX, +}; + +#define X86_CAP_FMT_NUM "%d:%d" +#define x86_cap_flag_num(flag) ((flag) >> 5), ((flag) & 31) + +#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 X86_CAP_FMT_NUM +#define x86_cap_flag x86_cap_flag_num +#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) \ + arch_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 )) + +/* + * {REQUIRED,DISABLED}_MASK_CHECK below may seem duplicated with the + * following BUILD_BUG_ON_ZERO() check but when NCAPINTS gets changed, all + * header macros which use NCAPINTS need to be changed. The duplicated macro + * use causes the compiler to issue errors for all headers so that all usage + * sites can be corrected. + */ +#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) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 20, feature_bit) || \ + REQUIRED_MASK_CHECK || \ + BUILD_BUG_ON_ZERO(NCAPINTS != 21)) + +#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) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 20, feature_bit) || \ + DISABLED_MASK_CHECK || \ + BUILD_BUG_ON_ZERO(NCAPINTS != 21)) + +#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 __percpu *)&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) + +/* + * Static testing of CPU features. Used the same as boot_cpu_has(). It + * statically patches the target code for additional performance. Use + * static_cpu_has() only in fast paths, where every cycle counts. Which + * means that the boot_cpu_has() variant is already fast enough for the + * majority of cases and you should stick to using it as it is generally + * only two instructions: a RIP-relative MOV and a TEST. + * + * Do not use an "m" constraint for [cap_byte] here: gcc doesn't know + * that this is only used on a fallback path and will sometimes cause + * it to manifest the address of boot_cpu_data in a register, fouling + * the mainline (post-initialization) code. + */ +static __always_inline bool _static_cpu_has(u16 bit) +{ + asm_volatile_goto( + ALTERNATIVE_TERNARY("jmp 6f", %P[feature], "", "jmp %l[t_no]") + ".pushsection .altinstr_aux,\"ax\"\n" + "6:\n" + " testb %[bitnum]," _ASM_RIP(%P[cap_byte]) "\n" + " jnz %l[t_yes]\n" + " jmp %l[t_no]\n" + ".popsection\n" + : : [feature] "i" (bit), + [bitnum] "i" (1 << (bit & 7)), + [cap_byte] "i" (&((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) \ +) + +#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 */ |