1 #ifndef _ASM_X86_VSYSCALL_H 2 #define _ASM_X86_VSYSCALL_H 3 4 #include <linux/seqlock.h> 5 #include <uapi/asm/vsyscall.h> 6 7 #define VGETCPU_RDTSCP 1 8 #define VGETCPU_LSL 2 9 10 /* kernel space (writeable) */ 11 extern int vgetcpu_mode; 12 extern struct timezone sys_tz; 13 14 #include <asm/vvar.h> 15 16 extern void map_vsyscall(void); 17 18 /* 19 * Called on instruction fetch fault in vsyscall page. 20 * Returns true if handled. 21 */ 22 extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address); 23 24 #ifdef CONFIG_X86_64 25 26 #define VGETCPU_CPU_MASK 0xfff 27 __getcpu(void)28static inline unsigned int __getcpu(void) 29 { 30 unsigned int p; 31 32 if (VVAR(vgetcpu_mode) == VGETCPU_RDTSCP) { 33 /* Load per CPU data from RDTSCP */ 34 native_read_tscp(&p); 35 } else { 36 /* Load per CPU data from GDT */ 37 asm volatile ("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG)); 38 } 39 40 return p; 41 } 42 #endif /* CONFIG_X86_64 */ 43 44 #endif /* _ASM_X86_VSYSCALL_H */ 45