diff options
Diffstat (limited to 'arch/x86/include/asm/special_insns.h')
-rw-r--r-- | arch/x86/include/asm/special_insns.h | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h new file mode 100644 index 00000000000..41fc93a2e22 --- /dev/null +++ b/arch/x86/include/asm/special_insns.h @@ -0,0 +1,199 @@ +#ifndef _ASM_X86_SPECIAL_INSNS_H +#define _ASM_X86_SPECIAL_INSNS_H + + +#ifdef __KERNEL__ + +static inline void native_clts(void) +{ + asm volatile("clts"); +} + +/* + * Volatile isn't enough to prevent the compiler from reordering the + * read/write functions for the control registers and messing everything up. + * A memory clobber would solve the problem, but would prevent reordering of + * all loads stores around it, which can hurt performance. Solution is to + * use a variable and mimic reads and writes to it to enforce serialization + */ +static unsigned long __force_order; + +static inline unsigned long native_read_cr0(void) +{ + unsigned long val; + asm volatile("mov %%cr0,%0\n\t" : "=r" (val), "=m" (__force_order)); + return val; +} + +static inline void native_write_cr0(unsigned long val) +{ + asm volatile("mov %0,%%cr0": : "r" (val), "m" (__force_order)); +} + +static inline unsigned long native_read_cr2(void) +{ + unsigned long val; + asm volatile("mov %%cr2,%0\n\t" : "=r" (val), "=m" (__force_order)); + return val; +} + +static inline void native_write_cr2(unsigned long val) +{ + asm volatile("mov %0,%%cr2": : "r" (val), "m" (__force_order)); +} + +static inline unsigned long native_read_cr3(void) +{ + unsigned long val; + asm volatile("mov %%cr3,%0\n\t" : "=r" (val), "=m" (__force_order)); + return val; +} + +static inline void native_write_cr3(unsigned long val) +{ + asm volatile("mov %0,%%cr3": : "r" (val), "m" (__force_order)); +} + +static inline unsigned long native_read_cr4(void) +{ + unsigned long val; + asm volatile("mov %%cr4,%0\n\t" : "=r" (val), "=m" (__force_order)); + return val; +} + +static inline unsigned long native_read_cr4_safe(void) +{ + unsigned long val; + /* This could fault if %cr4 does not exist. In x86_64, a cr4 always + * exists, so it will never fail. */ +#ifdef CONFIG_X86_32 + asm volatile("1: mov %%cr4, %0\n" + "2:\n" + _ASM_EXTABLE(1b, 2b) + : "=r" (val), "=m" (__force_order) : "0" (0)); +#else + val = native_read_cr4(); +#endif + return val; +} + +static inline void native_write_cr4(unsigned long val) +{ + asm volatile("mov %0,%%cr4": : "r" (val), "m" (__force_order)); +} + +#ifdef CONFIG_X86_64 +static inline unsigned long native_read_cr8(void) +{ + unsigned long cr8; + asm volatile("movq %%cr8,%0" : "=r" (cr8)); + return cr8; +} + +static inline void native_write_cr8(unsigned long val) +{ + asm volatile("movq %0,%%cr8" :: "r" (val) : "memory"); +} +#endif + +static inline void native_wbinvd(void) +{ + asm volatile("wbinvd": : :"memory"); +} + +extern void native_load_gs_index(unsigned); + +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else + +static inline unsigned long read_cr0(void) +{ + return native_read_cr0(); +} + +static inline void write_cr0(unsigned long x) +{ + native_write_cr0(x); +} + +static inline unsigned long read_cr2(void) +{ + return native_read_cr2(); +} + +static inline void write_cr2(unsigned long x) +{ + native_write_cr2(x); +} + +static inline unsigned long read_cr3(void) +{ + return native_read_cr3(); +} + +static inline void write_cr3(unsigned long x) +{ + native_write_cr3(x); +} + +static inline unsigned long read_cr4(void) +{ + return native_read_cr4(); +} + +static inline unsigned long read_cr4_safe(void) +{ + return native_read_cr4_safe(); +} + +static inline void write_cr4(unsigned long x) +{ + native_write_cr4(x); +} + +static inline void wbinvd(void) +{ + native_wbinvd(); +} + +#ifdef CONFIG_X86_64 + +static inline unsigned long read_cr8(void) +{ + return native_read_cr8(); +} + +static inline void write_cr8(unsigned long x) +{ + native_write_cr8(x); +} + +static inline void load_gs_index(unsigned selector) +{ + native_load_gs_index(selector); +} + +#endif + +/* Clear the 'TS' bit */ +static inline void clts(void) +{ + native_clts(); +} + +#endif/* CONFIG_PARAVIRT */ + +#define stts() write_cr0(read_cr0() | X86_CR0_TS) + +static inline void clflush(volatile void *__p) +{ + asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p)); +} + +#define nop() asm volatile ("nop") + + +#endif /* __KERNEL__ */ + +#endif /* _ASM_X86_SPECIAL_INSNS_H */ |