1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/mm/mmzone.c
4 *
5 * management codes for pgdats, zones and page flags
6 */
7
8
9 #include <linux/stddef.h>
10 #include <linux/mm.h>
11 #include <linux/mmzone.h>
12
first_online_pgdat(void)13 struct pglist_data *first_online_pgdat(void)
14 {
15 return NODE_DATA(first_online_node);
16 }
17
next_online_pgdat(struct pglist_data * pgdat)18 struct pglist_data *next_online_pgdat(struct pglist_data *pgdat)
19 {
20 int nid = next_online_node(pgdat->node_id);
21
22 if (nid == MAX_NUMNODES)
23 return NULL;
24 return NODE_DATA(nid);
25 }
26
27 /*
28 * next_zone - helper magic for for_each_zone()
29 */
next_zone(struct zone * zone)30 struct zone *next_zone(struct zone *zone)
31 {
32 pg_data_t *pgdat = zone->zone_pgdat;
33
34 if (zone < pgdat->node_zones + MAX_NR_ZONES - 1)
35 zone++;
36 else {
37 pgdat = next_online_pgdat(pgdat);
38 if (pgdat)
39 zone = pgdat->node_zones;
40 else
41 zone = NULL;
42 }
43 return zone;
44 }
45
zref_in_nodemask(struct zoneref * zref,const nodemask_t * nodes)46 static inline int zref_in_nodemask(struct zoneref *zref,
47 const nodemask_t *nodes)
48 {
49 #ifdef CONFIG_NUMA
50 return node_isset(zonelist_node_idx(zref), *nodes);
51 #else
52 return 1;
53 #endif /* CONFIG_NUMA */
54 }
55
56 /* Returns the next zone at or below highest_zoneidx in a zonelist */
__next_zones_zonelist(struct zoneref * z,enum zone_type highest_zoneidx,const nodemask_t * nodes)57 struct zoneref *__next_zones_zonelist(struct zoneref *z,
58 enum zone_type highest_zoneidx,
59 const nodemask_t *nodes)
60 {
61 /*
62 * Find the next suitable zone to use for the allocation.
63 * Only filter based on nodemask if it's set
64 */
65 if (unlikely(nodes == NULL))
66 while (zonelist_zone_idx(z) > highest_zoneidx)
67 z++;
68 else
69 while (zonelist_zone_idx(z) > highest_zoneidx ||
70 (zonelist_zone(z) && !zref_in_nodemask(z, nodes)))
71 z++;
72
73 return z;
74 }
75
lruvec_init(struct lruvec * lruvec)76 void lruvec_init(struct lruvec *lruvec)
77 {
78 enum lru_list lru;
79
80 memset(lruvec, 0, sizeof(struct lruvec));
81 spin_lock_init(&lruvec->lru_lock);
82 spin_lock_init(&lruvec->cost_lock);
83 zswap_lruvec_state_init(lruvec);
84
85 for_each_lru(lru)
86 INIT_LIST_HEAD(&lruvec->lists[lru]);
87 /*
88 * The "Unevictable LRU" is imaginary: though its size is maintained,
89 * it is never scanned, and unevictable pages are not threaded on it
90 * (so that their lru fields can be reused to hold mlock_count).
91 * Poison its list head, so that any operations on it would crash.
92 */
93 list_del(&lruvec->lists[LRU_UNEVICTABLE]);
94
95 lru_gen_init_lruvec(lruvec);
96 }
97
98 #if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS)
folio_xchg_last_cpupid(struct folio * folio,int cpupid)99 int folio_xchg_last_cpupid(struct folio *folio, int cpupid)
100 {
101 unsigned long old_flags, flags;
102 int last_cpupid;
103
104 old_flags = READ_ONCE(folio->flags.f);
105 do {
106 flags = old_flags;
107 last_cpupid = (flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
108
109 flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT);
110 flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT;
111 } while (unlikely(!try_cmpxchg(&folio->flags.f, &old_flags, flags)));
112
113 return last_cpupid;
114 }
115 #endif
116