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 ((4 * MEMTIER_CHUNK_SIZE) + (MEMTIER_CHUNK_SIZE >> 1))
22
23 struct memory_tier;
24 struct 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
36 struct access_coordinate;
37
38 #ifdef CONFIG_NUMA
39 extern bool numa_demotion_enabled;
40 extern struct memory_dev_type *default_dram_type;
41 extern nodemask_t default_dram_nodes;
42 struct memory_dev_type *alloc_memory_type(int adistance);
43 void put_memory_type(struct memory_dev_type *memtype);
44 void init_node_memory_type(int node, struct memory_dev_type *default_type);
45 void clear_node_memory_type(int node, struct memory_dev_type *memtype);
46 int register_mt_adistance_algorithm(struct notifier_block *nb);
47 int unregister_mt_adistance_algorithm(struct notifier_block *nb);
48 int mt_calc_adistance(int node, int *adist);
49 int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
50 const char *source);
51 int mt_perf_to_adistance(struct access_coordinate *perf, int *adist);
52 struct memory_dev_type *mt_find_alloc_memory_type(int adist,
53 struct list_head *memory_types);
54 void mt_put_memory_types(struct list_head *memory_types);
55 #ifdef CONFIG_MIGRATION
56 int next_demotion_node(int node);
57 void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
58 bool node_is_toptier(int node);
59 #else
next_demotion_node(int node)60 static inline int next_demotion_node(int node)
61 {
62 return NUMA_NO_NODE;
63 }
64
node_get_allowed_targets(pg_data_t * pgdat,nodemask_t * targets)65 static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
66 {
67 *targets = NODE_MASK_NONE;
68 }
69
node_is_toptier(int node)70 static 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 */
alloc_memory_type(int adistance)84 static inline struct memory_dev_type *alloc_memory_type(int adistance)
85 {
86 return NULL;
87 }
88
put_memory_type(struct memory_dev_type * memtype)89 static inline void put_memory_type(struct memory_dev_type *memtype)
90 {
91
92 }
93
init_node_memory_type(int node,struct memory_dev_type * default_type)94 static inline void init_node_memory_type(int node, struct memory_dev_type *default_type)
95 {
96
97 }
98
clear_node_memory_type(int node,struct memory_dev_type * memtype)99 static inline void clear_node_memory_type(int node, struct memory_dev_type *memtype)
100 {
101
102 }
103
next_demotion_node(int node)104 static inline int next_demotion_node(int node)
105 {
106 return NUMA_NO_NODE;
107 }
108
node_get_allowed_targets(pg_data_t * pgdat,nodemask_t * targets)109 static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
110 {
111 *targets = NODE_MASK_NONE;
112 }
113
node_is_toptier(int node)114 static inline bool node_is_toptier(int node)
115 {
116 return true;
117 }
118
register_mt_adistance_algorithm(struct notifier_block * nb)119 static inline int register_mt_adistance_algorithm(struct notifier_block *nb)
120 {
121 return 0;
122 }
123
unregister_mt_adistance_algorithm(struct notifier_block * nb)124 static inline int unregister_mt_adistance_algorithm(struct notifier_block *nb)
125 {
126 return 0;
127 }
128
mt_calc_adistance(int node,int * adist)129 static inline int mt_calc_adistance(int node, int *adist)
130 {
131 return NOTIFY_DONE;
132 }
133
mt_set_default_dram_perf(int nid,struct access_coordinate * perf,const char * source)134 static inline int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
135 const char *source)
136 {
137 return -EIO;
138 }
139
mt_perf_to_adistance(struct access_coordinate * perf,int * adist)140 static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adist)
141 {
142 return -EIO;
143 }
144
mt_find_alloc_memory_type(int adist,struct list_head * memory_types)145 static inline struct memory_dev_type *mt_find_alloc_memory_type(int adist,
146 struct list_head *memory_types)
147 {
148 return NULL;
149 }
150
mt_put_memory_types(struct list_head * memory_types)151 static inline void mt_put_memory_types(struct list_head *memory_types)
152 {
153 }
154 #endif /* CONFIG_NUMA */
155 #endif /* _LINUX_MEMORY_TIERS_H */
156