1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * include/linux/memory.h - generic memory definition 4 * 5 * This is mainly for topological representation. We define the 6 * basic "struct memory_block" here, which can be embedded in per-arch 7 * definitions or NUMA information. 8 * 9 * Basic handling of the devices is done in drivers/base/memory.c 10 * and system devices are handled in drivers/base/sys.c. 11 * 12 * Memory block are exported via sysfs in the class/memory/devices/ 13 * directory. 14 * 15 */ 16 #ifndef _LINUX_MEMORY_H_ 17 #define _LINUX_MEMORY_H_ 18 19 #include <linux/node.h> 20 #include <linux/compiler.h> 21 #include <linux/mutex.h> 22 23 #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS) 24 25 /** 26 * struct memory_group - a logical group of memory blocks 27 * @nid: The node id for all memory blocks inside the memory group. 28 * @blocks: List of all memory blocks belonging to this memory group. 29 * @present_kernel_pages: Present (online) memory outside ZONE_MOVABLE of this 30 * memory group. 31 * @present_movable_pages: Present (online) memory in ZONE_MOVABLE of this 32 * memory group. 33 * @is_dynamic: The memory group type: static vs. dynamic 34 * @s.max_pages: Valid with &memory_group.is_dynamic == false. The maximum 35 * number of pages we'll have in this static memory group. 36 * @d.unit_pages: Valid with &memory_group.is_dynamic == true. Unit in pages 37 * in which memory is added/removed in this dynamic memory group. 38 * This granularity defines the alignment of a unit in physical 39 * address space; it has to be at least as big as a single 40 * memory block. 41 * 42 * A memory group logically groups memory blocks; each memory block 43 * belongs to at most one memory group. A memory group corresponds to 44 * a memory device, such as a DIMM or a NUMA node, which spans multiple 45 * memory blocks and might even span multiple non-contiguous physical memory 46 * ranges. 47 * 48 * Modification of members after registration is serialized by memory 49 * hot(un)plug code. 50 */ 51 struct memory_group { 52 int nid; 53 struct list_head memory_blocks; 54 unsigned long present_kernel_pages; 55 unsigned long present_movable_pages; 56 bool is_dynamic; 57 union { 58 struct { 59 unsigned long max_pages; 60 } s; 61 struct { 62 unsigned long unit_pages; 63 } d; 64 }; 65 }; 66 67 struct memory_block { 68 unsigned long start_section_nr; 69 unsigned long state; /* serialized by the dev->lock */ 70 int online_type; /* for passing data to online routine */ 71 int nid; /* NID for this memory block */ 72 /* 73 * The single zone of this memory block if all PFNs of this memory block 74 * that are System RAM (not a memory hole, not ZONE_DEVICE ranges) are 75 * managed by a single zone. NULL if multiple zones (including nodes) 76 * apply. 77 */ 78 struct zone *zone; 79 struct device dev; 80 struct vmem_altmap *altmap; 81 struct memory_group *group; /* group (if any) for this block */ 82 struct list_head group_next; /* next block inside memory group */ 83 #if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG) 84 atomic_long_t nr_hwpoison; 85 #endif 86 }; 87 88 int arch_get_memory_phys_device(unsigned long start_pfn); 89 unsigned long memory_block_size_bytes(void); 90 int set_memory_block_size_order(unsigned int order); 91 92 /* These states are exposed to userspace as text strings in sysfs */ 93 #define MEM_ONLINE (1<<0) /* exposed to userspace */ 94 #define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */ 95 #define MEM_OFFLINE (1<<2) /* exposed to userspace */ 96 #define MEM_GOING_ONLINE (1<<3) 97 #define MEM_CANCEL_ONLINE (1<<4) 98 #define MEM_CANCEL_OFFLINE (1<<5) 99 #define MEM_PREPARE_ONLINE (1<<6) 100 #define MEM_FINISH_OFFLINE (1<<7) 101 102 struct memory_notify { 103 /* 104 * The altmap_start_pfn and altmap_nr_pages fields are designated for 105 * specifying the altmap range and are exclusively intended for use in 106 * MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers. 107 */ 108 unsigned long altmap_start_pfn; 109 unsigned long altmap_nr_pages; 110 unsigned long start_pfn; 111 unsigned long nr_pages; 112 int status_change_nid_normal; 113 int status_change_nid; 114 }; 115 116 struct notifier_block; 117 struct mem_section; 118 119 /* 120 * Priorities for the hotplug memory callback routines (stored in decreasing 121 * order in the callback chain) 122 */ 123 #define DEFAULT_CALLBACK_PRI 0 124 #define SLAB_CALLBACK_PRI 1 125 #define HMAT_CALLBACK_PRI 2 126 #define CXL_CALLBACK_PRI 5 127 #define MM_COMPUTE_BATCH_PRI 10 128 #define CPUSET_CALLBACK_PRI 10 129 #define MEMTIER_HOTPLUG_PRI 100 130 #define KSM_CALLBACK_PRI 100 131 132 #ifndef CONFIG_MEMORY_HOTPLUG memory_dev_init(void)133 static inline void memory_dev_init(void) 134 { 135 return; 136 } register_memory_notifier(struct notifier_block * nb)137 static inline int register_memory_notifier(struct notifier_block *nb) 138 { 139 return 0; 140 } unregister_memory_notifier(struct notifier_block * nb)141 static inline void unregister_memory_notifier(struct notifier_block *nb) 142 { 143 } memory_notify(unsigned long val,void * v)144 static inline int memory_notify(unsigned long val, void *v) 145 { 146 return 0; 147 } hotplug_memory_notifier(notifier_fn_t fn,int pri)148 static inline int hotplug_memory_notifier(notifier_fn_t fn, int pri) 149 { 150 return 0; 151 } 152 #else /* CONFIG_MEMORY_HOTPLUG */ 153 extern int register_memory_notifier(struct notifier_block *nb); 154 extern void unregister_memory_notifier(struct notifier_block *nb); 155 int create_memory_block_devices(unsigned long start, unsigned long size, 156 struct vmem_altmap *altmap, 157 struct memory_group *group); 158 void remove_memory_block_devices(unsigned long start, unsigned long size); 159 extern void memory_dev_init(void); 160 extern int memory_notify(unsigned long val, void *v); 161 extern struct memory_block *find_memory_block(unsigned long section_nr); 162 typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *); 163 extern int walk_memory_blocks(unsigned long start, unsigned long size, 164 void *arg, walk_memory_blocks_func_t func); 165 extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func); 166 167 extern int memory_group_register_static(int nid, unsigned long max_pages); 168 extern int memory_group_register_dynamic(int nid, unsigned long unit_pages); 169 extern int memory_group_unregister(int mgid); 170 struct memory_group *memory_group_find_by_id(int mgid); 171 typedef int (*walk_memory_groups_func_t)(struct memory_group *, void *); 172 int walk_dynamic_memory_groups(int nid, walk_memory_groups_func_t func, 173 struct memory_group *excluded, void *arg); 174 #define hotplug_memory_notifier(fn, pri) ({ \ 175 static __meminitdata struct notifier_block fn##_mem_nb =\ 176 { .notifier_call = fn, .priority = pri };\ 177 register_memory_notifier(&fn##_mem_nb); \ 178 }) 179 180 #ifdef CONFIG_NUMA 181 void memory_block_add_nid(struct memory_block *mem, int nid, 182 enum meminit_context context); 183 #endif /* CONFIG_NUMA */ 184 #endif /* CONFIG_MEMORY_HOTPLUG */ 185 186 /* 187 * Kernel text modification mutex, used for code patching. Users of this lock 188 * can sleep. 189 */ 190 extern struct mutex text_mutex; 191 192 #endif /* _LINUX_MEMORY_H_ */ 193