arch/ia64/kernel/numa.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License as published by
   4  * the Free Software Foundation; either version 2 of the License, or
   5  * (at your option) any later version.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  15  *
  16  * ia64 kernel NUMA specific stuff
  17  *
  18  * Copyright (C) 2002 Erich Focht <efocht@ess.nec.de>
  19  * Copyright (C) 2004 Silicon Graphics, Inc.
  20  *   Jesse Barnes <jbarnes@sgi.com>
  21  */
  22 #include <linux/topology.h>
  23 #include <linux/module.h>
  24 #include <asm/processor.h>
  25 #include <asm/smp.h>
  26
  27 u16 cpu_to_node_map[NR_CPUS] __cacheline_aligned;
  28 EXPORT_SYMBOL(cpu_to_node_map);
  29
  30 cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned;
  31
  32 void __cpuinit map_cpu_to_node(int cpu, int nid)
  33 {
  34         int oldnid;
  35         if (nid < 0) { /* just initialize by zero */
  36                 cpu_to_node_map[cpu] = 0;
  37                 return;
  38         }
  39         /* sanity check first */
  40         oldnid = cpu_to_node_map[cpu];
  41         if (cpu_isset(cpu, node_to_cpu_mask[oldnid])) {
  42                 return; /* nothing to do */
  43         }
  44         /* we don't have cpu-driven node hot add yet...
  45            In usual case, node is created from SRAT at boot time. */
  46         if (!node_online(nid))
  47                 nid = first_online_node;
  48         cpu_to_node_map[cpu] = nid;
  49         cpu_set(cpu, node_to_cpu_mask[nid]);
  50         return;
  51 }
  52
  53 void __cpuinit unmap_cpu_from_node(int cpu, int nid)
  54 {
  55         WARN_ON(!cpu_isset(cpu, node_to_cpu_mask[nid]));
  56         WARN_ON(cpu_to_node_map[cpu] != nid);
  57         cpu_to_node_map[cpu] = 0;
  58         cpu_clear(cpu, node_to_cpu_mask[nid]);
  59 }
  60
  61
  62 /**
  63  * build_cpu_to_node_map - setup cpu to node and node to cpumask arrays
  64  *
  65  * Build cpu to node mapping and initialize the per node cpu masks using
  66  * info from the node_cpuid array handed to us by ACPI.
  67  */
  68 void __init build_cpu_to_node_map(void)
  69 {
  70         int cpu, i, node;
  71
  72         for(node=0; node < MAX_NUMNODES; node++)
  73                 cpus_clear(node_to_cpu_mask[node]);
  74
  75         for(cpu = 0; cpu < NR_CPUS; ++cpu) {
  76                 node = -1;
  77                 for (i = 0; i < NR_CPUS; ++i)
  78                         if (cpu_physical_id(cpu) == node_cpuid[i].phys_id) {
  79                                 node = node_cpuid[i].nid;
  80                                 break;
  81                         }
  82                 map_cpu_to_node(cpu, node);
  83         }
  84 }