diff options
Diffstat (limited to 'arch/x86/include/asm/cpufeature.h')
-rw-r--r-- | arch/x86/include/asm/cpufeature.h | 100 |
1 files changed, 7 insertions, 93 deletions
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 3cce9f3c5cb1..a261cf2e7907 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -125,103 +125,19 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; #define cpu_has_osxsave boot_cpu_has(X86_FEATURE_OSXSAVE) #define cpu_has_hypervisor boot_cpu_has(X86_FEATURE_HYPERVISOR) /* - * Do not add any more of those clumsy macros - use static_cpu_has_safe() for + * Do not add any more of those clumsy macros - use static_cpu_has() for * fast paths and boot_cpu_has() otherwise! */ #if __GNUC__ >= 4 && defined(CONFIG_X86_FAST_FEATURE_TESTS) -extern void warn_pre_alternatives(void); -extern bool __static_cpu_has_safe(u16 bit); +extern bool __static_cpu_has(u16 bit); /* * Static testing of CPU features. Used the same as boot_cpu_has(). * These are only valid after alternatives have run, but will statically * patch the target code for additional performance. */ -static __always_inline __pure bool __static_cpu_has(u16 bit) -{ -#ifdef CC_HAVE_ASM_GOTO - -#ifdef CONFIG_X86_DEBUG_STATIC_CPU_HAS - - /* - * Catch too early usage of this before alternatives - * have run. - */ - asm_volatile_goto("1: jmp %l[t_warn]\n" - "2:\n" - ".section .altinstructions,\"a\"\n" - " .long 1b - .\n" - " .long 0\n" /* no replacement */ - " .word %P0\n" /* 1: do replace */ - " .byte 2b - 1b\n" /* source len */ - " .byte 0\n" /* replacement len */ - " .byte 0\n" /* pad len */ - ".previous\n" - /* skipping size check since replacement size = 0 */ - : : "i" (X86_FEATURE_ALWAYS) : : t_warn); - -#endif - - asm_volatile_goto("1: jmp %l[t_no]\n" - "2:\n" - ".section .altinstructions,\"a\"\n" - " .long 1b - .\n" - " .long 0\n" /* no replacement */ - " .word %P0\n" /* feature bit */ - " .byte 2b - 1b\n" /* source len */ - " .byte 0\n" /* replacement len */ - " .byte 0\n" /* pad len */ - ".previous\n" - /* skipping size check since replacement size = 0 */ - : : "i" (bit) : : t_no); - return true; - t_no: - return false; - -#ifdef CONFIG_X86_DEBUG_STATIC_CPU_HAS - t_warn: - warn_pre_alternatives(); - return false; -#endif - -#else /* CC_HAVE_ASM_GOTO */ - - u8 flag; - /* Open-coded due to __stringify() in ALTERNATIVE() */ - asm volatile("1: movb $0,%0\n" - "2:\n" - ".section .altinstructions,\"a\"\n" - " .long 1b - .\n" - " .long 3f - .\n" - " .word %P1\n" /* feature bit */ - " .byte 2b - 1b\n" /* source len */ - " .byte 4f - 3f\n" /* replacement len */ - " .byte 0\n" /* pad len */ - ".previous\n" - ".section .discard,\"aw\",@progbits\n" - " .byte 0xff + (4f-3f) - (2b-1b)\n" /* size check */ - ".previous\n" - ".section .altinstr_replacement,\"ax\"\n" - "3: movb $1,%0\n" - "4:\n" - ".previous\n" - : "=qm" (flag) : "i" (bit)); - return flag; - -#endif /* CC_HAVE_ASM_GOTO */ -} - -#define static_cpu_has(bit) \ -( \ - __builtin_constant_p(boot_cpu_has(bit)) ? \ - boot_cpu_has(bit) : \ - __builtin_constant_p(bit) ? \ - __static_cpu_has(bit) : \ - boot_cpu_has(bit) \ -) - -static __always_inline __pure bool _static_cpu_has_safe(u16 bit) +static __always_inline __pure bool _static_cpu_has(u16 bit) { #ifdef CC_HAVE_ASM_GOTO asm_volatile_goto("1: jmp %l[t_dynamic]\n" @@ -255,7 +171,7 @@ static __always_inline __pure bool _static_cpu_has_safe(u16 bit) t_no: return false; t_dynamic: - return __static_cpu_has_safe(bit); + return __static_cpu_has(bit); #else u8 flag; /* Open-coded due to __stringify() in ALTERNATIVE() */ @@ -293,22 +209,21 @@ static __always_inline __pure bool _static_cpu_has_safe(u16 bit) ".previous\n" : "=qm" (flag) : "i" (bit), "i" (X86_FEATURE_ALWAYS)); - return (flag == 2 ? __static_cpu_has_safe(bit) : flag); + return (flag == 2 ? __static_cpu_has(bit) : flag); #endif /* CC_HAVE_ASM_GOTO */ } -#define static_cpu_has_safe(bit) \ +#define static_cpu_has(bit) \ ( \ __builtin_constant_p(boot_cpu_has(bit)) ? \ boot_cpu_has(bit) : \ - _static_cpu_has_safe(bit) \ + _static_cpu_has(bit) \ ) #else /* * gcc 3.x is too stupid to do the static test; fall back to dynamic. */ #define static_cpu_has(bit) boot_cpu_has(bit) -#define static_cpu_has_safe(bit) boot_cpu_has(bit) #endif #define cpu_has_bug(c, bit) cpu_has(c, (bit)) @@ -316,7 +231,6 @@ static __always_inline __pure bool _static_cpu_has_safe(u16 bit) #define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit)) #define static_cpu_has_bug(bit) static_cpu_has((bit)) -#define static_cpu_has_bug_safe(bit) static_cpu_has_safe((bit)) #define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit)) #define MAX_CPU_FEATURES (NCAPINTS * 32) |