mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 01:51:53 +00:00
8f12dea613
Targetting paravirt, this patch introduces native_read_tscp, in place of rdtscp() macro. When in a paravirt guest, this will involve a function call, and thus, cannot be done in the vdso area. These users then have to call the native version directly Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
36 lines
817 B
C
36 lines
817 B
C
/*
|
|
* 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>
|
|
#include "vextern.h"
|
|
|
|
long __vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
|
|
{
|
|
unsigned int p;
|
|
|
|
if (*vdso_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")));
|