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