/* * 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" notrace 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")));