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
first_online_pgdat(void)12 struct pglist_data *first_online_pgdat(void)
13 {
14 return NODE_DATA(first_online_node);
15 }
16
next_online_pgdat(struct pglist_data * pgdat)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 */
next_zone(struct zone * zone)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
zref_in_nodemask(struct zoneref * zref,nodemask_t * nodes)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 */
next_zones_zonelist(struct zoneref * z,enum zone_type highest_zoneidx,nodemask_t * nodes)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
memmap_valid_within(unsigned long pfn,struct page * page,struct zone * zone)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
lruvec_init(struct lruvec * lruvec)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)
page_cpupid_xchg_last(struct page * page,int cpupid)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