linux/arch/x86/include/asm/vsyscall.h

45 lines
873 B
C

#ifndef _ASM_X86_VSYSCALL_H
#define _ASM_X86_VSYSCALL_H
#include <linux/seqlock.h>
#include <uapi/asm/vsyscall.h>
#define VGETCPU_RDTSCP 1
#define VGETCPU_LSL 2
/* kernel space (writeable) */
extern int vgetcpu_mode;
extern struct timezone sys_tz;
#include <asm/vvar.h>
extern void map_vsyscall(void);
/*
* Called on instruction fetch fault in vsyscall page.
* Returns true if handled.
*/
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 /* _ASM_X86_VSYSCALL_H */