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 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; 41struct memory_dev_type *alloc_memory_type(int adistance); 42void put_memory_type(struct memory_dev_type *memtype); 43void init_node_memory_type(int node, struct memory_dev_type *default_type); 44void clear_node_memory_type(int node, struct memory_dev_type *memtype); 45int register_mt_adistance_algorithm(struct notifier_block *nb); 46int unregister_mt_adistance_algorithm(struct notifier_block *nb); 47int mt_calc_adistance(int node, int *adist); 48int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, 49 const char *source); 50int mt_perf_to_adistance(struct access_coordinate *perf, int *adist); 51#ifdef CONFIG_MIGRATION 52int next_demotion_node(int node); 53void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets); 54bool node_is_toptier(int node); 55#else 56static inline int next_demotion_node(int node) 57{ 58 return NUMA_NO_NODE; 59} 60 61static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets) 62{ 63 *targets = NODE_MASK_NONE; 64} 65 66static 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 */ 79static inline struct memory_dev_type *alloc_memory_type(int adistance) 80{ 81 return NULL; 82} 83 84static inline void put_memory_type(struct memory_dev_type *memtype) 85{ 86 87} 88 89static inline void init_node_memory_type(int node, struct memory_dev_type *default_type) 90{ 91 92} 93 94static inline void clear_node_memory_type(int node, struct memory_dev_type *memtype) 95{ 96 97} 98 99static inline int next_demotion_node(int node) 100{ 101 return NUMA_NO_NODE; 102} 103 104static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets) 105{ 106 *targets = NODE_MASK_NONE; 107} 108 109static inline bool node_is_toptier(int node) 110{ 111 return true; 112} 113 114static inline int register_mt_adistance_algorithm(struct notifier_block *nb) 115{ 116 return 0; 117} 118 119static inline int unregister_mt_adistance_algorithm(struct notifier_block *nb) 120{ 121 return 0; 122} 123 124static inline int mt_calc_adistance(int node, int *adist) 125{ 126 return NOTIFY_DONE; 127} 128 129static inline int mt_set_default_dram_perf(int nid, struct access_coordinate *perf, 130 const char *source) 131{ 132 return -EIO; 133} 134 135static 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