arch/x86/kernel/topology.c

   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/nodemask.h>
  29 #include <linux/mmzone.h>
  30 #include <linux/init.h>
  31 #include <linux/smp.h>
  32 #include <asm/cpu.h>
  33
  34 static DEFINE_PER_CPU(struct x86_cpu, cpu_devices);
  35
  36 #ifdef CONFIG_HOTPLUG_CPU
  37 int __ref arch_register_cpu(int num)
  38 {
  39         /*
  40          * CPU0 cannot be offlined due to several
  41          * restrictions and assumptions in kernel. This basically
  42          * doesn't add a control file, one cannot attempt to offline
  43          * BSP.
  44          *
  45          * Also certain PCI quirks require not to enable hotplug control
  46          * for all CPU's.
  47          */
  48         if (num)
  49                 per_cpu(cpu_devices, num).cpu.hotpluggable = 1;
  50
  51         return register_cpu(&per_cpu(cpu_devices, num).cpu, num);
  52 }
  53 EXPORT_SYMBOL(arch_register_cpu);
  54
  55 void arch_unregister_cpu(int num)
  56 {
  57         unregister_cpu(&per_cpu(cpu_devices, num).cpu);
  58 }
  59 EXPORT_SYMBOL(arch_unregister_cpu);
  60 #else /* CONFIG_HOTPLUG_CPU */
  61
  62 static int __init arch_register_cpu(int num)
  63 {
  64         return register_cpu(&per_cpu(cpu_devices, num).cpu, num);
  65 }
  66 #endif /* CONFIG_HOTPLUG_CPU */
  67
  68 static int __init topology_init(void)
  69 {
  70         int i;
  71
  72 #ifdef CONFIG_NUMA
  73         for_each_online_node(i)
  74                 register_one_node(i);
  75 #endif
  76
  77         for_each_present_cpu(i)
  78                 arch_register_cpu(i);
  79
  80         return 0;
  81 }
  82 subsys_initcall(topology_init);