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 EXPORT_SYMBOL(node_to_cpu_mask);
  32
  33 void map_cpu_to_node(int cpu, int nid)
  34 {
  35         int oldnid;
  36         if (nid < 0) { /* just initialize by zero */
  37                 cpu_to_node_map[cpu] = 0;
  38                 return;
  39         }
  40         /* sanity check first */
  41         oldnid = cpu_to_node_map[cpu];
  42         if (cpumask_test_cpu(cpu, &node_to_cpu_mask[oldnid])) {
  43                 return; /* nothing to do */
  44         }
  45         /* we don't have cpu-driven node hot add yet...
  46            In usual case, node is created from SRAT at boot time. */
  47         if (!node_online(nid))
  48                 nid = first_online_node;
  49         cpu_to_node_map[cpu] = nid;
  50         cpumask_set_cpu(cpu, &node_to_cpu_mask[nid]);
  51         return;
  52 }
  53
  54 void unmap_cpu_from_node(int cpu, int nid)
  55 {
  56         WARN_ON(!cpumask_test_cpu(cpu, &node_to_cpu_mask[nid]));
  57         WARN_ON(cpu_to_node_map[cpu] != nid);
  58         cpu_to_node_map[cpu] = 0;
  59         cpumask_clear_cpu(cpu, &node_to_cpu_mask[nid]);
  60 }
  61
  62
  63 /**
  64  * build_cpu_to_node_map - setup cpu to node and node to cpumask arrays
  65  *
  66  * Build cpu to node mapping and initialize the per node cpu masks using
  67  * info from the node_cpuid array handed to us by ACPI.
  68  */
  69 void __init build_cpu_to_node_map(void)
  70 {
  71         int cpu, i, node;
  72
  73         for(node=0; node < MAX_NUMNODES; node++)
  74                 cpumask_clear(&node_to_cpu_mask[node]);
  75
  76         for_each_possible_early_cpu(cpu) {
  77                 node = -1;
  78                 for (i = 0; i < NR_CPUS; ++i)
  79                         if (cpu_physical_id(cpu) == node_cpuid[i].phys_id) {
  80                                 node = node_cpuid[i].nid;
  81                                 break;
  82                         }
  83                 map_cpu_to_node(cpu, node);
  84         }
  85 }