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 #ifdef CONFIG_MIGRATION 52 int next_demotion_node(int node); 53 void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets); 54 bool node_is_toptier(int node); 55 #else 56 static inline int next_demotion_node(int node) 57 { 58 return NUMA_NO_NODE; 59 } 60 61 static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets) 62 { 63 *targets = NODE_MASK_NONE; 64 } 65 66 static inline bool node_is_toptier(int node) 67 { 68 return true; 69 } 70 #endif 71 72 #else 73 74 #define numa_demotion_enabled false 75 #define default_dram_type NULL 76 /* 77 * CONFIG_NUMA implementation returns non NULL error. 78 */ 79 static inline struct memory_dev_type *alloc_memory_type(int adistance) 80 { 81 return NULL; 82 } 83 84 static inline void put_memory_type(struct memory_dev_type *memtype) 85 { 86 87 } 88 89 static inline void init_node_memory_type(int node, struct memory_dev_type *default_type) 90 { 91 92 } 93 94 static inline void clear_node_memory_type(int node, struct memory_dev_type *memtype) 95 { 96 97 } 98 99 static inline int next_demotion_node(int node) 100 { 101 return NUMA_NO_NODE; 102 } 103 104 static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets) 105 { 106 *targets = NODE_MASK_NONE; 107 } 108 109 static inline bool node_is_toptier(int node) 110 { 111 return true; 112 } 113 114 static inline int register_mt_adistance_algorithm(struct notifier_block *nb) 115 { 116 return 0; 117 } 118 119 static inline int unregister_mt_adistance_algorithm(struct notifier_block *nb) 120 { 121 return 0; 122 } 123 124 static inline int mt_calc_adistance(int node, int *adist) 125 { 126 return NOTIFY_DONE; 127 } 128 129 static inline int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, 130 const char *source) 131 { 132 return -EIO; 133 } 134 135 static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adist) 136 { 137 return -EIO; 138 } 139 #endif /* CONFIG_NUMA */ 140 #endif /* _LINUX_MEMORY_TIERS_H */ 141