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