1/*
2 * Populate sysfs with topology information
3 *
4 * Written by: Matthew Dobson, IBM Corporation
5 * Original Code: Paul Dorwin, IBM Corporation, Patrick Mochel, OSDL
6 *
7 * Copyright (C) 2002, IBM Corp.
8 *
9 * All rights reserved.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful, but
17 * WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
19 * NON INFRINGEMENT. See the GNU General Public License for more
20 * details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 *
26 * Send feedback to <colpatch@us.ibm.com>
27 */
28#include <linux/interrupt.h>
29#include <linux/nodemask.h>
30#include <linux/export.h>
31#include <linux/mmzone.h>
32#include <linux/init.h>
33#include <linux/smp.h>
34#include <linux/irq.h>
35#include <asm/io_apic.h>
36#include <asm/cpu.h>
37
38static DEFINE_PER_CPU(struct x86_cpu, cpu_devices);
39
40#ifdef CONFIG_HOTPLUG_CPU
41int arch_register_cpu(int cpu)
42{
43 struct x86_cpu *xc = per_cpu_ptr(&cpu_devices, cpu);
44
45 xc->cpu.hotpluggable = cpu > 0;
46 return register_cpu(cpu: &xc->cpu, num: cpu);
47}
48EXPORT_SYMBOL(arch_register_cpu);
49
50void arch_unregister_cpu(int num)
51{
52 unregister_cpu(cpu: &per_cpu(cpu_devices, num).cpu);
53}
54EXPORT_SYMBOL(arch_unregister_cpu);
55#else /* CONFIG_HOTPLUG_CPU */
56
57int __init arch_register_cpu(int num)
58{
59 return register_cpu(&per_cpu(cpu_devices, num).cpu, num);
60}
61#endif /* CONFIG_HOTPLUG_CPU */
62
63static int __init topology_init(void)
64{
65 int i;
66
67 for_each_present_cpu(i)
68 arch_register_cpu(i);
69
70 return 0;
71}
72subsys_initcall(topology_init);
73

source code of linux/arch/x86/kernel/topology.c