1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_MEMORY_TIERS_H
3 #define _LINUX_MEMORY_TIERS_H
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>
11 * Each tier cover a abstrace distance chunk size of 128
13 #define MEMTIER_CHUNK_BITS 7
14 #define MEMTIER_CHUNK_SIZE (1 << MEMTIER_CHUNK_BITS)
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.
21 #define MEMTIER_ADISTANCE_DRAM ((4 * MEMTIER_CHUNK_SIZE) + (MEMTIER_CHUNK_SIZE >> 1))
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 */
31 /* Nodes of same abstract distance */
36 struct access_coordinate;
39 extern bool numa_demotion_enabled;
40 extern struct memory_dev_type *default_dram_type;
41 struct memory_dev_type *alloc_memory_type(int adistance);
42 void put_memory_type(struct memory_dev_type *memtype);
43 void init_node_memory_type(int node, struct memory_dev_type *default_type);
44 void clear_node_memory_type(int node, struct memory_dev_type *memtype);
45 int register_mt_adistance_algorithm(struct notifier_block *nb);
46 int unregister_mt_adistance_algorithm(struct notifier_block *nb);
47 int mt_calc_adistance(int node, int *adist);
48 int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
50 int mt_perf_to_adistance(struct access_coordinate *perf, int *adist);
51 struct memory_dev_type *mt_find_alloc_memory_type(int adist,
52 struct list_head *memory_types);
53 void mt_put_memory_types(struct list_head *memory_types);
54 #ifdef CONFIG_MIGRATION
55 int next_demotion_node(int node);
56 void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
57 bool node_is_toptier(int node);
59 static inline int next_demotion_node(int node)
64 static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
66 *targets = NODE_MASK_NONE;
69 static inline bool node_is_toptier(int node)
77 #define numa_demotion_enabled false
78 #define default_dram_type NULL
80 * CONFIG_NUMA implementation returns non NULL error.
82 static inline struct memory_dev_type *alloc_memory_type(int adistance)
87 static inline void put_memory_type(struct memory_dev_type *memtype)
92 static inline void init_node_memory_type(int node, struct memory_dev_type *default_type)
97 static inline void clear_node_memory_type(int node, struct memory_dev_type *memtype)
102 static inline int next_demotion_node(int node)
107 static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
109 *targets = NODE_MASK_NONE;
112 static inline bool node_is_toptier(int node)
117 static inline int register_mt_adistance_algorithm(struct notifier_block *nb)
122 static inline int unregister_mt_adistance_algorithm(struct notifier_block *nb)
127 static inline int mt_calc_adistance(int node, int *adist)
132 static inline int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
138 static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adist)
143 static inline struct memory_dev_type *mt_find_alloc_memory_type(int adist,
144 struct list_head *memory_types)
149 static inline void mt_put_memory_types(struct list_head *memory_types)
152 #endif /* CONFIG_NUMA */
153 #endif /* _LINUX_MEMORY_TIERS_H */