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 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
   7 # define DBG(x...) printk(KERN_DEBUG x)
   8 #else
   9 # define DBG(x...)
  10 #endif
  11
  12 /*
  13  * Which logical CPUs are on which nodes
  14  */
  15 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
  16 EXPORT_SYMBOL(node_to_cpumask_map);
  17
  18 /*
  19  * Allocate node_to_cpumask_map based on number of available nodes
  20  * Requires node_possible_map to be valid.
  21  *
  22  * Note: node_to_cpumask() is not valid until after this is done.
  23  * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
  24  */
  25 void __init setup_node_to_cpumask_map(void)
  26 {
  27         unsigned int node, num = 0;
  28
  29         /* setup nr_node_ids if not done yet */
  30         if (nr_node_ids == MAX_NUMNODES) {
  31                 for_each_node_mask(node, node_possible_map)
  32                         num = node;
  33                 nr_node_ids = num + 1;
  34         }
  35
  36         /* allocate the map */
  37         for (node = 0; node < nr_node_ids; node++)
  38                 alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
  39
  40         /* cpumask_of_node() will now work */
  41         pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
  42 }
  43
  44 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
  45 /*
  46  * Returns a pointer to the bitmask of CPUs on Node 'node'.
  47  */
  48 const struct cpumask *cpumask_of_node(int node)
  49 {
  50         if (node >= nr_node_ids) {
  51                 printk(KERN_WARNING
  52                         "cpumask_of_node(%d): node > nr_node_ids(%d)\n",
  53                         node, nr_node_ids);
  54                 dump_stack();
  55                 return cpu_none_mask;
  56         }
  57         if (node_to_cpumask_map[node] == NULL) {
  58                 printk(KERN_WARNING
  59                         "cpumask_of_node(%d): no node_to_cpumask_map!\n",
  60                         node);
  61                 dump_stack();
  62                 return cpu_online_mask;
  63         }
  64         return node_to_cpumask_map[node];
  65 }
  66 EXPORT_SYMBOL(cpumask_of_node);
  67 #endif