1 /* 2 * linux/mm/mmzone.c 3 * 4 * management codes for pgdats, zones and page flags 5 */ 6 7 8 #include <linux/stddef.h> 9 #include <linux/mm.h> 10 #include <linux/mmzone.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 static inline int zref_in_nodemask(struct zoneref *zref, nodemask_t *nodes) 46 { 47 #ifdef CONFIG_NUMA 48 return node_isset(zonelist_node_idx(zref), *nodes); 49 #else 50 return 1; 51 #endif /* CONFIG_NUMA */ 52 } 53 54 /* Returns the next zone at or below highest_zoneidx in a zonelist */ 55 struct zoneref *next_zones_zonelist(struct zoneref *z, 56 enum zone_type highest_zoneidx, 57 nodemask_t *nodes) 58 { 59 /* 60 * Find the next suitable zone to use for the allocation. 61 * Only filter based on nodemask if it's set 62 */ 63 if (likely(nodes == NULL)) 64 while (zonelist_zone_idx(z) > highest_zoneidx) 65 z++; 66 else 67 while (zonelist_zone_idx(z) > highest_zoneidx || 68 (z->zone && !zref_in_nodemask(z, nodes))) 69 z++; 70 71 return z; 72 } 73 74 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL 75 int memmap_valid_within(unsigned long pfn, 76 struct page *page, struct zone *zone) 77 { 78 if (page_to_pfn(page) != pfn) 79 return 0; 80 81 if (page_zone(page) != zone) 82 return 0; 83 84 return 1; 85 } 86 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ 87 88 void lruvec_init(struct lruvec *lruvec) 89 { 90 enum lru_list lru; 91 92 memset(lruvec, 0, sizeof(struct lruvec)); 93 94 for_each_lru(lru) 95 INIT_LIST_HEAD(&lruvec->lists[lru]); 96 } 97 98 #if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS) 99 int page_cpupid_xchg_last(struct page *page, int cpupid) 100 { 101 unsigned long old_flags, flags; 102 int last_cpupid; 103 104 do { 105 old_flags = flags = page->flags; 106 last_cpupid = page_cpupid_last(page); 107 108 flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT); 109 flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT; 110 } while (unlikely(cmpxchg(&page->flags, old_flags, flags) != old_flags)); 111 112 return last_cpupid; 113 } 114 #endif 115