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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
13struct pglist_data *first_online_pgdat(void)
14{
15 return NODE_DATA(first_online_node);
16}
17
18struct 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 */
30struct 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
46static inline int zref_in_nodemask(struct zoneref *zref, nodemask_t *nodes)
47{
48#ifdef CONFIG_NUMA
49 return node_isset(zonelist_node_idx(zref), *nodes);
50#else
51 return 1;
52#endif /* CONFIG_NUMA */
53}
54
55/* Returns the next zone at or below highest_zoneidx in a zonelist */
56struct zoneref *__next_zones_zonelist(struct zoneref *z,
57 enum zone_type highest_zoneidx,
58 nodemask_t *nodes)
59{
60 /*
61 * Find the next suitable zone to use for the allocation.
62 * Only filter based on nodemask if it's set
63 */
64 if (unlikely(nodes == NULL))
65 while (zonelist_zone_idx(z) > highest_zoneidx)
66 z++;
67 else
68 while (zonelist_zone_idx(z) > highest_zoneidx ||
69 (zonelist_zone(z) && !zref_in_nodemask(z, nodes)))
70 z++;
71
72 return z;
73}
74
75void lruvec_init(struct lruvec *lruvec)
76{
77 enum lru_list lru;
78
79 memset(lruvec, 0, sizeof(struct lruvec));
80 spin_lock_init(&lruvec->lru_lock);
81 zswap_lruvec_state_init(lruvec);
82
83 for_each_lru(lru)
84 INIT_LIST_HEAD(&lruvec->lists[lru]);
85 /*
86 * The "Unevictable LRU" is imaginary: though its size is maintained,
87 * it is never scanned, and unevictable pages are not threaded on it
88 * (so that their lru fields can be reused to hold mlock_count).
89 * Poison its list head, so that any operations on it would crash.
90 */
91 list_del(&lruvec->lists[LRU_UNEVICTABLE]);
92
93 lru_gen_init_lruvec(lruvec);
94}
95
96#if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS)
97int folio_xchg_last_cpupid(struct folio *folio, int cpupid)
98{
99 unsigned long old_flags, flags;
100 int last_cpupid;
101
102 old_flags = READ_ONCE(folio->flags);
103 do {
104 flags = old_flags;
105 last_cpupid = (flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
106
107 flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT);
108 flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT;
109 } while (unlikely(!try_cmpxchg(&folio->flags, &old_flags, flags)));
110
111 return last_cpupid;
112}
113#endif
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
12struct pglist_data *first_online_pgdat(void)
13{
14 return NODE_DATA(first_online_node);
15}
16
17struct 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 */
29struct 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
45static 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 */
55struct zoneref *next_zones_zonelist(struct zoneref *z,
56 enum zone_type highest_zoneidx,
57 nodemask_t *nodes,
58 struct zone **zone)
59{
60 /*
61 * Find the next suitable zone to use for the allocation.
62 * Only filter based on nodemask if it's set
63 */
64 if (likely(nodes == NULL))
65 while (zonelist_zone_idx(z) > highest_zoneidx)
66 z++;
67 else
68 while (zonelist_zone_idx(z) > highest_zoneidx ||
69 (z->zone && !zref_in_nodemask(z, nodes)))
70 z++;
71
72 *zone = zonelist_zone(z);
73 return z;
74}
75
76#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
77int memmap_valid_within(unsigned long pfn,
78 struct page *page, struct zone *zone)
79{
80 if (page_to_pfn(page) != pfn)
81 return 0;
82
83 if (page_zone(page) != zone)
84 return 0;
85
86 return 1;
87}
88#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
89
90void lruvec_init(struct lruvec *lruvec)
91{
92 enum lru_list lru;
93
94 memset(lruvec, 0, sizeof(struct lruvec));
95
96 for_each_lru(lru)
97 INIT_LIST_HEAD(&lruvec->lists[lru]);
98}
99
100#if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS)
101int page_cpupid_xchg_last(struct page *page, int cpupid)
102{
103 unsigned long old_flags, flags;
104 int last_cpupid;
105
106 do {
107 old_flags = flags = page->flags;
108 last_cpupid = page_cpupid_last(page);
109
110 flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT);
111 flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT;
112 } while (unlikely(cmpxchg(&page->flags, old_flags, flags) != old_flags));
113
114 return last_cpupid;
115}
116#endif