diff options
Diffstat (limited to 'sys/amd64/include/cpufunc.h')
| -rw-r--r-- | sys/amd64/include/cpufunc.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/sys/amd64/include/cpufunc.h b/sys/amd64/include/cpufunc.h index 21257dd..5d4c0dc 100644 --- a/sys/amd64/include/cpufunc.h +++ b/sys/amd64/include/cpufunc.h @@ -475,6 +475,41 @@ load_es(u_int sel) __asm __volatile("movl %0,%%es" : : "rm" (sel)); } +#ifdef _KERNEL +/* This is defined in <machine/specialreg.h> but is too painful to get to */ +#ifndef MSR_FSBASE +#define MSR_FSBASE 0xc0000100 +#endif +static __inline void +load_fs(u_int sel) +{ + register u_int32_t fsbase __asm("ecx"); + + /* Preserve the fsbase value across the selector load */ + fsbase = MSR_FSBASE; + __asm __volatile("rdmsr; movl %0,%%fs; wrmsr" + : : "rm" (sel), "c" (fsbase) : "eax", "edx"); +} + +#ifndef MSR_GSBASE +#define MSR_GSBASE 0xc0000101 +#endif +static __inline void +load_gs(u_int sel) +{ + register u_int32_t gsbase __asm("ecx"); + + /* + * Preserve the gsbase value across the selector load. + * Note that we have to disable interrupts because the gsbase + * being trashed happens to be the kernel gsbase at the time. + */ + gsbase = MSR_GSBASE; + __asm __volatile("pushfq; cli; rdmsr; movl %0,%%gs; wrmsr; popfq" + : : "rm" (sel), "c" (gsbase) : "eax", "edx"); +} +#else +/* Usable by userland */ static __inline void load_fs(u_int sel) { @@ -486,6 +521,7 @@ load_gs(u_int sel) { __asm __volatile("movl %0,%%gs" : : "rm" (sel)); } +#endif /* void lidt(struct region_descriptor *addr); */ static __inline void |
