arch/x86/mm/numa.c

   1 /* Common code for 32 and 64-bit NUMA */
   2 #include <linux/topology.h>
   3 #include <linux/module.h>
   4 #include <linux/bootmem.h>
   5
   6 /*
   7  * Which logical CPUs are on which nodes
   8  */
   9 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
  10 EXPORT_SYMBOL(node_to_cpumask_map);
  11
  12 /*
  13  * Allocate node_to_cpumask_map based on number of available nodes
  14  * Requires node_possible_map to be valid.
  15  *
  16  * Note: node_to_cpumask() is not valid until after this is done.
  17  * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
  18  */
  19 void __init setup_node_to_cpumask_map(void)
  20 {
  21         unsigned int node, num = 0;
  22
  23         /* setup nr_node_ids if not done yet */
  24         if (nr_node_ids == MAX_NUMNODES) {
  25                 for_each_node_mask(node, node_possible_map)
  26                         num = node;
  27                 nr_node_ids = num + 1;
  28         }
  29
  30         /* allocate the map */
  31         for (node = 0; node < nr_node_ids; node++)
  32                 alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
  33
  34         /* cpumask_of_node() will now work */
  35         pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
  36 }
  37
  38 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
  39 /*
  40  * Returns a pointer to the bitmask of CPUs on Node 'node'.
  41  */
  42 const struct cpumask *cpumask_of_node(int node)
  43 {
  44         if (node >= nr_node_ids) {
  45                 printk(KERN_WARNING
  46                         "cpumask_of_node(%d): node > nr_node_ids(%d)\n",
  47                         node, nr_node_ids);
  48                 dump_stack();
  49                 return cpu_none_mask;
  50         }
  51         if (node_to_cpumask_map[node] == NULL) {
  52                 printk(KERN_WARNING
  53                         "cpumask_of_node(%d): no node_to_cpumask_map!\n",
  54                         node);
  55                 dump_stack();
  56                 return cpu_online_mask;
  57         }
  58         return node_to_cpumask_map[node];
  59 }
  60 EXPORT_SYMBOL(cpumask_of_node);
  61 #endif