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 #include <asm/numa.h>
   6 #include <asm/acpi.h>
   7
   8 int __initdata numa_off;
   9
  10 static __init int numa_setup(char *opt)
  11 {
  12         if (!opt)
  13                 return -EINVAL;
  14         if (!strncmp(opt, "off", 3))
  15                 numa_off = 1;
  16 #ifdef CONFIG_NUMA_EMU
  17         if (!strncmp(opt, "fake=", 5))
  18                 numa_emu_cmdline(opt + 5);
  19 #endif
  20 #ifdef CONFIG_ACPI_NUMA
  21         if (!strncmp(opt, "noacpi", 6))
  22                 acpi_numa = -1;
  23 #endif
  24         return 0;
  25 }
  26 early_param("numa", numa_setup);
  27
  28 /*
  29  * Which logical CPUs are on which nodes
  30  */
  31 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
  32 EXPORT_SYMBOL(node_to_cpumask_map);
  33
  34 /*
  35  * Allocate node_to_cpumask_map based on number of available nodes
  36  * Requires node_possible_map to be valid.
  37  *
  38  * Note: node_to_cpumask() is not valid until after this is done.
  39  * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
  40  */
  41 void __init setup_node_to_cpumask_map(void)
  42 {
  43         unsigned int node, num = 0;
  44
  45         /* setup nr_node_ids if not done yet */
  46         if (nr_node_ids == MAX_NUMNODES) {
  47                 for_each_node_mask(node, node_possible_map)
  48                         num = node;
  49                 nr_node_ids = num + 1;
  50         }
  51
  52         /* allocate the map */
  53         for (node = 0; node < nr_node_ids; node++)
  54                 alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
  55
  56         /* cpumask_of_node() will now work */
  57         pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
  58 }
  59
  60 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
  61 /*
  62  * Returns a pointer to the bitmask of CPUs on Node 'node'.
  63  */
  64 const struct cpumask *cpumask_of_node(int node)
  65 {
  66         if (node >= nr_node_ids) {
  67                 printk(KERN_WARNING
  68                         "cpumask_of_node(%d): node > nr_node_ids(%d)\n",
  69                         node, nr_node_ids);
  70                 dump_stack();
  71                 return cpu_none_mask;
  72         }
  73         if (node_to_cpumask_map[node] == NULL) {
  74                 printk(KERN_WARNING
  75                         "cpumask_of_node(%d): no node_to_cpumask_map!\n",
  76                         node);
  77                 dump_stack();
  78                 return cpu_online_mask;
  79         }
  80         return node_to_cpumask_map[node];
  81 }
  82 EXPORT_SYMBOL(cpumask_of_node);
  83 #endif