mm/mmzone.c

   1 /*
   2  * linux/mm/mmzone.c
   3  *
   4  * management codes for pgdats and zones.
   5  */
   6
   7
   8 #include <linux/config.h>
   9 #include <linux/stddef.h>
  10 #include <linux/mmzone.h>
  11 #include <linux/module.h>
  12
  13 struct pglist_data *first_online_pgdat(void)
  14 {
  15         return NODE_DATA(first_online_node);
  16 }
  17
  18 EXPORT_SYMBOL(first_online_pgdat);
  19
  20 struct pglist_data *next_online_pgdat(struct pglist_data *pgdat)
  21 {
  22         int nid = next_online_node(pgdat->node_id);
  23
  24         if (nid == MAX_NUMNODES)
  25                 return NULL;
  26         return NODE_DATA(nid);
  27 }
  28 EXPORT_SYMBOL(next_online_pgdat);
  29
  30
  31 /*
  32  * next_zone - helper magic for for_each_zone()
  33  */
  34 struct zone *next_zone(struct zone *zone)
  35 {
  36         pg_data_t *pgdat = zone->zone_pgdat;
  37
  38         if (zone < pgdat->node_zones + MAX_NR_ZONES - 1)
  39                 zone++;
  40         else {
  41                 pgdat = next_online_pgdat(pgdat);
  42                 if (pgdat)
  43                         zone = pgdat->node_zones;
  44                 else
  45                         zone = NULL;
  46         }
  47         return zone;
  48 }
  49 EXPORT_SYMBOL(next_zone);
  50