blob: 3b1ae1abfba9abc1f00332ccb6c7af0805a8e403 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
|
/*
* 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 dummy, p;
if (*vdso_vgetcpu_mode == VGETCPU_RDTSCP) {
/* Load per CPU data from RDTSCP */
rdtscp(dummy, dummy, 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")));
|
