diff options
| -rw-r--r-- | arch/x86/boot/mkcpustr.c | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/cpufeature.h | 28 | ||||
| -rw-r--r-- | arch/x86/include/asm/disabled-features.h | 27 |
3 files changed, 56 insertions, 0 deletions
diff --git a/arch/x86/boot/mkcpustr.c b/arch/x86/boot/mkcpustr.c index 4579eff0ef4d..637097e66a62 100644 --- a/arch/x86/boot/mkcpustr.c +++ b/arch/x86/boot/mkcpustr.c @@ -16,6 +16,7 @@ #include <stdio.h> #include "../include/asm/required-features.h" +#include "../include/asm/disabled-features.h" #include "../include/asm/cpufeature.h" #include "../kernel/cpu/capflags.c" diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 7b508758dfad..1492041b8a68 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -8,6 +8,10 @@ #include <asm/required-features.h> #endif +#ifndef _ASM_X86_DISABLED_FEATURES_H +#include <asm/disabled-features.h> +#endif + #define NCAPINTS 11 /* N 32-bit words worth of info */ #define NBUGINTS 1 /* N 32-bit bug flags */ @@ -274,6 +278,18 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; (((bit)>>5)==8 && (1UL<<((bit)&31) & REQUIRED_MASK8)) || \ (((bit)>>5)==9 && (1UL<<((bit)&31) & REQUIRED_MASK9)) ) +#define DISABLED_MASK_BIT_SET(bit) \ + ( (((bit)>>5)==0 && (1UL<<((bit)&31) & DISABLED_MASK0)) || \ + (((bit)>>5)==1 && (1UL<<((bit)&31) & DISABLED_MASK1)) || \ + (((bit)>>5)==2 && (1UL<<((bit)&31) & DISABLED_MASK2)) || \ + (((bit)>>5)==3 && (1UL<<((bit)&31) & DISABLED_MASK3)) || \ + (((bit)>>5)==4 && (1UL<<((bit)&31) & DISABLED_MASK4)) || \ + (((bit)>>5)==5 && (1UL<<((bit)&31) & DISABLED_MASK5)) || \ + (((bit)>>5)==6 && (1UL<<((bit)&31) & DISABLED_MASK6)) || \ + (((bit)>>5)==7 && (1UL<<((bit)&31) & DISABLED_MASK7)) || \ + (((bit)>>5)==8 && (1UL<<((bit)&31) & DISABLED_MASK8)) || \ + (((bit)>>5)==9 && (1UL<<((bit)&31) & DISABLED_MASK9)) ) + #define cpu_has(c, bit) \ (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ test_cpu_cap(c, bit)) @@ -282,6 +298,18 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; (__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 : \ + cpu_has(&boot_cpu_data, 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)) diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h new file mode 100644 index 000000000000..1a9955dbf0a0 --- /dev/null +++ b/arch/x86/include/asm/disabled-features.h @@ -0,0 +1,27 @@ +#ifndef _ASM_X86_DISABLED_FEATURES_H +#define _ASM_X86_DISABLED_FEATURES_H + +/* These features, although they might be available in a CPU + * will not be used because the compile options to support + * them are not present. + * + * This code allows them to be checked and disabled at + * compile time without an explicit #ifdef. Use + * cpu_feature_enabled(). + */ + +/* + * Make sure to add features to the correct mask + */ +#define DISABLED_MASK0 0 +#define DISABLED_MASK1 0 +#define DISABLED_MASK2 0 +#define DISABLED_MASK3 0 +#define DISABLED_MASK4 0 +#define DISABLED_MASK5 0 +#define DISABLED_MASK6 0 +#define DISABLED_MASK7 0 +#define DISABLED_MASK8 0 +#define DISABLED_MASK9 0 + +#endif /* _ASM_X86_DISABLED_FEATURES_H */ |