diff options
Diffstat (limited to 'arch/x86/include/asm/vsyscall.h')
| -rw-r--r-- | arch/x86/include/asm/vsyscall.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/include/asm/vsyscall.h b/arch/x86/include/asm/vsyscall.h index eaea1d31f75..80f80955cfd 100644 --- a/arch/x86/include/asm/vsyscall.h +++ b/arch/x86/include/asm/vsyscall.h @@ -33,6 +33,26 @@ extern void map_vsyscall(void); */ extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address); +#ifdef CONFIG_X86_64 + +#define VGETCPU_CPU_MASK 0xfff + +static inline unsigned int __getcpu(void) +{ + unsigned int p; + + if (VVAR(vgetcpu_mode) == VGETCPU_RDTSCP) { + /* Load per CPU data from RDTSCP */ + native_read_tscp(&p); + } else { + /* Load per CPU data from GDT */ + asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG)); + } + + return p; +} +#endif /* CONFIG_X86_64 */ + #endif /* __KERNEL__ */ #endif /* _ASM_X86_VSYSCALL_H */ |