LXR linux/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
  15u16 cpu_to_node_map[NR_CPUS] __cacheline_aligned;
  16EXPORT_SYMBOL(cpu_to_node_map);
  17
  18cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned;
  19EXPORT_SYMBOL(node_to_cpu_mask);
  20
  21void 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
  42void 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 */
  57void __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}
  74