/*
   * Copyright 2006 Andi Kleen, SUSE Labs.
   * Subject to the GNU Public License, v.2
   *
   * Fast user context implementation of getcpu()
   */
  
  #include <linux/kernel.h>
  #include <linux/getcpu.h>
  #include <linux/jiffies.h>
  #include <linux/time.h>
  #include <asm/vsyscall.h>
  #include <asm/vgtod.h>

  notrace long
  __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)

  {

  	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));
  	}

  	if (cpu)
  		*cpu = p & 0xfff;
  	if (node)
  		*node = p >> 12;
  	return 0;
  }
  
  long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
  	__attribute__((weak, alias("__vdso_getcpu")));