+static void __cpuinit write_rdtscp_cb(void *info)
+{
+ write_rdtscp_aux((unsigned long)info);
+}
+
+void __cpuinit vsyscall_set_cpu(int cpu)
+{
+ unsigned long *d;
+ unsigned long node = 0;
+#ifdef CONFIG_NUMA
+ node = cpu_to_node[cpu];
+#endif
+ if (cpu_has(&cpu_data[cpu], X86_FEATURE_RDTSCP)) {
+ void *info = (void *)((node << 12) | cpu);
+ /* Can happen on preemptive kernel */
+ if (get_cpu() == cpu)
+ write_rdtscp_cb(info);
+#ifdef CONFIG_SMP
+ else {
+ /* the notifier is unfortunately not executed on the
+ target CPU */
+ smp_call_function_single(cpu,write_rdtscp_cb,info,0,1);
+ }
+#endif
+ put_cpu();
+ }
+
+ /* Store cpu number in limit so that it can be loaded quickly
+ in user space in vgetcpu.
+ 12 bits for the CPU and 8 bits for the node. */
+ d = (unsigned long *)(cpu_gdt(cpu) + GDT_ENTRY_PER_CPU);
+ *d = 0x0f40000000000ULL;
+ *d |= cpu;
+ *d |= (node & 0xf) << 12;
+ *d |= (node >> 4) << 48;
+}
+