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 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, 49 const char *source); 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); 58 #else 59 static inline int next_demotion_node(int node) 60 { 61 return NUMA_NO_NODE; 62 } 63 64 static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets) 65 { 66 *targets = NODE_MASK_NONE; 67 } 68 69 static inline bool node_is_toptier(int node) 70 { 71 return true; 72 } 73 #endif 74 75 #else 76 77 #define numa_demotion_enabled false 78 #define default_dram_type NULL 79 /* 80 * CONFIG_NUMA implementation returns non NULL error. 81 */ 82 static inline struct memory_dev_type *alloc_memory_type(int adistance) 83 { 84 return NULL; 85 } 86 87 static inline void put_memory_type(struct memory_dev_type *memtype) 88 { 89 90 } 91 92 static inline void init_node_memory_type(int node, struct memory_dev_type *default_type) 93 { 94 95 } 96 97 static inline void clear_node_memory_type(int node, struct memory_dev_type *memtype) 98 { 99 100 } 101 102 static inline int next_demotion_node(int node) 103 { 104 return NUMA_NO_NODE; 105 } 106 107 static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets) 108 { 109 *targets = NODE_MASK_NONE; 110 } 111 112 static inline bool node_is_toptier(int node) 113 { 114 return true; 115 } 116 117 static inline int register_mt_adistance_algorithm(struct notifier_block *nb) 118 { 119 return 0; 120 } 121 122 static inline int unregister_mt_adistance_algorithm(struct notifier_block *nb) 123 { 124 return 0; 125 } 126 127 static inline int mt_calc_adistance(int node, int *adist) 128 { 129 return NOTIFY_DONE; 130 } 131 132 static inline int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, 133 const char *source) 134 { 135 return -EIO; 136 } 137 138 static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adist) 139 { 140 return -EIO; 141 } 142 143 static inline struct memory_dev_type *mt_find_alloc_memory_type(int adist, 144 struct list_head *memory_types) 145 { 146 return NULL; 147 } 148 149 static inline void mt_put_memory_types(struct list_head *memory_types) 150 { 151 } 152 #endif /* CONFIG_NUMA */ 153 #endif /* _LINUX_MEMORY_TIERS_H */ 154