arch/ia64/kernel/numa.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *
   4  * ia64 kernel NUMA specific stuff
   5  *
   6  * Copyright (C) 2002 Erich Focht <efocht@ess.nec.de>
   7  * Copyright (C) 2004 Silicon Graphics, Inc.
   8  *   Jesse Barnes <jbarnes@sgi.com>
   9  */
  10 #include <linux/topology.h>
  11 #include <linux/module.h>
  12 #include <asm/processor.h>
  13 #include <asm/smp.h>
  14
  15 u16 cpu_to_node_map[NR_CPUS] __cacheline_aligned;
  16 EXPORT_SYMBOL(cpu_to_node_map);
  17
  18 cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned;
  19 EXPORT_SYMBOL(node_to_cpu_mask);
  20
  21 void map_cpu_to_node(int cpu, int nid)
  22 {
  23         int oldnid;
  24         if (nid < 0) { /* just initialize by zero */
  25                 cpu_to_node_map[cpu] = 0;
  26                 return;
  27         }
  28         /* sanity check first */
  29         oldnid = cpu_to_node_map[cpu];
  30         if (cpumask_test_cpu(cpu, &node_to_cpu_mask[oldnid])) {
  31                 return; /* nothing to do */
  32         }
  33         /* we don't have cpu-driven node hot add yet...
  34            In usual case, node is created from SRAT at boot time. */
  35         if (!node_online(nid))
  36                 nid = first_online_node;
  37         cpu_to_node_map[cpu] = nid;
  38         cpumask_set_cpu(cpu, &node_to_cpu_mask[nid]);
  39         return;
  40 }
  41
  42 void unmap_cpu_from_node(int cpu, int nid)
  43 {
  44         WARN_ON(!cpumask_test_cpu(cpu, &node_to_cpu_mask[nid]));
  45         WARN_ON(cpu_to_node_map[cpu] != nid);
  46         cpu_to_node_map[cpu] = 0;
  47         cpumask_clear_cpu(cpu, &node_to_cpu_mask[nid]);
  48 }
  49
  50
  51 /**
  52  * build_cpu_to_node_map - setup cpu to node and node to cpumask arrays
  53  *
  54  * Build cpu to node mapping and initialize the per node cpu masks using
  55  * info from the node_cpuid array handed to us by ACPI.
  56  */
  57 void __init build_cpu_to_node_map(void)
  58 {
  59         int cpu, i, node;
  60
  61         for(node=0; node < MAX_NUMNODES; node++)
  62                 cpumask_clear(&node_to_cpu_mask[node]);
  63
  64         for_each_possible_early_cpu(cpu) {
  65                 node = NUMA_NO_NODE;
  66                 for (i = 0; i < NR_CPUS; ++i)
  67                         if (cpu_physical_id(cpu) == node_cpuid[i].phys_id) {
  68                                 node = node_cpuid[i].nid;
  69                                 break;
  70                         }
  71                 map_cpu_to_node(cpu, node);
  72         }
  73 }