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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_MEMORY_TIERS_H
3#define _LINUX_MEMORY_TIERS_H
4
5#include <linux/types.h>
6#include <linux/nodemask.h>
7#include <linux/kref.h>
8#include <linux/mmzone.h>
9#include <linux/notifier.h>
10/*
11 * Each tier cover a abstrace distance chunk size of 128
12 */
13#define MEMTIER_CHUNK_BITS 7
14#define MEMTIER_CHUNK_SIZE (1 << MEMTIER_CHUNK_BITS)
15/*
16 * Smaller abstract distance values imply faster (higher) memory tiers. Offset
17 * the DRAM adistance so that we can accommodate devices with a slightly lower
18 * adistance value (slightly faster) than default DRAM adistance to be part of
19 * the same memory tier.
20 */
21#define MEMTIER_ADISTANCE_DRAM ((4L * MEMTIER_CHUNK_SIZE) + (MEMTIER_CHUNK_SIZE >> 1))
22
23struct memory_tier;
24struct memory_dev_type {
25 /* list of memory types that are part of same tier as this type */
26 struct list_head tier_sibling;
27 /* list of memory types that are managed by one driver */
28 struct list_head list;
29 /* abstract distance for this specific memory type */
30 int adistance;
31 /* Nodes of same abstract distance */
32 nodemask_t nodes;
33 struct kref kref;
34};
35
36struct access_coordinate;
37
38#ifdef CONFIG_NUMA
39extern bool numa_demotion_enabled;
40extern struct memory_dev_type *default_dram_type;
41extern nodemask_t default_dram_nodes;
42struct memory_dev_type *alloc_memory_type(int adistance);
43void put_memory_type(struct memory_dev_type *memtype);
44void init_node_memory_type(int node, struct memory_dev_type *default_type);
45void clear_node_memory_type(int node, struct memory_dev_type *memtype);
46int register_mt_adistance_algorithm(struct notifier_block *nb);
47int unregister_mt_adistance_algorithm(struct notifier_block *nb);
48int mt_calc_adistance(int node, int *adist);
49int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
50 const char *source);
51int mt_perf_to_adistance(struct access_coordinate *perf, int *adist);
52struct memory_dev_type *mt_find_alloc_memory_type(int adist,
53 struct list_head *memory_types);
54void mt_put_memory_types(struct list_head *memory_types);
55#ifdef CONFIG_MIGRATION
56int next_demotion_node(int node);
57void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
58bool node_is_toptier(int node);
59#else
60static inline int next_demotion_node(int node)
61{
62 return NUMA_NO_NODE;
63}
64
65static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
66{
67 *targets = NODE_MASK_NONE;
68}
69
70static inline bool node_is_toptier(int node)
71{
72 return true;
73}
74#endif
75
76#else
77
78#define numa_demotion_enabled false
79#define default_dram_type NULL
80#define default_dram_nodes NODE_MASK_NONE
81/*
82 * CONFIG_NUMA implementation returns non NULL error.
83 */
84static inline struct memory_dev_type *alloc_memory_type(int adistance)
85{
86 return NULL;
87}
88
89static inline void put_memory_type(struct memory_dev_type *memtype)
90{
91
92}
93
94static inline void init_node_memory_type(int node, struct memory_dev_type *default_type)
95{
96
97}
98
99static inline void clear_node_memory_type(int node, struct memory_dev_type *memtype)
100{
101
102}
103
104static inline int next_demotion_node(int node)
105{
106 return NUMA_NO_NODE;
107}
108
109static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
110{
111 *targets = NODE_MASK_NONE;
112}
113
114static inline bool node_is_toptier(int node)
115{
116 return true;
117}
118
119static inline int register_mt_adistance_algorithm(struct notifier_block *nb)
120{
121 return 0;
122}
123
124static inline int unregister_mt_adistance_algorithm(struct notifier_block *nb)
125{
126 return 0;
127}
128
129static inline int mt_calc_adistance(int node, int *adist)
130{
131 return NOTIFY_DONE;
132}
133
134static inline int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
135 const char *source)
136{
137 return -EIO;
138}
139
140static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adist)
141{
142 return -EIO;
143}
144
145static inline struct memory_dev_type *mt_find_alloc_memory_type(int adist,
146 struct list_head *memory_types)
147{
148 return NULL;
149}
150
151static inline void mt_put_memory_types(struct list_head *memory_types)
152{
153}
154#endif /* CONFIG_NUMA */
155#endif /* _LINUX_MEMORY_TIERS_H */
156

source code of linux/include/linux/memory-tiers.h